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Sample records for inorganic membrane materials

  1. Thermal and chemical degradation of inorganic membrane materials. Topical report

    SciTech Connect

    Krishnan, G.N.; Sanjurjo, A.; Wood, B.J.; Lau, K.H.

    1994-04-01

    This report describes the results of a literature review to evaluate the long-term thermal and chemical degradation of inorganic membranes that are being developed to separate gaseous products produced by the gasification or combustion of coal in fixed-, fluidized-, and entrained-bed gasifiers, direct coal-fired turbines, and pressurized-fluidized-bed combustors. Several impurities, such as H{sub 2}S, NH{sub 3}, SO{sub 2}, NO{sub x}, and trace metal compounds are generated during coal conversion, and they must be removed from the coal gas or the combustor flue gas to meet environmental standards. The use of membranes to separate these noxious gases is an attractive alternative to their removal by sorbents such as zinc titanate or calcium oxide. Inorganic membranes that have a high separation efficiency and exhibit both thermal and chemical stability would improve the economics of power generation from coal. The U.S. Department of Energy is supporting investigations to develop inorganic membranes for separating hydrogen from coal gas streams and noxious impurities from hot coal- and flue-gas streams. Membrane materials that have been investigated in the past include glass (silica), alumina, zirconia, carbon, and metals (Pd and Pt).

  2. Thermal/chemical degradation of inorganic membrane materials

    SciTech Connect

    Krishnan, G.N.; Sanjurgo, A.; Wood, B.J.

    1993-09-01

    The specific objectives of this program are to (1) identify and evaluate long-term degradation mechanisms for inorganic membranes exposed to hot coal gasification and combustion gas streams using data from the existing literature, (2) quantify the extent of the degradation process for the most serious mechanisms by performing experiments under laboratory-scale conditions, and (3) develop a predictive model that allows estimation of membrane degradation under operating conditions. To achieve the above objectives, the program is divided into the following tasks: (1) Development of evaluation methodology; (2) evaluation of potential long-term degradation mechanism; (3) submission of a topical report and a plan for experimental testing; (4) experimental testing; and (5) model development. Tasks 4 and 5 are separate options that may be exercised by the US Department of Energy at the conclusion of Task 3. Accomplishments are presented for Tasks 1, 2 and 3.

  3. Thermal and chemical degradation of inorganic membrane materials. Final report, August 1992--May 1995

    SciTech Connect

    Damle, A.S.; Krishnan, G.N.; Sanjurjo, A.; Wood, B.J.; Lau, K.H.

    1995-05-01

    SRI International conducted a theoretical and experimental program to evaluate the long-term thermal and chemical degradation of inorganic membranes that are being developed to separate the gaseous products of coal gasification. A variety of developmental efforts are underway, including a number of projects sponsored by the US Department of Energy (DOE), to improve the selectivity and permeability of porous inorganic membranes. DOE is also sponsoring efforts to extend the use of metallic membranes to new applications. Most developmental efforts have focused on hydrogen separation by inorganic membranes, which may be used to maximize hydrogen production from coal gas or to remove H{sub 2}S and NH{sub 3} contaminants via thermal or catalytic decomposition in integrated-gasification combined-cycle (IGCC) systems. Inorganic membranes that have a high separation efficiency and exhibit both thermal and chemical stability would improve the economics of power generation from coal. Membrane materials that have been investigated include glass (silica), alumina, carbon, and metals (Pd and Pt). This report describes inorganic membrane materials, long term membrane exposure tests, membrane permeation tests, coal gasifier exposure tests, conclusions, and recommendations.

  4. Supported inorganic membranes

    DOEpatents

    Sehgal, Rakesh; Brinker, Charles Jeffrey

    1998-01-01

    Supported inorganic membranes capable of molecular sieving, and methods for their production, are provided. The subject membranes exhibit high flux and high selectivity. The subject membranes are substantially defect free and less than about 100 nm thick. The pores of the subject membranes have an average critical pore radius of less than about 5 .ANG., and have a narrow pore size distribution. The subject membranes are prepared by coating a porous substrate with a polymeric sol, preferably under conditions of low relative pressure of the liquid constituents of the sol. The coated substrate is dried and calcined to produce the subject supported membrane. Also provided are methods of derivatizing the surface of supported inorganic membranes with metal alkoxides. The subject membranes find use in a variety of applications, such as the separation of constituents of gaseous streams, as catalysts and catalyst supports, and the like.

  5. Bridged polysilsesquioxanes: Hybrid organic-inorganic materials as fuel cell polyelectrolyte membranes and functional nanoparticles

    NASA Astrophysics Data System (ADS)

    Khiterer, Mariya

    2007-05-01

    This dissertation describes the design, fabrication, and characterization of organic-inorganic hybrid materials. Several classes of bridged polysilsesquioxanes are presented. The first class is a membrane material suitable for fuel cell technology as a proton conducting polyelectrolyte. The second class includes hybrid nanoparticles for display device applications and chromatographic media. Chapter 1 is an introduction to hybrid organic-inorganic materials. Sol-gel chemistry is discussed, followed by a survey of prominent examples of silica hybrids. Examples of physical organic-silica blends and covalent organo-silicas, including ORMOCERSRTM, polyhedral oligomeric silsesquioxanes, and bridged polysilsesquioxanes are discussed. Bridged polysilsesquioxanes are described in great detail. Monomer synthesis, sol-gel chemistry, processing, characterization, and physical properties are included. Chapter 2 describes the design of polyelectrolyte bridged polysilsesquioxane membranes. The materials contain covalently bound sulfonic acid groups originating from the corresponding disulfides. These organic-inorganic hybrid materials integrate a network supporting component which is systematically changed to fine-tune their physical properties. The membranes are characterized as PEM fuel cell electrolytes, where proton conductivities of 4-6 mS cm-1 were measured. In Chapter 3 techniques for the preparation of bridged polysilsesquioxane nanoparticles are described. An inverse water-in-oil microemulsion polymerization method is developed to prepare cationic nanoparticles, including viologen-bridged materials with applications in electrochromic display devices. An aqueous ammonia system is used to prepare neutral nanoparticles containing hydrocarbon bridging groups, which have potential applications as chromatographic media. Chapter 4 describes electrochromic devices developed in collaboration with the Heflin group of Virginia Tech, which incorporate viologen bridged nanoparticles

  6. Gas separations using inorganic membranes

    SciTech Connect

    Egan, B.Z.; Singh, S.P.N.; Fain, D.E.; Roettger, G.E.; White, D.E.

    1992-04-01

    This report summarizes the results from a research and development program to develop, fabricate, and evaluate inorganic membranes for separating gases at high temperatures and pressures in hostile process environments encountered in fossil energy conversion processes such as coal gasification. The primary emphasis of the research was on the separation and recovery of hydrogen from synthesis gas. Major aspects of the program included assessment of the worldwide research and development activity related to gas separations using inorganic membranes, identification and selection of candidate membrane materials, fabrication and characterization of membranes using porous membrane technology developed at the Oak Ridge K-25 Site, and evaluation of the separations capability of the fabricated membranes in terms of permeabilities and fluxes of gases.

  7. Inorganic membranes and solid state sciences

    NASA Astrophysics Data System (ADS)

    Cot, Louis; Ayral, André; Durand, Jean; Guizard, Christian; Hovnanian, Nadine; Julbe, Anne; Larbot, André

    2000-05-01

    The latest developments in inorganic membranes are closely related to recent advances in solid state science. Sol-gel processing, plasma-enhanced chemical vapor deposition and hydrothermal synthesis are methods that can be used for inorganic membrane preparation. Innovative concepts from material science (templating effect, nanophase materials, growing of continuous zeolite layers, hybrid organic-inorganic materials) have been applied by our group to the preparation of inorganic membrane materials. Sol-gel-derived nanophase ceramic membranes are presented with current applications in nanofiltration and catalytic membrane reactors. Silica membranes with an ordered porosity, due to liquid crystal phase templating effect, are described with potential application in pervaporation. Defect-free and thermally stable zeolite membranes can be obtained through an original synthesis method, in which zeolite crystals are grown inside the pores of a support. Hybrid organic-inorganic materials with permselective properties for gas separation and facilitated transport of solutes in liquid media, have been successfully adapted to membrane applications. Potential membrane developments offered by CVD deposition techniques are also illustrated through several examples related to the preparation of purely inorganic and hybrid organic-inorganic membrane materials.

  8. New inorganic materials

    SciTech Connect

    Birchall, J.D.; Kelly, A.

    1983-05-01

    Inorganic chemistry is preparing to contribute to the conservation of energy and of hydrocarbons by manipulating inorganic chemical compounds at low temperature. In this regard cement preparation and qualities are extensively discussed. Related techniques with regard to glasses are mentioned. The manipulation of inorganic compounds at low temperature is being aided by advances in the understanding of material properties such as porosity. Interestingly, the importance of the control of porosity had not emerged from all the previous work on high-temperature methods of fabrication. It may be too early to speak of a new Neolithic age, but its beginnings are clearly with us.

  9. Geological and Inorganic Materials.

    ERIC Educational Resources Information Center

    Jackson, L. L.; And Others

    1989-01-01

    Presents a review focusing on techniques and their application to the analysis of geological and inorganic materials that offer significant changes to research and routine work. Covers geostandards, spectroscopy, plasmas, microbeam techniques, synchrotron X-ray methods, nuclear activation methods, chromatography, and electroanalytical methods.…

  10. Hierarchy in inorganic membranes.

    PubMed

    Caro, Juergen

    2016-06-13

    Thin films of a few μm thickness for particle filtration and gas separation cannot be applied as self-supporting layers since they are mechanically insufficiently strong. Therefore, these top layers for particle filtration and gas separation are usually deposited on porous mechanically strong supports with a hierarchical pore structure. To reduce the pressure drop of a gas stream over the membrane and to ensure high fluxes in filtration and gas separation, the cross section of the support is usually asymmetric or graded with a small thickness of the layer with the smallest pore size called the top layer. Since the pressure drop over a capillary with radius r is ∼r(4), the layer with the smallest pore size should be as thin as possible. The disk-like planar supports are usually prepared by sequential tape casting which is an expensive technology. Tubular supports with a hierarchical cross section can be prepared in one step by hollow fiber spinning, double mantle spinning or centrifugal casting.

  11. Novel polymer and inorganic/organic hybrid composite materials for proton exchange membrane applications

    NASA Astrophysics Data System (ADS)

    Yang, Zhiwei

    In this study, various novel proton exchange membranes (PEM) have been synthesized and investigated for high temperature PEM applications. Sulfonic acid functionalized polysilsesquioxane hybrid membranes with the empirical formula of R-Si-(O)1.5 consist of a highly cross-linked Si-O backbone and pendant organic side chain R, which is terminated in a proton conducting functional group (i.e., sulfonic acid). The membranes exhibited excellent proton conductivities (sigma) of >10-2 S/cm under low humidity conditions and a wide range of temperatures. The fuel cell (FC) performance of the membranes under low humidity conditions has been evaluated. Acid-doped linear meta-polyaniline membranes have been prepared through solution casting of m-PANI. The obtained membrane shows good proton conductivities at temperatures above 100°C, achieving 10-2.7 S/cm under 120°C and practically no humidity conditions. The effects of doping acids, doping levels and humidity on the conductivity are discussed. Polyethylenimine (PEI)/SiO2 nanocomposites membranes have been synthesized through sol-gel processes. The introduction of SiO2 clusters into high molecule weight, linear PEI greatly improved its thermal stability at high temperatures and O2 atmosphere. During the sol-gel processes, trifluoromethanesulfonimide (HTFSI) was added to dope the amine groups of PEI and form immobilized proton-conducting ionic liquids, which provide the hybrid membranes with proton-conducting behavior. The resultant membranes show good proton conductivities at high temperatures and low to zero humidity conditions. The effects of temperature, humidity and mobility of active groups on the conductivity are discussed. Various organic amine/HTFSI ionic group functionalized polysilsesquioxane hybrid membranes have been prepared. The Si-O backbone provides excellent thermal/chemical/mechanical properties and the HTFSI-doped amine end groups provide the proton conducting properties. The membranes exhibited proton

  12. Inorganic polymer engineering materials

    SciTech Connect

    Stone, M.L.

    1993-06-01

    Phosphazene-based, inorganic-polymer composites have been produced and evaluated as potential engineering materials. The thermal, chemical, and mechanical properties of several different composites made from one polymer formulation have been measured. Measured properties are very good, and the composites show excellent promise for structural applications in harsh environments. Chopped fiberglass, mineral, cellulose, and woodflour filled composites were tested. Chopped fiberglass filled composites showed the best overall properties. The phosphazene composites are very hard and rigid. They have low dielectric constants and typical linear thermal expansion coefficients for polymers. In most cases, the phosphazene materials performed as well or better than analogous, commercially available, filled phenolic composites. After 3 to 5 weeks of exposure, both the phosphazene and phenolics were degraded to aqueous bases and acids. The glass filled phosphazene samples were least affected.

  13. Development of Inorganic Membranes for Hydrogen Separation

    SciTech Connect

    Bischoff, Brian L; Adcock, Kenneth Dale; Powell, Lawrence E; Sutton, Theodore G; Miller, Curtis Jack

    2007-01-01

    The purpose of this work is to improve the method of fabricating tubular metal supported microporous inorganic membranes. Earlier work focused on the original development of inorganic membranes for the purification of hydrogen. These membranes are now being scaled up for demonstration in a coal gasification plant for the separation of hydrogen from coal-derived synthesis gas for a project funded by the Office of Fossil Energy's Gasification and Coal Fuels programs [1]. This project is part of FutureGen, an initiative to build the world's first integrated sequestration and hydrogen production research power plant. Although previous work in the Advanced Research Materials Program project led to development of a tubular metal supported microporous membrane which was approved by the Department of Energy for testing, the membranes generally have lower than desired selectivities for hydrogen over other gases common in synthesis gas including carbon dioxide. The work on this project over three years will lead to general improvements in fabrication techniques that will result in membranes having higher separation factors and higher fluxes. Scanning electron microscopy and profilometry data will be presented to show qualitatively and quantitatively the surface roughness of the support tubes. We will discuss how the roughness affects membrane quality and methods to improve the quality of the support tube surface.

  14. Inorganic dual-layer microporous supported membranes

    DOEpatents

    Brinker, C. Jeffrey; Tsai, Chung-Yi; Lu, Yungfeng

    2003-03-25

    The present invention provides for a dual-layer inorganic microporous membrane capable of molecular sieving, and methods for production of the membranes. The inorganic microporous supported membrane includes a porous substrate which supports a first inorganic porous membrane having an average pore size of less than about 25 .ANG. and a second inorganic porous membrane coating the first inorganic membrane having an average pore size of less than about 6 .ANG.. The dual-layered membrane is produced by contacting the porous substrate with a surfactant-template polymeric sol, resulting in a surfactant sol coated membrane support. The surfactant sol coated membrane support is dried, producing a surfactant-templated polymer-coated substrate which is calcined to produce an intermediate layer surfactant-templated membrane. The intermediate layer surfactant-templated membrane is then contacted with a second polymeric sol producing a polymeric sol coated substrate which is dried producing an inorganic polymeric coated substrate. The inorganic polymeric coated substrate is then calcined producing an inorganic dual-layered microporous supported membrane in accordance with the present invention.

  15. Inorganic membranes: The new industrial revolution

    SciTech Connect

    Fain, D.E.

    1994-12-31

    Separation systems are a vital part of most industrial processes. These systems account for a large fraction of the capital equipment used and the operating costs of industrial processes. Inorganic membranes have the potential for providing separation systems that can significantly reduce both the capital equipment and operating costs. These separation processes include waste management and recycle as well as the primary production of raw materials and products. The authors are rapidly learning to understand the effect of physical and chemical properties on the different transport mechanisms that occur in inorganic membranes. Such understanding can be expected to provide the information needed to design, engineer and manufacture inorganic membranes to produce very high separation factors for almost any separation function. To implement such a revolution, the authors need to organize a unique partnership between the national laboratories, and industry. The university can provide research to understand the materials and transport mechanisms that produce various separations, the national laboratories the development of an economical fabrication and manufacturing capability, and industry the practical understanding of the operational problems required to achieve inplementation.

  16. Development of Inorganic Membranes for Hydrogen Separation

    SciTech Connect

    Bischoff, B.L.; Judkins, R.R.

    2003-04-23

    This paper presents information and data relative to recent advances in the development at Oak Ridge National Laboratory of porous inorganic membranes for high-temperature hydrogen separation. The Inorganic Membrane Technology Laboratory, which was formerly an organizational element of Bechtel Jacobs Company, LLC, was formally transferred to Oak Ridge National Laboratory on August 1, 2002, as a result of agreements reached between Bechtel Jacobs Company, the management and integration contractor at the East Tennessee Technology Park (formerly the Oak Ridge Gaseous Diffusion Plant or Oak Ridge K-25 Site); UT-Battelle, the management and operating contractor of Oak Ridge National Laboratory; and the U.S. Department of Energy (DOE) Oak Ridge Operations Office. Research emphasis during the last year has been directed toward the development of high-permeance (high-flux) and high-separation-factor metal-supported membranes. Performance data for these membranes are presented and are compared with performance data for membranes previously produced under this program and for membranes produced by other researchers. New insights into diffusion mechanisms are included in the discussion. Fifteen products, many of which are the results of research sponsored by the DOE Fossil Energy Advanced Research Materials Program, have been declared unclassified and have been approved for commercial production.

  17. Principles of Inorganic Materials Design

    NASA Astrophysics Data System (ADS)

    Lalena, John N.; Cleary, David

    2005-04-01

    A unique interdisciplinary approach to inorganic materials design Textbooks intended for the training of chemists in the inorganic materials field often omit many relevant topics. With its interdisciplinary approach, this book fills that gap by presenting concepts from chemistry, physics, materials science, metallurgy, and ceramics in a unified treatment targeted towards the chemistry audience. Semiconductors, metal alloys and intermetallics, as well as ceramic substances are covered. Accordingly, the book should also be useful to students and working professionals in a variety of other disciplines. This book discusses a number of topics that are pertinent to the design of new inorganic materials but are typically not covered in standard solid-state chemistry books. The authors start with an introduction to structure at the mesoscopic level and progress to smaller-length scales. Next, detailed consideration is given to both phenomenological and atomistic-level descriptions of transport properties, the metal-nonmetal transition, magnetic and dielectric properties, optical properties, and mechanical properties. Finally, the authors present introductions to phase equilibria, synthesis, and nanomaterials. Other features include: Worked examples demonstrating concepts unfamiliar to the chemist Extensive references to related literature, leading readers to more in-depth coverage of particular topics Biographies introducing the reader to great contributors to the field of inorganic materials science in the twentieth century With their interdisciplinary approach, the authors have set the groundwork for communication and understanding among professionals in varied disciplines who are involved with inorganic materials engineering. Armed with this publication, students and researchers in inorganic and physical chemistry, physics, materials science, and engineering will be better equipped to face today's complex design challenges. This textbook is appropriate for senior

  18. Electrostatically gated membrane permeability in inorganic protocells

    NASA Astrophysics Data System (ADS)

    Li, Mei; Harbron, Rachel L.; Weaver, Jonathan V. M.; Binks, Bernard P.; Mann, Stephen

    2013-06-01

    Although several strategies are now available to produce functional microcompartments analogous to primitive cell-like structures, little progress has been made in generating protocell constructs with self-controlled membrane permeability. Here we describe the preparation of water-dispersible colloidosomes based on silica nanoparticles and delineated by a continuous semipermeable inorganic membrane capable of self-activated, electrostatically gated permeability. We use crosslinking and covalent grafting of a pH-responsive copolymer to generate an ultrathin elastic membrane that exhibits selective release and uptake of small molecules. This behaviour, which depends on the charge of the copolymer coronal layer, serves to trigger enzymatic dephosphorylation reactions specifically within the protocell aqueous interior. This system represents a step towards the design and construction of alternative types of artificial chemical cells and protocell models based on spontaneous processes of inorganic self-organization.

  19. Electrostatically gated membrane permeability in inorganic protocells.

    PubMed

    Li, Mei; Harbron, Rachel L; Weaver, Jonathan V M; Binks, Bernard P; Mann, Stephen

    2013-06-01

    Although several strategies are now available to produce functional microcompartments analogous to primitive cell-like structures, little progress has been made in generating protocell constructs with self-controlled membrane permeability. Here we describe the preparation of water-dispersible colloidosomes based on silica nanoparticles and delineated by a continuous semipermeable inorganic membrane capable of self-activated, electrostatically gated permeability. We use crosslinking and covalent grafting of a pH-responsive copolymer to generate an ultrathin elastic membrane that exhibits selective release and uptake of small molecules. This behaviour, which depends on the charge of the copolymer coronal layer, serves to trigger enzymatic dephosphorylation reactions specifically within the protocell aqueous interior. This system represents a step towards the design and construction of alternative types of artificial chemical cells and protocell models based on spontaneous processes of inorganic self-organization.

  20. Inorganic Phosphor Materials for Lighting.

    PubMed

    Lin, Yuan-Chih; Karlsson, Maths; Bettinelli, Marco

    2016-04-01

    This chapter addresses the development of inorganic phosphor materials capable of converting the near UV or blue radiation emitted by a light emitting diode to visible radiation that can be suitably combined to yield white light. These materials are at the core of the new generation of solid-state lighting devices that are emerging as a crucial clean and energy saving technology. The chapter introduces the problem of white light generation using inorganic phosphors and the structure-property relationships in the broad class of phosphor materials, normally containing lanthanide or transition metal ions as dopants. Radiative and non-radiative relaxation mechanisms are briefly described. Phosphors emitting light of different colors (yellow, blue, green, and red) are described and reviewed, classifying them in different chemical families of the host (silicates, phosphates, aluminates, borates, and non-oxide hosts). This research field has grown rapidly and is still growing, but the discovery of new phosphor materials with optimized properties (in terms of emission efficiency, chemical and thermal stability, color, purity, and cost of fabrication) would still be of the utmost importance.

  1. Plasma chemistry for inorganic materials

    NASA Technical Reports Server (NTRS)

    Matsumoto, O.

    1980-01-01

    Practical application of plasma chemistry to the development of inorganic materials using both low temperature and warm plasmas are summarized. Topics cover: the surface nitrification and oxidation of metals; chemical vapor deposition; formation of minute oxide particles; the composition of oxides from chloride vapor; the composition of carbides and nitrides; freezing high temperature phases by plasma arc welding and plasma jet; use of plasma in the development of a substitute for petroleum; the production of silicon for use in solar cell batteries; and insulating the inner surface of nuclear fusion reactor walls.

  2. Carbon dioxide removal with inorganic membranes

    SciTech Connect

    Judkins, R.R.; Fain, D.E.

    1993-12-31

    The increasing concentrations of greenhouse gases, particularly carbon dioxide, in the atmosphere has sparked a great deal of interest in the removal of CO{sub 2} from flue gases of fossil fueled plants. Presently, several techniques for the removal of CO{sub 2} are considered to have potential, but are lacking in practicality. For example, amine scrubbing of flue gas streams is potential, but are lacking in practically. For example, amine scrubbing of flue gas streams is effective in removing CO{sub 2}, but costs are high; efficiency suffers; and other acid gases must be removed prior to amine stripping. Membrane systems for CO{sub 2} removal are held in high regard, and inorganic, particularly ceramic, membranes offer the potential for high temperature, thus energy saving, removal.

  3. Comparison of the filtration characteristics of organic and inorganic membranes in a membrane-coupled anaerobic bioreactor.

    PubMed

    Kang, In-Joong; Yoon, Seong-Hoon; Lee, Chung-Hak

    2002-04-01

    Comparison of filtration characteristics of organic and inorganic membranes was made in terms of physicochemical properties of the membrane materials, cake layer formation, backflushing and backfeeding effects in a membrane-coupled anaerobic bioreactor. For the inorganic membrane, struvite (MgNH4PO4 x 6H2O) was found to have accumulated inside the membrane pore and plays a key role in flux decline. For the organic, however, a thick cake layer composed of biomass and struvite formed on the membrane surface, thus causing a major hydraulic resistance. In order to mitigate flux decline for both membranes, backflushing and backfeeding modes were examined. With acidic (pH 2.0) backflushing, the flux was approximately doubled for the organic membrane. However, unexpectedly a negative effect was observed for the inorganic membrane. An alkaline backflushing instead of acidic backflushing gave rise to a flux improvement by a factor of two without any negative effect, even for the inorganic membrane. The backfeeding mode gave rise to a much higher flux compared with the normal mode in both types of membrane, although the flux returned to the same level as that with the normal mode after 6 days for the inorganic membrane. The differences between the two types of membranes were explained by membrane morphology, a ligand exchange reaction as well as a surface charge effect.

  4. Nanostructured YSZ membranes derived from inorganic salts

    NASA Astrophysics Data System (ADS)

    Zhang, Cunlin; Liao, Yang; He, Shuli; Sun, Defeng; Chen, Wen

    2005-01-01

    The nanostuctured YSZ (Yttria Stabilized Zirconia) membranes on Si(110) substrates are successfully prepared by sol-gel technology derived from inorganic salts ZrOCl2"8H2O, H2C2O4"2H2O and Y(NO3)3"6H2O. By means of controlling the supersaturation and diffusion velocity in solution when the zirconyl oxalate xerogels are repeptized, spherical colloidal paricles with different distributions are obtained. we propose that the peptization of xerogels can be considered as a process of nucleation and growth of colloidal particles. The membranes are preparated by spinning the modified sols on Si(110) substrates. After calcining at 800°C for 1 hour, the membranes are crack-free and mirrorlike. The membranes consist of monodisperse fine spherical crystallines in the range of 20~220nm in diameter, which microstructures are controlled by changing the size and distribution of colloidal particles in sols.

  5. High temperature inorganic membranes for separating hydrogen

    SciTech Connect

    Fain, D.E.; Roettger, G.E.

    1995-08-01

    Effort has continued to accumulate data on the transport of gases over the temperature range from room temperature to 275{degrees}C with inorganic membranes having a range of pore radii from approximately 0.25 nm to 3 mn. An experimental alumina membrane having an estimated mean pore radius of 0.25 nm has been fabricated and tested. Extensive testing of this membrane indicated that the separation factor for helium and carbon tetrafluoride at 250{degrees}C was 59 and the extrapolated high temperature separation factor was 1,193. For safety reasons, earlier flow measurements concentrated on helium, carbon dioxide, and carbon tetrafluoride. New data have been acquired with hydrogen to verify the agreement with the other gases. During the measurements with hydrogen, it was noted that a considerable amount of moisture was present in the test gas. The source of this moisture and its effect on permeance was examined. Improvements were implemented to the flow test system to minimize the water content of the hydrogen test gas, and subsequent flow measurements have shown excellent results with hydrogen. The extrapolation of separation factors as a function of temperature continues to show promise as a means of using the hard sphere model to determine the pore size of membranes. The temperature dependence of helium transport through membranes appears to be considerably greater than other gases for the smallest pore sizes. The effort to extend temperature dependence to the hard sphere model continues to be delayed, primarily because of a lack of adequate adsorption data.

  6. Design and properties of functional hybrid organic-inorganic membranes for fuel cells.

    PubMed

    Laberty-Robert, C; Vallé, K; Pereira, F; Sanchez, C

    2011-02-01

    This critical review presents a discussion on the major advances in the field of organic-inorganic hybrid membranes for fuel cells application. The hybrid organic-inorganic approach, when the organic part is not conductive, reproduces to some extent the behavior of Nafion where discrete hydrophilic and hydrophilic domains are homogeneously distributed. A large variety of proton conducting or non conducting polymers can be combined with various functionalized, inorganic mesostructured particles or an inorganic network in order to achieve high proton conductivity, and good mechanical and chemical properties. The tuning of the interface between these two components and the control over chemical and processing conditions are the key parameters in fabricating these hybrid organic-inorganic membranes with a high degree of reproducibility. This dynamic coupling between chemistry and processing requires the extensive use and development of complementary ex situ measurements with in situ characterization techniques, following in real time the molecular precursor solutions to the formation of the final hybrid organic-inorganic membranes. These membranes combine the intrinsic physical and chemical properties of both the inorganic and organic components. The development of the sol-gel chemistry allows a fine tuning of the inorganic network, which exhibits acid-based functionalized pores (-SO(3)H, -PO(3)H(2), -COOH), tunable pore size and connectivity, high surface area and accessibility. As such, these hybrid membranes containing inorganic materials are a promising family for controlling conductivity, mechanical and chemical properties (349 references).

  7. Inorganic Nanoporous Membranes for Immunoisolated Cell-Based Drug Delivery

    PubMed Central

    Mendelsohn, Adam; Desai, Tejal

    2014-01-01

    Materials advances enabled by nanotechnology have brought about promising approaches to improve the encapsulation mechanism for immunoisolated cell-based drug delivery. Cell-based drug delivery is a promising treatment for many diseases but has thus far achieved only limited clinical success. Treatment of insulin dependent diabetes mellitus (IDDM) by transplantation of pancreatic β-cells represents the most anticipated application of cell-based drug delivery technology. This review outlines the challenges involved with maintaining transplanted cell viability and discusses how inorganic nanoporous membranes may be useful in achieving clinical success. PMID:20384222

  8. Photochromic organic-inorganic hybrid materials.

    PubMed

    Pardo, Rosario; Zayat, Marcos; Levy, David

    2011-02-01

    Photochromic organic-inorganic hybrid materials have attracted considerable attention owing to their potential application in photoactive devices, such as optical memories, windows, photochromic decorations, optical switches, filters or non-linear optics materials. The growing interest in this field has largely expanded the use of photochromic materials for the purpose of improving existing materials and exploring new photochromic hybrid systems. This tutorial review summarizes the design and preparation of photochromic hybrid materials, and particularly those based on the incorporation of organic molecules in organic-inorganic matrices by the sol-gel method. This is the most commonly used method for the preparation of these materials as it allows vitreous hybrid materials to be obtained at low temperatures, and controls the interaction between the organic molecule and its embedding matrix, and hence allows tailoring of the performance of the resulting devices.

  9. Combinatorial synthesis of inorganic or composite materials

    DOEpatents

    Goldwasser, Isy; Ross, Debra A.; Schultz, Peter G.; Xiang, Xiao-Dong; Briceno, Gabriel; Sun, Xian-Dong; Wang, Kai-An

    2010-08-03

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials or, alternatively, allowing the components to interact to form at least two different materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, nonbiological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  10. Preparation and screening of crystalline inorganic materials

    DOEpatents

    Schultz, Peter G.; Xiang, Xiaodong; Goldwasser, Isy; Brice{hacek over }o, Gabriel; Sun, Xiao-Dong; Wang, Kai-An

    2008-10-28

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  11. Combinatorial screening of inorganic and organometallic materials

    DOEpatents

    Schultz, Peter G.; Xiang, Xiaodong; Goldwasser, Isy

    2002-01-01

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  12. Separation of gaseous mixtures using inorganic nanofiltration membranes

    SciTech Connect

    Niezyniecki, G.M.; Anderson, M.A.; Hill, C.G. Jr.

    1994-12-31

    The use of membranes for gas phase separations dates back to the separation of isotopes of uranium hexafluoride in the 1940`s. Presently, both organic and inorganic membranes are used in a variety of industrial separation processes. Potential advantages of ceramic membranes over polymeric membranes include the ability to perform separations at elevated temperatures and in the presence of organic vapors. Various ceramic membranes have been fabricated via sol-gel techniques. These membranes are characterized by mean pore diameters of less than 15 angstroms. The permeabilities of these membranes have been measured for a variety of gases. In addition, permselectivities have been determined for mixtures of these gases. Increases in permeability are observed with increases in applied pressure. The permeability of these membranes to propylene is as much as thirty times greater than to nitrogen. Experimental results indicate that the transport of gases through these membranes involves a surface transport mechanism in addition to Knudsen diffusion.

  13. Inorganic polymer-derived ceramic membranes

    SciTech Connect

    Brinker, C.J.; Sehgal, R.; Raman, N.; Schunk, P.R.; Headley, T.J.

    1993-12-31

    Polymeric silica sols were used to prepare membranes on commercial {gamma}-A1{sub 2}O{sub 3} supports. Aging of the silica sols was shown to be effective to form discrete membrane layers. He/N{sub 2} selectivity factors exceeding ideal Knudsen values were observed when the sols were prepared under conditions in which the condensation rate was minimized. It is proposed that the average pore size of the membrane depends on the balance of capillary pressure and modulus during membrane deposition and that the breadth of the pore size distribution might be influenced by the extent of condensation accompanying membrane deposition. The use of organic templates may allow independent control of pore size, pore shape, and pore volume. The membranes are to be used in processing natural gas (gas separation/purification).

  14. Stretchable, curvilinear electronics based on inorganic materials.

    PubMed

    Kim, Dae-Hyeong; Xiao, Jianliang; Song, Jizhou; Huang, Yonggang; Rogers, John A

    2010-05-18

    All commercial forms of electronic/optoelectronic technologies use planar, rigid substrates. Device possibilities that exploit bio-inspired designs or require intimate integration with the human body demand curvilinear shapes and/or elastic responses to large strain deformations. This article reviews progress in research designed to accomplish these outcomes with established, high-performance inorganic electronic materials and modest modifications to conventional, planar processing techniques. We outline the most well developed strategies and illustrate their use in demonstrator devices that exploit unique combinations of shape, mechanical properties and electronic performance. We conclude with an outlook on the challenges and opportunities for this emerging area of materials science and engineering.

  15. Gas separation performance of inorganic polyphosphazene membranes

    SciTech Connect

    Stone, M.L.

    1995-07-01

    The objective of this research program was to develop, characterize, and evaluate the potential of phosphazene polymers for separations performed in harsh environments. The program was divided into two general areas, gas separations and metal ion separations involving aqueous solutions. Each of these two areas is the subject of a topical report; this report deals with the gas separations. Throughout the world, there is rapidly growing interest in membrane separation as an energy efficient way to separate components of a process stream or waste stream, such as in desalination of water or clarification of fruit juices. In some cases membranes perform separations that are otherwise very difficult, such as breaking azeotropes. In the early stages of the work reported here, there was interest in separating acid gases from process flue gases and in natural gas sweetening. As a result, research was undertaken to characterize membrane performance. First, a pure gas test apparatus was developed to determine the permeabilities of a number of gases through various membranes at a variety of temperatures. Second, an automated mixed gas test cell was developed in which membranes could be exposed to mixtures of pairs of gases. Each of these approaches has its advantages and each will be discussed separately.

  16. Development of taste sensing system using inorganic membrane

    NASA Astrophysics Data System (ADS)

    Kojima, Yohichiro; Hasegawa, Yuki

    2011-09-01

    We developed a novel taste sensor for liquid and verified its effectiveness using coffee. We fabricated an inorganic metal oxide membrane liquid sensor using the laser ablation method. The sensor shows a sufficient sensitivity for electrolyte solutions, while it shows a relatively low response for non-electrolyte solutions. We differentiated and identified five brands of commercially available coffee using the sensor.

  17. Polyoxometalates: from inorganic chemistry to materials science.

    PubMed

    Casañ-Pastor, Nieves; Gómez-Romero, Pedro

    2004-05-01

    Polyoxometalates have been traditionally the subject of study of molecular inorganic chemistry. Yet, these polynuclear molecules, reminiscent of oxide clusters, present a wide range of structures and with them ideal frameworks for the deployment of a plethora of useful magnetic, electroionic, catalytic, bioactive and photochemical properties. With this in mind, a new trend towards the application of these remarkable species in materials science is beginning to develop. In this review we analyze this trend and discuss two main lines of thought for the application of polyoxometalates as materials. On the one hand, there is their use as clusters with inherently useful properties on themselves, a line which has produced fundamental studies of their magnetic, electronic or photoelectrochemical properties and has shown these clusters as models for quantum-sized oxides. On the other hand, the encapsulation or integration of polyoxometalates into organic, polymeric or inorganic matrices or substrates opens a whole new field within the area of hybrid materials for harnessing the multifunctional properties of these versatile species in a wide variety of applications, ranging from catalysis to energy storage to biomedicine.

  18. Interaction of Inorganic Nanoparticles With Cell Membranes

    DTIC Science & Technology

    2008-10-20

    explain the change in the Zeta-potential of the beads we studied the adsorption of protein on Chitosan coated SPIONs. The particles were incubated in...protein adsorption which enables us understand better the pathway of our particles through the membrane and inside the cell. Combined with...investigation regarding the protein adsorption and their influence on the colloidal stability we have now the tools to investigate and perhaps to understand

  19. Hollow fiber inorganic membranes for gas separations

    SciTech Connect

    Way, J.D. ); Roberts, D.L. )

    1992-01-01

    There is increasing interest to develop high temperature, high pressure membrane technology to perform a variety of gas separations such as acid gas removal from synthetic gas streams found in coal-fired power generation systems, hydrogen recovery in petrochemical production, and CO/H{sub 2} ratio adjustment in the production of oxychemicals. Pure gas permeabilities of He, H{sub 2}, CO{sub 2}, N{sub 2}, and CO were measured for microporous silica hollow fiber membranes as a function of temperature. The transport mechanism for gas permeation is clearly non-Knudsen since several heavier gases permeate faster then lighter gases. An excellent correlation is obtained between permeability and kinetic diameter of the penetrant. The proposed mass transfer mechanism is a combination of surface diffusion and molecular sieving. High ideal separation factors (permeability ratios) are observed at 343 K for H{sub 2}/N{sub 2} and H{sub 2}/CO of 163 62.4, respectively, which compare very favorably with polymeric and molecular sieve gas separation membranes.

  20. Performance of porous inorganic membranes in non-osmotic desalination.

    PubMed

    Duke, M C; Mee, S; da Costa, J C Diniz

    2007-09-01

    The supply security of fresh drinking water is decreasing and raising a critical situation for communities worldwide. Inorganic membranes such as alumina and molecular sieve silica have in the past been shown to be highly effective at separating gases and could offer promise as liquid separators due to their high flux and stability. In this work, we develop a range of inorganic membranes with pore size ranging from 0.3 to 500nm and relate this to separation and transport performance. Best separation results were achieved for the silica membrane pressurised to only 7bar, exhibiting a flux of around 1.8kgm(-2)h(-1) and NaCl rejection of 98% with 3.5wt% (seawater-like) feed. Potable water from seawater-like feed was achieved from the membrane in a single stage after regeneration. Conditions such as pressure and temperature were also modified showing performance characteristics and diffusion mechanisms. The non-osmotic set-up for inorganic membranes is therefore a viable technology for desalination.

  1. Fabricating porous materials using interpenetrating inorganic-organic composite gels

    DOEpatents

    Seo, Dong-Kyun; Volosin, Alex

    2016-06-14

    Porous materials are fabricated using interpenetrating inorganic-organic composite gels. A mixture or precursor solution including an inorganic gel precursor, an organic polymer gel precursor, and a solvent is treated to form an inorganic wet gel including the organic polymer gel precursor and the solvent. The inorganic wet gel is then treated to form a composite wet gel including an organic polymer network in the body of the inorganic wet gel, producing an interpenetrating inorganic-organic composite gel. The composite wet gel is dried to form a composite material including the organic polymer network and an inorganic network component. The composite material can be treated further to form a porous composite material, a porous polymer or polymer composite, a porous metal oxide, and other porous materials.

  2. Functionalized inorganic membranes for gas separation

    DOEpatents

    Ku, Anthony Yu-Chung; Ruud, James Anthony; Molaison, Jennifer Lynn; Schick, Louis Andrew ,; Ramaswamy, Vidya

    2008-07-08

    A porous membrane for separation of carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity. The porous membrane comprises a porous support layer comprising alumina, silica, zirconia or stabilized zirconia; a porous separation layer comprising alumina, silica, zirconia or stabilized zirconia, and a functional layer comprising a ceramic oxide contactable with the fluid stream to preferentially transport carbon dioxide. In particular, the functional layer may be MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3 or a mixture thereof; wherein A is Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; and A.sup.3 is Sr or Ba.

  3. Forward osmosis with a novel thin-film inorganic membrane.

    PubMed

    You, Shijie; Tang, Chuyang; Yu, Chen; Wang, Xiuheng; Zhang, Jinna; Han, Jia; Gan, Yang; Ren, Nanqi

    2013-08-06

    Forward osmosis (FO) represents a new promising membrane technology for liquid separation driven by the osmotic pressure of aqueous solution. Organic polymeric FO membranes are subject to severe internal concentration polarization due to asymmetric membrane structure, and low stability due to inherent chemical composition. To address these limitations, this study focuses on the development of a new kind of thin-film inorganic (TFI) membrane made of microporous silica xerogels immobilized onto a stainless steel mesh (SSM) substrate. The FO performances of the TFI membrane were evaluated upon a lab-scale cell-type FO reactor using deionized water as feed solution and sodium chloride (NaCl) as draw solution. The results demonstrated that the TFI membrane could achieve transmembrane water flux of 60.3 L m(-2) h(-1) driven by 2.0 mol L(-1) NaCl draw solution at ambient temperature. Meanwhile, its specific solute flux, i.e. the solute flux normalized by the water flux (0.19 g L(-1)), was 58.7% lower than that obained for a commercial cellulose triacetate (CTA) membrane (0.46 g L(-1)). The quasi-symmetry thin-film microporous structure of the silica membrane is responsible for low-level internal concentration polarization, and thus enhanced water flux during FO process. Moreover, the TFI membrne demonstrated a substantially improved stability in terms of mechanical strength, and resistance to thermal and chemical stimulation. This study not only provides a new method for fabricating quasi-symmetry thin-film inorganic silica membrane, but also suggests an effective strategy using this alternative membrane to achieve improved FO performances for scale-up applications.

  4. OXIDATIVE COUPLING OF METHANE USING INORGANIC MEMBRANE REACTORS

    SciTech Connect

    Dr. Y.H. Ma; Dr. W.R. Moser; Dr. A.G. Dixon; Dr. A.M. Ramachandra; Dr. Y. Lu; C. Binkerd

    1998-04-01

    The objective of this research is to study the oxidative coupling of methane in catalytic inorganic membrane reactors. A specific target is to achieve conversion of methane to C{sub 2} hydrocarbons at very high selectivity and higher yields than in conventional non-porous, co-feed, fixed bed reactors by controlling the oxygen supply through the membrane. A membrane reactor has the advantage of precisely controlling the rate of delivery of oxygen to the catalyst. This facility permits balancing the rate of oxidation and reduction of the catalyst. In addition, membrane reactors minimize the concentration of gas phase oxygen thus reducing non selective gas phase reactions, which are believed to be a main route for the formation of CO{sub x} products. Such gas phase reactions are a cause of decreased selectivity in the oxidative coupling of methane in conventional flow reactors. Membrane reactors could also produce higher product yields by providing better distribution of the reactant gases over the catalyst than the conventional plug flow reactors. Membrane reactor technology also offers the potential for modifying the membranes both to improve catalytic properties as well as to regulate the rate of the permeation/diffusion of reactants through the membrane to minimize by-product generation. Other benefits also exist with membrane reactors, such as the mitigation of thermal hot-spots for highly exothermic reactions such as the oxidative coupling of methane. The application of catalytically active inorganic membranes has potential for drastically increasing the yield of reactions which are currently limited by either thermodynamic equilibria, product inhibition, or kinetic selectivity.

  5. Organic materials as templates for the formation of mesoporous inorganic materials and ordered inorganic nanocomposites

    NASA Astrophysics Data System (ADS)

    Ziegler, Christopher R.

    Hierarchically structured inorganic materials are everywhere in nature. From unicellular aquatic algae such as diatoms to the bones and/or cartilage that comprise the skeletal systems of vertebrates. Complex mechanisms involving site-specific chemistries and precision kinetics are responsible for the formation of such structures. In the synthetic realm, reproduction of even the most basic hierarchical structure effortlessly produced in nature is difficult. However, through the utilization of self-assembling structures or "templates", such as polymers or amphiphilic surfactants, combined with some favorable interaction between a chosen inorganic, the potential exists to imprint an inorganic material with a morphology dictated via synthetic molecular self-assembly. In doing so, a very basic hierarchical structure is formed on the angstrom and nanometer scales. The work presented herein utilizes the self-assembly of either surfactants or block copolymers with the desired inorganic or inorganic precursor to form templated inorganic structures. Specifically, mesoporous silica spheres and copolymer directed calcium phosphate-polymer composites were formed through the co-assembly of an organic template and a precursor to form the desired mesostructured inorganic. For the case of the mesoporous silica spheres, a silica precursor was mixed with cetyltrimethylammonium bromide and cysteamine, a highly effective biomimetic catalyst for the conversion of alkoxysilanes to silica. Through charge-based interactions between anionic silica species and the micelle-forming cationic surfactant, ordered silica structures resulted. The incorporation of a novel, effective catalyst was found to form highly condensed silica spheres for potential application as catalyst supports or an encapsulation media. Ordered calcium phosphate-polymer composites were formed using two routes. Both routes take advantage of hydrogen bonding and ionic interactions between the calcium and phosphate precursors

  6. Thiolated eggshell membranes sorb and speciate inorganic selenium.

    PubMed

    Yang, Ting; Chen, Ming-Li; Hu, Xian-Wei; Wang, Zhao-Wen; Wang, Jian-Hua; Dasgupta, Purnendu K

    2011-01-07

    Eggshell membranes (ESMs) provide a unique, disulfide bond-rich surface. Thioglycolate reduction was used to generate thiol (-SH) groups on the ESM surface by S-S bond cleavage. The thiol-bearing ESMs (TESMs) were characterized by scanning electron microscopy and Raman spectroscopy. The fibrous network structure of the ESM is retained in the TESMs. TESMs adsorb both Se(IV) and Se(VI) but by different mechanisms: Se(VI) is retained reversibly, possibly via ionic interactions, while Se(IV) is reduced to Se(0) and deposited. We thus demonstrate speciation of selenium species, by using samples (a) as such and after prior oxidation to Se(VI), (b) preconcentration on a TESM microcolumn, (c) elution by 0.5 M HNO(3) that only elutes Se(VI) and (d) detection by graphite furnace atomic absorption spectrometry (GFAAS). The Se(IV) amount is determined by difference. For a 1.0 mL sample, the enrichment factor was 17.2, the S/N = 3 detection limit was 0.06 μg L(-1) and the precision was 3.3% at 0.50 μg L(-1). The linear range was 0.25-2.50 μg L(-1). The procedure was validated by analyzing selenium in certified reference materials of human hair (GBW 09101) and rice (GBW 10010). We further demonstrate utility by speciation of inorganic selenium in a series of water samples.

  7. Inorganic membranes for carbon capture and power generation

    NASA Astrophysics Data System (ADS)

    Snider, Matthew T.

    Inorganic membranes are under consideration for cost-effective reductions of carbon emissions from coal-fired power plants, both in the capture of pollutants post-firing and in the direct electrochemical conversion of coal-derived fuels for improved plant efficiency. The suitability of inorganic membrane materials for these purposes stems as much from thermal and chemical stability in coal plant operating conditions as from high performance in gas separations and power generation. Hydrophilic, micro-porous zeolite membrane structures are attractive for separating CO2 from N2 in gaseous waste streams due to the attraction of CO2 to the membrane surface and micropore walls that gives the advantage to CO2 transport. Recent studies have indicated that retention of the templating agent used in zeolite synthesis can further block N2 from the micropore interior and significantly improve CO2/N2 selectivity. However, the role of the templating agent in micro-porous transport has not been well investigated. In this work, gas sorption studies were conducted by high-pressure thermo-gravimetric analysis on Zeolite Y membrane materials to quantify the effect of the templating agent on CO2, N2, and H2O adsorption/desorption, as well as to examine the effect of humidification on overall membrane performance. In equilibrium conditions, the N2 sorption enthalpy was nearly unchanged by the presence of the templating agent, but the N2 pore occupation was reduced ˜1000x. Thus, the steric nature of the blocking of N2 from the micropores by the templating agent was confirmed. CO2 and H2O sorption enthalpies were similarly unaffected by the templating agent, and the micropore occupations were only reduced as much as the void volume taken up by the templating agent. Thus, the steric blocking effect did not occur for molecules more strongly attracted to the micropore walls. Additionally, in time-transient measurements the CO 2 and H2O mobilities were significantly enhanced by the presence

  8. Interfacial and transport properties of nanoconstrained inorganic and organic materials

    NASA Astrophysics Data System (ADS)

    Kocherlakota, Lakshmi Suhasini

    Nanoscale constraints impact the material properties of both organic and inorganic systems. The systems specifically studied here are (i) nanoconstrained polymeric systems, poly(l-trimethylsilyl-1-propyne) (PTMSP) and poly(ethylene oxide) (PEO) relevant to gas separation membranes (ii) Zwitterionic polymers poly(sulfobetaine methacrylate)(pSBMA), poly(carboxybetaine acrylamide) (pCBAA), and poly(oligo(ethylene glycol) methyl methacrylate) (PEGMA) brushes critical for reducing bio-fouling (iii) Surface properties of N-layer graphene sheets. Interfacial constraints in ultrathin poly(l-trimethylsilyl-1-propyne) (PTMSP) membranes yielded gas permeabilities and CO2/helium selectivities that exceed bulk PTMSP membrane transport properties by up to three-fold for membranes of submicrometer thickness. Indicative of a free volume increase, a molecular energetic mobility analysis (involving intrinsic friction analysis) revealed enhanced methyl side group mobilities in thin PTMSP membranes with maximum permeation, compared to bulk films. Aging studies conducted over the timescales relevant to the conducted experiments signify that the free volume states in the thin film membranes are highly unstable in the presence of sorbing gases such as CO2. To maintain this high free volume configuration of polymer while improving the temporal stability an "inverse" architecture to conventional polymer nanocomposites was investigated, in which the polymer phase of PTMSP and PEO were interfacially and dimensionally constrained in nanoporous anodic aluminum oxide (AAO) membranes. While with this architecture the benefits of nanocomposite and ultrathin film membranes of PTMSP could be reproduced and improved upon, also the temporal stability could be enhanced substantially. The PEO-AAO nanocomposite membranes also revealed improved gas selectivity properties of CO2 over helium. In the thermal transition studies of zwitterionic pSBMA brushes a reversible critical transition temperature of 60

  9. Computational Screening of All Stoichiometric Inorganic Materials.

    PubMed

    Davies, Daniel W; Butler, Keith T; Jackson, Adam J; Morris, Andrew; Frost, Jarvist M; Skelton, Jonathan M; Walsh, Aron

    2016-10-13

    Forming a four-component compound from the first 103 elements of the periodic table results in more than 10(12) combinations. Such a materials space is intractable to high-throughput experiment or first-principle computation. We introduce a framework to address this problem and quantify how many materials can exist. We apply principles of valency and electronegativity to filter chemically implausible compositions, which reduces the inorganic quaternary space to 10(10) combinations. We demonstrate that estimates of band gaps and absolute electron energies can be made simply on the basis of the chemical composition and apply this to the search for new semiconducting materials to support the photoelectrochemical splitting of water. We show the applicability to predicting crystal structure by analogy with known compounds, including exploration of the phase space for ternary combinations that form a perovskite lattice. Computer screening reproduces known perovskite materials and predicts the feasibility of thousands more. Given the simplicity of the approach, large-scale searches can be performed on a single workstation.

  10. The study of inorganic scintillating materials

    NASA Astrophysics Data System (ADS)

    Dudkin, G. N.; Kuznetsov, S. I.; Padalko, V. N.; Syrtanov, M. S.

    2017-05-01

    The procedure for measuring the temporal characteristics and light output of inorganic scintillating materials excited by β-, γ-, and α-particles from radioactive sources is described. Results of measurements of characteristics are presented for ∼30 scintillating compounds including cerium-doped yttrium silicate and scandium borate; europium-doped strontium phosphate; cerium-doped strontium silicate, calcium silicate and magnesium calcium silicate, etc. Upon β- and γ-excitation, cerium-doped scandium borate gives the highest light output with a fluorescent lifetime of 40 ± 4 ns. The highest light output for α-excitation was from cerium-doped yttrium aluminum perovskite, with a fluorescent lifetime of 29 ± 3 ns.

  11. Temperature effect on transport performance by inorganic nanofiltration membranes

    SciTech Connect

    Tsuru, Toshinori; Izumi, Shuhei; Yoshioka, Tomohisa; Asaeda, Masashi

    2000-03-01

    The effect of temperature on nanofiltration performance was examined using three inorganic membranes with a molecular-weight cutoff of approximately 200, 600, and 2,000, respectively. The inorganic porous membranes were prepared from silica-zirconia colloidal sols and used in nanofiltration experiments for neutral solutes over a temperature range of 20 to 60 C. The rejection of solutes decreased with an increase in temperature for the membranes, while the permeate volume flux increased. Three transport coefficients--reflection coefficient, solute permeability, and water permeability--were obtained using the Spiegler-Kedem equation, which accounts for the contribution of convection and diffusion to solute flux. As a result, the reflection coefficient corresponding to the fraction of solutes reflected by the membrane in convective flow was almost constant, irrespective of experimental temperature. The dependency was larger for larger solutes and membranes with smaller pore diameters. Therefore, the hindered diffusion of solutes through micropores was indicative of an activated process. Moreover, pure water permeability, after correction for the temperature effect on viscosity, also increased with experimental temperature.

  12. Improved Membrane Materials for PEM Fuel Cell Application

    SciTech Connect

    Kenneth A. Mauritz; Robert B. Moore

    2008-06-30

    The overall goal of this project is to collect and integrate critical structure/property information in order to develop methods that lead to significant improvements in the durability and performance of polymer electrolyte membrane fuel cell (PEMFC) materials. This project is focused on the fundamental improvement of PEMFC membrane materials with respect to chemical, mechanical and morphological durability as well as the development of new inorganically-modified membranes.

  13. Synthesis and characterization of inorganic materials precipitated into polymeric and novel liquid crystalline systems

    NASA Astrophysics Data System (ADS)

    Lubeck, Christopher Ryan

    The use of nanostructured, hybrid materials possesses great future potential. Many examples of nanostructured materials exist within nature, such as animal bone, animal teeth, and seashells. This research, inspired by nature, strove to mimic salient properties of natural materials, utilizing methods observed within nature to produce materials. Further, this research increased the functionality of the templates from "mere" template to functional participant. Different chemical methods to produce hybrid materials were employed within this research to achieve these goals. First, electro-osmosis was utilized to drive ions into a polymeric matrix to form hybrid inorganic polymer material, creating a material inspired by naturally occurring bone or seashell in which the inorganic component provides strength and the polymeric material decreases the brittleness of the combined hybrid material. Second, self-assembled amphiphiles, forming higher ordered structures, acted as a template for inorganic cadmium sulfide. Electronically active molecules based on ethylene oxide and aniline segments were synthesized to create interaction between the templating material and the resulting inorganic cadmium sulfide. The templating process utilized self-assembly to create the inorganic structure through the interaction of the amphiphiles with water. The use of self-assembly is itself inspired by nature. Self-assembled structures are observed within living cells as cell walls and cell membranes are created through hydrophilic and hydrophobic interactions. Finally, the mesostructured inorganic cadmium sulfide was itself utilized as a template to form mesostructured copper sulfide.

  14. Inorganic nanotubes and fullerene-like materials.

    PubMed

    Tenne, Reshef

    2002-12-02

    Following the discovery of fullerenes and carbon nanotubes, it was shown that nanoparticles of inorganic layered compounds, like MoS2, are unstable in the planar form and they form closed cage structures with polyhedral or nanotubular shapes. Various issues on the structure, synthesis, and properties of such inorganic fullerene-like structures are reviewed, together with some possible applications.

  15. Inorganic polymers and materials. Final report

    SciTech Connect

    Sneddon, Larry G.

    2001-01-01

    This DOE-sponsored project was focused on the design, synthesis, characterization, and applications of new types of boron and silicon polymers with a goal of attaining processable precursors to advanced ceramic materials of technological importance. This work demonstrated a viable design strategy for the systematic formation of polymeric precursors to ceramics based on the controlled functionalization of preformed polymers with pendant groups of suitable compositions and crosslinking properties. Both the new dipentylamine-polyborazylene and pinacolborane-hydridopolysilazane polymers, unlike the parent polyborazylene and other polyborosilazanes, are stable as melts and can be easily spun into polymer fibers. Subsequent pyrolyses of these polymer fibers then provide excellent routes to BN and SiNCB ceramic fibers. The ease of synthesis of both polymer systems suggests new hybrid polymers with a range of substituents appended to polyborazylene or polysilazane backbones, as well as other types of preceramic polymers, should now be readily achieved, thereby allowing even greater control over polymer and ceramic properties. This control should now enable the systematic tailoring of the polymers and derived ceramics for use in different technological applications. Other major recent achievements include the development of new types of metal-catalyzed methods needed for the polymerization and modification of inorganic monomers and polymers, and the modification studies of polyvinylsiloxane and related polymers with substituents that enable the formation of single source precursors to high-strength, sintered SiC ceramics.

  16. Deasphalting of a long residue using ultrafiltration inorganic membranes

    SciTech Connect

    Guizard, C.; Rambault, D.; Cot, L.

    1994-12-31

    Separation by membrane technology is now a well established technique for water purification and other aqueous applications. Non-aqueous applications, especially in the chemical and the petroleum industries, are a more recent development. The ceramic membranes available on the market are reported to have excellent pore size uniformity, thermal and mechanical properties superior to competitive polymer membranes and high stability in organic media. Therefore, their specific properties make them ideally suited for direct deasphalting of petroleum residues by ultrafiltration. Inorganic ultrafiltration membranes have been successfully applied to remove directly asphaltenes from a long residue Basrha; an asphaltene retention rate higher than 75% and a permeate flux as high as 40 l/h.m{sup 2} have been achieved with a zirconia/carbon composite membrane with pore size of 6.3 nm in diameter. Typical process parameters are a temperature of 150{degrees}C, a transmembrane pressure of 8 bar and a fluid velocity of 11.5 m/s. Fouling of the membrane was not evidenced over a period of 500 minutes.

  17. Oxidative coupling of methane using inorganic membrane reactor

    SciTech Connect

    Ma, Y.H.; Moser, W.R.; Dixon, A.G.

    1995-12-31

    The goal of this research is to improve the oxidative coupling of methane in a catalytic inorganic membrane reactor. A specific target is to achieve conversion of methane to C{sub 2} hydrocarbons at very high selectivity and relatively higher yields than in fixed bed reactors by controlling the oxygen supply through the membrane. A membrane reactor has the advantage of precisely controlling the rate of delivery of oxygen to the catalyst. This facility permits balancing the rate of oxidation and reduction of the catalyst. In addition, membrane reactors minimize the concentration of gas phase oxygen thus reducing non selective gas phase reactions, which are believed to be a main route for formation of CO{sub x} products. Such gas phase reactions are a cause for decreased selectivity in oxidative coupling of methane in conventional flow reactors. Membrane reactors could also produce higher product yields by providing better distribution of the reactant gases over the catalyst than the conventional plug flow reactors. Modeling work which aimed at predicting the observed experimental trends in porous membrane reactors was also undertaken in this research program.

  18. Inorganic-based proton conductive composite membranes for elevated temperature and reduced relative humidity PEM fuel cells

    NASA Astrophysics Data System (ADS)

    Wang, Chunmei

    Proton exchange membrane (PEM) fuel cells are regarded as highly promising energy conversion systems for future transportation and stationary power generation and have been under intensive investigations for the last decade. Unfortunately, cutting edge PEM fuel cell design and components still do not allow economically commercial implementation of this technology. The main obstacles are high cost of proton conductive membranes, low-proton conductivity at low relative humidity (RH), and dehydration and degradation of polymer membranes at high temperatures. The objective of this study was to develop a systematic approach to design a high proton conductive composite membrane that can provide a conductivity of approximately 100 mS cm-1 under hot and dry conditions (120°C and 50% RH). The approach was based on fundamental and experimental studies of the proton conductivity of inorganic additives and composite membranes. We synthesized and investigated a variety of organic-inorganic Nafion-based composite membranes. In particular, we analyzed their fundamental properties, which included thermal stability, morphology, the interaction between inorganic network and Nafion clusters, and the effect of inorganic phase on the membrane conductivity. A wide range of inorganic materials was studied in advance in order to select the proton conductive inorganic additives for composite membranes. We developed a conductivity measurement method, with which the proton conductivity characteristics of solid acid materials, zirconium phosphates, sulfated zirconia (S-ZrO2), phosphosilicate gels, and Santa Barbara Amorphous silica (SBA-15) were discussed in detail. Composite membranes containing Nafion and different amounts of functionalized inorganic additives (sulfated inorganics such as S-ZrO2, SBA-15, Mobil Composition of Matter MCM-41, and S-SiO2, and phosphonated inorganic P-SiO2) were synthesized with different methods. We incorporated inorganic particles within Nafion clusters

  19. Casting fine grained, fully dense, strong inorganic materials

    SciTech Connect

    Brown, Sam W.; Spencer, Larry S.; Phillips, Michael R.

    2015-11-24

    Methods and apparatuses for casting inorganic materials are provided. The inorganic materials include metals, metal alloys, metal hydrides and other materials. Thermal control zones may be established to control the propagation of a freeze front through the casting. Agitation from a mechanical blade or ultrasonic energy may be used to reduce porosity and shrinkage in the casting. After solidification of the casting, the casting apparatus may be used to anneal the cast part.

  20. Production of Hydrogen Using Nuclear Energy and Inorganic Membranes

    SciTech Connect

    Bischoff, Brian L.; Trowbridge, Lee D.; Mansur, Louis K.; Forsberg, Charles W.

    2004-07-01

    The sulfur family of thermochemical processes are the leading candidates worldwide for production of hydrogen (H{sub 2}) using nuclear energy. These processes thermo-catalytically crack water yielding hydrogen and oxygen. The processes consist of a series of chemical reactions where all the chemicals are recycled in the process except for water. The processes are potentially efficient, scalable to large sizes, and use no expensive chemical reagents; however, these processes have one major disadvantage: high operating temperatures (800 to 900 deg. C). The high-temperature chemical reaction common to all of these cycles is the equilibrium thermal decomposition of sulfuric acid. There is a potential to lower the peak temperature by 200+ deg. C if the high-temperature decomposition products of sulfuric acid, O{sub 2}, H{sub 2}O, and SO{sub 2}, can be separated from SO{sub 3} using an inorganic membrane. The goal of this project is to conduct proof-of-principle experiments and associated analysis to demonstrate the potential for inorganic membranes to dramatically improve the sulfur family of thermochemical processes. We will present preliminary data of the separation efficiency of the product gases from SO{sub 3}. (authors)

  1. Inorganic Nanoparticles/Metal Organic Framework Hybrid Membrane Reactors for Efficient Photocatalytic Conversion of CO2.

    PubMed

    Maina, James W; Schütz, Jürg A; Grundy, Luke; Des Ligneris, Elise; Yi, Zhifeng; Kong, Lingxue; Pozo-Gonzalo, Cristina; Ionescu, Mihail; Dumée, Ludovic F

    2017-09-29

    Photocatalytic conversion of carbon dioxide (CO2) to useful products has potential to address the adverse environmental impact of global warming. However, most photocatalysts used to date exhibit limited catalytic performance, due to poor CO2 adsorption capacity, inability to efficiently generate photoexcited electrons, and/or poor transfer of the photogenerated electrons to CO2 molecules adsorbed on the catalyst surface. The integration of inorganic semiconductor nanoparticles across metal organic framework (MOF) materials has potential to yield new hybrid materials, combining the high CO2 adsorption capacity of MOF and the ability of the semiconductor nanoparticles to generate photoexcited electrons. Herein, controlled encapsulation of TiO2 and Cu-TiO2 nanoparticles within zeolitic imidazolate framework (ZIF-8) membranes was successfully accomplished, using rapid thermal deposition (RTD), and their photocatalytic efficiency toward CO2 conversion was investigated under UV irradiation. Methanol and carbon monoxide (CO) were found to be the only products of the CO2 reduction, with yields strongly dependent upon the content and composition of the dopant semiconductor particles. CuTiO2 nanoparticle doped membranes exhibited the best photocatalytic performance, with 7 μg of the semiconductor nanoparticle enhancing CO yield of the pristine ZIF-8 membrane by 233%, and methanol yield by 70%. This work opens new routes for the fabrication of hybrid membranes containing inorganic nanoparticles and MOFs, with potential application not only in catalysis but also in electrochemical, separation, and sensing applications.

  2. Asymmetric block copolymers for supramolecular templating of inorganic nanospace materials.

    PubMed

    Bastakoti, Bishnu Prasad; Li, Yunqi; Kimura, Tatsuo; Yamauchi, Yusuke

    2015-05-06

    This review focuses on polymeric micelles consisting of asymmetric block copolymers as designed templates for several inorganic nanospace materials with a wide variety of compositions. The presence of chemically distinct domains of asymmetric triblock and diblock copolymers provide self-assemblies with more diverse morphological and functional features than those constructed by EOn POm EOn type symmetric triblock copolymers, thereby affording well-designed nanospace materials. This strategy can produce unprecedented nanospace materials, which are very difficult to prepare through other conventional organic templating approaches. Here, the recent development on the synthesis of inorganic nanospace materials are mainly focused on, such as hollow spheres, tubes, and porous oxides, using asymmetric triblock copolymers.

  3. Hydrogen Production via a Commerically Ready Inorganic membrane Reactor

    SciTech Connect

    Paul Liu

    2007-06-30

    It has been known that use of the hydrogen selective membrane as a reactor (MR) could potentially improve the efficiency of the water shift reaction (WGS), one of the least efficient unit operations for production of high purity hydrogen from syngas. However, no membrane reactor technology has been reduced to industrial practice thus far, in particular for a large-scale operation. This implementation and commercialization barrier is attributed to the lack of a commercially viable hydrogen selective membrane with (1) material stability under the application environment and (2) suitability for large-scale operation. Thus, in this project, we have focused on (1) the deposition of the hydrogen selective carbon molecular sieve (CMS) membrane we have developed on commercially available membranes as substrate, and (2) the demonstration of the economic viability of the proposed WGS-MR for hydrogen production from coal-based syngas. The commercial stainless steel (SS) porous substrate (i.e., ZrO{sub 2}/SS from Pall Corp.) was evaluated comprehensively as the 1st choice for the deposition of the CMS membrane for hydrogen separation. The CMS membrane synthesis protocol we developed previously for the ceramic substrate was adapted here for the stainless steel substrate. Unfortunately no successful hydrogen selective membranes had been prepared during Yr I of this project. The characterization results indicated two major sources of defect present in the SS substrate, which may have contributed to the poor CMS membrane quality. Near the end of the project period, an improved batch of the SS substrate (as the 2nd generation product) was received from the supplier. Our characterization results confirm that leaking of the crimp boundary no longer exists. However, the thermal stability of the ZrO{sub 2}/SS substrate through the CMS membrane preparation condition must be re-evaluated in the future. In parallel with the SS membrane activity, the preparation of the CMS membranes

  4. Emerging of Inorganic Hole Transporting Materials For Perovskite Solar Cells.

    PubMed

    Rajeswari, Ramireddy; Mrinalini, Madoori; Prasanthkumar, Seelam; Giribabu, Lingamallu

    2017-07-01

    Hole transporting material (HTM) is a significant component to achieve the high performance perovskite solar cells (PSCs). Over the years, inorganic, organic and hybrid (organic-inorganic) material based HTMs have been developed and investigated successfully. Today, perovskite solar cells achieved the efficiency of 22.1 % with with 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine) 9,9-spirobifluorene (spiro-OMeTAD) as HTM. Nevertheless, synthesis and cost of organic HTMs is a major challenging issue and therefore alternative materials are required. From the past few years, inorganic HTMs showed large improvement in power conversion efficiency (PCE) and stability. Recently CuOx reached the PCE of 19.0% with better stability. These developments affirms that inorganic HTMs are better alternativesto the organic HTMs for next generation PSCs. In this report, we mainly focussed on the recent advances of inorganic and hybrid HTMs for PSCs and highlighted the efficiency and stability of PSCs improved by changing metal oxides as HTMs. Consequently, we expect that energy levels of these inorganic HTMs matches very well with the valence band of perovskites and improved efficiency helps in future practical deployment of low cost PSCs. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Investigation of novel inorganic resist materials for EUV lithography

    NASA Astrophysics Data System (ADS)

    Krysak, Marie E.; Blackwell, James M.; Putna, Steve E.; Leeson, Michael J.; Younkin, Todd R.; Harlson, Shane; Frasure, Kent; Gstrein, Florian

    2014-04-01

    Recently, both PSI1 and ASML2 illustrated champion EUVL resolution using slow, non-chemically amplified inorganic resists. However, the requirements for EUVL manufacturing require simultaneous delivery of high resolution, good sensitivity, and low line edge/width roughness (LER/LWR) on commercial grade hardware. As a result, we believe that new classes of materials should be explored and understood. This paper focuses on our efforts to assess metal oxide based nanoparticles as novel EUV resists3. Various spectroscopic techniques were used to probe the patterning mechanism of these materials. EUV exposure data is presented to investigate the feasibility of employing inorganic materials as viable EUV resists.

  6. Nanostructural surface engineering of grafted polymers on inorganic oxide substrates for membrane separations

    NASA Astrophysics Data System (ADS)

    Yoshida, Wayne Hiroshi

    Nanostructural engineering of inorganic substrates by free radical graft polymerization was studied with the goal of developing new membrane materials for pervaporation. Graft polymerization consisted of modification of surface hydroxyls with vinyl trimethoxysilane, followed by solution graft polymerization reaction using either vinyl acetate (VAc) or vinyl pyrrolidone (VP). The topology of the modified surfaces was studied by atomic force microscopy (AFM) on both atomically smooth silicon wafer substrates and microporous inorganic membrane supports in order to deduce the effects of modification on the nanostructural properties of the membrane. While unmodified wafers showed a root-mean-square (RMS) surface roughness of 0.21 +/- 0.03 nm, roughness increased to 3.15 +/- 0.23 nm upon silylation. Under poor solvent conditions (i.e., air), surfaces modified with higher poly(vinyl acetate) (PVAc) or poly(vinyl pyrrolidone) (PVP) polymer graft yields displayed lateral inhomogeneities in the polymer layer. Although RMS surface roughness was nearly identical (0.81--0.85 nm) for PVAc-modified surfaces grafted at different monomer concentrations, the skewness of the height distribution decreased from 2.22 to 0.78 as polymer graft yield increased from 0.8 to 3.5 mg/m2. The polymer-modified surfaces were used to create inorganic pervaporation membranes consisting of a single macromolecular separation layer formed by graft polymerization. PVAc grafted silica membranes (500A native pore size) were found selective for MTBE in the separation of 0.1--1% (v/v) MTBE from water, achieving MTBE enrichment factors as high as 371 at a permeate flux of 0.38 l/m2 hr and a Reynolds number of 6390; however, these membranes could not separate anhydrous organic mixtures. Pervaporative separation of methanol/MTBE mixtures was possible with PVAc and PVP-modified alumina supports of 50A native pore size, where the separation layer consisted of grafted polymer chains with estimated radius of

  7. Superhydrophobic and superhydrophilic surface-enhanced separation performance of porous inorganic membranes for biomass-to-biofuel conversion applications

    DOE PAGES

    Hu, Michael Z.; Engtrakul, Chaiwat; Bischoff, Brian L.; ...

    2016-11-14

    A new class of inorganic-based membranes, i.e., High-Performance Architectured Surface Selective (HiPAS) membranes, is introduced to provide high perm-selective flux by exploiting unique separation mechanisms induced by superhydrophobic or superhydrophilic surface interactions and confined capillary condensation in enlarged membrane pores (~8 nm). The super-hydro-tunable HiPAS membranes were originally developed for the purpose of bio-oil/biofuel processing to achieve selective separations at higher flux relative to size selective porous membranes (e.g., inorganic zeolite-based membranes) and better high-temperature tolerance than polymer membranes (>250 C) for hot vapor processing. Due to surface-enhanced separation selectivity, HiPAS membranes can thus possibly enable larger pores to facilitatemore » large-flux separations by increasing from sub-nanometer pores to mesopores (2-50 nm) for vapor phase or micron-scale pores for liquid phase separations. In this paper, we describe an innovative membrane concept and a materials synthesis strategy to fabricate HiPAS membranes, and demonstrate selective permeation in both vapor- and liquid-phase applications. High permeability and selectivity were demonstrated using surrogate mixtures, such as ethanol-water, toluene-water, and toluene-phenol-water. The overall membrane evaluation results show promise for the future processing of biomass pyrolysis and upgraded product vapors and condensed liquid bio-oil intermediates.« less

  8. Superhydrophobic and superhydrophilic surface-enhanced separation performance of porous inorganic membranes for biomass-to-biofuel conversion applications

    SciTech Connect

    Hu, Michael Z.; Engtrakul, Chaiwat; Bischoff, Brian L.; Jang, Gyoung G.; Theiss, Timothy J.; Davis, Mark F.

    2016-11-14

    A new class of inorganic-based membranes, i.e., High-Performance Architectured Surface Selective (HiPAS) membranes, is introduced to provide high perm-selective flux by exploiting unique separation mechanisms induced by superhydrophobic or superhydrophilic surface interactions and confined capillary condensation in enlarged membrane pores (~8 nm). The super-hydro-tunable HiPAS membranes were originally developed for the purpose of bio-oil/biofuel processing to achieve selective separations at higher flux relative to size selective porous membranes (e.g., inorganic zeolite-based membranes) and better high-temperature tolerance than polymer membranes (>250 C) for hot vapor processing. Due to surface-enhanced separation selectivity, HiPAS membranes can thus possibly enable larger pores to facilitate large-flux separations by increasing from sub-nanometer pores to mesopores (2-50 nm) for vapor phase or micron-scale pores for liquid phase separations. In this paper, we describe an innovative membrane concept and a materials synthesis strategy to fabricate HiPAS membranes, and demonstrate selective permeation in both vapor- and liquid-phase applications. High permeability and selectivity were demonstrated using surrogate mixtures, such as ethanol-water, toluene-water, and toluene-phenol-water. The overall membrane evaluation results show promise for the future processing of biomass pyrolysis and upgraded product vapors and condensed liquid bio-oil intermediates.

  9. ADHESIVE RESTORATIVE DENTAL MATERIALS. A LITERATURE SURVEY OF INORGANIC POLYMERS.

    DTIC Science & Technology

    A new adhesive restorative dental material must meet rigid requirements. These must be kept in mind in screening inorganic polymer systems reported...polymer systems which appear most promising for use as dental materials are the Class 2 polymers containing linear silicon-oxygen backbones and Class

  10. Organic templates for the generation of inorganic materials.

    PubMed

    van Bommel, Kjeld J C; Friggeri, Arianna; Shinkai, Seiji

    2003-03-03

    Mankind's fascination with shapes and patterns, many examples of which come from nature, has greatly influenced areas such as art and architecture. Science too has long since been interested in the origin of shapes and structures found in nature. Whereas organic chemistry in general, and supramolecular chemistry especially, has been very successful in creating large superstructures of often stunning morphology, inorganic chemistry has lagged behind. Over the last decade, however, researchers in various fields of chemistry have been studying novel methods through which the shape of inorganic materials can be controlled at the micro- or even nanoscopic level. A method that has proven very successful is the formation of inorganic structures under the influence of (bio)organic templates, which has resulted in the generation of a large variety of structured inorganic structures that are currently unattainable through any other method.

  11. Hydrogen Selective Inorganic membranes for Gas Separations under High Pressure Intermediate Temperature Hydrocarbonic Envrionment

    SciTech Connect

    Rich Ciora; Paul KT Liu

    2012-06-27

    inorganic membrane field. Further, this newly developed full scale bundle concept can be extended to other thin film inorganic membrane technology (Pd, zeolite, etc), providing a potential commercialization pathway for these membrane materials that demonstrate high potential in a variety of separation applications yet remain a laboratory 'novelty' for lack of a full scale support. Overall, the project has been highly successful and all of the project objectives have been met. We have developed the first of its kind commercial scale carbon molecular sieve membrane and demonstrated its performance in field testing under aggressive operating conditions and in the presence of chemical contaminants that would rapidly destroy alternative organic and inorganic membranes. This innovative membrane permits H{sub 2} recovery from gas streams that up until now have not been successfully treated with membrane or conventional technology. Our end user participant is currently pursuing the field demonstration of this membrane for hydrogen recovery at its refinery site.

  12. Inorganic-organic electrolyte materials for energy applications

    NASA Astrophysics Data System (ADS)

    Fei, Shih-To

    emphasizes the flammability studies. Chapter 4 expands the application of the ethyleneoxy phosphazene system to dye sensitized solar cell systems, and uses this material as a model for the study of electrode-electrolyte interfaces. We report here the results of our study on polymer electrolyte infiltration and its effect on dye-sensitized solar cells. In-depth studies have been made to compare the effects of different cell assembly procedures on the electrochemical properties as well as infiltration of electrolytes into various electrode designs. The first part of the study is based on the use of thermoplastic phosphazene electrolytes and how the overall fabrication procedure affects electrochemical performance, and the second is the use of cross-section microscopy to characterize the degree of electrolyte infiltration into various nanostructured titanium dioxide electrode surfaces. The results of this study should eventually improve the efficiency and longevity of thermally stable polymer dye solar cell systems. In Chapter 5 the effect of pendant polymer design on methanol fuel cell membrane performance was investigated. A synthetic method is described to produce a proton conductive polymer membrane with a polynorbornane backbone and inorganic-organic cyclic phosphazene pendent groups that bear sulfonic acid units. This hybrid polymer combines the inherent hydrophobicity and flexibility of the organic polymer with the tuning advantages of the cyclic phosphazene to produce a membrane with high proton conductivity and low methanol crossover at room temperature. The ion exchange capacity (IEC), the water swelling behavior of the polymer, and the effect of gamma radiation crosslinking were studied, together with the proton conductivity and methanol permeability of these materials. A typical membrane had an IEC of 0.329 mmolg-1 and had water swelling of 50 wt%. The maximum proton conductivity of 1.13x10 -4 Scm-1 at room temperature is less than values reported for some

  13. Thermochromic materials and devices: Inorganic systems

    SciTech Connect

    Jorgenson, G.V.; Lee, J.C.

    1990-12-31

    This chapter discusses the technological application of a class of materials with a chameleon-like nature, that is, they exhibit the properties of metals under certain conditions of temperature and pressure, and semiconductor-to-dielectric properties under other conditions. Many materials exhibit this behavior, most notably the transition metal oxides and sulfides. Typically, the transition from one state to another in transition metal oxides is accompanied by a sharp change in electrical conductivity (as large as 10{sup 7} in some oxides of vanadium), as well as changes in other physical properties such as crystalline symmetry. The changes in electrical conductivity alter, in turn, IR transmittance, and some of these effects extend into the visible spectrum. A material such as this, whose transition occurs at the appropriate temperature, would be useful for solar energy control in buildings. For example, a coating of thermochromic (TC) material on glass would transmit solar energy at temperatures below its transition temperature (T{sub t}), and when the temperature rises above T{sub t}, the TC material would reflect the incident solar energy. Thus, solar influx would be high at low ambient temperature and low at high temperature. Though very few of these materials have T{sub t} in the range required for such an application, one can adjust T{sub t} by using dopants. Many models have been developed to explain the transition mechanism in TC materials, especially in the vanadium oxides, and the authors review some of these theories here. They also discuss thermochromism in stoichiometric compounds and in doped compounds and present the results of a program to dope VO{sub 2} for a solar control glazing applications. Tungsten-doped VO{sub 2} thin films with useful T{sub t} ({approx} 10 to 18 C) were routinely deposited on glass substrates. The chapter closes with a discussion of the performance of these films and their commercial applicability.

  14. Inorganic Photovoltaics Materials and Devices: Past, Present, and Future

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Bailey, Sheila G.; Rafaelle, Ryne P.

    2005-01-01

    This report describes recent aspects of advanced inorganic materials for photovoltaics or solar cell applications. Specific materials examined will be high-efficiency silicon, gallium arsenide and related materials, and thin-film materials, particularly amorphous silicon and (polycrystalline) copper indium selenide. Some of the advanced concepts discussed include multi-junction III-V (and thin-film) devices, utilization of nanotechnology, specifically quantum dots, low-temperature chemical processing, polymer substrates for lightweight and low-cost solar arrays, concentrator cells, and integrated power devices. While many of these technologies will eventually be used for utility and consumer applications, their genesis can be traced back to challenging problems related to power generation for aerospace and defense. Because this overview of inorganic materials is included in a monogram focused on organic photovoltaics, fundamental issues and metrics common to all solar cell devices (and arrays) will be addressed.

  15. Conceptual inorganic materials discovery - a road map.

    PubMed

    Jansen, Martin

    2015-06-03

    Synthesis of novel solids, which is a pivotal starting point in innovative materials research, is markedly impeded by the lack of predictability. A conception is presented that enables syntheses of new materials to be rationally planned. The approach is based on the atomic configuration space, and the potential energies associated to the atomic arrangements. Each minimum of the respective hyperspace of potential energy corresponds to a chemical compound capable of existence. Thus the whole realm of known and not-yet-known chemical compounds is represented in virtuo on that energy landscape. From this view it follows further that the full sets of the corresponding materials' properties are pre-determined. Within the scope of the "Energy Landscape Concept of Chemical Matter" presented, targets for synthesis are identified in a rational manner by searching the underlying potential energy landscapes for (meta)stable candidates computationally. Subsequently, the gained information are transferred to finite temperatures, which enables phase diagrams to be calculated, including metastable manifestations of matter, from first principles. The subsequent steps in materials discovery, e.g., assessing the properties and the impact of defects on the performance of the solids predicted are addressed briefly. The approach presented is complete and physically consistent; its feasibility has been proven and validated experimentally. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Screening combinatorial arrays of inorganic materials with spectroscopy or microscopy

    DOEpatents

    Schultz, Peter G.; Xiang, Xiaodong; Goldwasser, Isy

    2004-02-03

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  17. Inorganic photochromic and cathodochromic recording materials.

    NASA Technical Reports Server (NTRS)

    Duncan, R. C., Jr.; Faughnan, B. W.; Phillips, W.

    1971-01-01

    Discussion of studies at RCA Laboratories of the properties of rare-earth-doped CaF2, transition-metal-doped SrTiO3 and iron- or sulfur-doped sodalite as photochromic materials which change color during light or electron beam exposures. Particular attention is given to their photochromic characteristics in single-crystal and powder forms and to their cathodochromic properties in powder form. Details are given on the photochromic mechanisms, spectra, optical density, thermal decay rates, and coloring and bleaching efficiency of their single crystals and on the diffuse reflectance spectra, saturated photochromic contrast ratio, switching and erase sensitivities, and cathodochromic excitation of their photochromic powders. The many attractive characteristics of these materials when used in display storage systems are indicated.

  18. Inorganic photochromic and cathodochromic recording materials.

    NASA Technical Reports Server (NTRS)

    Duncan, R. C., Jr.; Faughnan, B. W.; Phillips, W.

    1971-01-01

    Discussion of studies at RCA Laboratories of the properties of rare-earth-doped CaF2, transition-metal-doped SrTiO3 and iron- or sulfur-doped sodalite as photochromic materials which change color during light or electron beam exposures. Particular attention is given to their photochromic characteristics in single-crystal and powder forms and to their cathodochromic properties in powder form. Details are given on the photochromic mechanisms, spectra, optical density, thermal decay rates, and coloring and bleaching efficiency of their single crystals and on the diffuse reflectance spectra, saturated photochromic contrast ratio, switching and erase sensitivities, and cathodochromic excitation of their photochromic powders. The many attractive characteristics of these materials when used in display storage systems are indicated.

  19. Combinatorial Screening Of Inorganic And Organometallic Materials

    SciTech Connect

    Li, Yi , Li, Jing , Britton, Ted W.

    2002-06-25

    A method for differentiating and enumerating nucleated red blood cells in a blood sample is described. The method includes the steps of lysing red blood cells of a blood sample with a lytic reagent, measuring nucleated blood cells by DC impedance measurement in a non-focused flow aperture, differentiating nucleated red blood cells from other cell types, and reporting nucleated red blood cells in the blood sample. The method further includes subtracting nucleated red blood cells and other interference materials from the count of remaining blood cells, and reporting a corrected white blood cell count of the blood sample. Additionally, the method further includes measuring spectrophotometric absorbance of the sample mixture at a predetermined wavelength of a hemoglobin chromogen formed upon lysing the blood sample, and reporting hemoglobin concentration of the blood sample.

  20. Organic-inorganic materials containing nanoparticles of zirconium hydrophosphate for baromembrane separation

    NASA Astrophysics Data System (ADS)

    Dzyazko, Yuliya S.; Rozhdestvenskaya, Ludmila M.; Zmievskii, Yu G.; Vilenskii, Alexander I.; Myronchuk, Valerii G.; Kornienko, Ludmila V.; Vasilyuk, Sergey V.; Tsyba, Nikolay N.

    2015-02-01

    Organic-inorganic membranes were obtained by stepwise modification of poly(ethyleneterephthalate) track membrane with nanoparticles of zirconium hydrophosphate. The modifier was inserted inside pores of the polymer, a size of which is 0.33 μm. Inner active layer was formed by this manner. Evolution of morphology and functional properties of the membranes were investigated using methods of porosimetry, potentiometry and electron microscopy. The nanoparticles (4 to 10 nm) were found to form aggregates, which block pores of the polymer. Pores between the aggregates (4 to 8 nm) as well as considerable surface charge density provide significant transport numbers of counter ions (up to 0.86 for Na+). The materials were applied to baromembrane separation of corn distillery. It was found that precipitate is formed mainly inside the pores of the pristine membrane. In the case of the organic-inorganic material, the deposition occurs onto the outer surface and can be removed by mechanical way. Location of the active layer inside membranes protects it against damage.

  1. Electrospun Superhydrophobic Organic/Inorganic Composite Nanofibrous Membranes for Membrane Distillation.

    PubMed

    Li, Xiong; Yu, Xufeng; Cheng, Cheng; Deng, Li; Wang, Min; Wang, Xuefen

    2015-10-07

    Electrospun superhydrophobic organic/inorganic composite nanofibrous membranes exhibiting excellent direct contact membrane distillation (DCMD) performance were fabricated by a facile route combining the hydrophobization of silica nanoparticles (SiO2 NPs) and colloid electrospinning of the hydrophobic silica/poly(vinylidene fluoride) (PVDF) matrix. Benefiting from the utilization of SiO2 NPs with three different particle sizes, the electrospun nanofibrous membranes (ENMs) were endowed with three different delicate nanofiber morphologies and fiber diameter distribution, high porosity, and superhydrophobic property, which resulted in excellent waterproofing and breathability. Significantly, structural attributes analyses have indicated the major contributing role of fiber diameter distribution on determining the augment of permeate vapor flux through regulating mean flow pore size (MFP). Meanwhile, the extremely high liquid entry pressure of water (LEPw, 2.40 ± 0.10 bar), robust nanofiber morphology of PVDF immobilized SiO2 NPs, remarkable mechanical properties, thermal stability, and corrosion resistance endowed the as-prepared membranes with prominent desalination capability and stability for long-term MD process. The resultant choreographed PVDF/silica ENMs with optimized MFP presented an outstanding permeate vapor flux of 41.1 kg/(m(2)·h) and stable low permeate conductivity (∼2.45 μs/cm) (3.5 wt % NaCl salt feed; ΔT = 40 °C) over a DCMD test period of 24 h without membrane pores wetting detected. This result was better than those of typical commercial PVDF membranes and PVDF and modified PVDF ENMs reported so far, suggesting them as promising alternatives for MD applications.

  2. Preparation of geopolymer-based inorganic membrane for removing Ni(2+) from wastewater.

    PubMed

    Ge, Yuanyuan; Yuan, Yuan; Wang, Kaituo; He, Yan; Cui, Xuemin

    2015-12-15

    A type of novel free-sintering and self-supporting inorganic membrane for wastewater treatment was fabricated in this study. This inorganic membrane was synthesised using metakaolin and sodium silicate solutions moulded according to a designed molar ratio (SiO2/Al2O3=2.96, Na2O/Al2O3=0.8 and H2O/Na2O=19) which formed a homogenous structure and had a relative concentration pore size distribution, via scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analyses. In this work, the Ni(2+) removal effect of geopolymer inorganic membrane was studied under different pH value, initial concentration of Ni(2+) solutions and initial operation temperature. Results showed that geopolymer inorganic membrane efficiently removes Ni(2+) from wastewater because of the combined actions of the adsorption and rejection of this membrane on Ni(2+) during membrane separation. Therefore, geopolymer inorganic membrane may have positive potential applications in removing Ni(2+) or other heavy metal ions from aqueous industrial wastewater.

  3. Tracking inorganic foulants irreversibly accumulated on low-pressure membranes for treating surface water.

    PubMed

    Yamamura, Hiroshi; Kimura, Katsuki; Higuchi, Kumiko; Watanabe, Yoshimasa; Ding, Qing; Hafuka, Akira

    2015-12-15

    While low-pressure membrane filtration processes (i.e., microfiltration and ultrafiltration) can offer precise filtration than sand filtration, they pose the problem of reduced efficiency due to membrane fouling. Although many studies have examined membrane fouling by organic substances, there is still not enough data available concerning membrane fouling by inorganic substances. The present research investigated changes in the amounts of inorganic components deposited on the surface of membrane filters over time using membrane specimens sampled thirteen times at arbitrary time intervals during pilot testing in order to determine the mechanism by which irreversible fouling by inorganic substances progresses. The experiments showed that the inorganic components that primarily contribute to irreversible fouling vary as filtration continues. It was discovered that, in the initial stage of operation, the main membrane-fouling substance was iron, whereas the primary membrane-fouling substances when operation finished were manganese, calcium, and silica. The amount of iron accumulated on the membrane increased up to the thirtieth day of operation, after which it reached a steady state. After the accumulation of iron became static, subsequent accumulation of manganese was observed. The fact that the removal rates of these inorganic components also increased gradually shows that the size of the exclusion pores of the membrane filter narrows as operation continues. Studying particle size distributions of inorganic components contained in source water revealed that while many iron particles are approximately the same size as membrane pores, the fraction of manganese particles slightly smaller than the pores in diameter was large. From these results, it is surmised that iron particles approximately the same size as the pores block them soon after the start of operation, and as the membrane pores narrow with the development of fouling, they become further blocked by manganese

  4. Rational design of inorganic dielectric materials with expected permittivity.

    PubMed

    Xie, Congwei; Oganov, Artem R; Dong, Dong; Liu, Ning; Li, Duan; Debela, Tekalign Terfa

    2015-11-30

    Techniques for rapid design of dielectric materials with appropriate permittivity for many important technological applications are urgently needed. It is found that functional structure blocks (FSBs) are helpful in rational design of inorganic dielectrics with expected permittivity. To achieve this, coordination polyhedra are parameterized as FSBs and a simple empirical model to evaluate permittivity based on these FSB parameters is proposed. Using this model, a wide range of examples including ferroelectric, high/low permittivity materials are discussed, resulting in several candidate materials for experimental follow-up.

  5. Rational design of inorganic dielectric materials with expected permittivity

    PubMed Central

    Xie, Congwei; Oganov, Artem R.; Dong, Dong; Liu, Ning; Li, Duan; Debela, Tekalign Terfa

    2015-01-01

    Techniques for rapid design of dielectric materials with appropriate permittivity for many important technological applications are urgently needed. It is found that functional structure blocks (FSBs) are helpful in rational design of inorganic dielectrics with expected permittivity. To achieve this, coordination polyhedra are parameterized as FSBs and a simple empirical model to evaluate permittivity based on these FSB parameters is proposed. Using this model, a wide range of examples including ferroelectric, high/low permittivity materials are discussed, resulting in several candidate materials for experimental follow-up. PMID:26617342

  6. Strongly coupled inorganic/nanocarbon hybrid materials for advanced electrocatalysis.

    PubMed

    Liang, Yongye; Li, Yanguang; Wang, Hailiang; Dai, Hongjie

    2013-02-13

    Electrochemical systems, such as fuel cell and water splitting devices, represent some of the most efficient and environmentally friendly technologies for energy conversion and storage. Electrocatalysts play key roles in the chemical processes but often limit the performance of the entire systems due to insufficient activity, lifetime, or high cost. It has been a long-standing challenge to develop efficient and durable electrocatalysts at low cost. In this Perspective, we present our recent efforts in developing strongly coupled inorganic/nanocarbon hybrid materials to improve the electrocatalytic activities and stability of inorganic metal oxides, hydroxides, sulfides, and metal-nitrogen complexes. The hybrid materials are synthesized by direct nucleation, growth, and anchoring of inorganic nanomaterials on the functional groups of oxidized nanocarbon substrates including graphene and carbon nanotubes. This approach affords strong chemical attachment and electrical coupling between the electrocatalytic nanoparticles and nanocarbon, leading to nonprecious metal-based electrocatalysts with improved activity and durability for the oxygen reduction reaction for fuel cells and chlor-alkali catalysis, oxygen evolution reaction, and hydrogen evolution reaction. X-ray absorption near-edge structure and scanning transmission electron microscopy are employed to characterize the hybrids materials and reveal the coupling effects between inorganic nanomaterials and nanocarbon substrates. Z-contrast imaging and electron energy loss spectroscopy at single atom level are performed to investigate the nature of catalytic sites on ultrathin graphene sheets. Nanocarbon-based hybrid materials may present new opportunities for the development of electrocatalysts meeting the requirements of activity, durability, and cost for large-scale electrochemical applications.

  7. Combined organic-inorganic fouling of forward osmosis hollow fiber membranes.

    PubMed

    Arkhangelsky, Elizabeth; Wicaksana, Filicia; Tang, Chuyang; Al-Rabiah, Abdulrahman A; Al-Zahrani, Saeed M; Wang, Rong

    2012-12-01

    This research focused on combined organic-inorganic fouling and cleaning studies of forward osmosis (FO) membranes. Various organic/inorganic model foulants such as sodium alginate, bovine serum albumin (BSA) and silica nanoparticles were applied to polyamide-polyethersulfone FO hollow fiber membranes fabricated in our laboratory. In order to understand all possible interactions, experiments were performed with a single foulant as well as combinations of foulants. Experimental results suggested that the degree of FO membrane fouling could be promoted by synergistic effect of organic foulants, the presence of divalent cations, low cross-flow velocity and high permeation drag force. The water flux of fouled FO hollow fibers could be fully restored by simple physical cleaning. It was also found that hydrodynamic regime played an important role in combined organic-inorganic fouling of FO membranes.

  8. Recent NMR developments applied to organic-inorganic materials.

    PubMed

    Bonhomme, Christian; Gervais, Christel; Laurencin, Danielle

    2014-02-01

    In this contribution, the latest developments in solid state NMR are presented in the field of organic-inorganic (O/I) materials (or hybrid materials). Such materials involve mineral and organic (including polymeric and biological) components, and can exhibit complex O/I interfaces. Hybrids are currently a major topic of research in nanoscience, and solid state NMR is obviously a pertinent spectroscopic tool of investigation. Its versatility allows the detailed description of the structure and texture of such complex materials. The article is divided in two main parts: in the first one, recent NMR methodological/instrumental developments are presented in connection with hybrid materials. In the second part, an exhaustive overview of the major classes of O/I materials and their NMR characterization is presented. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Synthesis and electron microscopy of inorganic and hybrid organic-inorganic mesoporous and macroporous materials

    NASA Astrophysics Data System (ADS)

    Blanford, Christopher Francis

    This work describes the creation and analysis of ordered porous inorganic and organic-inorganic hybrid materials with an emphasis on the qualitative and quantitative characterization by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Two major systems were studied: MCM-41-type mesoporous molecular sieves and three-dimensionally ordered macroporous (3DOM) materials. The microanalysis of mesoporous samples is discussed first. Samples of unmodified siliceous MCM-41, MCM-41 with grafted titanium dioxide species, and MCM-41 with incorporated 3-mercaptopropyl groups were examined in the TEM at three accelerating voltages. The beam stability of all the samples increased with increasing accelerating voltage. The particles were significantly more resistant to beam damage with the surfactant template in place, when the samples were synthesized above room temperature, and when the silicate precursor was hydrolyzed in acid. The samples with organic and inorganic groups were more stable than siliceous analogs. The discussion of 3DOM materials begins with their synthesis and characterization: 3DOM materials were created from colloidal crystals of uniform, sub-micrometer diameter polystyrene and poly(methyl methacrylate) spheres. Metal alkoxides, solutions of metal salts, and mixed salt-alkoxide precursors were employed to create 3DOM metal oxides, silicates with incorporated organic groups and polyoxometalate clusters, metals, and metal alloys. SEM and TEM were used extensively to characterize the morphology, crystallinity, grain size, and phase of the 3DOM products. The formation of 3DOM nickel oxide was studied by heating a nickel oxalate-colloidal crystal composite in an environmental SEM. The growth of the grains in 3DOM cobalt metal and 3DOM iron oxide were observed by high-temperature TEM. The arrangement of the pores in 3DOM materials was studied by analyzing diffractograms of TEM images of single particles tilted into different orientations

  10. Cluster-based inorganic-organic hybrid materials.

    PubMed

    Schubert, Ulrich

    2011-02-01

    Clusters as building blocks have been used for two types of inorganic-organic hybrid materials. The first are hybrid polymers, with polymer-like properties and structures, where the cluster units crosslink the polymer chains. They are prepared by co-polymerization of organic monomers with functional ligands attached to the clusters. The second type is crystalline metal-organic framework structures which are obtained by coordination chemistry approaches, i.e. by coordinating multifunctional organic ligands to cluster units. This tutorial review shows that both types of cluster-based materials are limiting cases with many options for varying both the cluster units as well as the connecting organic entities.

  11. Zwitterionic materials for antifouling membrane surface construction.

    PubMed

    He, Mingrui; Gao, Kang; Zhou, Linjie; Jiao, Zhiwei; Wu, Mengyuan; Cao, Jialin; You, Xinda; Cai, Ziyi; Su, Yanlei; Jiang, Zhongyi

    2016-08-01

    Membrane separation processes are often perplexed by severe and ubiquitous membrane fouling. Zwitterionic materials, keeping electric neutrality with equivalent positive and negative charged groups, are well known for their superior antifouling properties and have been broadly utilized to construct antifouling surfaces for medical devices, biosensors and marine coatings applications. In recent years, zwitterionic materials have been more and more frequently utilized for constructing antifouling membrane surfaces. In this review, the antifouling mechanisms of zwitterionic materials as well as their biomimetic prototypes in cell membranes will be discussed, followed by the survey of common approaches to incorporate zwitterionic materials onto membrane surfaces including surface grafting, surface segregation, biomimetic adhesion, surface coating and so on. The potential applications of these antifouling membranes are also embedded. Finally, we will present a brief perspective on the future development of zwitterionic materials modified antifouling membranes. Membrane fouling is a severe problem hampering the application of membrane separation technology. The properties of membrane surfaces play a critical role in membrane fouling and antifouling behavior/performance. Antifouling membrane surface construction has evolved as a hot research issue for the development of membrane processes. Zwitterionic modification of membrane surfaces has been recognized as an effective strategy to resist membrane fouling. This review summarizes the antifouling mechanisms of zwitterionic materials inspired by cell membranes as well as the popular approaches to incorporate them onto membrane surfaces. It can help form a comprehensive knowledge about the principles and methods of modifying membrane surfaces with zwitterionic materials. Finally, we propose the possible future research directions of zwitterionic materials modified antifouling membranes. Copyright © 2016 Acta Materialia Inc

  12. High Surface Area Inorganic Membrane for Water Removal

    SciTech Connect

    2008-12-01

    This factsheet describes a research project whose objective is to demonstrate the fabrication and performance advantages of minichannel planar membrane modules made of porous metallic supports of surface area packing density one order of magnitude higher than the conventional membrane tube. The new, transformational, ceramic/metallic, hybrid membrane technology will be used for water/ethanol separations and reduce energy consumption by >20% over distillation and adsorption.

  13. Predicting and Designing Optical Properties of Inorganic Materials

    NASA Astrophysics Data System (ADS)

    Rondinelli, James M.; Kioupakis, Emmanouil

    2015-07-01

    Modern first-principles calculations based on density functional theory and related techniques enable the predictive modeling of the linear and nonlinear optical properties of materials without adjustable or empirical parameters. Today, atomistic calculations are an indispensable tool by which to understand the interrelationship between the underlying structure and the measured optical properties and are particularly suited for the design of new materials with desirable optical responses and performance. In this article, we discuss the first-principles design methodology, and we review recent results from the literature that exemplify the predictive power of the method for numerous inorganic materials and nanostructures. We also discuss topics of active research and future opportunities that will enable the wider adoption of atomistic simulation techniques for predictive materials design.

  14. Synthesis of Inorganic Materials, 2nd, Revised and Updated Edition

    NASA Astrophysics Data System (ADS)

    Schubert, Ulrich; Hüsing, Nicola

    2005-02-01

    This second edition of a very well received advanced textbook retains the chemist's viewpoint in its comprehensive overview of methods for chemical synthesis of inorganic materials. The second chapter now includes a section on biomorphic ceramics, while one on LEDs has been added to Chapter 3. Chapter 4 now includes a more thorough explanation of borate glasses, with certain sections being completely rearranged. In addition, Chapter 6 has been extensively revised, and a whole new sub-chapter added on coordination polymers. The general principles and requirements are discussed for each method given, along with selected examples of technically applied materials, as well as the material properties and applications of the resulting products. Furthermore, numerous tables with further examples help in assessing the scope and limitation of the various methods and in choosing a suitable synthesis for any given problem. Intended for both courses in inorganic chemistry and materials science, this volume is equally valuable for all researchers working on the borderline of these two disciplines.

  15. Attenuation contrast between biomolecular and inorganic materials at terahertz frequencies

    NASA Astrophysics Data System (ADS)

    Chan, T. L. J.; Bjarnason, J. E.; Lee, A. W. M.; Celis, M. A.; Brown, E. R.

    2004-09-01

    Wideband photomixing spectroscopy is used in the present work to contrast the transmission spectra of macromolecules commonly found in biomaterials such as potato starch, wheat flour and cornstarch, and proteins (Cytoplex™), and micromolecules such as sucrose, and inorganic materials such as sodium bicarbonate, and calcium sulfate. Powdered samples were measured at 0.1-0.5THz frequencies. A significant difference in attenuation is found between these samples. At 300GHz starch shows an absorption coefficient of ˜6cm-1 whereas Cytoplex shows 1-3cm-1, while inorganic micromolecules have ˜1cm-1. The absorption in starch increases rapidly with frequency tending to follow a power law α =fn with n typically between 1.5 and 2.0. In contrast, protein materials display a slower dependence on frequency with n between 1.0 and 1.5, and simple molecules show the least n among all three categories. The difference between these ubiquitous macromolecular and micromolecular materials is explained in terms of water content and molecular structure.

  16. Use of silica sols in inorganic molecular sieving membranes

    SciTech Connect

    Sehgal, R.; Brinker, C.J.; Huling, J.C.

    1995-07-01

    Polymeric silica sols, were deposited on commercial {gamma}-alumina supports to prepare gas separation membranes. Optimization of the sol fractal dimension and radius of gyration and minimization of condensation rate led to formation of a discrete film with pores of molecular dimensions. Two coatings of this sol (A2{sup **}) led to a membrane with ideal separation factor of 7 for helium versus nitrogen after calcination to 400C (helium permeance 0.002 cm{sup 3}/cm{sup 2}-s-cm Hg). Partial sintering of these membranes resulted in a further reduction in pore size or narrowing of pore size distribution as evidenced by larger separation factors e.g. 9 for helium versus nitrogen (helium permeance 0.0028 cm{sup 3}/cm{sup 2}-s-cm Hg) with only one A2{sup **} coating. Single gas measurements also showed high ideal separation factors for helium versus methane, propylene, sulfur hexafluoride and carbon dioxide. The deposited A2{sup **} membrane was reacted with titanium isopropoxide (Ti(O i-Pr){sub 4}) to improve both its thermal and chemical stability and modify its pore size. This reaction led to an increase in the membrane selectivity to >300 for He versus N{sub 2} below to 120C, and CO{sub 2} versus CH{sub 4}, when measured below 200C. A2{sup **} was also used as a host matrix for preparing imogolite composite membranes that showed molecular sieving behavior.

  17. Hydrogen Production via a Commercially Ready Inorganic membrane Reactor

    SciTech Connect

    Paul K.T. Liu

    2005-08-23

    Single stage low-temperature-shift water-gas-shift (WGS-LTS) via a membrane reactor (MR) process was studied through both mathematical simulation and experimental verification in this quarter. Our proposed MR yields a reactor size that is 10 to >55% smaller than the comparable conventional reactor for a CO conversion of 80 to 90%. In addition, the CO contaminant level in the hydrogen produced via MR ranges from 1,000 to 4,000 ppm vs 40,000 to >70,000 ppm via the conventional reactor. The advantages of the reduced WGS reactor size and the reduced CO contaminant level provide an excellent opportunity for intensification of the hydrogen production process by the proposed MR. To prepare for the field test planned in Yr III, a significant number (i.e., 98) of full-scale membrane tubes have been produced with an on-spec ratio of >76% during this first production trial. In addition, an innovative full-scale membrane module has been designed, which can potentially deliver >20 to 30 m{sup 2}/module making it suitable for large-scale applications, such as power generation. Finally, we have verified our membrane performance and stability in a refinery pilot testing facility on a hydrocracker purge gas. No change in membrane performance was noted over the >100 hrs of testing conducted in the presence of >30% H{sub 2}S, >5,000 ppm NH{sub 3} (estimated), and heavy hydrocarbons on the order of 25%. The high stability of these membranes opens the door for the use of our membrane in the WGS environment with significantly reduced pretreatment burden.

  18. Cavitational synthesis of nanostructured inorganic materials for enhanced heterogeneous catalysis

    NASA Astrophysics Data System (ADS)

    Krausz, Ivo Michael

    The synthesis of nanostructured inorganic materials by hydrodynamic cavitation processing was investigated. The goal of this work was to develop a general synthesis technique for nanostructured materials with a control over crystallite size in the 1--20 nm range. Materials with crystallite sizes in this range have shown enhanced catalytic activity compared to materials with larger crystallite sizes. Several supported and unsupported inorganic materials were studied to understand the effects of cavitation on crystallite size. Cavitation processing of calcium fluoride resulted in more spherical particles, attached to one another by melted necks. This work produced the first evidence of shock wave heating of nanostructured materials by hydrodynamic cavitation processing. Hydrodynamic cavitation synthesis of various catalytic support materials indicated that their phase composition and purity could be controlled by adjustment of the processing parameters. Zirconia/alumina supports synthesized using hydro-dynamic cavitation and calcined to 1368 K retained a high purity cubic zirconia phase, whereas classically prepared samples showed a phase transformation to monoclinic zirconia. Similarly, the synthesis of alumina resulted in materials with varying Bohmite and Bayerite contents as a function of the process parameters. High temperature calcination resulted in stable alumina supports with varying amounts of delta-, and theta-alumina. Synthesis studies of palladium and silver showed modest variations in crystallite size as a function of cavitation process parameters. Calcination resulted in larger grain materials, indicating a disappearance of intergrain boundaries. Based on these results, a new synthesis method was studied involving controlled agglomeration of small silver crystallites by hydrodynamic cavitation processing, followed by deposition on alumina. The optimal pH, concentration, and processing time for controlling the silver crystallite size in the cavitation

  19. Development of foamed Inorganic Polymeric Materials based on Perlite

    NASA Astrophysics Data System (ADS)

    Tsaousi, G.-M.; Douni, I.; Taxiarchou, M.; Panias, D.; Paspaliaris, I.

    2016-04-01

    This work deals with the development of lightweight geopolymeric boards for use in construction sector utilizing a solid perlitic waste as the main raw material. Hydrogen peroxide (H2O2) was used for the foaming of geopolymeric pastes and the production of porous and lightweight inorganic polymeric materials. The effect of geopolymeric synthesis parameters, such as the composition of activator and the curing conditions, on paste's properties that affect the foaming process, such as setting time and viscosity, were studied in detailed. Finally, the effects of H2O2 concentration on the properties (apparent density and % cell volume) and the microstructure of foamed boards were also studied. The produced porous boards have effective densities in-between 540 - 900 Kg/m3 and the thermal conductivity of the optimum product is 0.08 W/mK. Based on their properties, the developed lightweight geopolymeric boards have high potential to be used as building elements in construction industry.

  20. Fluidized Bed Opposed Jet Mill System for Processing Inorganic Materials

    NASA Astrophysics Data System (ADS)

    Al-Nuzal, S. M. D.; Mohammed, M. I.

    2017-08-01

    A jet mill system was built aiming to give values for processing inorganic materials, to be used for different industry. The milling housing of the system is composed of; milling chamber, compressed air nozzles which deliver compressed air in the milling chamber to accelerate sample particles. The classifier wheel is composed of two concentric pieces welded together under argon and coupled to a AC Motor, 0 - 9000 rpm, 2 kW, with AC frequencies convertor. The performances of this jet mill system were tried on five cheap locally available materials, viz. white sand, glass, iron oxide, black carbon and alum. It is possible to get particle sizes of less than 1 μm with narrow distribution of particle sizes.

  1. Supported liquid inorganic membranes for nuclear waste separation

    DOEpatents

    Bhave, Ramesh R; DeBusk, Melanie M; DelCul, Guillermo D; Delmau, Laetitia H; Narula, Chaitanya K

    2015-04-07

    A system and method for the extraction of americium from radioactive waste solutions. The method includes the transfer of highly oxidized americium from an acidic aqueous feed solution through an immobilized liquid membrane to an organic receiving solvent, for example tributyl phosphate. The immobilized liquid membrane includes porous support and separating layers loaded with tributyl phosphate. The extracted solution is subsequently stripped of americium and recycled at the immobilized liquid membrane as neat tributyl phosphate for the continuous extraction of americium. The sequestered americium can be used as a nuclear fuel, a nuclear fuel component or a radiation source, and the remaining constituent elements in the aqueous feed solution can be stored in glassified waste forms substantially free of americium.

  2. Multiscale Inorganic Hierarchically Materials: Towards an Improved Orthopaedic Regenerative Medicine.

    PubMed

    Ruso, Juan M; Sartuqui, Javier; Messina, Paula V

    2015-01-01

    as the experiments to integrate them into engineer hierarchical inorganic materials for their practical application in calcified tissue reparation are evaluated.

  3. Preparations of an inorganic-framework proton exchange nanochannel membrane

    NASA Astrophysics Data System (ADS)

    Yan, X. H.; Jiang, H. R.; Zhao, G.; Zeng, L.; Zhao, T. S.

    2016-09-01

    In this work, a proton exchange membrane composed of straight and aligned proton conducting nanochannels is developed. Preparation of the membrane involves the surface sol-gel method assisted with a through-hole anodic aluminum oxide (AAO) template to form the framework of the PEM nanochannels. A monomolecular layer (SO3Hsbnd (CH2)3sbnd Sisbnd (OCH3)3) is subsequently added onto the inner surfaces of the nanochannels to shape a proton-conducting pathway. Straight nanochannels exhibit long range order morphology, contributing to a substantial improvement in the proton mobility and subsequently proton conductivity. In addition, the nanochannel size can be altered by changing the surface sol-gel condition, allowing control of the active species/charge carrier selectivity via pore size exclusion. The proton conductivity of the nanochannel membrane is reported as high as 11.3 mS cm-1 at 70 °C with a low activation energy of 0.21 eV (20.4 kJ mol-1). First-principle calculations reveal that the activation energy for proton transfer is impressively low (0.06 eV and 0.07 eV) with the assistance of water molecules.

  4. Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials

    SciTech Connect

    Wang, Yifeng; Miller, Andy; Bryan, Charles R; Kruichar, Jessica Nicole

    2015-04-07

    Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials are described. For example, a method of capturing and immobilizing radioactive nuclei includes flowing a gas stream through an exhaust apparatus. The exhaust apparatus includes a metal fluorite-based inorganic material. The gas stream includes a radioactive species. The radioactive species is removed from the gas stream by adsorbing the radioactive species to the metal fluorite-based inorganic material of the exhaust apparatus.

  5. Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials

    SciTech Connect

    Wang, Yifeng; Miller, Andy; Bryan, Charles R.; Kruichak, Jessica Nicole

    2015-11-17

    Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials are described. For example, a method of capturing and immobilizing radioactive nuclei includes flowing a gas stream through an exhaust apparatus. The exhaust apparatus includes a metal fluorite-based inorganic material. The gas stream includes a radioactive species. The radioactive species is removed from the gas stream by adsorbing the radioactive species to the metal fluorite-based inorganic material of the exhaust apparatus.

  6. Zeolite inorganic scaffolds for novel biomedical application: Effect of physicochemical characteristic of zeolite membranes on cell adhesion and viability

    NASA Astrophysics Data System (ADS)

    Tavolaro, Palmira; Catalano, Silvia; Martino, Guglielmo; Tavolaro, Adalgisa

    2016-09-01

    The design, preparation and selection of inorganic materials useful as functional scaffolds for cell adhesion is a complex question based both on the understanding of the chemical behavior of the materials and individual cells, and on their interactions. Pure zeolite membranes formed from synthetic crystals offer chemically-capable being modulated silanolic surfaces that are amenable to adhesion and growth of fibroblasts. We report the facile preparation of reusable, very longlasting, biocompatible, easily sterilized synthetic scaffolds in a zeolite membrane configuration, which are very stable in aqueous media (apart from ionic strength and pH values), able to adsorb pollutant species and to confine undesired toxic ions (present in culture media). This may ultimately lead to the development of cell supports for economic antibiotic-free culture media.

  7. Organic-inorganic hybrid materials: nanoparticle containing organogels with myriad applications.

    PubMed

    Peveler, William J; Bear, Joseph C; Southern, Paul; Parkin, Ivan P

    2014-11-28

    The synthesis of hybrid inorganic-organic materials from a single-component organogelator is reported. Varied functional inorganic materials were included and the resultant physico-chemical properties of the gels are presented. These materials are quick, versatile, can be cast into virtually any form, and the nanoparticles are easily reclaimed.

  8. Inorganic membranes for hydrogen production and purification: a critical review and perspective.

    PubMed

    Lu, G Q; Diniz da Costa, J C; Duke, M; Giessler, S; Socolow, R; Williams, R H; Kreutz, T

    2007-10-15

    Hydrogen as a high-quality and clean energy carrier has attracted renewed and ever-increasing attention around the world in recent years, mainly due to developments in fuel cells and environmental pressures including climate change issues. In thermochemical processes for hydrogen production from fossil fuels, separation and purification is a critical technology. Where water-gas shift reaction is involved for converting the carbon monoxide to hydrogen, membrane reactors show great promises for shifting the equilibrium. Membranes are also important to the subsequent purification of hydrogen. For hydrogen production and purification, there are generally two classes of membranes both being inorganic: dense phase metal and metal alloys, and porous ceramic membranes. Porous ceramic membranes are normally prepared by sol-gel or hydrothermal methods, and have high stability and durability in high temperature, harsh impurity and hydrothermal environments. In particular, microporous membranes show promises in water gas shift reaction at higher temperatures. In this article, we review the recent advances in both dense phase metal and porous ceramic membranes, and compare their separation properties and performance in membrane reactor systems. The preparation, characterization and permeation of the various membranes will be presented and discussed. We also aim to examine the critical issues in these membranes with respect to the technical and economical advantages and disadvantages. Discussions will also be made on the relevance and importance of membrane technology to the new generation of zero-emission power technologies.

  9. Soil Inorganic Carbon Formation: Can Parent Material Overcome Climate?

    NASA Astrophysics Data System (ADS)

    Stanbery, C.; Will, R. M.; Seyfried, M. S.; Benner, S. G.; Flores, A. N.; Guilinger, J.; Lohse, K. A.; Good, A.; Black, C.; Pierce, J. L.

    2014-12-01

    Soil carbon is the third largest carbon reservoir and is composed of both organic and inorganic constituents. However, the storage and flux of soil carbon within the global carbon cycle are not fully understood. While organic carbon is often the focus of research, the factors controlling the formation and dissolution of soil inorganic carbon (SIC) are complex. Climate is largely accepted as the primary control on SIC, but the effects of soil parent material are less clear. We hypothesize that effects of parent material are significant and that SIC accumulation will be greater in soils formed from basalts than granites due to the finer textured soils and more abundant calcium and magnesium cations. This research is being conducted in the Reynolds Creek Experimental Watershed (RCEW) in southwestern Idaho. The watershed is an ideal location because it has a range of gradients in precipitation (250 mm to 1200 mm), ecology (sagebrush steppe to juniper), and parent materials (a wide array of igneous and sedimentary rock types) over a relatively small area. Approximately 20 soil profiles will be excavated throughout the watershed and will capture the effects of differing precipitation amounts and parent material on soil characteristics. Several samples at each site will be collected for analysis of SIC content and grain size distribution using a pressure calcimeter and hydrometers, respectively. Initial field data suggests that soils formed over basalts have a higher concentration of SIC than those on granitic material. If precipitation is the only control on SIC, we would expect to see comparable amounts in soils formed on both rock types within the same precipitation zone. However, field observations suggest that for all but the driest sites, soils formed over granite had no SIC detected while basalt soils with comparable precipitation had measurable amounts of SIC. Grain size distribution appears to be a large control on SIC as the sandier, granitic soils promote

  10. Photophysical Properties of Novel Organic, Inorganic, and Hybrid Semiconductor Materials

    NASA Astrophysics Data System (ADS)

    Chang, Angela Yenchi

    For the past 200 years, novel materials have driven technological progress, and going forward these advanced materials will continue to deeply impact virtually all major industrial sectors. Therefore, it is vital to perform basic and applied research on novel materials in order to develop new technologies for the future. This dissertation describes the results of photophysical studies on three novel materials with electronic and optoelectronic applications, namely organic small molecules DTDCTB with C60 and C70, colloidal indium antimonide (InSb) nanocrystals, and an organic-inorganic hybrid perovskite with the composition CH3NH3PbI 3-xClx, using transient absorption (TA) and photoluminescence (PL) spectroscopy. In chapter 2, we characterize the timescale and efficiency of charge separation and recombination in thin film blends comprising DTDCTB, a narrow-band gap electron donor, and either C60 or C70 as an electron acceptor. TA and time-resolved PL studies show correlated, sub-picosecond charge separation times and multiple timescales of charge recombination. Our results indicate that some donors fail to charge separate in donor-acceptor mixed films, which suggests material manipulations may improve device efficiency. Chapter 3 describes electron-hole pair dynamics in strongly quantum-confined, colloidal InSb nanocrystal quantum dots. For all samples, TA shows a bleach feature that, for several picoseconds, dramatically red-shifts prior to reaching a time-independent position. We suggest this unusual red-shift relates transient population flow through two energetically comparable conduction band states. From pump-power-dependent measurements, we also determine biexciton lifetimes. In chapter 4, we examine carrier dynamics in polycrystalline methylammonium lead mixed halide perovskite (CH3NH3PbI3-xCl x) thin films as functions of temperature and photoexcitation wavelength. At room temperature, the long-lived TA signals stand in contrast to PL dynamics, where the

  11. Assessment of the potential for refinery applications of inorganic membrane technology: An identification and screening analysis. Final report

    SciTech Connect

    Johnson, H.E.; Schulman, B.L.

    1993-05-01

    Commercial application of membrane technology in the separation of gas, liquid, and solid streams has grown to a business with worldwide revenues exceeding $1 billion annually. Use of organic membranes for industrial gas separation, particularly in the refining industry, is one of the major growth areas. However, organic membranes based on polymeric separation barriers, are susceptible to damage by liquids, and careful precautions must be taken to retain the system integrity. Researchers are currently developing small pore sized inorganic membranes which may substantially increase the efficiency and economics in selected refinery separation applications. Expected advantages of these advanced inorganic membranes include high permeability, high selectivity, and low manufacturing cost. SFA Pacific conducted a screening analysis to identify applications for inorganic membrane technology in the petroleum refining industry and their potential cost advantages over competing separation systems. Two meetings were held in connection with this project. Copies of Viewgraphs presented by SFA Pacific at these meetings are attached in Appendices A and C. Potential high priority applications and market impacts of advanced inorganic membrane technology in the refining industry are addressed in this report, and include the following areas: Competitive separation technologies; application of those technologies; incentives for inorganic membranes; market benefits and impacts of inorganic membranes.

  12. A Mechanistic Study of Chemically Modified Inorganic Membranes for Gas and Liquid Separations

    SciTech Connect

    Way, J Douglas

    2011-01-21

    This final report will summarize the progress made during the period August 1, 1993 - October 31, 2010 with support from DOE grant number DE-FG03-93ER14363. The objectives of the research have been to investigate the transport mechanisms in micro- and mesoporous, metal oxide membranes and to examine the relationship between the microstructure of the membrane, the membrane surface chemistry, and the separation performance of the membrane. Examples of the membrane materials under investigation are the microporous silica hollow fiber membrane manufactured by PPG Industries, chemically modified mesoporous oxide membranes, and polymer membranes containing microporous oxides (mixed matrix membranes). Analytical techniques such as NMR, FTIR and Raman spectroscopy, thermal analysis, and gas adsorption were used to investigate membrane microstructure and to probe the chemical interactions occurring at the gas-membrane interface.

  13. Sol-gel based silica electrodes for inorganic membrane direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Kim, Hyea; Kohl, Paul A.

    Inorganic glass electrodes are of interest for use with inorganic proton exchange membranes for direct methanol fuel cells. Platinum-ruthenium glass electrodes (PtRu/C-SiO 2) have been prepared by incorporating the PtRu/C nanoparticles into a silica-based matrix. The SiO 2 matrix was synthesized through the sol-gel reaction of 3-(trihydroxysilyl)-1-propanesulfonic acid (3TPS) and 3-glycidoxypropyltrimethoxysilane (GPTMS). The distribution of the PtRu/C particles can be controlled by changing the properties of the gel matrix. The effect of gelation time, mole fraction of reactants within the sol, curing temperature, and glass ionomer content were investigated. The adhesion of the catalyst layer on the membrane, catalytic activity for methanol oxidation, and inhibition of methanol permeation through the membrane have been characterized and optimized. The electroless deposition of PtRu onto the PtRu/C nanoparticles was performed to increase the sheet conductivity of the electrode. It was found that the electrolessly deposited metal improved the catalytic activity for methanol oxidation and decreased the methanol cross-over. The methanol fuel cell performance using the inorganic membrane electrode assembly was 236 μA cm -2 at 0.4 V and was stable for more than 10 days.

  14. Release of inorganic material during coal devolatilization. Milestone report

    SciTech Connect

    Baxter, L.L.

    1995-07-01

    Experimental results presented in this paper indicate that coal devolatilization products convectively remove a fraction of the nonvolatile components of inorganic material atomically dispersed in the coal matrix. Results from three facilities burning six different coals illustrate this mechanism of ash transformation and release from coal particles. Titanium is chosen to illustrate this type of mass release from coal particles on the basis of its low volatility and mode of occurrence in the coal. During moderate rates of devolatilization (10{sup 4} K/s heating rate), no significant loss of titanium is noted. At more rapid rates of heating/devolatilization (10{sup 5} K/s) a consistent but minor (3-4 %) loss of titanium is noted. During rapid devolatilization (5xl0{sup 5} K/s and higher), significant (10-20 %) amounts of titanium leave the coal. The loss of titanium monitored in coals ranging in rank from subbituminous to high-volatile bituminous coals and under conditions typical of pulverized-coal combustion. The amount of titanium lost during devolatilization exhibits a complex rank dependence. These results imply that other atomically dispersed material (alkali and alkaline earth elements) may undergo similar mechanisms of transformation and release.

  15. An inorganic-organic proton exchange membrane for fuel cells with a controlled nanoscale pore structure.

    PubMed

    Moghaddam, Saeed; Pengwang, Eakkachai; Jiang, Ying-Bing; Garcia, Armando R; Burnett, Daniel J; Brinker, C Jeffrey; Masel, Richard I; Shannon, Mark A

    2010-03-01

    Proton exchange membrane fuel cells have the potential for applications in energy conversion and energy storage, but their development has been impeded by problems with the membrane electrode assembly. Here, we demonstrate that a silicon-based inorganic-organic membrane offers a number of advantages over Nafion--the membrane widely used as a proton exchange membrane in hydrogen fuel cells--including higher proton conductivity, a lack of volumetric size change, and membrane electrode assembly construction capabilities. Key to achieving these advantages is fabricating a silicon membrane with pores with diameters of approximately 5-7 nm, adding a self-assembled molecular monolayer on the pore surface, and then capping the pores with a layer of porous silica. The silica layer reduces the diameter of the pores and ensures their hydration, resulting in a proton conductivity that is two to three orders of magnitude higher than that of Nafion at low humidity. A membrane electrode assembly constructed with this proton exchange membrane delivered an order of magnitude higher power density than that achieved previously with a dry hydrogen feed and an air-breathing cathode.

  16. Soft templating strategies for the synthesis of mesoporous materials: inorganic, organic-inorganic hybrid and purely organic solids.

    PubMed

    Pal, Nabanita; Bhaumik, Asim

    2013-03-01

    With the discovery of MCM-41 by Mobil researchers in 1992 the journey of the research on mesoporous materials started and in the 21st century this area of scientific investigation have extended into numerous branches, many of which contribute significantly in emerging areas like catalysis, energy, environment and biomedical research. As a consequence thousands of publications came out in large varieties of national and international journals. In this review, we have tried to summarize the published works on various synthetic pathways and formation mechanisms of different mesoporous materials viz. inorganic, organic-inorganic hybrid and purely organic solids via soft templating pathways. Generation of nanoscale porosity in a solid material usually requires participation of organic template (more specifically surfactants and their supramolecular assemblies) called structure-directing agent (SDA) in the bottom-up chemical reaction process. Different techniques employed for the syntheses of inorganic mesoporous solids, like silicas, metal doped silicas, transition and non-transition metal oxides, mixed oxides, metallophosphates, organic-inorganic hybrids as well as purely organic mesoporous materials like carbons, polymers etc. using surfactants are depicted schematically and elaborately in this paper. Moreover, some of the frontline applications of these mesoporous solids, which are directly related to their functionality, composition and surface properties are discussed at the appropriate places. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Synthesis and characterization of microporous inorganic membranes for propylene/propane separation

    NASA Astrophysics Data System (ADS)

    Ma, Xiaoli

    Membrane-based gas separation is promising for efficient propylene/propane (C3H6/C3H8) separation with low energy consumption and minimum environment impact. Two microporous inorganic membrane candidates, MFI-type zeolite membrane and carbon molecular sieve membrane (CMS) have demonstrated excellent thermal and chemical stability. Application of these membranes into C3H6/C3H 8 separation has not been well investigated. This dissertation presents fundamental studies on membrane synthesis, characterization and C3H 6/C3H8 separation properties of MFI zeolite membrane and CMS membrane. MFI zeolite membranes were synthesized on α-alumina supports by secondary growth method. Novel positron annihilation spectroscopy (PAS) techniques were used to non-destructively characterize the pore structure of these membranes. PAS reveals a bimodal pore structure consisting of intracrystalline zeolitic micropores of ~0.6 nm in diameter and irregular intercrystalline micropores of 1.4 to 1.8 nm in size for the membranes. The template-free synthesized membrane exhibited a high permeance but a low selectivity in C3H 6/C3H8 mixture separation. CMS membranes were synthesized by coating/pyrolysis method on mesoporous gamma-alumina support. Such supports allow coating of thin, high-quality polymer films and subsequent CMS membranes with no infiltration into support pores. The CMS membranes show strong molecular sieving effect, offering a high C3H 6/C3H8 mixture selectivity of ~30. Reduction in membrane thickness from 500 nm to 300 nm causes an increase in C3H8 permeance and He/N2 selectivity, but a decrease in the permeance of He, N 2 and C3H6 and C3H6/C 3H8 selectivity. This can be explained by the thickness dependent chain mobility of the polymer film resulting in final carbon membrane of reduced pore size with different effects on transport of gas of different sizes, including possible closure of C3H6-accessible micropores. CMS membranes demonstrate excellent C3H6/C 3H8 separation

  18. Fabrication and characterization of materials and structures for hybrid organic-inorganic photonics

    NASA Astrophysics Data System (ADS)

    Haško, Daniel; Chovan, Jozef; Uherek, František

    2017-03-01

    Hybrid organic-inorganic integrated photonics integrate the organic material, as a part of active layer, with inorganic structure, and it is the organic component that extends the functionalities as compared to inorganic photonics. This paper presents the results of fabrication and characterization of inorganic and organic layers, as well as of hybrid organic-inorganic structures. Inorganic oxide and nitride materials and structures were grown using plasma enhanced chemical vapor deposition. As a substrate for tested organic layers and for preparation of multilayer structures, commercially available SiO2 created by thermal oxidation on Si was used. The hybrid organic-inorganic structures were prepared by spin coating of organic materials on SiO2/Si inorganic structures. As the basic photonics devices, the testing strip inorganic and organic waveguides were fabricated using reactive ion etching. The shape of fabricated testing waveguides was trapezoidal and etched structures were able to guide the radiation. The presented technology enabled to prepare hybrid organic-inorganic structures of comparable dimensions and shape. The fabricated waveguides dimensions and shape will be used for optimisation and design of new lithographic mask to prepare photonic components with required characteristics.

  19. The effects of aspect ratio of inorganic fillers on the structure and property of composite ion-exchange membranes.

    PubMed

    Klaysom, Chalida; Moon, Seung-Hyeon; Ladewig, Bradley P; Lu, G Q Max; Wang, Lianzhou

    2011-11-15

    A new type of nanocomposite ion-exchange membranes containing sulfonated polyethersulfone (sPES) polymer matrix and sulfonated surface-functionalized mesoporous silica (SS) inorganic fillers was prepared. Various characterizations revealed that the addition of inorganic fillers with different shapes had a significant influence on the membrane structure. The mesoporous inorganic fillers not only created extra pore and water channels, assisting the ionic migration and improving conductivity of the composites, but also provided additional fixed charge groups upon surface modification. This allows the Donnan exclusion to work effectively and thus improve the selectivity of membranes. It was proved that the incorporation of appropriate amount of SS additive could significantly improve the conductivity (up to 20 folds) and permselectivity (about 14%) of the sPES membranes. The performance of these newly developed membranes in desalination by electrodialysis was comparable with that of a commercial membrane (FKE). Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Membrane behavior of clay liner materials

    NASA Astrophysics Data System (ADS)

    Kang, Jong Beom

    Membrane behavior represents the ability of porous media to restrict the migration of solutes, leading to the existence of chemico-osmosis, or the flow of liquid in response to a chemical concentration gradient. Membrane behavior is an important consideration with respect to clay soils with small pores and interactive electric diffuse double layers associated with individual particles, such as bentonite. The results of recent studies indicate the existence of membrane behavior in bentonite-based hydraulic barriers used in waste containment applications. Thus, measurement of the existence and magnitude of membrane behavior in such clay soils is becoming increasingly important. Accordingly, this research focused on evaluating the existence and magnitude of membrane behavior for three clay-based materials that typically are considered for use as liners for waste containment applications, such as landfills. The three clay-based liner materials included a commercially available geosynthetic clay liner (GCL) consisting of sodium bentonite sandwiched between two geotextiles, a compacted natural clay known locally as Nelson Farm Clay, and compacted NFC amended with 5% (dry wt.) of a sodium bentonite. The study also included the development and evaluation of a new flexible-wall cell for clay membrane testing that was used subsequently to measure the membrane behaviors of the three clay liner materials. The consolidation behavior of the GCL under isotropic states of stress also was evaluated as a preliminary step in the determination of the membrane behavior of the GCL under different effective consolidation stresses.

  1. Recent advances in inorganic materials for LDI-MS analysis of small molecules.

    PubMed

    Shi, C Y; Deng, C H

    2016-05-10

    In this review, various inorganic materials were summarized for the analysis of small molecules by laser desorption/ionization mass spectrometry (LDI-MS). Due to its tremendous advantages, such as simplicity, high speed, high throughput, small analyte volumes and tolerance towards salts, LDI-MS has been widely used in various analytes. During the ionization process, a suitable agent is required to assist the ionization, such as an appropriate matrix for matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). However, it is normally difficult to analyze small molecules with the MALDI technique because conventional organic matrices may produce matrix-related peaks in the low molecular-weight region, which limits the detection of small molecules (m/z < 700 Da). Therefore, more and more inorganic materials, including carbon-based materials, silicon-based materials and metal-based materials, have been developed to assist the ionization of small molecules. These inorganic materials can transfer energy and improve the ionization efficiency of analytes. In addition, functionalized inorganic materials can act as both an adsorbent and an agent in the enrichment and ionization of small molecules. In this review, we mainly focus on present advances in inorganic materials for the LDI-MS analysis of small molecules in the last five years, which contains the synthetic protocols of novel inorganic materials and the detailed results achieved by inorganic materials. On the other hand, this review also summarizes the application of inorganic materials as adsorbents in the selective enrichment of small molecules, which provides a new field for the application of inorganic materials.

  2. Synthesis and applications of bioinspired inorganic nanostructured materials

    NASA Astrophysics Data System (ADS)

    Bassett, David C.

    2011-12-01

    Although the study of biominerals may be traced back many centuries, it is only recently that biological principles have been applied to synthetic systems in processes termed "biomimetic" and "bioinspired" to yield materials syntheses that are otherwise not possible and may also reduce the expenditure of energy and/or eliminate toxic byproducts. Many investigators have taken inspiration from interesting and unusual minerals formed by organisms, in a process termed biomineralisation, to tailor the nanostructure of inorganic materials not necessarily found biogenically. However, the fields of nanoparticle synthesis and biomineralisation remain largely separate, and this thesis is an attempt to apply new studies on biomineralisation to nanomaterials science. Principally among the proteins that influence biomineralisation is a group comprised largely of negatively charged aspartic acid residues present in serum. This study is an investigation determining the ability of these serum proteins and other anolagous biomolecules to stabilise biologically relevant amorphous minerals and influence the formation of a variety of materials at the nanoscale. Three different materials were chosen to demonstrate this effect; gold was templated into nanosized single crystals by the action of bioorganic molecules, and the utility of these nanoparticles as a biosensor was explored. The influence of bioorganic molecules on the phase selection and crystal size restriction of titanium dioxide, an important semiconductor with many applications, was explored. The use of bioorganically derived nanoparticles of titanium dioxide was then demonstrated as a highly efficient photocatalyst. Finally, calcium carbonate, a prevalent biomineral was shown to form highly ordered structures over a variety of length scales and different crystalline polymorphs under the influence of a templating protein. In addition, an alternative route to producing calcium phosphate nanoparticle dispersions by mechanical

  3. A green sorbent of esterified egg-shell membrane for highly selective uptake of arsenate and speciation of inorganic arsenic.

    PubMed

    Chen, Ming-Li; Gu, Cui-Bo; Yang, Ting; Sun, Yan; Wang, Jian-Hua

    2013-11-15

    Egg-shell membrane (ESM) is a promising adsorbent for heavy metal uptake. However, carboxylic groups on ESM surface barrier arsenic adsorption. Herein, ESM is modified by esterification and the methyl esterified egg-shell membrane (MESM) possesses positive charge within pH 1-9. As a novel green sorbent material, MESM exhibits 200-fold improvement on sorption capacity of arsenate with respect to bare ESM. It presents an ultra-high selectivity of 256:1 toward arsenate against arsenite. At pH 6, 100% sorption efficiency is achieved for 2 μg L(-1) As(V) by 10 mg MESM, while virtually no adsorption of As(III) is observed. This provides great potential for selective sorption of arsenate in the presence of arsenite. By loading 4.0 mL sample within 0.05-5.00 μg L(-1) As(V) followed by elution with 300 μL HCl (1.5 mol L(-1)), a detection limit of 15 ng L(-1) is obtained along with a RSD of 3.5% at 0.5 μg L(-1). Total inorganic arsenic is achieved by converting As(III) to As(V) and following the same sorption process. This procedure is applied for arsenate determination and inorganic arsenic speciation in Hijiki and water samples. The results are confirmed by graphite furnace atomic absorption spectrometry and spiking recovery. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. 2010 Membranes: Materials & Processes Gordon Research Conference

    SciTech Connect

    Jerry Lin

    2010-07-30

    The GRC series on Membranes: Materials and Processes have gained significant international recognition, attracting leading experts on membranes and other related areas from around the world. It is now known for being an interdisciplinary and synergistic meeting. The next summer's edition will keep with the past tradition and include new, exciting aspects of material science, chemistry, chemical engineering, computer simulation with participants from academia, industry and national laboratories. This edition will focus on cutting edge topics of membranes for addressing several grand challenges facing our society, in particular, energy, water, health and more generally sustainability. During the technical program, we want to discuss new membrane structure and characterization techniques, the role of advanced membranes and membrane-based processes in sustainability/environment (including carbon dioxide capture), membranes in water processes, and membranes for biological and life support applications. As usual, the informal nature of the meeting, excellent quality of the oral presentations and posters, and ample opportunity to meet many outstanding colleagues make this an excellent conference for established scientists as well as for students. A Gordon Research Seminar (GRS) on the weekend prior to the GRC meeting will provide young researchers an opportunity to present their work and network with outstanding experts. It will also be a right warm-up for the conference participants to join and enjoy the main conference.

  5. Recent advances in the fabrication and structure-specific applications of graphene-based inorganic hybrid membranes.

    PubMed

    Zhao, Xinne; Zhang, Panpan; Chen, Yuting; Su, Zhiqiang; Wei, Gang

    2015-03-12

    The preparation and applications of graphene (G)-based materials are attracting increasing interests due to their unique electronic, optical, magnetic, thermal, and mechanical properties. Compared to G-based hybrid and composite materials, G-based inorganic hybrid membrane (GIHM) offers enormous advantages ascribed to their facile synthesis, planar two-dimensional multilayer structure, high specific surface area, and mechanical stability, as well as their unique optical and mechanical properties. In this review, we report the recent advances in the technical fabrication and structure-specific applications of GIHMs with desirable thickness and compositions. In addition, the advantages and disadvantages of the methods utilized for creating GIHMs are discussed in detail. Finally, the potential applications and key challenges of GIHMs for future technical applications are mentioned.

  6. Identifying Affinity Classes of Inorganic Materials Binding Sequences via a Graph-Based Model.

    PubMed

    Du, Nan; Knecht, Marc R; Swihart, Mark T; Tang, Zhenghua; Walsh, Tiffany R; Zhang, Aidong

    2015-01-01

    Rapid advances in bionanotechnology have recently generated growing interest in identifying peptides that bind to inorganic materials and classifying them based on their inorganic material affinities. However, there are some distinct characteristics of inorganic materials binding sequence data that limit the performance of many widely-used classification methods when applied to this problem. In this paper, we propose a novel framework to predict the affinity classes of peptide sequences with respect to an associated inorganic material. We first generate a large set of simulated peptide sequences based on an amino acid transition matrix tailored for the specific inorganic material. Then the probability of test sequences belonging to a specific affinity class is calculated by minimizing an objective function. In addition, the objective function is minimized through iterative propagation of probability estimates among sequences and sequence clusters. Results of computational experiments on two real inorganic material binding sequence data sets show that the proposed framework is highly effective for identifying the affinity classes of inorganic material binding sequences. Moreover, the experiments on the structural classification of proteins (SCOP) data set shows that the proposed framework is general and can be applied to traditional protein sequences.

  7. Effect of Acid-Base Property of Inorganic Nanoparticles on Antifouling Performance of PVDF Composite Ultrafiltration Membranes

    NASA Astrophysics Data System (ADS)

    He, Mingjia; Shi, Baoli

    Pure poly(vinylidene fluoride) (PVDF) membrane and PVDF composite membranes modified by three kinds of inorganic nanoparticles (SiO2, Al2O3, and TiO2) were made using a phase inversion method and characterized by pure water flux, retention efficiency of Bovine serum albumin (BSA), flux reduction coefficient, and scanning electron microscope (SEM). The results of flux reduction coefficient illustrated that PVDF membrane modified by nanoparticles had better antifouling property in the order of TiO2, Al2O3, SiO2. The Lewis acid-base properties of the nanoparticle materials were measured by inverse gas chromatography (IGC). The Lewis acid number, Ka, and Lewis base number, Kb, had the following order Ka TiO2 < Ka Al2O3 < Ka SiO2, and Kb TiO2 > Kb Al2O3 > Kb SiO2. The experimental results indicated that PVDF membrane modified by nanoparticles with relatively strong base exhibited excellent antifouling performance.

  8. Computer simulation of inorganic membrane morphology: 2 -- Effect of infiltration at the membrane support interface

    SciTech Connect

    Randon, J.; Julbe, A.; David, P.; Jaafari, K. . Lab. de Physicochimie des Materiaux); Elmaleh, S. . Groupe de Genie des Procedes)

    1993-12-01

    The purpose of this work is to demonstrate, through computer modeling of a ceramic membrane filtration element, that infiltration of a membrane into the ceramic support can have a drastic effect on the porosity at the interface and hence on the hydraulic resistance of the filtration element. A computer model using round spheres has been developed, allowing a realistic picture of the support (infiltrated or not) and of the membrane on top of it. This model allows a determination of the porosity in the support and at the membrane/support interface; it shows the effect of infiltration on the porosity. Experimentally, infiltrated and noninfiltrated TiO[sub 2] membranes have been prepared on tubular ceramic supports and their filtration performances have been compared. The results reveal that in order to increase the permeability of filtration elements, their preparation must limit the size of infiltrated zones.

  9. Bifunctionalized organic-inorganic charged nanocomposite membrane for pervaporation dehydration of ethanol.

    PubMed

    Tripathi, Bijay P; Kumar, Mahendra; Saxena, Arunima; Shahi, Vinod K

    2010-06-01

    Chitosan was modified into N-p-carboxy benzyl chitosan (NCBC) by introducing an aromatic ring grafted with acidic -COOH group and highly stable and cross-linked nanostructured NCBC-silica composite membranes were prepared for pervaporation dehydration of water-ethanol mixture. These membranes were tailored to comprise three regions namely: hydrophobic region, highly charged region and selective region, in which weak acidic group (-COOH) was grafted at organic segment while strong acidic group (-SO(3)H) was grafted at inorganic segment to achieve high stability and less swelling in water-ethanol mixture. Cross-linking density and NCBC-silica content in membrane matrix has been systematically optimized to control the nanostructure of the developed polymer matrix for studying the effects of molecular structure on the swelling, and PV performance. Among prepared membranes, nanocomposite membrane with 3h cross-linking time and 90% (w/w) of NCBC-silica content (PCS-3-3) exhibited 1.66×10(-4)cm(3)(STP) cm/cm(2) s cmHg water permeability (P(W)), while 1.35×10(-7) cm(3)(STP) cm/cm(2) s cmHg ethanol permeability (P(EtOH)) of developed membrane and 1231 PV selectivity factor at 30 °C for separating water from 90% (w/w) ethanol mixture.

  10. Catalyzed CO.sub.2-transport membrane on high surface area inorganic support

    DOEpatents

    Liu, Wei

    2014-05-06

    Disclosed are membranes and methods for making the same, which membranes provide improved permeability, stability, and cost-effective manufacturability, for separating CO.sub.2 from gas streams such as flue gas streams. High CO.sub.2 permeation flux is achieved by immobilizing an ultra-thin, optionally catalyzed fluid layer onto a meso-porous modification layer on a thin, porous inorganic substrate such as a porous metallic substrate. The CO.sub.2-selective liquid fluid blocks non-selective pores, and allows for selective absorption of CO.sub.2 from gas mixtures such as flue gas mixtures and subsequent transport to the permeation side of the membrane. Carbon dioxide permeance levels are in the order of 1.0.times.10.sup.-6 mol/(m.sup.2sPa) or better. Methods for making such membranes allow commercial scale membrane manufacturing at highly cost-effective rates when compared to conventional commercial-scale CO.sub.2 separation processes and equipment for the same and such membranes are operable on an industrial use scale.

  11. Catalyzed CO.sub.2-transport membrane on high surface area inorganic support

    DOEpatents

    Liu, Wei

    2014-05-06

    Disclosed are membranes and methods for making the same, which membranes provide improved permeability, stability, and cost-effective manufacturability, for separating CO.sub.2 from gas streams such as flue gas streams. High CO.sub.2 permeation flux is achieved by immobilizing an ultra-thin, optionally catalyzed fluid layer onto a meso-porous modification layer on a thin, porous inorganic substrate such as a porous metallic substrate. The CO.sub.2-selective liquid fluid blocks non-selective pores, and allows for selective absorption of CO.sub.2 from gas mixtures such as flue gas mixtures and subsequent transport to the permeation side of the membrane. Carbon dioxide permeance levels are in the order of 1.0.times.10.sup.-6 mol/(m.sup.2sPa) or better. Methods for making such membranes allow commercial scale membrane manufacturing at highly cost-effective rates when compared to conventional commercial-scale CO.sub.2 separation processes and equipment for the same and such membranes are operable on an industrial use scale.

  12. Fabrication of superhydrophilic-underwater superoleophobic inorganic anti-corrosive membranes for high-efficiency oil/water separation.

    PubMed

    Liu, Luyan; Chen, Chen; Yang, Siyu; Xie, Hua; Gong, MaoGang; Xu, Xiaoliang

    2016-01-14

    The issue of oil/water separation has recently become a global concern due to the frequency of oil spills and the increase in industrial waste water. Thus, membrane-based materials with unique wettability are desired to separate both of these from a mixture. Nevertheless, the fabrication of energy efficient and stable membranes appropriate for the separation process remains challenging. Herein, synergistic superhydrophilic-underwater superoleophobic inorganic membranes were inventively created by a maneuverable galvanic displacement reaction on copper mesh. The "water-loving" meshes were then used to study gravity driven oil-water separation, where a separation efficiency (the ratio of the amount of oil remaining above the membrane after the separation process to the amount of oil in original mixture) of up to 97% was achieved for various oil-water mixtures, and furthermore the wetting properties and separating performances were maintained without further attenuation after exposure to corrosive environments. Notably, the "repelling-oil" mode can switch to a superhydrophobic mode which acts as a supplementary "oil slick absorbing" material floating above the water surface and has potential in tackling oil slick clean-up issues, in comparison to the former mode which possesses better "separation ability". In addition, the original "repelling-oil" state can be reinstated with ease. The novel method involving a "one-cyclic transformation course" abandons extra chemical addition. The facile and green route presented here acts as an excellent test for the fabrication of a dual-functioning membrane with potential use in efficient oil-water separation, even in harsh environments, and off-shore oil spill cleanup.

  13. Strongly coupled inorganic-nano-carbon hybrid materials for energy storage.

    PubMed

    Wang, Hailiang; Dai, Hongjie

    2013-04-07

    The global shift of energy production from fossil fuels to renewable energy sources requires more efficient and reliable electrochemical energy storage devices. In particular, the development of electric or hydrogen powered vehicles calls for much-higher-performance batteries, supercapacitors and fuel cells than are currently available. In this review, we present an approach to synthesize electrochemical energy storage materials to form strongly coupled hybrids (SC-hybrids) of inorganic nanomaterials and novel graphitic nano-carbon materials such as carbon nanotubes and graphene, through nucleation and growth of nanoparticles at the functional groups of oxidized graphitic nano-carbon. We show that the inorganic-nano-carbon hybrid materials represent a new approach to synthesize electrode materials with higher electrochemical performance than traditional counterparts made by simple physical mixtures of electrochemically active inorganic particles and conducting carbon materials. The inorganic-nano-carbon hybrid materials are novel due to possible chemical bonding between inorganic nanoparticles and oxidized carbon, affording enhanced charge transport and increased rate capability of electrochemical materials without sacrificing specific capacity. Nano-carbon with various degrees of oxidation provides a novel substrate for nanoparticle nucleation and growth. The interactions between inorganic precursors and oxidized-carbon substrates provide a degree of control over the morphology, size and structure of the resulting inorganic nanoparticles. This paper reviews the recent development of inorganic-nano-carbon hybrid materials for electrochemical energy storage and conversion, including the preparation and functionalization of graphene sheets and carbon nanotubes to impart oxygen containing groups and defects, and methods of synthesis of nanoparticles of various morphologies on oxidized graphene and carbon nanotubes. We then review the applications of the SC

  14. IRIS Toxicological Review of Inorganic Arsenic (Preliminary Assessment Materials)

    EPA Science Inventory

    In April 2014, EPA released the draft literature searches and associated search strategies, evidence tables, and exposure response arrays for inorganic arsenic (iAs) to obtain input from stakeholders and the public prior to developing the draft IRIS assessment. Specifically, EPA ...

  15. Material Properties of Inorganic Bovine Cancellous Bovine: Nukbone

    NASA Astrophysics Data System (ADS)

    Piña, Cristina; Palma, Benito; Munguía, Nadia

    2006-09-01

    In this work, inorganic cancellous bovine bone implants prepared in the Instituto de Investigaciones en Materiales — UNAM were characterized. Elementary chemical analysis was made, toxic elements concentration were measured and the content of organic matter also. These implants fulfill all the requirements of the ASTM standards, and therefore it is possible their use in medical applications.

  16. Hybrid organic-inorganic materials based on hydroxyapatite structure

    NASA Astrophysics Data System (ADS)

    Moussa, Sana Ben; Bachouâ, Hassen; Gruselle, Michel; Beaunier, Patricia; Flambard, Alexandrine; Badraoui, Béchir

    2017-04-01

    The present article details the formation of calcium hydroxyapatite synthesized by the hydrothermal way, in presence of glycine or sarcosine. The presence of these amino-acids during the synthetic processes reduces the crystalline growthing through the formation of hybrid organic-inorganic species The crystallite sizes are decreasing and the morphology is modified with the increase of the amino-acid concentration.

  17. IRIS Toxicological Review of Inorganic Arsenic (Preliminary Assessment Materials)

    EPA Science Inventory

    In April 2014, EPA released the draft literature searches and associated search strategies, evidence tables, and exposure response arrays for inorganic arsenic (iAs) to obtain input from stakeholders and the public prior to developing the draft IRIS assessment. Specifically, EPA ...

  18. Sol-gel strategies for amorphous inorganic membranes exhibiting molecular sieving characteristics

    SciTech Connect

    Raman, N.K.; Delattre, L.; Prakash, S.S.; Brinker, C.J. |

    1994-12-31

    We have used several sol-gel strategies to prepare supported inorganic membranes by a process that combines the features of slip-casting and dip-coating. To be viable the deposited membranes must exhibit both high flux and high selectivity. For porous membranes these requirements are met by extremely thin, defect-free porous films exhibiting a narrow size distribution of very small pores. This paper considers the use of polymeric silica and hybrid-organosilyl precursor sols in the context of the underlying physics and chemistry of the membrane deposition process. Since the average membrane pore size is ultimately established by the collapse of the gel network upon drying, it is necessary to promote polymer interpenetration and collapse during membrane deposition in order to achieve the very small pore sizes necessary for molecular sieving. For polymeric sols, this is accomplished using rather weakly branched polymers characterized by fractal dimension D < 1.5 under deposition conditions in which the silica condensation rate is minimized. By analogy to organic polymer sols and gels, we believe that the breadth of the pore size distribution can be influenced by the occurrence of micro-phase separation during membrane deposition. Minimization of the condensation rate not only fosters polymer collapse but should inhibit phase separation, leading to a narrower pore size distribution. The formation of microporosity through collapse of the gel network requires that small pores are achieved at the expense of membrane porosity. Incorporation of organic template ligands within a dense silica matrix followed by their removal allows us to independently control pore size and pore volume through the size and volume fraction of the organic template. Such strategies can be used to create microporous films with large volume fraction porosities.

  19. AIEgens-Functionalized Inorganic-Organic Hybrid Materials: Fabrications and Applications.

    PubMed

    Li, Dongdong; Yu, Jihong

    2016-12-01

    Inorganic materials functionalized with organic fluorescent molecules combine advantages of them both, showing potential applications in biomedicine, chemosensors, light-emitting, and so on. However, when more traditional organic dyes are doped into the inorganic materials, the emission of resulting hybrid materials may be quenched, which is not conducive to the efficiency and sensitivity of detection. In contrast to the aggregation-caused quenching (ACQ) system, the aggregation-induced emission luminogens (AIEgens) with high solid quantum efficiency, offer new potential for developing highly efficient inorganic-organic hybrid luminescent materials. So far, many AIEgens have been incorporated into inorganic materials through either physical doping caused by aggregation induced emission (AIE) or chemical bonding (e.g., covalent bonding, ionic bonding, and coordination bonding) caused by bonding induced emission (BIE) strategy. The hybrid materials exhibit excellent photoactive properties due to the intramolecular motion of AIEgens is restricted by inorganic matrix. Recent advances in the fabrication of AIEgens-functionalized inorganic-organic hybrid materials and their applications in biomedicine, chemical sensing, and solid-state light emitting are presented.

  20. Characterization of inorganic carbon-supported microfiltration and ultrafiltration membranes by aqueous phenol adsorption

    SciTech Connect

    Bialopiotrowicz, T.; Blanpain-Avet, P.; Lalande, M.

    1999-06-01

    The adsorption of phenol on inorganic carbon-supported microfiltration and ultrafiltration membranes has been determined. Using the statistical Student`s t-test, it has been shown that phenol adsorption data are well fitted to the Langmuir and BET isotherm equations. It was thus concluded that the adsorption of phenol was monomolecular and that the specific surface area (SSA) calculated from these data was essential. M1 and M2 ultrafiltration membranes were found to have a higher SSA than microfiltration M14 and carbon support membranes. Assuming that a simple model of the porous structure consisted of a packed bed of spherical particles, it was possible to determine an apparent average pore diameter from SSA data using the Carman-Kozeny equation. The SSA determined from phenol adsorption was found to be close to that measured from mercury porosimetry for the microfiltration membrane and carbon support. Such a result is due to the fact that there is a common basis between the Carman-Kozeny equation employed in the adsorption method and the determination of the ratio 4 V/A (V = total porous volume, A = total pore area) in the mercury porosimetry method (as both methods consider a constant volume/surface ratio of the pores along the microporous membrane thickness).

  1. Composite inorganic membranes containing nanoparticles of hydrated zirconium dioxide for electrodialytic separation.

    PubMed

    Dzyazko, Yuliya S; Volfkovich, Yurii M; Sosenkin, Valentin E; Nikolskaya, Nadejda F; Gomza, Yurii P

    2014-01-01

    The aim of the work was to elucidate the nature of charge-selective properties of macroporous composite inorganic membranes modified with nanoparticles of hydrated zirconium dioxide. The membranes have been investigated using methods of standard contact porosimetry, potentiometry, electron microscopy and small-angle X-ray scattering. The ion exchanger has been found to deposit inside pores of ceramics. Differential curves of pore volume distribution have been resolved using Lorentz functions; each maximum has been related to structure elements of the matrix and ion exchanger by means of calculations according to homogeneous and heterogeneous geometrical models. It was found that the voids, the radius of which is 4 to 8 nm, are responsible for charge selectivity of the composite membranes. These pores are formed due to blocking of macropores of ceramics with aggregates of nanoparticles of the ion exchanger; the radius of these aggregates is 20 to 24 nm. The membranes were applied to desalination of the solution containing NaCl. The removal degree of the salt from the solution reached 95% and 9% for the composite and unmodified membranes, respectively.

  2. Composite inorganic membranes containing nanoparticles of hydrated zirconium dioxide for electrodialytic separation

    NASA Astrophysics Data System (ADS)

    Dzyazko, Yuliya S.; Volfkovich, Yurii M.; Sosenkin, Valentin E.; Nikolskaya, Nadejda F.; Gomza, Yurii P.

    2014-05-01

    The aim of the work was to elucidate the nature of charge-selective properties of macroporous composite inorganic membranes modified with nanoparticles of hydrated zirconium dioxide. The membranes have been investigated using methods of standard contact porosimetry, potentiometry, electron microscopy and small-angle X-ray scattering. The ion exchanger has been found to deposit inside pores of ceramics. Differential curves of pore volume distribution have been resolved using Lorentz functions; each maximum has been related to structure elements of the matrix and ion exchanger by means of calculations according to homogeneous and heterogeneous geometrical models. It was found that the voids, the radius of which is 4 to 8 nm, are responsible for charge selectivity of the composite membranes. These pores are formed due to blocking of macropores of ceramics with aggregates of nanoparticles of the ion exchanger; the radius of these aggregates is 20 to 24 nm. The membranes were applied to desalination of the solution containing NaCl. The removal degree of the salt from the solution reached 95% and 9% for the composite and unmodified membranes, respectively.

  3. Composite inorganic membranes containing nanoparticles of hydrated zirconium dioxide for electrodialytic separation

    PubMed Central

    2014-01-01

    The aim of the work was to elucidate the nature of charge-selective properties of macroporous composite inorganic membranes modified with nanoparticles of hydrated zirconium dioxide. The membranes have been investigated using methods of standard contact porosimetry, potentiometry, electron microscopy and small-angle X-ray scattering. The ion exchanger has been found to deposit inside pores of ceramics. Differential curves of pore volume distribution have been resolved using Lorentz functions; each maximum has been related to structure elements of the matrix and ion exchanger by means of calculations according to homogeneous and heterogeneous geometrical models. It was found that the voids, the radius of which is 4 to 8 nm, are responsible for charge selectivity of the composite membranes. These pores are formed due to blocking of macropores of ceramics with aggregates of nanoparticles of the ion exchanger; the radius of these aggregates is 20 to 24 nm. The membranes were applied to desalination of the solution containing NaCl. The removal degree of the salt from the solution reached 95% and 9% for the composite and unmodified membranes, respectively. PMID:24948892

  4. Inorganic and Radiochemical Analysis of AW-101 and AN-107 ''Diluted Feed'' Materials

    SciTech Connect

    MW Urie; JJ Wagner; LR Greenwood; OT Farmer; SK Fiskum; RT Ratner; CZ Soderquist

    1999-11-11

    This report presents the inorganic and radiochemical analytical results for AW-101 and AN-107 diluted feed materials. The analyses were conducted in support of the BNFL Proposal No. 29952/29953 Task 2.1. The inorganic and radiochemical analysis results obtained from the diluted feed materials are used to provide initial characterization information for subsequent processing testing. Quality Assurance (QA) Plan MCS-033 provides the operational and quality control protocols for the analytical activities.

  5. A non-aqueous procedure to synthesize amino group bearing nanostructured organic-inorganic hybrid materials.

    PubMed

    Göring, M; Seifert, A; Schreiter, K; Müller, P; Spange, S

    2014-09-04

    Amino-functionalized organic-inorganic hybrid materials with a narrow distributed nanostructure of 2-4 nm in size were obtained by means of a template-free and non-aqueous procedure. Simultaneous twin polymerization of novel amino group containing twin monomers with 2,2'-spirobi[4H-1,3,2-benzodioxasiline] has been applied for this purpose. The amino groups of the organic-inorganic hybrid material are useful for post derivatization.

  6. Influence of inorganic complexes on the transport of trace metals through permeation liquid membrane.

    PubMed

    Bayen, Stéphane; Gunkel-Grillon, Peggy; Worms, Isabelle; Martin, Michel; Buffle, Jacques

    2009-07-30

    Under specific conditions (pH, concentrations), trace metals may form, with environmental inorganic ligands, neutral complexes which, in principle, might diffuse passively through biological membranes or influence the response of (bio)analytical sensors for trace metals based on permeation liquid membrane (PLM). In this study, metal (Cu, Cd, Pb) transport through the planar PLM device was evaluated in the presence of major environmental inorganic ligands such as sulfate, carbonate and chloride under conditions where neutral complexes may be formed (up to 73% of neutral metal complex in the solution). In the presence of sulfate, comparison of predicted and experimental PLM fluxes of Cu, Pb and Cd, suggests that passive transport of neutral sulfate-metal complexes does not occur. This was confirmed by comparing fluxes in the presence and absence of carrier. In the presence of carbonate (for Cd, Cu and Pb) and chloride (for Pb and Cd), however, experimental PLM fluxes were greater than predicted (up to 4 and 25 times in the presence of carbonate and chloride, respectively), but experiments in the absence of carrier in the membrane revealed that no passive transport of neutral complexes (MCl(2) or MCO(3)) occurs through PLM. A possible mechanism is discussed. In parallel to the experiments with PLM, the influence of carbonate on the internalization fluxes of Cu(II) and Pb(II) by the freshwater algae, Chlamydomonas reinhardtii, was assessed. Similarly to the results of PLM, the fluxes of these two metals were larger than expected (based on the free metal ion activity model). Thus, even though PLM and bioaccumulation mechanisms are certainly different, similar unexpected behaviours occur for the metal transport through the PLM and biological membrane of C. reinhardtii, in the presence of carbonate.

  7. A Pure Inorganic ZnO-Co3O4 Overlapped Membrane for Efficient Oil/Water Emulsions Separation

    PubMed Central

    Liu, Na; Lin, Xin; Zhang, Weifeng; Cao, Yingze; Chen, Yuning; Feng, Lin; Wei, Yen

    2015-01-01

    The earth's environmental problems, especially for water remediation, need effective methods to solve. Materials with special wettability are developed for the separation of oil/water mixtures. However, the separation of emulsified oil/water mixtures can be a real challenge. There is still much deficiencies, on account of the surfactant, which could link water molecules and oil molecules to form a stabilized system. Here we report a pure inorganic ZnO-Co3O4 overlapped membrane to give a brand new solution to emulsified oil/water mixture separation. Fabricated by an easy and cost-efficient way, such a membrane combines the properties of under-water superoleophobicity and under-oil superhydrophobicity, which can be successfully used for the efficient separation of both surfactant-free and surfactant-stabilized emulsions, solely driven by gravity. This ZnO-Co3O4 overlapped membrane shows great potential applications to industrial wastewater treatment, domestic sewage purification and other water remediation. PMID:25900797

  8. Inorganic-Organic Polymers and Their Role in Materials Science

    DTIC Science & Technology

    1994-05-18

    developments. Poly(dimethylsiloxane) is widely used in biomedicine as an inert elastomer and as a matrix for the diffusion release of birth control...has been acheved by the preparation of composites that involve MEEP (21) and silicon, titanium , zArconium, or aluminum oxide crosslinked gels.[7Z7 3...flj 1140. [311 R. D. Miller, L. Rabolt, R. Sontyakman, W. Fleming, G. N. Fickes , B. L Farmre, H. Kunmany in Inorganic and Orgaomenac Polyme (Eds. M

  9. Structure and properties of polybenzimidazole/silica nanocomposite electrolyte membrane: influence of organic/inorganic interface.

    PubMed

    Singha, Shuvra; Jana, Tushar

    2014-12-10

    Although increased number of reports in recent years on proton exchange membrane (PEM) developed from nanocomposites of polybenzimidazole (PBI) with inorganic fillers brought hope to end the saga of contradiction between proton conductivity and variety of stabilities, such as mechanical, thermal,chemical, etc.; it still remains a prime challenge to develop a highly conducting PEM with superior aforementioned stabilities. In fact the very limited understanding of the interactions especially interfacial interaction between PBI and inorganic filler leads to confusion over the choice of inorganic filler type and their surface functionalities. Taking clue from our earlier study based on poly(4,4'-diphenylether-5,5'-bibenzimidazole) (OPBI)/silica nanocomposites, where silica nanoparticles modified with short chain amine showed interfacial interaction-dependent properties, in this work we explored the possibility of enhanced interfacial interaction and control over the interface by optimizing the chemistry of the silica surface. We functionalized the surface of silica nanoparticles with a longer aliphatic chain having multiple amine groups (named as long chain amine modified silica and abbreviated as LAMS). FTIR and (13)C solid-state NMR provided proof of hydrogen bonding interactions between the amine groups of modifier and those of OPBI. LAMS nanoparticles yielded a more distinguished self-assembly extending all over the OPBI matrix with increasing concentrations. The crystalline nature of these self-assembled clusters was probed by wide-angle X-ray diffraction (WAXD) studies and the morphological features were captured by transmission electron microscope (TEM). We demonstrated the changes in storage modulus and glass transition temperature (Tg) of the membranes, the fundamental parameters that are more sensitive to interfacial structure using temperature dependent dynamic mechanical analysis (DMA). All the nanocomposite membranes displayed enhanced mechanical, thermal

  10. Conductive Polymer-Inorganic Hybrid Materials through Synergistic Mutual Doping of the Constituents.

    PubMed

    Wang, Weike; Chen, Chaoqiu; Tollan, Christopher; Yang, Fan; Beltrán, Mikel; Qin, Yong; Knez, Mato

    2017-08-23

    Polymer-matrix-based inorganic-organic hybrid materials are at the cutting edge of current research for their great promise of merging properties of soft and hard solids in one material. Infiltration of polymers with vapors of reactive metal organics is a pathway for postsynthetic blending of the polymer with inorganic materials. Here, we show that this process is also an excellent method for fabricating conductive hybrid materials. Polyaniline (PANI) was infiltrated with ZnO and the initially insulating polymer was converted to a PANI/ZnO hybrid with conductivities as high as 18.42 S/cm. The conductivity is based on a synergistic effect of the constituting materials, where the inorganic and the polymeric fractions mutually act as dopants for the counterpart. The process temperature is a very important factor for successful infiltration, and the number of applied infiltration cycles allows tuning the level of conductivity of the resulting PANI/ZnO.

  11. Tetraalkylphosphonium polyoxometalate ionic liquids : novel, organic-inorganic hybrid materials.

    SciTech Connect

    Rickert, P. G.; Antonio, M. P.; Firestone, M. A.; Kubatko, K.-A.; Szreder, T.; Wishart, J. F.; Dietz, M. L.; Chemistry; Univ. of Notre Dame; BNL

    2007-01-01

    Pairing of a Keggin or Lindqvist polyoxometalate (POM) anion with an appropriate tetraalkylphosphonium cation is shown to yield the first members of a new family of ionic liquids (ILs). Detailed characterization of one of them, an ambient-temperature 'liquid POM' comprising the Lindqvist salt of the trihexyl(tetradecyl) phosphonium cation, by voltammetry, viscometry, conductimetry, and thermal analysis indicates that it exhibits conductivity and viscosity comparable to those of the one previously described inorganic-organic POM-IL hybrid but with substantially improved thermal stability.

  12. Engineering the Interface Between Inorganic Materials and Cells

    SciTech Connect

    Schaffer, David

    2014-05-31

    To further optimize cell function in hybrid “living materials”, it would be advantageous to render mammalian cells responsive to novel “orthogonal” cues, i.e. signals they would not ordinarily respond to but that can be engineered to feed into defined intracellular signaling pathways. We recently developed an optogenetic method, based on A. thaliana Cry2, for rapid and reversible protein oligomerization in response to blue light. We also demonstrated the ability to use this method to channel the light input into several defined signaling pathways, work that will enhance communication between inorganic devices and living systems.

  13. From iron oxide nanoparticles towards advanced iron-based inorganic materials designed for biomedical applications.

    PubMed

    Figuerola, Albert; Di Corato, Riccardo; Manna, Liberato; Pellegrino, Teresa

    2010-08-01

    In the last decade the progress achieved on the synthesis of inorganic nanostructures has been accompanied by the parallel exploitation of these systems in various fields, among them are biology and medicine. We provide here an overview of the iron-based inorganic nanostructured materials that have been developed and tested in these fields. We will highlight the major concepts on the preparation, physical properties and applications of such nanostructures, starting from the most investigated iron oxide nanoparticles. We will describe then the new generation of inorganic hybrid nanostructures, which are structures that integrate in each nano-object multiple inorganic nanocrystals of different materials. In our discussion we will focus on those works that have provided a sound proof of concept on the potential of the various systems as diagnostic and therapeutic agents. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. Materials for next-generation molecularly selective synthetic membranes

    NASA Astrophysics Data System (ADS)

    Koros, William J.; Zhang, Chen

    2017-03-01

    Materials research is key to enable synthetic membranes for large-scale, energy-efficient molecular separations. Materials with rigid, engineered pore structures add an additional degree of freedom to create advanced membranes by providing entropically moderated selectivities. Scalability -- the capability to efficiently and economically pack membranes into practical modules -- is a critical yet often neglected factor to take into account for membrane materials screening. In this Progress Article, we highlight continuing developments and identify future opportunities in scalable membrane materials based on these rigid features, for both gas and liquid phase applications. These advanced materials open the door to a new generation of membrane processes beyond existing materials and approaches.

  15. Materials for next-generation molecularly selective synthetic membranes.

    PubMed

    Koros, William J; Zhang, Chen

    2017-03-01

    Materials research is key to enable synthetic membranes for large-scale, energy-efficient molecular separations. Materials with rigid, engineered pore structures add an additional degree of freedom to create advanced membranes by providing entropically moderated selectivities. Scalability - the capability to efficiently and economically pack membranes into practical modules - is a critical yet often neglected factor to take into account for membrane materials screening. In this Progress Article, we highlight continuing developments and identify future opportunities in scalable membrane materials based on these rigid features, for both gas and liquid phase applications. These advanced materials open the door to a new generation of membrane processes beyond existing materials and approaches.

  16. Microfiltration process by inorganic membranes for clarification of TongBi liquor.

    PubMed

    Li, Bo; Huang, Minyan; Fu, Tingming; Pan, Linmei; Yao, Weiwei; Guo, Liwei

    2012-02-01

    Membrane separation is an alternative separation technology to the conventional method of filtration. Hence, it has attracted use in the purification and concentration of Chinese Herbal Medicine Extracts (CHMEs). The purpose of this work was to study the process of microfiltration of Tongbi liquor (TBL), a popular Chinese herbal drink, using ceramic membranes. Zirconium oxide and aluminum oxide membranes with pore mean sizes of 0.2 μm and 0.05 μm, respectively, are used for comparisons in terms of flux, transmittance of the ingredients, physical-chemical parameters, removal of macromolecular materials and fouling resistance. The results show that 0.2 μm zirconium oxide membrane is more suitable. The stable permeate flux reaches 135 L·h(-1)·m(-2), the cumulative transmittance of the indicator is 65.53%. Macromolecular materials, such as starch, protein, tannin, pectin and total solids were largely eliminated in retentate after filtration using 0.2 μm ZrO2 ceramic membrane, resulting in clearer TBL. Moreover, this work also reveals that continuous ultrasound could strengthen membrane process that the permeate flux increases significantly. This work demonstrates that the purification of CHME with ceramic membranes is possible and yielded excellent results.

  17. Composite Membranes Containing Nanoparticles of Inorganic Ion Exchangers for Electrodialytic Desalination of Glycerol

    NASA Astrophysics Data System (ADS)

    Dzyazko, Yu S.; Rozhdestvenska, L. M.; Vasilyuk, S. L.; Kudelko, K. O.; Belyakov, V. N.

    2017-06-01

    Composite membranes were obtained by modification of heterogeneous polymer cation and anion-exchange membranes with nanoparticles of zirconium hydrophosphate and hydrated zirconium dioxide, respectively. The ion-exchange materials were investigated with the methods of electron microscopy, potentiometry, voltammetry, and impedance spectroscopy. Single nanoparticles, which were precipitated in aqueous media, form aggregates, when the composites are in a contact with polar organic solvent. Both single nanoparticles (up to 10 nm) and their aggregates (up to 200 nm) were precipitated in ion-exchange polymers in glycerol media. Non-aggregated nanoparticles improve electrical conductivity of the ion-exchange materials, the aggregates are barriers against fouling. The membranes were applied to NaCl removal from highly concentrated glycerine-water mixture containing organic additives (byproduct of biodiesel production). As opposite to pristine materials, the composites demonstrate stability against fouling.

  18. Composite Membranes Containing Nanoparticles of Inorganic Ion Exchangers for Electrodialytic Desalination of Glycerol.

    PubMed

    Dzyazko, Yu S; Rozhdestvenska, L M; Vasilyuk, S L; Kudelko, K O; Belyakov, V N

    2017-12-01

    Composite membranes were obtained by modification of heterogeneous polymer cation and anion-exchange membranes with nanoparticles of zirconium hydrophosphate and hydrated zirconium dioxide, respectively. The ion-exchange materials were investigated with the methods of electron microscopy, potentiometry, voltammetry, and impedance spectroscopy. Single nanoparticles, which were precipitated in aqueous media, form aggregates, when the composites are in a contact with polar organic solvent. Both single nanoparticles (up to 10 nm) and their aggregates (up to 200 nm) were precipitated in ion-exchange polymers in glycerol media. Non-aggregated nanoparticles improve electrical conductivity of the ion-exchange materials, the aggregates are barriers against fouling. The membranes were applied to NaCl removal from highly concentrated glycerine-water mixture containing organic additives (byproduct of biodiesel production). As opposite to pristine materials, the composites demonstrate stability against fouling.

  19. Novel Inorganic/Polymer Composite Membranes for CO2 Capture

    SciTech Connect

    Ho, W.S. Winston; Dutta, Prabir K.; Schmit, Steve J.

    2016-10-01

    The objective of this project is to develop a cost-effective design and manufacturing process for new membrane modules that capture CO2 from flue gas in coal-fired power plants. The membrane consisted of a thin selective layer including inorganic (zeolite) embedded in a polymer structure so that it can be made in a continuous manufacturing process. The membrane was incorporated in spiral-wound modules for the field test with actual flue gas at the National Carbon Capture Center (NCCC) in Wilsonville, AL and bench scale tests with simulated flue gas at the Ohio State University (OSU). Using the modules for post-combustion CO2 capture is expected to achieve the DOE target of $40/tonne CO2 captured (in 2007 dollar) for 2025. Membranes with the amine-containing polymer cover layer on zeolite-Y (ZY) nanoparticles deposited on the polyethersulfone (PES) substrate were successfully synthesized. The membranes showed a high CO2 permeance of about 1100 GPU (gas permeation unit, 1 GPU = 10-6 cm3 (STP)/(cm2 • s • cm Hg), 3000 GPU = 10-6 mol/(m2 • s • Pa)) with a high CO2/N2 selectivity of > 200 at the typical flue gas conditions at 57°C (about 17% water vapor in feed gas) and > 1400 GPU CO2 permeance with > 500 CO2/N2 selectivity at 102°C (~ 80% water vapor). The synthesis of ZY nanoparticles was successfully scaled up, and the pilot-scale membranes were also successfully fabricated using the continuous membrane machine at OSU. The transport performance of the pilot-scale membranes agreed reasonably well with the lab-scale membranes. The results from both the lab-scale and scale-up membranes were used for the techno-economic analysis. The scale-up membranes were fabricated into prototype spiral-wound membrane modules for continuous testing with simulated or real flue gas. For real flue gas testing, we worked with NCCC, in

  20. Inorganic membrane reactors: A distributed feed approach for partial oxidation reactions

    SciTech Connect

    Tonkovich, A.L.Y.; Zilka, J.L.; Jimenez, D.M.

    1995-12-01

    Inorganic membrane reactors have been investigated for the oxidative dehydrogenation of ethane to ethylene. The production of ethylene competes with complete ethane combustion when the oxygen feed nears stoichiometric levels with ethane. High selectivity is achieved when the feed is oxygen-lean, but this results in a low ethane conversion per pass. A membrane reactor (MBR) has been experimentally demonstrated to improve ethylene yields per pass. A tube and shell reactor configuration is used and compared to a traditional tubular reactor (PFR). The oxygen feed is distributed along the length of the reactor through a porous alumina membrane. The distributed feed increases local ethane to oxygen feed ratios within the reactor, while introducing a low overall feed ratio into the MBR. Thus high ethylene selectivities can be obtained along with high ethane conversions. The MBR outperforms the PFR at low overall feed ratios. The performance of the two reactors merge as the feed ratio nears the stoichiometric point of two, and in some cases the PFR outperforms the MBR at higher feed ratios.

  1. Lunar building materials: Some considerations on the use of inorganic polymers. [adhesives, coatings, and binders

    NASA Technical Reports Server (NTRS)

    Lee, S. M.

    1979-01-01

    The use of inorganic polymer systems synthesized from the available lunar chemical elements, viz., silicon, aluminum, and oxygen to make adhesives, binders, and sealants needed in the fabrication of lunar building materials and the assembly of structures is considered. Inorganic polymer systems, their background, status, and shortcomings, and the use of network polymers as a possible approach to synthesis are examined as well as glassy metals for unusual structural strength, and the use of cold-mold materials as well as foam-sintered lunar silicates for lightweight shielding and structural building materials.

  2. The Sustainable Inorganic Materials Management (SIM2) Consortium at KU Leuven

    NASA Astrophysics Data System (ADS)

    Jones, P. T.; Van Gerven, T.; Van Acker, K.; Pontikes, Y.; Cizer, Ö.; Binnemans, K.; Blanpain, B.

    The transition towards resource efficient, closed-loop economies is an urgent necessity as our world is facing resource shortages and unprecedented environmental challenges. Research groups in Metallurgy, Geology, Chemical Engineering, Building Materials, Chemistry, Economics, Process Psychology and Law at KU Leuven (Belgium) have recently connected their expertise in the area of recovery and recycling of inorganic materials into a structural collaboration, the `Sustainable Inorganic Materials Management' (SIM2) program. This has led to a growth and an intensification of research projects as well as local and international research cooperation, propelling SIM2 to a flagship topic for the involved research groups and for the KU Leuven as a whole.

  3. Inorganic nanoparticles kill Toxoplasma gondii via changes in redox status and mitochondrial membrane potential

    PubMed Central

    Adeyemi, Oluyomi Stephen; Murata, Yuho; Sugi, Tatsuki; Kato, Kentaro

    2017-01-01

    This study evaluated the anti-Toxoplasma gondii potential of gold, silver, and platinum nanoparticles (NPs). Inorganic NPs (0.01–1,000 µg/mL) were screened for antiparasitic activity. The NPs caused >90% inhibition of T. gondii growth with EC50 values of ≤7, ≤1, and ≤100 µg/mL for gold, silver, and platinum NPs, respectively. The NPs showed no host cell cytotoxicity at the effective anti-T. gondii concentrations; the estimated selectivity index revealed a ≥20-fold activity toward the parasite versus the host cell. The anti-T. gondii activity of the NPs, which may be linked to redox signaling, affected the parasite mitochondrial membrane potential and parasite invasion, replication, recovery, and infectivity potential. Our results demonstrated the antiparasitic potential of NPs. The findings support the further exploration of NPs as a possible source of alternative and effective anti-T. gondii agents. PMID:28280332

  4. Inorganic nanoparticles kill Toxoplasma gondii via changes in redox status and mitochondrial membrane potential.

    PubMed

    Adeyemi, Oluyomi Stephen; Murata, Yuho; Sugi, Tatsuki; Kato, Kentaro

    2017-01-01

    This study evaluated the anti-Toxoplasma gondii potential of gold, silver, and platinum nanoparticles (NPs). Inorganic NPs (0.01-1,000 µg/mL) were screened for antiparasitic activity. The NPs caused >90% inhibition of T. gondii growth with EC50 values of ≤7, ≤1, and ≤100 µg/mL for gold, silver, and platinum NPs, respectively. The NPs showed no host cell cytotoxicity at the effective anti-T. gondii concentrations; the estimated selectivity index revealed a ≥20-fold activity toward the parasite versus the host cell. The anti-T. gondii activity of the NPs, which may be linked to redox signaling, affected the parasite mitochondrial membrane potential and parasite invasion, replication, recovery, and infectivity potential. Our results demonstrated the antiparasitic potential of NPs. The findings support the further exploration of NPs as a possible source of alternative and effective anti-T. gondii agents.

  5. Auto-organisation of hybrid organic-inorganic materials prepared by sol-gel process.

    PubMed

    Boury, Bruno; Corriu, Robert J P

    2002-04-21

    Silica-based hybrid organic-inorganic materials prepared by sol-gel chemistry exhibit chemical and physical properties revealing their anisotropic organisation. Besides the opportunities that this phenomenon opens for the preparation of new materials, it also provides arguments to the chemist looking for a better comprehension and control of the organisation of solids.

  6. Polymer synthesis toward fuel cell membrane materials

    NASA Astrophysics Data System (ADS)

    Rebeck, Nathaniel T.

    Fuel cells are a promising technology that will be part of the future energy landscape. New membranes for alkaline and proton exchange membrane fuel cells are needed to improve the performance, simplify the system, and reduce cost. Polymer chemistry can be applied to develop new polymers and to assemble polymers into improved membranes that need less water, have increased performance and are less expensive, thereby removing the deficiencies of current membranes. Nucleophilic aromatic substitution polymerization typically produces thermally stable engineering polymers that can be easily functionalized. New functional monomers were developed to explore new routes to novel functional polymers. Sulfonamides were discovered as new activating groups for polymerization of high molecular weight thermooxidatively stable materials with sulfonic acid latent functionality. While the sulfonamide functional polymers could be produced, the sulfonamide group proved to be too stable to convert into a sulfonic acid after reaction. The reactivity of 2-aminophenol was investigated to search for a new class of ion conducting polymer materials. Both the amine and the phenol groups are found to be reactive in a nucleophilic aromatic substitution, however not to the extent to allow the formation of high molecular weight polymer materials. Layer-by-layer films were assembled from aqueous solutions of poly(styrene sulfonate) and trimethylammonium functionalized poly(phenylene oxide). The deposition conditions were adjusted to increase the free charge carrier content, and chloride conductivites reached almost 30 mS/cm for the best films. Block and random poly(phenylene oxide) copolymers were produced from 2,6-dimethylphenol and 2,6-diphenylphenol and the methyl substituted repeat units were functionalized with trimethylammonium bromide. The block copolymers displayed bromide conductivities up to 26 mS/cm and outperformed the random copolymers, indicating that morphology has an effect on ion

  7. UNDERSTANDING THE EFFECT OF DYNAMIC FEED CONDITIONS ON WATER RECOVERY FROM IC ENGINE EXHAUST BY CAPILLARY CONDENSATION WITH INORGANIC MEMBRANES

    SciTech Connect

    DeBusk, Melanie Moses; Bischoff, Brian L; Hunter, James A; Klett, James William; Nafziger, Eric J; Daw, C Stuart

    2014-01-01

    An inorganic membrane water recovery concept is evaluated as a method to recovering water from the exhaust of an internal combustion engine. Integrating the system on-board a vehicle would create a self-sustaining water supply that would make engine water injection technologies consumer transparent . In laboratory experiments, water recovery from humidified air was measured to evaluate how different operating parameters affect the membrane system s efficiency. The observed impact of transmembrane pressure and gas flow rate suggest that gas residence time is more important than water flux through the membrane. Heat transfer modeling suggests that increasing membrane length can be used to improve efficiency and allow greater flow per membrane, an important parameter for practical applications where space is limited. The membrane water recovery concept was also experimentally validated by extracting water from diesel exhaust coming from a stationary generator. The insight afforded by these studies provides a basis for developing improved membrane designs that balance both efficiency and cost.

  8. Organic-inorganic hybrid anion exchange hollow fiber membranes: a novel device for drug delivery.

    PubMed

    Wang, Na; Wu, Cuiming; Cheng, Yiyun; Xu, Tongwen

    2011-04-15

    The clinical use of nonsteroidal anti-inflammatory drugs (NSAIDs) (such as sodium salicylate (NaSA)) for the treatment of chronic arthritis is limited due to the adverse effects and patient non-compliance. In order to solve these problems, anion exchange hollow fiber membranes (AEHFMs) are proposed for the first time here as potential drug carriers. Brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) is used as the starting membrane material. In-situ sol-gel process of γ-methacryloxypropyl trimethoxysilane (γ-MPS) in BPPO matrix is operated so as to enhance the membranes' thermal and dimensional stability. The performances of the membranes in controlled release of the drug (NaSA as the model drug) are improved accordingly. Loading and release experiments illustrate that the hybrid AEHFM can bind salicylate (SA⁻) at a high loading efficiency (28.4%), and the retention of the drug on the membrane matrix is significantly prolonged (drug released in 7 days under physiological condition: 51.9%, neglecting the drug bound by protein). Meanwhile, the membrane is biocompatible and can support the adherence, growth, and survival of human cells. Overall, the prepared AEHFM is a promising scaffolding material for drug delivery and tissue engineering.

  9. Tidal day organic and inorganic material flux of ponds in the Liberty Island freshwater tidal wetland.

    PubMed

    Lehman, Peggy W; Mayr, Shawn; Liu, Leji; Tang, Alison

    2015-01-01

    The loss of inorganic and organic material export and habitat produced by freshwater tidal wetlands is hypothesized to be an important contributing factor to the long-term decline in fishery production in San Francisco Estuary. However, due to the absence of freshwater tidal wetlands in the estuary, there is little information on the export of inorganic and organic carbon, nutrient or phytoplankton community biomass and the associated mechanisms. A single-day study was conducted to assess the potential contribution of two small vegetated ponds and one large open-water pond to the inorganic and organic material flux within the freshwater tidal wetland Liberty Island in San Francisco Estuary. The study consisted of an intensive tidal day (25.5 h) sampling program that measured the flux of inorganic and organic material at three ponds using continuous monitoring of flow, chlorophyll a, turbidity and salt combined with discrete measurements of phytoplankton community carbon, total and dissolved organic carbon and nutrient concentration at 1.5 h intervals. Vegetated ponds had greater material concentrations than the open water pond and, despite their small area, contributed up to 81% of the organic and 61% of the inorganic material flux of the wetland. Exchange between ponds was important to wetland flux. The small vegetated pond in the interior of the wetland contributed as much as 72-87% of the total organic carbon and chlorophyll a and 10% of the diatom flux of the wetland. Export of inorganic and organic material from the small vegetated ponds was facilitated by small-scale topography and tidal asymmetry that produced a 40% greater material export on ebb tide. The small vegetated ponds contrasted with the large open water pond, which imported 29-96% of the inorganic and 4-81% of the organic material into the wetland from the adjacent river. This study identified small vegetated ponds as an important source of inorganic and organic material to the wetland and the

  10. [The action of week inorganic acids and lower carboxylic acids on the conductivity of bilayer lipid membranes].

    PubMed

    Kilivnik, K E; Khmarskaia, L A; Ksenzhek, O S

    2009-01-01

    The ability of weak inorganic acids (H2S, HCN) and lower carboxylic acids to interact with bilayer lipid membranes, change their conductivity, and act as protonophores has been investigated. The mechanism of changes in BLM conductivity was studied. Factors influencing the interaction of acids with model lipid membranes were determined. Maximum changes in conductivity were observed at pH values equal to the dissociation constants of weak acids and depend on the coefficients of distribution "octanol-water".

  11. Ionic Liquids and Poly(ionic liquid)s for Morphosynthesis of Inorganic Materials.

    PubMed

    Gao, Min-Rui; Yuan, Jiayin; Antonietti, Markus

    2016-10-06

    Ionic liquids (ILs) are new, innovative ionic solvents with rich physicochemical properties and intriguing pre-organized solvent structures; these materials offer great potential to impact across versatile areas of scientific research, for example, synthetic inorganic chemistry. Recent use of ILs as precursors, templates, and solvents has led to inorganic materials with tailored sizes, dimensionalities, morphologies, and functionalities that are difficult to obtain, or even not accessible, by using conventional solvents. Poly(ionic liquid)s (PILs) polymerized from IL monomers also raise the prospect of modifying nucleation, growth, and crystallization of inorganic objects, shedding light on the synthesis of a wide range of new materials. Here we survey recent key progress in using ILs and PILs in the field of synthetic inorganic chemistry. As well as highlighting the unique features of ILs and PILs that enable advanced synthesis, the effects of adding other solvents to the final products, along with the emerging applications of the created inorganic materials will be discussed. We finally provide an outlook on several development opportunities that could lead to new advancements of this exciting research field.

  12. An ab initio electronic transport database for inorganic materials

    NASA Astrophysics Data System (ADS)

    Ricci, Francesco; Chen, Wei; Aydemir, Umut; Snyder, G. Jeffrey; Rignanese, Gian-Marco; Jain, Anubhav; Hautier, Geoffroy

    2017-07-01

    Electronic transport in materials is governed by a series of tensorial properties such as conductivity, Seebeck coefficient, and effective mass. These quantities are paramount to the understanding of materials in many fields from thermoelectrics to electronics and photovoltaics. Transport properties can be calculated from a material's band structure using the Boltzmann transport theory framework. We present here the largest computational database of electronic transport properties based on a large set of 48,000 materials originating from the Materials Project database. Our results were obtained through the interpolation approach developed in the BoltzTraP software, assuming a constant relaxation time. We present the workflow to generate the data, the data validation procedure, and the database structure. Our aim is to target the large community of scientists developing materials selection strategies and performing studies involving transport properties.

  13. A Review on Recent Patents and Applications of Inorganic Material Binding Peptides.

    PubMed

    Thota, Veeranjaneyulu; Perry, Carole C

    2017-01-01

    Although the popularity of using combinatorial display techniques for recognising unique peptides having high affinity for inorganic (nano) particles has grown rapidly, there are no systematic reviews showcasing current developments or patents on binding peptides specific to these materials. In this review, we summarize and discuss recent progress in patents on material binding peptides specifically exploring inorganic nano surfaces such as metals, metal oxides, minerals, carbonbased materials, polymer based materials, magnetic materials and semiconductors. We consider both the peptide display strategies used and the exploitation of the identified peptides in the generation of advanced nanomaterials. In order to get a clear picture on the number of patents and literature present to date relevant to inorganic material binding biomolecules and their applications, a thorough online search was conducted using national and worldwide databases. The literature search include standard bibliographic databases while patents included EPO Espacenet, WIPO patent scope, USPTO, Google patent search, Patent lens, etc. along with commercial databases such as Derwent and Patbase. Both English and American spellings were included in the searches. The initial number of patents found related to material binders were 981. After reading and excluding irrelevant patents such as organic binding peptides, works published before 2001, repeated patents, documents not in English etc., 51 highly relevant patents published from 2001 onwards were selected and analysed. These patents were further separated into six categories based on their target inorganic material and combinatorial library used. They include relevant patents on metal, metal oxide or combination binding peptides (19), magnetic and semiconductor binding peptides (8), carbon based (3), mineral (5), polymer (8) and other binders (9). Further, how these material specific binders have been used to synthesize simple to complex bio- or

  14. Inorganic materials as supports for covalent enzyme immobilization: methods and mechanisms.

    PubMed

    Zucca, Paolo; Sanjust, Enrico

    2014-09-09

    Several inorganic materials are potentially suitable for enzymatic covalent immobilization, by means of several different techniques. Such materials must meet stringent criteria to be suitable as solid matrices: complete insolubility in water, reasonable mechanical strength and chemical resistance under the operational conditions, the capability to form manageable particles with high surface area, reactivity towards derivatizing/functionalizing agents. Non-specific protein adsorption should be always considered when planning covalent immobilization on inorganic solids. A huge mass of experimental work has shown that silica, silicates, borosilicates and aluminosilicates, alumina, titania, and other oxides, are the materials of choice when attempting enzyme immobilizations on inorganic supports. More recently, some forms of elemental carbon, silicon, and certain metals have been also proposed for certain applications. With regard to the derivatization/functionalization techniques, the use of organosilanes through silanization is undoubtedly the most studied and the most applied, although inorganic bridge formation and acylation with selected acyl halides have been deeply studied. In the present article, the most common inorganic supports for covalent immobilization of the enzymes are reviewed, with particular focus on their advantages and disadvantages in terms of enzyme loadings, operational stability, undesired adsorption, and costs. Mechanisms and methods for covalent immobilization are also discussed, focusing on the most widespread activating approaches (such as glutaraldehyde, cyanogen bromide, divinylsulfone, carbodiimides, carbonyldiimidazole, sulfonyl chlorides, chlorocarbonates, N-hydroxysuccinimides).

  15. Inorganic materials for photovoltaics: Status and futures challenges

    NASA Astrophysics Data System (ADS)

    Slaoui, A.

    2017-07-01

    This paper review the present technologies for the fabrication of solar cells and modules based on the most common semiconductors namely silicon, CuInGaSe(S) and CdTe materials as well as on III-V concentrated photovoltaic cells and modules. For silion technology, we give insights on the growth of monocrystalline and multicrystalline silicon wafers and then we describe the most common solar cells designs and how to fabricate them. We also provide information about the fabrication of silicon modules and their performances. As for the thin-films solar cells, we present the structurale and optical properties of the CIGS and CdTe materials as well as the solar cell structures. The multi-junction concept cell that involves several III-V materials of different bandgaps is also described, and data on their fabrication, performances and mounting as modules are presented. Finally, a short outlook on the coming materials for solar cells is provided.

  16. Liquid-liquid phase separation in particles containing secondary organic material free of inorganic salts

    NASA Astrophysics Data System (ADS)

    Song, Mijung; Liu, Pengfei; Martin, Scot T.; Bertram, Allan K.

    2017-09-01

    Particles containing secondary organic material (SOM) are ubiquitous in the atmosphere and play a role in climate and air quality. Recently, research has shown that liquid-liquid phase separation (LLPS) occurs at high relative humidity (RH) (greater than ˜ 95 %) in α-pinene-derived SOM particles free of inorganic salts, while LLPS does not occur in isoprene-derived SOM particles free of inorganic salts. We expand on these findings by investigating LLPS at 290 ± 1 K in SOM particles free of inorganic salts produced from ozonolysis of β-caryophyllene, ozonolysis of limonene, and photo-oxidation of toluene. LLPS was observed at greater than ˜ 95 % RH in the biogenic SOM particles derived from β-caryophyllene and limonene while LLPS was not observed in the anthropogenic SOM particles derived from toluene. This work combined with the earlier work on LLPS in SOM particles free of inorganic salts suggests that the occurrence of LLPS in SOM particles free of inorganic salts is related to the oxygen-to-carbon elemental ratio (O : C) of the organic material. These results help explain the difference between the hygroscopic parameter κ of SOM particles measured above and below water saturation in the laboratory and field, and have implications for predicting the cloud condensation nucleation properties of SOM particles.

  17. Radiation induced EPR centers in foodstuffs and inorganic materials.

    PubMed

    Pilbrow, J R; Troup, G J; Hutton, D R; Rosengarten, G; Zhong, Y C; Hunter, C R

    1993-01-01

    EPR investigations of a variety of irradiated materials have provided the potential for useful dosimetry applications. Herbs and spices imported into Australia have been investigated to establish whether or not they have been irradiated. Post-irradiation studies have shown that there is more than one free radical species in most cases which decay rapidly with time. Changes to transition metal ion signals, e.g., Cu2+ or Fe3+, appear to be permanent against further irradiation. Thus if these signals change upon irradiation, the material almost certainly has not previously been irradiated. Power saturation studies of alanine, a favored dosimetry material, suggest two distinguishable types of behavior consistent with the presence of spin-flip transitions. Irradiation of vanadium doped beryl yields stable VO2+ ions which may provide a useful dosimetry material. Dosimetry applications would appear to demand low cost, user friendly, automated EPR spectrometers. A patented option based on a 2.5 GHz microstrip microwave bridge will be described briefly.

  18. Microscopic origin of entropy-driven polymorphism in hybrid organic-inorganic perovskite materials

    NASA Astrophysics Data System (ADS)

    Butler, Keith T.; Svane, Katrine; Kieslich, Gregor; Cheetham, Anthony K.; Walsh, Aron

    2016-11-01

    Entropy is a critical, but often overlooked, factor in determining the relative stabilities of crystal phases. The importance of entropy is most pronounced in softer materials, where small changes in free energy can drive phase transitions, which has recently been demonstrated in the case of organic-inorganic hybrid-formate perovskites. In this Rapid Communication we demonstrate the interplay between composition and crystal structure that is responsible for the particularly pronounced role of entropy in determining polymorphism in hybrid organic-inorganic materials. Using ab initio based lattice dynamics, we probe the origins and effects of vibrational entropy of four archetype perovskite (A B X3 ) structures. We consider an inorganic material (SrTiO3), an A -site hybrid-halide material (CH3NH3) PbI3 , a X -site hybrid material KSr (BH4)3 , and a mixed A - and X -site hybrid-formate material (N2H5) Zn (HCO2)3 , comparing the differences in entropy between two common polymorphs. The results demonstrate the importance of low-frequency intermolecular modes in determining the phase stability in these materials. The understanding gained allows us to propose a general principle for the relative stability of different polymorphs of hybrid materials as temperature is increased.

  19. IRIS Toxicological Review for Inorganic Arsenic (Scoping and Problem Formulation Materials)

    EPA Science Inventory

    In November 2012, EPA released scoping and problem formulation materials for the IRIS assessment of inorganic arsenic for public comment and discussion. The scoping information was based on input from EPA's program and regional offices and was provided for informational purposes....

  20. IRIS Toxicological Review for Inorganic Arsenic (Scoping and Problem Formulation Materials)

    EPA Science Inventory

    In November 2012, EPA released scoping and problem formulation materials for the IRIS assessment of inorganic arsenic for public comment and discussion. The scoping information was based on input from EPA's program and regional offices and was provided for informational purposes....

  1. Advanced Civil Engineering Materials Based on Inorganic Polymers

    DTIC Science & Technology

    1993-04-29

    to evaluate cement chemistries more suitable for macrodefect- free cement materials. Therefore, the thrust of this work is oriented to the chemistry...uses conventional cement in advanced applications. Generically, such materiais are called macrodefect- free cements (MDF cements). MDF cements develop... aggregate particles, to the water-to-solids ratio, to the rheology, which is related to the degree of dispersion of the solids originally present, and to the

  2. Sugar-decorated hydroxyapatite: an inorganic material bioactivated with carbohydrates.

    PubMed

    Russo, Laura; Landi, Elena; Tampieri, Anna; Natalello, Antonino; Doglia, Silvia M; Gabrielli, Luca; Cipolla, Laura; Nicotra, Francesco

    2011-09-06

    An efficient method for the direct and covalent decoration of granules of nanostructured apatite with a sample monosaccharide is presented; the hydroxyapatite material was directly functionalised with a short azido-containing spacer arm, to which α-propargyl glucopyranoside has been chemoselectively ligated by Huisgen-type cycloaddition. The 'glycosylated' hydroxypatite was characterised by its ability to interact with glucose recognising lectins. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Transition metal chalcogenides: ultrathin inorganic materials with tunable electronic properties.

    PubMed

    Heine, Thomas

    2015-01-20

    CONSPECTUS: After the discovery of graphene and the development of powerful exfoliation techniques, experimental preparation of two-dimensional (2D) crystals can be expected for any layered material that is known to chemistry. Besides graphene and hexagonal boron nitride (h-BN), transition metal chalcogenides (TMC) are among the most studied ultrathin materials. In particular, single-layer MoS2, a direct band gap semiconductor with ∼1.9 eV energy gap, is popular in physics and nanoelectronics, because it nicely complements semimetallic graphene and insulating h-BN monolayer as a construction component for flexible 2D electronics and because it was already successfully applied in the laboratory as basis material for transistors and other electronic and optoelectronic devices. Two-dimensional crystals are subject to significant quantum confinement: compared with their parent layered 3D material, they show different structural, electronic, and optical properties, such as spontaneous rippling as free-standing monolayer, significant changes of the electronic band structure, giant spin-orbit splitting, and enhanced photoluminescence. Most of those properties are intrinsic for the monolayer and already absent for two-layer stacks of the same 2D crystal. For example, single-layer MoS2 is a direct band gap semiconductor with spin-orbit splitting of 150 meV in the valence band, while the bilayer of the same material is an indirect band gap semiconductor without observable spin-orbit splitting. All these properties have been observed experimentally and are in excellent agreement with calculations based on density-functional theory. This Account reports theoretical studies of a subgroup of transition metal dichalcogenides with the composition MX2, with M = Mo, or W and X = Se or S, also referred to as "MoWSeS materials". Results on the electronic structure, quantum confinement, spin-orbit coupling, spontaneous monolayer rippling, and change of electronic properties in the

  4. Organic/inorganic hybrid amine and sulfonic acid tethered silica materials: Synthesis, characterization and application

    NASA Astrophysics Data System (ADS)

    Hicks, Jason Christopher

    The major goals of this thesis were to: (1) create a site-isolated aminosilica material with higher amine loadings than previously reported isolation methods, (2) use spectroscopic, reactivity, and catalytic (olefin polymerization precatalysts) probes to determine isolation of amine groups on these organic/inorganic hybrid materials, (3) synthesize an organic/inorganic hybrid material capable of activating Group 4 olefin polymerization precatalysts, and (4) synthesize a high amine loaded organic/inorganic hybrid material capable of reversibly capturing CO2 in a simulated flue gas stream. The underlying motivation of this research involved the synthesis and design of novel amine and sulfonic acid materials. Traditional routes to synthesize aminosilicas have led to the formation of a high loading of multiple types of amine sites on the silica surface. Part of this research involved the creation of a new aminosilica material via a protection/deprotection method designed to prevent multiple sites, while maintaining a relatively high loading. As a characterization technique, fluorescence spectroscopy of pyrene-based fluorophores loaded on traditional aminosilicas and site-isolated aminosilicas was used to probe the degree of site-isolation obtained with these methods. Also, this protection/deprotection method was compared to other reported isolation techniques with heterogeneous Group 4 constrained-geometry inspired catalysts (CGCs). It was determined that the degree of separation of the amine sites could be controlled with protection/deprotection methods. Furthermore, an increase in the reactivity of the amines and the catalytic activity of CGCs built off of the amines was determined for aminosilicas synthesized by a protection/deprotection method. The second part of this work involved developing organic/inorganic hybrid materials as heterogeneous Bronsted acidic cocatalysts for activation of olefin polymerization precatalysts. This was the first reported organic/inorganic

  5. Sulfonic acid-functionalized hybrid organic-inorganic proton exchange membranes synthesized by sol-gel using 3-mercaptopropyl trimethoxysilane (MPTMS)

    NASA Astrophysics Data System (ADS)

    Mosa, J.; Durán, A.; Aparicio, M.

    2015-11-01

    Organic/inorganic hybrid membranes based on (3-glycidoxypropyl) trimethoxysilane (GPTMS) and 3-mercaptopropyl trimethoxysilane (MPTMS) have been prepared by sol-gel method and organic polymerisation, as candidate materials for proton exchange membranes in direct alcohol fuel cell (DMFC) applications. The -SH groups of MPTMS are oxidized to sulfonic acid groups, which are attributed to enhance the proton conductivity of hybrid membranes. FTIR, XPS and contact angle were used to characterize and confirm the hybrid structure and oxidation reaction progress. Membranes characterization also includes ion exchange capacity, water uptake, methanol permeability and proton conductivity to confirm their applicability in fuel cells. All the membranes were homogeneous and thermally and chemically resistant. In particular, the hybrid membranes demonstrated proton conductivities as high as 0.16 S cm-1 at high temperature, while exhibiting a low methanol permeability as compared to Nafion®. These results are associated with proton conducting paths through the silica pseudo-PEO network in which sulfonic acid groups work as proton donor.

  6. Perspective: Toward "synthesis by design": Exploring atomic correlations during inorganic materials synthesis

    NASA Astrophysics Data System (ADS)

    Soderholm, L.; Mitchell, J. F.

    2016-05-01

    Synthesis of inorganic extended solids is a critical starting point from which real-world functional materials and their consequent technologies originate. However, unlike the rich mechanistic foundation of organic synthesis, with its underlying rules of assembly (e.g., functional groups and their reactivities), the synthesis of inorganic materials lacks an underpinning of such robust organizing principles. In the latter case, any such rules must account for the diversity of chemical species and bonding motifs inherent to inorganic materials and the potential impact of mass transport on kinetics, among other considerations. Without such assembly rules, there is less understanding, less predictive power, and ultimately less control of properties. Despite such hurdles, developing a mechanistic understanding for synthesis of inorganic extended solids would dramatically impact the range of new material discoveries and resulting new functionalities, warranting a broad call to explore what is possible. Here we discuss our recent approaches toward a mechanistic framework for the synthesis of bulk inorganic extended solids, in which either embryonic atomic correlations or fully developed phases in solutions or melts can be identified and tracked during product selection and crystallization. The approach hinges on the application of high-energy x-rays, with their penetrating power and large Q-range, to explore reaction pathways in situ. We illustrate this process using two examples: directed assembly of Zr clusters in aqueous solution and total phase awareness during crystallization from K-Cu-S melts. These examples provide a glimpse of what we see as a larger vision, in which large scale simulations, data-driven science, and in situ studies of atomic correlations combine to accelerate materials discovery and synthesis, based on the assembly of well-defined, prenucleated atomic correlations.

  7. Perspective: Toward “synthesis by design”: Exploring atomic correlations during inorganic materials synthesis

    SciTech Connect

    Soderholm, L.; Mitchell, J. F.

    2016-05-26

    Synthesis of inorganic extended solids is a critical starting point from which real-world functional materials and their consequent technologies originate. However, unlike the rich mechanistic foundation of organic synthesis, with its underlying rules of assembly (e.g., functional groups and their reactivities), the synthesis of inorganic materials lacks an underpinning of such robust organizing principles. In the latter case, any such rules must account for the diversity of chemical species and bonding motifs inherent to inorganic materials and the potential impact of mass transport on kinetics, among other considerations. Without such assembly rules, there is less understanding, less predictive power, and ultimately less control of properties. Despite such hurdles, developing a mechanistic understanding for synthesis of inorganic extended solids would dramatically impact the range of new material discoveries and resulting new functionalities, warranting a broad call to explore what is possible. Here we discuss our recent approaches toward a mechanistic framework for the synthesis of bulk inorganic extended solids, in which either embryonic atomic correlations or fully developed phases in solutions or melts can be identified and tracked during product selection and crystallization. The approach hinges on the application of high-energy x-rays, with their penetrating power and large Q-range, to explore reaction pathways in situ. We illustrate this process using two examples: directed assembly of Zr clusters in aqueous solution and total phase awareness during crystallization from K–Cu–S melts. These examples provide a glimpse of what we see as a larger vision, in which large scale simulations, data-driven science, and in situ studies of atomic correlations combine to accelerate materials discovery and synthesis, based on the assembly of well-defined, prenucleated atomic correlations.

  8. Perspective: Toward “synthesis by design”: Exploring atomic correlations during inorganic materials synthesis

    DOE PAGES

    Soderholm, L.; Mitchell, J. F.

    2016-05-26

    Synthesis of inorganic extended solids is a critical starting point from which real-world functional materials and their consequent technologies originate. However, unlike the rich mechanistic foundation of organic synthesis, with its underlying rules of assembly (e.g., functional groups and their reactivities), the synthesis of inorganic materials lacks an underpinning of such robust organizing principles. In the latter case, any such rules must account for the diversity of chemical species and bonding motifs inherent to inorganic materials and the potential impact of mass transport on kinetics, among other considerations. Without such assembly rules, there is less understanding, less predictive power, andmore » ultimately less control of properties. Despite such hurdles, developing a mechanistic understanding for synthesis of inorganic extended solids would dramatically impact the range of new material discoveries and resulting new functionalities, warranting a broad call to explore what is possible. Here we discuss our recent approaches toward a mechanistic framework for the synthesis of bulk inorganic extended solids, in which either embryonic atomic correlations or fully developed phases in solutions or melts can be identified and tracked during product selection and crystallization. The approach hinges on the application of high-energy x-rays, with their penetrating power and large Q-range, to explore reaction pathways in situ. We illustrate this process using two examples: directed assembly of Zr clusters in aqueous solution and total phase awareness during crystallization from K–Cu–S melts. These examples provide a glimpse of what we see as a larger vision, in which large scale simulations, data-driven science, and in situ studies of atomic correlations combine to accelerate materials discovery and synthesis, based on the assembly of well-defined, prenucleated atomic correlations.« less

  9. Inorganic Composite Materials in Japan: Status and Trends

    DTIC Science & Technology

    1989-11-01

    Squeeze-cast SiC whisker- reinforced Al for space applications Nippon Carbon Al/Nicalon preform wire 19,20 Nippon Denso * Whisker-reinforced Cu 21...matrices for tem- were numerous indications of this coming peratures around 300 ’C. change during our visit, to start with the A slight shift of focus toward...and organizer of numerous technical and professional meetings, principally through the American Ceramic Society and the Materials Research Society. -U.S, GOVERNMENT PRttdTING o~r IC q:~ 27), ONRFE M7 53

  10. Effect of membrane polymeric materials on relationship between surface pore size and membrane fouling in membrane bioreactors

    NASA Astrophysics Data System (ADS)

    Miyoshi, Taro; Yuasa, Kotaku; Ishigami, Toru; Rajabzadeh, Saeid; Kamio, Eiji; Ohmukai, Yoshikage; Saeki, Daisuke; Ni, Jinren; Matsuyama, Hideto

    2015-03-01

    We investigated the effect of different membrane polymeric materials on the relationship between membrane pore size and development of membrane fouling in a membrane bioreactor (MBR). Membranes with different pore sizes were prepared using three different polymeric materials, cellulose acetate butyrate (CAB), polyvinyl butyral (PVB), and polyvinylidene fluoride (PVDF), and the development of membrane fouling in each membrane was evaluated by batch filtration tests using a mixed liquor suspension obtained from a laboratory-scale MBR. The results revealed that the optimal membrane pore size to mitigate membrane fouling differed depending on membrane polymeric material. For PVDF membranes, the degree of membrane fouling decreased as membrane pore size increased. In contrast, CAB membranes with smaller pores had less fouling propensity than those with larger ones. Such difference can be attributed to the difference in major membrane foulants in each membrane; in PVDF, they were small colloids or dissolved organics in which proteins are abundant, and in CAB, microbial flocs. The results obtained in this study strongly suggested that optimum operating conditions of MBRs differ depending on the characteristics of the used membrane.

  11. Specific Templating of Inorganic Materials on Self-Assembled Clathrin Proteins

    NASA Astrophysics Data System (ADS)

    Heilshorn, Sarah

    2010-03-01

    Nature has evolved numerous methods for the reproducible self-assembly of nanoscale architectures that are ideal templates for patterning inorganic nanostructures. For example, the protein clathrin assembles into a variety of 2D and 3D structures depending on environmental conditions during assembly. The ability of this single protein to form multiple architectures makes clathrin an ideal model system for investigating the kinetic and thermodynamic principles of self-assembly, which will lead to the ability to predictably control template architecture. We design bi-functional peptide linkers to serve as molecular bridges between distinct sites on the clathrin monomers and specific inorganic materials including gold, titania, and cobalt oxide. By generating a family of bi-functional peptides, we develop a flexible, modular system that enables the rapid development of multiple inorganic nanostructures from a single protein template without requiring re-design of the template. We present examples of gold and anatase titania catalysts fabricated through this method.

  12. Covalent organic/inorganic hybrid proton-conductive membrane with semi-interpenetrating polymer network: Preparation and characterizations

    NASA Astrophysics Data System (ADS)

    Fu, Rong-Qiang; Woo, Jung-Je; Seo, Seok-Jun; Lee, Jae-Suk; Moon, Seung-Hyeon

    2008-05-01

    A series of new covalent organic/inorganic hybrid proton-conductive membranes, each with a semi-interpenetrating polymer network (semi-IPN), for direct methanol fuel cell (DMFC) applications is prepared through the following sequence: (i) copolymerization of impregnated styrene (St), p-vinylbenzyl chloride (VBC) and divinylbenzene (DVB) within a supporting polyvinyl chloride (PVC) film; (ii) reaction of the chloromethyl group with 3-(methylamine)propyl-trimethoxysilane (MAPTMS); (ii) a sol-gel process under acidic conditions; (iv) a sulfonation reaction. The developed membranes are characterized in terms of Fourier transform infrared/attenuated total reflectance (FTIR/ATR), scanning electron microscopy/energy-dispersive X-ray analysis (SEM/EDXA), elemental analysis (EA) and thermogravimetric analysis (TGA), which confirm the formation of the target membranes. The developed copolymer chains are interpenetrating with the PVC matrix to form the semi-IPN structure, and the inorganic silica is covalently bound to the copolymers. These features provide the membranes with high mechanical strength. The effect of silica content is investigated. As the silica content increases, proton conductivity and water content decrease, whereas oxidative stability is improved. In particular, methanol permeability and methanol uptake are reduced largely by the silica. The ratio of proton conductivity to methanol permeability for the hybrid membranes is higher than that of Nafion 117. All these properties make the hybrid membranes a potential candidate for DMFC applications.

  13. Cellulose as Sustainable Materials for Separation Membranes

    NASA Astrophysics Data System (ADS)

    Chu, Benjamin

    2013-03-01

    Polysaccharides, while complex, form one of the most abundant sustainable resources on earth. We want to take advantage of fundamental advances in materials understanding across length and time scales to investigate the interrelationships between structure, morphology, processing, properties, performance, and cost to meet the specific challenges arising from separation membranes for water purification. Non-woven fiber mats have unique properties, such as interconnected pores, a very large surface-to-volume ratio, and a high capacity for surface modifications. The breakthrough concept of combining fibrous mats composed of different fiber diameters for fabricating scaffolds as a unique platform for water purification is presented. Further, we take advantage of recent advances in chemical modifications, structural studies using synchrotron X-rays, and physical scale-up transformations to drastically improve filtration membrane development. Support of this work by the NSF, ONR, NIH and Stony Brook Univ. is gratefully acknowledged. The Chu/Hsiao group on water purification includes Profs. B.S.Hsiao and C.Burger, Drs. H-Y.Ma, D-F.Fang, R.Wang, and grad students: X.Wang, Z. Wang, Y.Su, R. Yang

  14. Nanostructured inorganic materials: Synthesis and associated electrochemical properties

    NASA Astrophysics Data System (ADS)

    Yau, Shali Zhu

    Synthetic strategy for preparing potential battery materials at low temperature was developed. Magnetite (Fe3O4), silver hollandnite (AgxMn8O16), magnesium manganese oxide (MgxMnO 2˙yH2O), and silver vanadium phosphorous oxide (Ag 2VO2PO4) were studied. Magnetite (Fe3O4) was prepared by coprecipitation induced by triethylamine from aqueous iron(II) and iron(III) chloride solutions of varying concentrations. Variation of the iron(II) and iron(III) concentrations results in crystallite size control of the Fe3O4 products. Materials characterization of the Fe3O4 samples is reported, including Brunauer-Emmitt-Teller (BET) surface area, x-ray powder diffraction (XRD), transmission electron microscopy (TEM), particle size, and saturation magnetization results. A strong correlation between discharge capacity and voltage recovery behavior versus crystallite size was observed when tested as an electrode material in lithium electrochemical cells. Silver hollandite (AgxMn8O16) was successfully synthesized through a low temperature reflux reaction. The crystallite size and silver content of AgxMn8O16 by varying the reactant ratio of silver permanganate (AgMnO4) and manganese sulfate monohydrate (MnSO4˙H2O). Silver hollandite was characterized by Brunauer-Emmitt-Teller (BET) surface area, inductively coupled plasma-optical emission (ICP-OES) spectrometry, helium pycnometry, simultaneous thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), and x-ray powder diffraction (XRD). The crystallite size showed a strong correlation with silver content, BET surface area, and particle sizes. The silver hollandite cathode showed good discharge capacity retention in 30 cycles of discharge-charge. There were a good relationship between crystallite size and rate capability and pulse ability. Magnesium manganese oxide (MgxMnO2˙yH 2O) was made by redox reaction by mixing sodium hydroxide (NaOH), manganese sulfate monohydrate (MnSO4˙HO2), and potassium persulfate (K2S2O8

  15. Intrinsic mechanical properties and strengthening methods in inorganic crystalline materials

    NASA Astrophysics Data System (ADS)

    Mecking, H.; Hartig, Ch.; Seeger, J.

    1991-06-01

    The paper deals with strength and fracture in metals, ceramics and intermetallic compounds. The emphasis is on the interrelation between microstructure and macroscopic behavior and how the concepts for alloy design are mirroring this interrelationship. The three materials classes are distinguished by the physical nature of the atomic bonding forces. In metals metallic bonding predominates which causes high ductility but poor strength. Accordingly material development concentrates on production of microstructures which optimize the yield strength without unacceptable loss in ductility. In ceramics covalent bonding prevails which results in high hardness and high elastic stiffness but at the same time extreme brittleness. Contrary to the metal-ease material development aims at a kind of pseudo ductility in order to rise the fracture toughness to sufficiently high levels. In intermetallic phases the atomic bonds are a mixture of metallic and covalent bonding where depending on the alloying system the balance between the two contributions may be quite different. Accordingly the properties of intermetallics are in the range between metals and ceramics. By a variety of microstructural measures their properties can be changed in direction. either towards metallic or ceramic behavior. General rules for alloy design are not available, rather every system demands very specific experience since properties depend to a considerable part on intrinsic properties of lattice defects such as dislocations, antiphase boundaries, stacking faults and grain boundaries. Cet article traite de la résistance et de la fracture des métaux, des céramiques et des composés intermétalliques. L'accent est mis sur les correspondances entre la microstructure et le comportement macroscopique ainsi que sur la façon dont de tels concepts se reflètent dans la création de nouveaux alliages. C'est la nature des forces de liaisons qui distingue chaque type de matériaux. Dans les métaux, les

  16. Laboratory illustrations of the transformations and deposition of inorganic material in biomass boilers

    SciTech Connect

    Baxter, L.L.; Jenkins, B.M.

    1995-08-01

    Boilers fired with certain woody biomass fuels have proven to be a viable, reliable means of generating electrical power. The behavior of the inorganic material in the fuels is one of the greatest challenges to burning the large variety of fuels available to biomass combustors. Unmanageable ash deposits and interactions between ash and bed material cause loss in boiler availability and significant increase in maintenance costs. The problems related to the behavior of inorganic material now exceed all other combustion-related challenges in biomass-fired boilers. This paper reviews the mechanisms of ash deposit formation, the relationship between fuel properties and ash deposit properties, and a series of laboratory tests in Sandia`s Multifuel Combustor designed to illustrate how fuel type, boiler design, and boiler operating conditions impact ash deposit properties.

  17. Laboratory illustrations of the transformations and deposition of inorganic material in biomass boilers

    SciTech Connect

    Baxter, L.L.; Jenkins, B.M.

    1995-12-31

    Boilers fired with certain woody biomass fuels have proven to be a viable, reliable means of generating electrical power. The behavior of the inorganic material in die fuels is one of the greatest challenges to burning the large variety of fuels available to biomass combustors. Unmanageable ash deposits and interactions between ash and bed material cause loss in holler availability and significant increase in maintenance costs. The problems related to the behavior of inorganic material now exceed all other combustion-related challenges in biomass-fired boilers. This paper reviews the mechanisms of ash deposit formation, the relationship between fuel properties and ash deposit properties, and a series of laboratory tests in Sandia`s Multifuel Combustor designed to illustrate how fuel type, boiler design, and boiler operating conditions impact ash deposit properties.

  18. Laboratory illustrations of the transformations and deposition of inorganic material in biomass boilers

    SciTech Connect

    Baxter, L.L.; Jenkins, B.M.

    1995-12-31

    Boilers fired with certain woody biomass fuels have proven to be a viable, reliable means of generating electrical power. The behavior of the inorganic material in the fuels is one of the greatest challenges to burning the large variety of fuels available to biomass combustors. Unmanageable ash deposits and interactions between ash and bed material cause loss in boiler availability and significant increase in maintenance costs. The problems related to the behavior of inorganic material now exceed all other combustion-related challenges in biomass-fired boilers. This paper reviews the mechanisms of ash deposit formation, the relationship between fuel properties and ash deposit properties, and a series of laboratory tests in Sandia`s Multifuel Combustor designed to illustrate how fuel type, boiler design, and boiler operating conditions impact ash deposit properties.

  19. Photosensitized reduction of water to hydrogen using novel Maya blue-like organic-inorganic hybrid material.

    PubMed

    Zhang, Xiaojie; Jin, Zhiliang; Li, Yuexiang; Li, Shuben; Lu, Gongxuan

    2009-05-01

    On the basis of the understanding that membranes play an important role in the separation of the intermediate photoproducts in the photosynthetic process, a novel efficient hydrogen evolution system was constructed with Maya blue-like organic-inorganic hybrid material as a photocatalyst, in which palygorskite acts as matrix and Eosin Y as a photosensitizer. Under visible light irradiation (lambda > or = 420 nm), the highest rate of hydrogen evolution and apparent quantum yield are about 3247.2 micromol h(-1) (g Eosin Y)(-1) and 12.5%, respectively. Negatively charged palygorskite particles could control the photosensitized electron-transfer reaction by means of electrostatic interaction. Based on the activities of hydrogen generation and the experimental measurements of UV-vis absorbance and fluorescence, a probable mechanism for photosensitized hydrogen evolution was postulated.

  20. Hybrid Organic/Inorganic Materials Depth Profiling Using Low Energy Cesium Ions.

    PubMed

    Noël, Céline; Houssiau, Laurent

    2016-05-01

    The structures developed in organic electronics, such as organic light emitting diodes (OLEDs) or organic photovoltaics (OPVs) devices always involve hybrid interfaces, joining metal or oxide layers with organic layers. No satisfactory method to probe these hybrid interfaces physical chemistry currently exists. One promising way to analyze such interfaces is to use in situ ion beam etching, but this requires ion beams able to depth profile both inorganic and organic layers. Mono- or diatomic ion beams commonly used to depth profile inorganic materials usually perform badly on organics, while cluster ion beams perform excellently on organics but yield poor results when organics and inorganics are mixed. Conversely, low energy Cs(+) beams (<500 eV) allow organic and inorganic materials depth profiling with comparable erosion rates. This paper shows a successful depth profiling of a model hybrid system made of metallic (Au, Cr) and organic (tyrosine) layers, sputtered with 500 eV Cs(+) ions. Tyrosine layers capped with metallic overlayers are depth profiled easily, with high intensities for the characteristic molecular ions and other specific fragments. Metallic Au or Cr atoms are recoiled into the organic layer where they cause some damage near the hybrid interface as well as changes in the erosion rate. However, these recoil implanted metallic atoms do not appear to severely degrade the depth profile overall quality. This first successful hybrid depth profiling report opens new possibilities for the study of OLEDs, organic solar cells, or other hybrid devices.

  1. Hybrid Organic/Inorganic Materials Depth Profiling Using Low Energy Cesium Ions

    NASA Astrophysics Data System (ADS)

    Noël, Céline; Houssiau, Laurent

    2016-05-01

    The structures developed in organic electronics, such as organic light emitting diodes (OLEDs) or organic photovoltaics (OPVs) devices always involve hybrid interfaces, joining metal or oxide layers with organic layers. No satisfactory method to probe these hybrid interfaces physical chemistry currently exists. One promising way to analyze such interfaces is to use in situ ion beam etching, but this requires ion beams able to depth profile both inorganic and organic layers. Mono- or diatomic ion beams commonly used to depth profile inorganic materials usually perform badly on organics, while cluster ion beams perform excellently on organics but yield poor results when organics and inorganics are mixed. Conversely, low energy Cs+ beams (<500 eV) allow organic and inorganic materials depth profiling with comparable erosion rates. This paper shows a successful depth profiling of a model hybrid system made of metallic (Au, Cr) and organic (tyrosine) layers, sputtered with 500 eV Cs+ ions. Tyrosine layers capped with metallic overlayers are depth profiled easily, with high intensities for the characteristic molecular ions and other specific fragments. Metallic Au or Cr atoms are recoiled into the organic layer where they cause some damage near the hybrid interface as well as changes in the erosion rate. However, these recoil implanted metallic atoms do not appear to severely degrade the depth profile overall quality. This first successful hybrid depth profiling report opens new possibilities for the study of OLEDs, organic solar cells, or other hybrid devices.

  2. Universal dispersing agent for electrophoretic deposition of inorganic materials with improved adsorption, triggered by chelating monomers.

    PubMed

    Liu, Yangshuai; Luo, Dan; Ata, Mustafa S; Zhang, Tianshi; Wallar, Cameron J; Zhitomirsky, Igor

    2016-01-15

    Poly[1-[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,2-ethanediyl, sodium salt] (PAZO) is a polymeric functional material with a number of unique physical properties, which attracted significant interest of different scientific communities. Films of PAZO were deposited by anodic electrophoretic deposition (EPD) under constant current and constant voltage conditions. The deposition kinetics was analyzed under different conditions and the deposition mechanism was discussed. New strategy was developed for the EPD of different inorganic materials and composites using PAZO as a dispersing, charging, binding and film forming agent. It was found that PAZO exhibits remarkable adsorption on various inorganic materials due to the presence of chelating salicylate ligands in its molecular structure. The salicylate ligands of PAZO monomers provide multiple adsorption sites by complexation of metal atoms on particle surfaces and allow for efficient electrosteric stabilization of particle suspensions. The remarkable performance of PAZO in its application in EPD have been exemplified by deposition of a wide variety of inorganic materials including the single element oxides (NiO, ZnO, Fe2O3) the complex oxides (Al2TiO5, BaTiO3, ZrSiO4, CoFe2O4) different nitrides (TiN, Si3N4, BN) as well as pure Ni metal and hydrotalcite clay. The use of PAZO can avoid limitation of other dispersing agents in deposition and co-deposition of different materials. Composite films were obtained using PAZO as a co-dispersant for different inorganic materials. The deposit composition, microstructure and deposition yield can be varied. The EPD method offers the advantages of simplicity, high deposition rate, and ability to deposit thin or thick films.

  3. A flexible all-inorganic fuel cell membrane with conductivity above Nafion, and durable operation at 150 °C

    NASA Astrophysics Data System (ADS)

    Ansari, Y.; Tucker, T. G.; Huang, W.; Klein, I. S.; Lee, S.-Y.; Yarger, J. L.; Angell, C. A.

    2016-01-01

    The search for fuel cell membranes has focused on carbon backbone polymers, among which Nafion seems to best survive the most severe of the degradation mechanisms - attack by peroxide radicals. Less attention has been given to inorganic membranes because of their generally inflexible nature and lower conductivity, though some SiO2-Nafion composites have shown improved properties. Nafion dominates, despite needing hydration, which then restricts operation to below 100 °C (so CO poisoning problems persist). Described herein is a low cost, flexible, and all-inorganic fiberglass reinforced gel membrane with conductivity exceeding that of Nafion at any temperature above 60 °C. Using Teflon fuel cells, maximum currents > 1 Acm-2 and OCV of 1.03 V at 150 °C are demonstrated. No detectable loss of cell potential was observed over 24 h during 50 mAcm-2 constant current operation at 120 °C while, at 150 °C and maximum power, the degradation rate is intermediate among other high conductivity H3PO4-PBI type membranes. The structure of the membrane is deduced, mainly from 29Si solid state-NMR. The -115 ppm resonance, which is extreme for Q4 Si(O) structures, identifies a zeolite-like SiO2 network, which is "floppy". 31P and 1H NMR establish nano-permeating H3PO4 as the source of the exceptional conductivity.

  4. Comparison of the biological NH3 removal characteristics among four inorganic packing materials.

    PubMed

    Hirai, M; Kamamoto, M; Yani, M; Shoda, M

    2001-01-01

    Four inorganic packing materials were evaluated in terms of their availability as a packing material of a packed tower deodorization apparatus (biofilter) from the viewpoints of biological NH3 removal characteristics and some physical properties. Porous ceramics (A), calcinated cristobalite (B), calcinated and formed obsidian (C), granulated and calculated soil (D) were used. The superiority of these packing materials determined based on the values of non-biological removal per unit weight or unit volume of packing material, complete removal capacity of NH3 per unit weight of packing material per day or unit volume of packing material per day and pressure drop of the packed bed was in the order of A approximately = C > B > or = D. Packing materials A and C with high porosity, maximum water content, and suitable mean pore diameter showed excellent removal capacity.

  5. High-throughput combinatorial database of electronic band structures for inorganic scintillator materials.

    PubMed

    Setyawan, Wahyu; Gaume, Romain M; Lam, Stephanie; Feigelson, Robert S; Curtarolo, Stefano

    2011-07-11

    For the purpose of creating a database of electronic structures of all the known inorganic compounds, we have developed a computational framework based on high-throughput ab initio calculations (AFLOW) and an online repository (www.aflowlib.org). In this article, we report the first step of this task: the calculation of band structures for 7439 compounds intended for the research of scintillator materials for γ-ray radiation detection. Data-mining is performed to select the candidates from 193,456 compounds compiled in the Inorganic Crystal Structure Database. Light yield and scintillation nonproportionality are predicted based on semiempirical band gaps and effective masses. We present a list of materials, potentially bright and proportional, and focus on those exhibiting small effective masses and effective mass ratios.

  6. Biomineralization-inspired synthesis of functional organic/inorganic hybrid materials: organic molecular control of self-organization of hybrids.

    PubMed

    Arakaki, Atsushi; Shimizu, Katsuhiko; Oda, Mayumi; Sakamoto, Takeshi; Nishimura, Tatsuya; Kato, Takashi

    2015-01-28

    Organisms produce various organic/inorganic hybrid materials, which are called biominerals. They form through the self-organization of organic molecules and inorganic elements under ambient conditions. Biominerals often have highly organized and hierarchical structures from nanometer to macroscopic length scales, resulting in their remarkable physical and chemical properties that cannot be obtained by simple accumulation of their organic and inorganic constituents. These observations motivate us to create novel functional materials exhibiting properties superior to conventional materials--both synthetic and natural. Herein, we introduce recent progress in understanding biomineralization processes at the molecular level and the development of organic/inorganic hybrid materials by these processes. We specifically outline fundamental molecular studies on silica, iron oxide, and calcium carbonate biomineralization and describe material synthesis based on these mechanisms. These approaches allow us to design a variety of advanced hybrid materials with desired morphologies, sizes, compositions, and structures through environmentally friendly synthetic routes using functions of organic molecules.

  7. Materials for next-generation desalination and water purification membranes

    NASA Astrophysics Data System (ADS)

    Werber, Jay R.; Osuji, Chinedum O.; Elimelech, Menachem

    2016-05-01

    Membrane-based separations for water purification and desalination have been increasingly applied to address the global challenges of water scarcity and the pollution of aquatic environments. However, progress in water purification membranes has been constrained by the inherent limitations of conventional membrane materials. Recent advances in methods for controlling the structure and chemical functionality in polymer films can potentially lead to new classes of membranes for water purification. In this Review, we first discuss the state of the art of existing membrane technologies for water purification and desalination, highlight their inherent limitations and establish the urgent requirements for next-generation membranes. We then describe molecular-level design approaches towards fabricating highly selective membranes, focusing on novel materials such as aquaporin, synthetic nanochannels, graphene and self-assembled block copolymers and small molecules. Finally, we highlight promising membrane surface modification approaches that minimize interfacial interactions and enhance fouling resistance.

  8. Chemically Integrated Inorganic-Graphene Two-Dimensional Hybrid Materials for Flexible Energy Storage Devices.

    PubMed

    Peng, Lele; Zhu, Yue; Li, Hongsen; Yu, Guihua

    2016-12-01

    State-of-the-art energy storage devices are capable of delivering reasonably high energy density (lithium ion batteries) or high power density (supercapacitors). There is an increasing need for these power sources with not only superior electrochemical performance, but also exceptional flexibility. Graphene has come on to the scene and advancements are being made in integration of various electrochemically active compounds onto graphene or its derivatives so as to utilize their flexibility. Many innovative synthesis techniques have led to novel graphene-based hybrid two-dimensional nanostructures. Here, the chemically integrated inorganic-graphene hybrid two-dimensional materials and their applications for energy storage devices are examined. First, the synthesis and characterization of different kinds of inorganic-graphene hybrid nanostructures are summarized, and then the most relevant applications of inorganic-graphene hybrid materials in flexible energy storage devices are reviewed. The general design rules of using graphene-based hybrid 2D materials for energy storage devices and their current limitations and future potential to advance energy storage technologies are also discussed.

  9. New organic-inorganic hybrid material based on functional cellulose nanowhisker, polypseudorotaxane and Au nanorods.

    PubMed

    Garavand, Ali; Dadkhah Tehrani, Abbas

    2016-11-05

    Organic-inorganic functional hybrid materials play a major role in the development of advanced functional materials and recently have gained growing interest of the worldwide community. In this context, new hybrid organic-inorganic gel consisting of cellulose nanowhisker xanthate (CNWX) and S-H functionalized polypseudorotaxane (PPR) as organic parts of gel and gold nanorods (GNRs) as inorganic cross-linking agent were prepared. Firstly, thiolated α-cyclodextrin (α-CD-SH) was threaded onto poly-(ethylene glycol) bis (mercaptoethanoate ester) (PEG-SH) to give polypseudorotaxane (PPR) and then it reacted with GNRs in the presence of CNWX to give the new hybrid gel material. The new synthesized gel and its components characterized by spectroscopic measurement methods such as FT-IR, UV-vis and NMR spectroscopy. Interestingly, hybrid gel showed new polygonal plate like morphology with 45-60nm thickness and 400-600nm width. The obtained gel may have potential application in many fields especially in biomedical applications.

  10. "Rinse and trickle": a protocol for TEM preparation and investigation of inorganic fibers from biological material.

    PubMed

    Vigliaturo, Ruggero; Capella, Silvana; Rinaudo, Caterina; Belluso, Elena

    2016-07-01

    The purpose of this work is to define a sample preparation protocol that allows inorganic fibers and particulate matter extracted from different biological samples to be characterized morphologically, crystallographically and chemically by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS). The method does not damage or create artifacts through chemical attacks of the target material. A fairly rapid specimen preparation is applied with the aim of performing as few steps as possible to transfer the withdrawn inorganic matter onto the TEM grid. The biological sample is previously digested chemically by NaClO. The salt is then removed through a series of centrifugation and rinse cycles in deionized water, thus drastically reducing the digestive power of the NaClO and concentrating the fibers for TEM analysis. The concept of equivalent hydrodynamic diameter is introduced to calculate the settling velocity during the centrifugation cycles. This technique is applicable to lung tissues and can be extended to a wide range of organic materials. The procedure does not appear to cause morphological damage to the fibers or modify their chemistry or degree of crystallinity. The extrapolated data can be used in interdisciplinary studies to understand the pathological effects caused by inorganic materials.

  11. Bioinspired synthesis of multifunctional inorganic and bio-organic hybrid materials.

    PubMed

    Andre, Rute; Tahir, Muhammad N; Natalio, Filipe; Tremel, Wolfgang

    2012-05-01

    Owing to their physical and chemical properties, inorganic functional materials have tremendous impacts on key technologies such as energy generation and storage, information, medicine, and automotive engineering. Nature, on the other hand, provides evolution-optimized processes, which lead to multifunctional inorganic-bio-organic materials with complex structures. Their formation occurs under physiological conditions, and is goverened by a combination of highly regulated biological processes and intrinsic chemical properties. Nevertheless, insights into the molecular mechanisms of biomineralization open up promising perspectives for bioinspired and biomimetic design and the development of inorganic-bio-organic multifunctional hybrids. Therefore, biomimetic approaches may disclose new synthetic routes under ambient conditions by integrating the concept of gene-regulated biomineralization principles. The skeletal structures of marine sponges provide an interesting example of biosilicification via enzymatically controlled and gene-regulated silica metabolism. Spicule formation is initiated intracellularly by a fine-tuned genetic mechanism, which involves silica deposition in vesicles (silicassomes) under the control of the enzyme silicatein, which has both catalytic and templating functions. In this review, we place an emphasis on the fabrication of biologically inspired materials with silicatein as a biocatalyst.

  12. Effect of "bridge" on the performance of organic-inorganic crosslinked hybrid proton exchange membranes via KH550

    NASA Astrophysics Data System (ADS)

    Han, Hailan; Li, Hai Qiang; Liu, Meiyu; Xu, Lishuang; Xu, Jingmei; Wang, Shuang; Ni, Hongzhe; Wang, Zhe

    2017-02-01

    A series of novel organic-inorganic crosslinked hybrid proton exchange membranes were prepared using sulfonated poly(arylene ether ketone sulfone) polymers containing carboxyl groups (C-SPAEKS), (3-aminopropyl)-triethoxysilane (KH550), and tetraethoxysilane (TEOS). KH550 acted as a "bridge" after reacting with carboxyl and sulfonic groups of C-SPAEKS to form covalent and ionic crosslinked structure between the C-SPAEKS and SiO2 phase. The crosslinked hybrid membranes (C-SPAEKS/K-SiO2) were characterized by FT-IR spectroscopy, TGA, and electrochemistry, etc. The thermal stability, mechanical properties and proton conductivity of the crosslinked hybrid membranes were improved by the presence of both crosslinked structure and inorganic phase. The proton conductivity of C-SPAEKS/K-SiO2-8 was recorded as 0.110 S cm-1, higher than that of Nafion® (0.028 S cm-1) at 120 °C. Moreover, the methanol permeability of the C-SPAEKS/K-SiO2-8 was measured as 3.86 × 10-7 cm2 s-1, much lower than that of Nafion® 117 membranes (29.4 × 10-7 cm2 s-1) at 25 °C.

  13. Use of reinforced inorganic cement materials for spark wire and drift chamber wire frames

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The results of a survey, materials test, and analysis study directed toward the development of an inorganic glass-fiber reinforced cement material for use in the construction of space qualified spark wire frames and drift chamber frames are presented. The purpose for this research was to evaluate the feasibility of using glass fiber reinforced cement (GFRC) for large dimensioned structural frames for supporting a number of precisely located spark wires in multiple planes. A survey of the current state of the art in fiber reinforced cement materials was made; material sample mixes were made and tested to determine their laboratory performances. Tests conducted on sample materials showed that compressive and flexural strengths of this material could approach values which would enable fabrication of structural spark wire frames.

  14. Comparison of the biological H2S removal characteristics among four inorganic packing materials.

    PubMed

    Hirai, M; Kamamoto, M; Yani, M; Shoda, M

    2001-01-01

    Four inorganic packing materials were evaluated in terms of their availability as packing materials of a packed tower deodorization apparatus (biofilter) from the viewpoints of biological H2S removal characteristics and some physical properties. Among porous ceramics (A), calcinated cristobalite (B), calcinated and formed obsidian (C), granulated and calcinated soil (D), the superiority of these packing materials determined based on the values of non-biological removal per unit weight or unit volume of packing material, complete removal capacity of H2S per unit weight of packing material per day or unit volume of packing material per day and pressure drop of the packed bed was in the order of A approximately equal to C > D approximately equal to B, which is correlated with the maximum water content, porosity, and mean pore diameter.

  15. Structure and distribution of inorganic components in the cake layer of a membrane bioreactor treating municipal wastewater.

    PubMed

    Zhou, Lijie; Xia, Siqing; Alvarez-Cohen, Lisa

    2015-11-01

    A laboratory-scale submerged anoxic-oxic membrane bioreactor treating municipal wastewater was operated to investigate the structure and distribution of the inorganic cake layer buildup on the membrane. BCR (European Community Bureau of Reference) sequential extraction, X-ray photoelectron spectroscopy (XPS), and both map and line scan of energy-dispersive X-ray analysis (EDX) were performed for cake layer characterization. BCR results showed that Si, Al, Ca, Mg, Fe, and Ba were the predominant inorganic elements in the cake layer, and they occurred mostly as crystal particles. Crystal SiO2 was the dominant inorganic compound while Ca in the form of CaSO4 (dominant) and CaCO3 were also present, but exerted little effect on the cake layer structure because most of these compounds were deposited as precipitates on the reactor bottom. EDX results indicated that Si and Al accumulated together along the cross-sectional cake layer in the form of Si-Al (SiO2-Al2O3) crystal particles. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Effect of electric pulse processing on physical and chemical properties of inorganic materials

    NASA Astrophysics Data System (ADS)

    Sakipova, S. E.; Nussupbekov, B. R.; Ospanova, D.; Khassenov, A.; Sakipova, Sh E.

    2015-04-01

    This article analyzes various aspects of the practical application of electric pulse technology of industrial raw materials processing as a result of a spark electric discharge in a liquid solution of the raw material under processing. The object of the study are samples of technogenic materials from a deposit in Central Kazakhstan, which are crushed and ground to particles with a preset degree of fragmentation. The electric pulse processing is performed by using different numbers of discharges. The effect of electric pulse processing with different electrical parameters is carried out on the basis of comparison of the properties and structure of metal-containing and industrial raw materials after machining and electric pulse processing. The X-ray spectral microanalysis was performed using a scanning microscope. The researchers obtained data on changes in the microstructure and elemental composition of inorganic material samples as a result of electric pulse processing. It was established that the technology of electric pulse crushing and grinding of inorganic materials makes it possible to obtain not only a final product with desired size of dispersed particles, but also to change their physical and chemical properties.

  17. Cryogenic Properties of Inorganic Insulation Materials for ITER Magnets: A Review

    SciTech Connect

    Simon, N.J.

    1994-12-01

    Results of a literature search on the cryogenic properties of candidate inorganic insulators for the ITER TF magnets are reported. The materials investigated include: Al{sub 2}O{sub 3}, AlN, MgO, porcelain, SiO{sub 2}, MgAl{sub 2}O{sub 4}, ZrO{sub 2}, and mica. A graphical presentation is given of mechanical, elastic, electrical, and thermal properties between 4 and 300 K. A companion report reviews the low temperature irradiation resistance of these materials.

  18. Electrochemical sensing of heavy metal ions with inorganic, organic and bio-materials.

    PubMed

    Cui, Lin; Wu, Jie; Ju, Huangxian

    2015-01-15

    As heavy metal ions severely harm human health, it is important to develop simple, sensitive and accurate methods for their detection in environment and food. Electrochemical detection featured with short analytical time, low power cost, high sensitivity and easy adaptability for in-situ measurement is one of the most developed methods. This review introduces briefly the recent achievements in electrochemical sensing of heavy metal ions with inorganic, organic and bio-materials modified electrodes. In particular, the unique properties of inorganic nanomaterials, organic small molecules or their polymers, enzymes and nucleic acids for detection of heavy metal ions are highlighted. By employing some representative examples, the design and sensing mechanisms of these electrodes are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Mapping Proxy Sensitivity: A New Technique for Compositional Analysis of Cultured Biominerals and Inorganically Precipitated Materials

    NASA Astrophysics Data System (ADS)

    Gagnon, A. C.; DePaolo, D. J.; DeYoreo, J.; Spero, H. J.; Russell, A. D.

    2011-12-01

    Mineral composition is controlled by a host of environmental factors during precipitation. To build accurate paleo-reconstructions we need to separate the impact of each parameter on proxy behavior and use these data to build a chemical-scale understanding of mineral growth. Biomineral culture and inorganic precipitation experiments, where growth parameters can be manipulated independently, are uniquely suited to calibrate proxies and probe mechanism. Culture and precipitation experiments often involve overgrowth of an initial material. For example, seed crystals are used to control mineralogy and avoid nucleation during inorganic precipitation, while culture experiments in marine organisms typically start with wild specimens. New growth corresponding to the experimental conditions must be resolved from the initial material. Separation is typically achieved using microanalysis, skeletal dissection, or estimates of the initial mass and composition. Each approach imposes limits on the accuracy, precision or types of materials that can be analyzed. Slow growth rates and complicated geometries can make these techniques especially challenging when applied to biominerals. We present a method of compositional analysis for use in biological culture and inorganic growth experiments that overcomes many of these challenges. This method relies on growth in a mixed element stable isotope spike, requires neither the initial mass nor the initial composition to be known, harnesses the precision and sensitivity of bulk analysis, and applies even when it is impossible to physically identify newly grown material. Error analysis suggests this method can significantly improve the precision of metal/calcium measurements in experimentally grown material compared to current methods. Furthermore, the method can isolate different events through time, separating, for example, the impact of day and night cycles on biomineral composition. We will present metal/calcium ratios measured using the

  20. Unusually stable ~100-fold reversible and instantaneous swelling of inorganic layered materials

    PubMed Central

    Geng, Fengxia; Ma, Renzhi; Nakamura, Akira; Akatsuka, Kosho; Ebina, Yasuo; Yamauchi, Yusuke; Miyamoto, Nobuyoshi; Tateyama, Yoshitaka; Sasaki, Takayoshi

    2013-01-01

    Cells can swell or shrink in certain solutions; however, no equivalent activity has been observed in inorganic materials. Although lamellar materials exhibit increased volume with increase in the lamellar period, the interlamellar expansion is usually limited to a few nanometres, with a simultaneous partial or complete exfoliation into individual atomic layers. Here we demonstrate a large monolithic crystalline swelling of layered materials. The gallery spacing can be instantly increased ~100-fold in one direction to ~90 nm, with the neighbouring layers separated primarily by H2O. The layers remain strongly held without peeling or translational shifts, maintaining a nearly perfect three-dimensional lattice structure of >3,000 layers. First-principle calculations yield a long-range directional structuring of the H2O molecules that may help to stabilize the highly swollen structure. The crystals can also instantaneously shrink back to their original sizes. These findings provide a benchmark for understanding the exfoliating layered materials. PMID:23535653

  1. International Scientific Conference on "Radiation-Thermal Effects and Processes in Inorganic Materials"

    NASA Astrophysics Data System (ADS)

    2015-04-01

    The International Scientific Conference on "Radiation-Thermal Effects and Processes in Inorganic Materials" is a traditional representative forum devoted to the discussion of fundamental problems of radiation physics and its technical applications. The first nine conferences were held four times in Tomsk, then in Ulan-Ude (Russia), Bishkek (Kyrgyzstan), Tashkent (Uzbekistan), Sharm El Sheikh (Egypt), and the island of Cyprus. The tenth conference was held in Tomsk, Russia. The program of the Conference covers a wide range of technical areas and modern aspects of radiation physics, its applications and related matters. Topics of interest include, but are not limited to: • Physical and chemical phenomena in inorganic materials in radiation, electrical and thermal fields; • Research methods and equipment modification states and properties of materials; • Technologies and equipment for their implementation; • The use of radiation-thermal processes in nanotechnology; • Adjacent to the main theme of the conference issues The conference was attended by leading scientists from countries near and far abroad who work in the field of radiation physics of solid state and of radiation material science. The School-Conference of Young Scientists was held during the conference. The event was held with the financial support of the Russian Foundation for Basic Research, projects No. 14-38-10210 and No. 14-02-20376.

  2. Biomineralization of unicellular organisms: an unusual membrane biochemistry for the production of inorganic nano- and microstructures.

    PubMed

    Bäuerlein, Edmund

    2003-02-10

    With evolution, Nature has ingeniously succeeded in giving rise to an impressive variety of inorganic structures. Every organism that synthesizes biogenic minerals does so in a form that is unique to that species. This biomineralization is apparently biologically controlled. It is thus expected that both the synthesis and the form of every specific biogenic mineral is genetically determined and controlled. An investigation of the mechanism of biomineralization has only become possible with the development of modern methods in molecular biology. Unicellular organisms such as magnetic bacteria, calcareous algae, and diatoms, all of which are amongst the simplest forms of life, are particularly suited to be investigated by these methods. Crystals and composites of proteins and amorphous inorganic polymers are formed as complex structures within these organisms; these structures are not known in conventional inorganic chemistry.

  3. Development of new inorganic luminescent materials by organic-metal complex route

    NASA Astrophysics Data System (ADS)

    Manavbasi, Alp

    The development of novel inorganic luminescent materials has provided important improvements in lighting, display, and other technologically-important optical devices. The optical characteristics of inorganic luminescent materials (phosphors) depend on their physicochemical characteristics, including the atomic structure, homogeneity in composition, microstructure, defects, and interfaces which are all controlled by thermodynamics and kinetics of synthesis from various raw materials. A large variety of technologically-important phosphors have been produced using conventional high-temperature solid-state methods. For the synthesis of functional ceramic materials with ionic dopants in a host lattice, (such as phosphors), synthesis using organic-metal complex methods and other wet chemistry routes have been found to be excellent techniques. These methods have inherent advantages such as good control of stoichiometry by molecular level of mixing, product homogeneity, simpler synthesis procedures, and use of relatively-low calcination temperatures. Supporting evidence for this claim is accomplished by a comparison of photoluminescence characteristics of a commercially available green phosphor, Zn2SiO4:Mn, with the same material system synthesized by organic-metal synthesis route. In this study, new inorganic luminescent materials were produced using rare-earth elements (Eu3+, Ce3+, Tb3+ ) and transition metals (Cu+, Pb2+) as dopants within the crystalline host lattices; SrZnO2, Ba2YAlO 5, M3Al2O6 (M=Ca,Sr,Ba). These novel phosphors were prepared using the organic-metal complex route. Polyvinyl alcohol, sucrose, and adipic acid were used as the organic component to prepare the ceramic precursors. Materials characterization of the synthesized precursor powders and calcined phosphor samples was performed usingX-Ray Diffraction, Scanning Electron Microscopy, Photon-Correlation spectroscopy, and Fourier Transform Infrared Spectroscopy techniques. In addition to the

  4. A brief review on graphene/inorganic nanostructure composites: materials for the future

    NASA Astrophysics Data System (ADS)

    Mitra, S.; Banerjee, S.; Datta, A.; Chakravorty, D.

    2016-09-01

    The exotic physical properties of graphene have led to intense research activities on the synthesis and characterization of graphene composites during the last decade. The methods developed for preparation of such materials and the different application areas are reviewed. Mainly the inorganic nanostructure/graphene composites have been discussed. The techniques of ex-situ and in-situ hybridization respectively, have been pointed out. Some of the application areas such as batteries, ultracapacitors for energy storage, fuel cells and solar cells for energy generation are discussed. The possible future directions of research are highlighted.

  5. Development of inorganic composite material based TiO2 for environmental application

    NASA Astrophysics Data System (ADS)

    Wahyuningsih, Sayekti; Handono Ramelan, Ari; Pramono, Edi; Purnawan, Candra; Anjani, Velina; Estianingsih, Puji; Rinawati, Ludfiaastu; Fadli, Khusnan

    2016-02-01

    Syntheses of various materials, for green energy nanotechnology applications have special attention to develop emerging areas, such as environmental as well as energy materials. Various approaches for preparing nanostructured photocatalysts, such as titanium dioxide, nickel oxide, lead oxide and their composites, was introduced. The use of nanomaterials as photocatalysts water detoxification by visible light photocatalyst of an inorganic composite as well as dye-sensitized photoreduction was also discussed. The enhancement of selective photocatalyst system was gain by the use of photocatalyst composite materials and applied potential bias on the system. The photoelectrocatalytic degradation of rhodamine B (RB) and Remazol Yellow FG (RY) as water contaminant using the thin film of modified TiO2 as the electrode was investigated via a series of potentials, and various pH. The result showed that the anodic potential bias influenced the degradation rate of water contaminant and exhibited better performance by the positive anodic bias was applied. The pH conditions influence the active dye structure whereas it will interact with inorganic semiconductor photocatalyst. Using dye- sensitized TiO2 system (DSTs), we have applied this system to build water decolorization as a novelty environmental remediation system.

  6. In situ studies of a platform for metastable inorganic crystal growth and materials discovery

    PubMed Central

    Shoemaker, Daniel P.; Hu, Yung-Jin; Chung, Duck Young; Halder, Gregory J.; Chupas, Peter J.; Soderholm, L.; Mitchell, J. F.; Kanatzidis, Mercouri G.

    2014-01-01

    Rapid shifts in the energy, technological, and environmental demands of materials science call for focused and efficient expansion of the library of functional inorganic compounds. To achieve the requisite efficiency, we need a materials discovery and optimization paradigm that can rapidly reveal all possible compounds for a given reaction and composition space. Here we provide such a paradigm via in situ X-ray diffraction measurements spanning solid, liquid flux, and recrystallization processes. We identify four new ternary sulfides from reactive salt fluxes in a matter of hours, simultaneously revealing routes for ex situ synthesis and crystal growth. Changing the flux chemistry, here accomplished by increasing sulfur content, permits comparison of the allowable crystalline building blocks in each reaction space. The speed and structural information inherent to this method of in situ synthesis provide an experimental complement to computational efforts to predict new compounds and uncover routes to targeted materials by design. PMID:25024201

  7. A new material concept for the red cell membrane.

    PubMed

    Evans, E A

    1973-09-01

    The proposition is made that the red cell membrane is a two-dimensional, incompressible material and a general stress-strain law is developed for finite deformations. In the linear form, the character of such a material is analogous to a two-dimensional Mooney material (e.g., rubber), indicating that the molecular structure in the plane of the membrane would consist of long chains, randomly kinked and cross-linked in the natural state. The loose network could be provided by the protein component and the lipid phase could exist interstitially as a liquid bilayer, giving the membrane its two-dimensional incompressibility. The material provides the capability of large deformations exhibited by the discocyte and yet the rigidity associated with the osmotic spherocyte state. It is demonstrated that a membrane of this type can form a sphere at constant area. An illustrative example of the application to single cell discocyte-to-osmotic spherocyte transformations is presented.

  8. Gas permeability of ENR/PVC membrane with the addition of inorganic fillers

    NASA Astrophysics Data System (ADS)

    Nor, Farhan Mohd; Abdullah, Ibrahim; Othaman, Rizafizah

    2013-11-01

    Epoxidized natural rubber (ENR) was blended with polyvinyl chloride to form a flexible and porous membrane. SiO2 and MgO were added into the membrane for pore formation and the effects of the addition was investigated by means of FTIR, TGA, SEM, EDX and gas permeability towards CO2 and N2 gases. FTIR result showed the presence of Si-O-Si asymmetric stretching at the absorption peak of 467 cm-1 for ENR/PVC/SiO2 membrane and MgO signature peak at 3700 cm-1 for ENR/PVC/MgO membrane. Thermal analysis showed that the thermal stability of ENR/PVC membrane increased with the addition of fillers. Morphological studies prove that subsequently, the pores in the membranes increased showing that some of the added fillers were drawn towards the water leaving empty spaces and tracks. The remaining fillers are homogenously distributed on the surface of the membranes. CO2 and N2 gas permeability increased with increasing filler content and the permeability of ENR/PVC/SiO2 membranes towards CO2 and N2 gasses was higher than ENR/PVC/MgO membranes.

  9. Polymer/inorganic nanocomposites with tailored hierarchical structure as advanced dielectric materials

    SciTech Connect

    Manias, Evangelos; Randall, Clive; Tomer, Vivek; Polyzos, Georgios

    2012-01-01

    Most advances and commercial successes of polymer/inorganic nanocomposites rely only on the dispersion of nanoparticles in a polymer matrix. Such approaches leave untapped opportunities where performance can be improved by controlling the larger length-scale structures. Here, we review selected examples where the hierarchical structure (from millimeter to nanometer) is tailored to control the transport properties of the materials, giving rise to marked property enhancements, relevant to dielectric materials for power capacitors. These examples address composite structures that are self-assembled, both at the nm and the micron scales, and, thus, can be produced using standard industrial practices. Specifically, polyethylene (PE) blends or poly(vinylidene fluoride) (PVDF) copolymers are reinforced with nanofillers; these composites are designed with high filler orientation, which yielded marked improvements in electric-field breakdown strength and, consequently, large improvements in their recoverable energy densities.

  10. Photochromic organic-inorganic composite materials prepared by sol-gel processing: properties and potentials

    NASA Astrophysics Data System (ADS)

    Hou, Lisong; Mennig, Martin; Schmidt, Helmut K.

    1994-09-01

    The sol-gel method which features a low-temperature wet-chemical process opens vast possibilities to incorporating organic dyes into solid matrices for various optical applications. In this paper we present our experimental results on the sol-gel derived photochromic organic- inorganic composite (Ormocer) materials following an introductory description of the sol-gel process and a brief review on the state of the art of the photochromic solids prepared using this method. Our photochromic spirooxazine-Ormocer gels and coatings possess better photochromic response and color-change speed than the corresponding photochromic polymer coatings and similar photochemical stability to the latter. Further developments are proposed as to tackle the temperature dependence problem and further tap the potentialities of the photochromic dye-Ormocer material for practical applications.

  11. Functionalization of linen/cotton pigment prints using inorganic nano structure materials.

    PubMed

    Ibahim, N A; Eid, B M; Abd El-Aziz, E; Abou Elmaaty, T M

    2013-09-12

    The present work opens up a novel strategy for the development of new multifunctional cellulosic pigment prints. The developed process aims at modifying the solvent-free pigment printing formulations via inclusion of certain inorganic nano materials namely silver (Ag-NPs), zinc oxide (ZnO-NPs), zirconium oxide (ZrO₂-NPs) or titanium dioxide (TiO₂-NPs) at 20 g/kg paste followed by screen printing and microwave fixation. The imparted functional properties together with the depth of the obtained prints are governed by the type of nano additives, type of binder and the pigment colorant. The imparted antibacterial and/or UV protection properties to the pigment prints were retained with an acceptable level (>70%) of durability even after 20 washing cycles. The presence of nano materials on the surface of the obtained pigment prints was confirmed using SEM images and EDX spectra.

  12. High Velocity Impact Interaction of Metal Particles with Porous Heterogeneous Materials with an Inorganic Matrix

    NASA Astrophysics Data System (ADS)

    Glazunov, A. A.; Ishchenko, A. N.; Afanasyeva, S. A.; Belov, N. N.; Burkin, V. V.; Rogaev, K. S.; Tabachenko, A. N.; Khabibulin, M. V.; Yugov, N. T.

    2016-03-01

    A computational-experimental investigation of stress-strain state and fracture of a porous heterogeneous material with an inorganic matrix, used as a thermal barrier coating of flying vehicles, under conditions of a high-velocity impact by a spherical steel projectile imitating a meteorite particle is discussed. Ballistic tests are performed at the velocities about 2.5 km/s. Numerical modeling of the high-velocity impact is described within the framework of a porous elastoplastic model including fracture and different phase states of the materials. The calculations are performed using the Euler and Lagrange numerical techniques for the velocities up to 10 km/s in a complete-space problem statement.

  13. Inorganic/organic doped carbon aerogels as biosensing materials for the detection of hydrogen peroxide.

    PubMed

    Dong, Sheying; Li, Nan; Suo, Gaochao; Huang, Tinglin

    2013-12-17

    In this article, three different inorganic/organic doped carbon aerogel (CA) materials (Ni-CA, Pd-CA, and Ppy-CA) were, respectively, mixed with ionic liquid (IL) to form three stable composite films, which were used as enhanced elements for an integrated sensing platform to increase the surface area and to improve the electronic transmission rate. Subsequently, the effect of the materials performances such as adsorption, specific surface area and conductivity on electrochemistry for myoglobin (Mb) was discussed using N2 adsorption-desorption isotherm measurements, scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). Moreover, they could act as sensors toward the detection of hydrogen peroxide (H2O2) with lower detection limits (1.68 μM, 1.02 μM, and 0.85 μM, for Ni-CA/IL/Mb-CPE, Pd-CA/IL/Mb-CPE, and Ppy-CA/IL/Mb-CPE, respectively) and smaller apparent Michaelis-Menten constants KM. The results indicated that the electroconductibility of the doped CA materials would become dominant, thus playing an important role in facilitating the electron transfer. Meanwhile, the synergetic effect with [BMIm]BF4 IL improved the capability of the composite inorganic/organic doped CA/IL matrix for protein immobilization. This work demonstrates the feasibility and the potential of a series of CA-based hybrid materials as biosensors, and further research and development are required to prepare other functional CAs and make them valuable for more extensive application in biosensing.

  14. Homogeneity study of a corn flour laboratory reference material candidate for inorganic analysis.

    PubMed

    Dos Santos, Ana Maria Pinto; Dos Santos, Liz Oliveira; Brandao, Geovani Cardoso; Leao, Danilo Junqueira; Bernedo, Alfredo Victor Bellido; Lopes, Ricardo Tadeu; Lemos, Valfredo Azevedo

    2015-07-01

    In this work, a homogeneity study of a corn flour reference material candidate for inorganic analysis is presented. Seven kilograms of corn flour were used to prepare the material, which was distributed among 100 bottles. The elements Ca, K, Mg, P, Zn, Cu, Fe, Mn and Mo were quantified by inductively coupled plasma optical emission spectrometry (ICP OES) after acid digestion procedure. The method accuracy was confirmed by analyzing the rice flour certified reference material, NIST 1568a. All results were evaluated by analysis of variance (ANOVA) and principal component analysis (PCA). In the study, a sample mass of 400mg was established as the minimum mass required for analysis, according to the PCA. The between-bottle test was performed by analyzing 9 bottles of the material. Subsamples of a single bottle were analyzed for the within-bottle test. No significant differences were observed for the results obtained through the application of both statistical methods. This fact demonstrates that the material is homogeneous for use as a laboratory reference material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Selective crystallization with preferred lithium-ion storage capability of inorganic materials

    PubMed Central

    2012-01-01

    Lithium-ion batteries are supposed to be a key method to make a more efficient use of energy. In the past decade, nanostructured electrode materials have been extensively studied and have presented the opportunity to achieve superior performance for the next-generation batteries which require higher energy and power densities and longer cycle life. In this article, we reviewed recent research activities on selective crystallization of inorganic materials into nanostructured electrodes for lithium-ion batteries and discuss how selective crystallization can improve the electrode performance of materials; for example, selective exposure of surfaces normal to the ionic diffusion paths can greatly enhance the ion conductivity of insertion-type materials; crystallization of alloying-type materials into nanowire arrays has proven to be a good solution to the electrode pulverization problem; and constructing conversion-type materials into hollow structures is an effective approach to buffer the volume variation during cycling. The major goal of this review is to demonstrate the importance of crystallization in energy storage applications. PMID:22353373

  16. Selective crystallization with preferred lithium-ion storage capability of inorganic materials.

    PubMed

    Liu, Fei; Song, Shuyan; Xue, Dongfeng; Zhang, Hongjie

    2012-02-21

    Lithium-ion batteries are supposed to be a key method to make a more efficient use of energy. In the past decade, nanostructured electrode materials have been extensively studied and have presented the opportunity to achieve superior performance for the next-generation batteries which require higher energy and power densities and longer cycle life. In this article, we reviewed recent research activities on selective crystallization of inorganic materials into nanostructured electrodes for lithium-ion batteries and discuss how selective crystallization can improve the electrode performance of materials; for example, selective exposure of surfaces normal to the ionic diffusion paths can greatly enhance the ion conductivity of insertion-type materials; crystallization of alloying-type materials into nanowire arrays has proven to be a good solution to the electrode pulverization problem; and constructing conversion-type materials into hollow structures is an effective approach to buffer the volume variation during cycling. The major goal of this review is to demonstrate the importance of crystallization in energy storage applications.

  17. Ultrathin two-dimensional inorganic materials: new opportunities for solid state nanochemistry.

    PubMed

    Sun, Yongfu; Gao, Shan; Lei, Fengcai; Xiao, Chong; Xie, Yi

    2015-01-20

    CONSPECTUS: The ultimate goal of solid state chemistry is to gain a clear correlation between atomic, defect, and electronic structure and intrinsic properties of solid state materials. Solid materials can generally be classified as amorphous, quasicrystalline, and crystalline based on their atomic arrangement, in which crystalline materials can be further divided into single crystals, microcrystals, and nanocrystals. Conventional solid state chemistry mainly focuses on studying single crystals and microcrystals, while recently nanocrystals have become a hot research topic in the field of solid state chemistry. As more and more nanocrystalline materials have been artificially fabricated, the solid state chemistry for studying those nanosolids has become a new subdiscipline: solid state nanochemistry. However, solid state nanochemistry, usually called "nanochemistry" for short, primarily studies the microstructures and macroscopic properties of a nanomaterial's aggregation states. Due to abundant microstructures in the aggregation states, it is only possible to build a simple but imprecise correlation between the microscopic morphology and the macroscopic properties of the nanostructures. Notably, atomically thin two-dimensional inorganic materials provide an ideal platform to establish clear structure-property relationships in the field of solid state nanochemistry, thanks to their homogeneous dispersion without the assistance of a capping ligand. In addition, their atomic structures including coordination number, bond length, and disorder degree of the examined atoms can be clearly disclosed by X-ray absorption fine structure spectroscopy. Also, their more exposed interior atoms would inevitably induce the formation of various defects, which would have a non-negligible effect on their physicochemical properties. Based on the obtained atomic and defect structural characteristics, density-functional calculations are performed to study their electronic structures

  18. Proton exchange membrane materials for the advancement of direct methanol fuel-cell technology

    DOEpatents

    Cornelius, Christopher J.

    2006-04-04

    A new class of hybrid organic-inorganic materials, and methods of synthesis, that can be used as a proton exchange membrane in a direct methanol fuel cell. In contrast with Nafion.RTM. PEM materials, which have random sulfonation, the new class of materials have ordered sulfonation achieved through self-assembly of alternating polyimide segments of different molecular weights comprising, for example, highly sulfonated hydrophilic PDA-DASA polyimide segment alternating with an unsulfonated hydrophobic 6FDA-DAS polyimide segment. An inorganic phase, e.g., 0.5 5 wt % TEOS, can be incorporated in the sulfonated polyimide copolymer to further improve its properties. The new materials exhibit reduced swelling when exposed to water, increased thermal stability, and decreased O.sub.2 and H.sub.2 gas permeability, while retaining proton conductivities similar to Nafion.RTM.. These improved properties may allow direct methanol fuel cells to operate at higher temperatures and with higher efficiencies due to reduced methanol crossover.

  19. Laser vibrometry for investigation of tympanic membrane implant materials

    NASA Astrophysics Data System (ADS)

    Zahnert, Thomas; Kuster, Manfred; Vogel, Uwe; Hofmann, Gert; Huettenbrink, Karl-Bernd

    1996-12-01

    The human tympanic membrane has reasonably good sound sensing properties. A destroyed tympanic membrane due to middle ear diseases or traumata may be repaired by different types of grafts. Middle ear surgery mostly uses autologous temporal fascia, cartilage, or cartilage perichondrium transplants. We have investigated the acoustical and mechanical properties of these materials and compared them with human tympanic membrane by constructing an ear canal model completed by an artificial tympanic membrane. Circular stretched human fascia, perichondrium, and cartilage preparations were exposed to static pressures up to 4 kPa and white noise sound pressure levels of 70 dB. The vibrational amplitudes and displacements due to static pressure of the graft material were measured by laser Doppler vibrometry and compared. The thin materials temporal fascia and perichondrium show similar amplitude frequency responses compared to the tympanic membrane for dynamic excitation. The displacement of these materials at static pressures above 4 kPA yields a higher compliance than tympanic membrane. The acoustical and mechanical properties of cartilage transplants change with the thickness of the slices. However, the thinner the cartilage slice combined with lower stability, the more similar is the frequency response with the intact tympanic membrane. The vibration amplitudes decrease more and more for layer thicknesses above 500 micrometers. Cartilage acts as an excellent transplant material which provides a better prognosis than different materials in cases of ventilation disorders with long-term middle ear pressure changes. Large cartilage slice transplants should not exceed layer thicknesses of 500 micrometer in order to prevent drawbacks to the transfer characteristics of the tympanic membrane.

  20. Inorganic compounds for passive solar energy storage: Solid-state dehydration materials and high specific heat materials

    NASA Astrophysics Data System (ADS)

    Struble, L. J.; Brown, P. W.

    1986-04-01

    Two classes of hydrated inorganic salts have been studied to assess their potential as materials for passive solar energy storage. The materials are part of the quaternary system CaO-Al2O3-SO3-H2O and related chemical systems, and the two classes are typified by ettringite, a trisubstituted salt, and Friedel's salt, a monosubstituted salt. The trisubstituted salts were studied for their possible application in latent heat storage, utilizing a low-temperature dehydration reaction, and both classes were studies for their application in sensible heat storage. In order to assess their potential for energy storage, the salts have been synthesized, characterized by several analytical techniques, and thermal properties measured. The dehydration data of that the trisubstituted salts vary somewhat with chemical composition, with the temperature of the onset of dehydration ranging from 6(0)C to 33(0)C, and enthalpy changes on dehydration ranging from 60 to 200 cal/g. Heat capacity is less variable with composition; values for the trisubstituted phases are 30 cal/g/(0)C and for the monosubstituted phases between 0.23 and 0.28 cal/g/(0)C. Preliminary experiments indicate that the dehydration is reversible, and suggest that the materials might have additional potential as solar desiccant materials. These thermal data demonstrate the trisubstituted salts have potential as latent heat storage materials, and that both classes of salts have potential as sensible heat storage materials.

  1. Relationship Between Interfacial Strength and Materials Properties in Hybrid Organic/Inorganic Nanomaterials

    NASA Astrophysics Data System (ADS)

    Snyder, Chad; Richardson, Mickey; Zhou, Jing; Holmes, Gale; Karim, Alamgir; D'Souza, Nandika

    2008-03-01

    Thermal interface materials (TIM's) are critical to the semiconductor electronics industry for heat dissipation, a potential show-stopper for future technology nodes. Essentially, an epoxy nanocomposite, TIMs suffer from a series of typical nanocomposite limitations including heat conduction in nanoscale inclusions, nanoparticle dispersion, void formation with thermal cycling, and interfacial resistance between the matrix and filler. It is postulated that the interfacial adhesion between the matrix and nanofiller is at the root cause of many of these difficulties, however, few techniques exist to characterize this critical property. Compounding this are the overall difficulties associated with characterizing these materials in their ultimate applications, i.e., thin films. To this end, a novel series of organic/inorganic hybrid nanostructured materials based on layered double hydroxides in epoxy matrices were designed as a test bed to develop the measurement techniques needed to elucidate the relationship between the material structure and dynamics and the ultimate materials properties. Initial results are presented based on characterization by mechanical, dielectric, and thermal spectroscopies.

  2. Medical applications of organic-inorganic hybrid materials within the field of silica-based bioceramics.

    PubMed

    Vallet-Regí, María; Colilla, Montserrat; González, Blanca

    2011-02-01

    Research on bioceramics has evolved from the use of inert materials for mere substitution of living tissues towards the development of third-generation bioceramics aimed at inducing bone tissue regeneration. Within this context hybrid bioceramics have remarkable features resulting from the synergistic combination of both inorganic and organic components that make them suitable for a wide range of medical applications. Certain bioceramics, such as ordered mesoporous silicas, can exhibit different kind of interaction with organic molecules to develop different functions. The weak interaction of these host matrixes with drug molecules confined in the mesoporous channels allows these hybrid systems to be used as controlled delivery devices. Moreover, mesoporous silicas can be used to fabricate three (3D)-dimensional scaffolds for bone tissue engineering. In this last case, different osteoinductive agents (peptides, hormones and growth factors) can be strongly grafted to the bioceramic matrix to act as attracting signals for bone cells to promote bone regeneration process. Finally, recent research examples of organic-inorganic hybrid bioceramics, such as stimuli-responsive drug delivery systems and nanosystems for targeting of cancer cells and gene transfection, are also tackled in this tutorial review (64 references).

  3. Review insights into the interactions of amino acids and peptides with inorganic materials using single molecule force spectroscopy.

    PubMed

    Das, Priyadip; Reches, Meital

    2015-09-01

    Understanding the interactions between proteins and inorganic surfaces is important for the development of new biomaterials and implants as they interface with the immune response by proteins. In addition, the adsorption of proteins to inorganic surfaces leads to the formation of a conditioning layer that facilitates bacterial attachments and biofilm formation. As biofilm provides bacterial resistance to antibiotics, biofilm formation is an undesirable process that could be prevented by resisting protein interactions with the substrate. Moreover, the interaction between proteins and inorganic materials is the basis for the formation of composite materials in nature. Understanding the underlying forces that governs these interactions would lead to the design of new and unique composite materials in vitro. This review focuses on the insights gained using single-molecule force spectroscopy by AFM on these interactions. This tool provides molecular information, at the single molecule level, on the interaction between a molecule on the AFM tip and a substrate.

  4. Inorganic fouling of an anaerobic membrane bioreactor treating leachate from the organic fraction of municipal solid waste (OFMSW) and a polishing aerobic membrane bioreactor.

    PubMed

    Trzcinski, Antoine P; Stuckey, David C

    2016-03-01

    The treatment of leachate (Average TCOD=11.97 g/L, 14.4% soluble) from the organic fraction of municipal solid waste was investigated using a Submerged Anaerobic Membrane BioReactor (SAMBR), followed by an aerobic membrane bioreactor (AMBR) to polish this effluent. This paper investigated the exact nature and composition of the inorganic precipitate in each of the reactors in the process. The flux decreased due to precipitation of calcium as monohydrocalcite (CaCO3·H2O) containing traces of metals onto the SAMBR membrane because of high CO2 partial pressures. Precipitation of calcium in the AMBR was also observed due to a higher pH. In this case, phosphorus also precipitated with calcium in two different phases: the background layer contained calcium, oxygen, carbon and small amounts of phosphorus (2-6.7%), while flakes containing calcium, oxygen and higher amounts of phosphorus (10-17%) were probably hydroxyapatite (Ca5(PO4)3OH). Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Synthesis of organic-inorganic hybrid azobenzene materials for the preparation of nanofibers by electrospinning

    NASA Astrophysics Data System (ADS)

    Bućko, Aleksandra; Zielińska, Sonia; Ortyl, Ewelina; Larkowska, Maria; Barille, Regis

    2014-12-01

    The new photochromic hybrid materials containing different mole fractions of highly photoactive 4-[(E)-[4-[ethyl(2-hydroxyethyl)amino]phenyl]azo]-N-(4-methylpyrimidin-2-yl)benzenesulfonamide (SMERe) were prepared by a low temperature sol-gel process. The guest-host systems with triethoxyphenylsilane matrix were obtained. These materials were used to form thin transparent films by a spin-coating technique. Then the ability of thin hybrid films to reversible trans-cis photoisomerization under illumination was investigated using ellipsometry and UV-Vis spectroscopy. The reversible changes of refractive index of the films under illumination were in the range of 0.005-0.056. The maximum absorption of these materials was located at 462-486 nm. Moreover, the organic-inorganic azobenzene materials were used to form nanofibers by electrospinning using various parameters of the process. The microstructure of electrospun fibers depended on sols properties (e.g. concentration and viscosity of the sols) and process conditions (e.g. the applied voltage, temperature or type of the collector) at ambient conditions. The morphology of obtained nanofibers was analyzed by an optical microscopy and scanning electron microscopy. In most instances, the beadless fibers were obtained. The wettability of the surface of electrospun fibers deposited on glass substrates was investigated.

  6. Molecular sieving silica membrane fabrication process

    DOEpatents

    Raman, Narayan K.; Brinker, Charles Jeffrey

    1998-01-01

    A process for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film.

  7. Molecular sieving silica membrane fabrication process

    DOEpatents

    Raman, Narayan K.; Brinker, Charles Jeffrey

    1999-01-01

    A process for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film.

  8. Molecular sieving silica membrane fabrication process

    DOEpatents

    Raman, N.K.; Brinker, C.J.

    1999-08-10

    A process is described for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film. 11 figs.

  9. Use of a biomimetic chromatographic stationary phase for study of the interactions occurring between inorganic anions and phosphatidylcholine membranes.

    PubMed Central

    Hu, Wenzhi; Haddad, Paul R; Hasebe, Kiyoshi; Mori, Masanobu; Tanaka, Kazuhiko; Ohno, Masako; Kamo, Naoki

    2002-01-01

    A liquid chromatographic method for the study of ion-membrane interactions is reported. A phosphatidylcholine biomimetic stationary phase was established by loading dimyristoylphosphatidylcholine (DMPC) onto a reversed-phase octadecylsilica packed column. This column was then used to study the interaction of some inorganic anions with the stationary phase by UV and conductivity detection. Ten inorganic anions were selected as model ions and were analyzed with the proposed chromatographic system. Anion-DMPC interactions of differing magnitudes were observed for all of the model anions. Perchlorate-DMPC interactions were strongest, followed by thiocyanate-DMPC, iodide-DMPC, chlorate-DMPC, nitrate-DMPC, bromide-DMPC, chloride-DMPC, fluoride-DMPC, and then sulfate-DMPC. Cations in the eluent, especially H(+) ions and divalent cations such as Ca(2+), showed strong effects on anion-DMPC interactions. The chromatographic data suggest that DMPC interacts with both the anions and the cations. Anion-DMPC interactions were dependent on the surface potential of the stationary phase: at low surface potentials anion-DMPC interactions were predominantly solvation dependent in nature whereas at more positive surface potentials anion-DMPC interactions were predominantly electrostatic in nature. Cation-DMPC interactions served to raise the surface potential, causing the anion-DMPC interactions to vary from solvation dependent to electrostatic. The chromatographic data were used to provide quantitative estimates of the enthalpies of the anion-DMPC interactions. PMID:12496102

  10. Inorganic materials acting as heterogeneous photocatalysts and catalysts in the same reactions.

    PubMed

    Palmisano, L; García-López, E I; Marcì, G

    2016-08-07

    General considerations on the differences and similarities between heterogeneous photocatalysis and thermal catalysis are presented. Some research papers are reviewed where a reaction has been carried out in the presence of an inorganic material used both as catalyst and photocatalyst. The existing literature often compares catalytic reactions undertaken with the contemporaneous presence of radiation, showing only that photocatalytic reactions can occur under milder experimental conditions and at much lower temperatures. Nevertheless, differences in mechanistic aspects, conversions and selectivities between catalytic and photocatalytic reactions should also be highlighted. These are due to various reasons, relating to the effects of the interaction of light with the solid surface, adsorption-desorption of species involved in the (photo)reactions, and activation energy.

  11. Ultrathin Cu2O as an efficient inorganic hole transporting material for perovskite solar cells.

    PubMed

    Yu, Weili; Li, Feng; Wang, Hong; Alarousu, Erkki; Chen, Yin; Lin, Bin; Wang, Lingfei; Hedhili, Mohamed Nejib; Li, Yangyang; Wu, Kewei; Wang, Xianbin; Mohammed, Omar F; Wu, Tom

    2016-03-21

    We demonstrate that ultrathin P-type Cu2O thin films fabricated by a facile thermal oxidation method can serve as a promising hole-transporting material in perovskite solar cells. Following a two-step method, inorganic-organic hybrid perovskite solar cells were fabricated and a power conversion efficiency of 11.0% was achieved. We found that the thickness and properties of Cu2O layers must be precisely tuned in order to achieve the optimal solar cell performance. The good performance of such perovskite solar cells can be attributed to the unique properties of ultrathin Cu2O, including high hole mobility, good energy level alignment with CH3NH3PbI3, and longer lifetime of photo-excited carriers. Combining the merits of low cost, facile synthesis, and high device performance, ultrathin Cu2O films fabricated via thermal oxidation hold promise for facilitating the developments of industrial-scale perovskite solar cells.

  12. Rapid Analysis of Inorganic Species in Herbaceous Materials Using Laser-Induced Breakdown Spectroscopy.

    PubMed

    Westover, Tyler L; Emerson, Rachel M

    2015-12-01

    Inorganic compounds in biomass, often referred to as ash, are known to be problematic in the thermochemical conversion of biomass to bio-oil or syngas and, ultimately, hydrocarbon fuels because they negatively influence reaction pathways, contribute to fouling and corrosion, poison catalysts, and impact waste streams. The most common ash-analysis methods, such as inductively coupled plasma-optical emission spectrometry/mass spectrometry (ICP-OES/MS), require considerable time and expensive reagents. Laser-induced breakdown spectroscopy (LIBS) is emerging as a technique for rapid analysis of the inorganic constituents in a wide range of biomass materials. This study compares analytical results using LIBS data to results obtained from three separate ICP-OES/MS methods for 12 samples, including six standard reference materials. Analyzed elements include aluminum, calcium, iron, magnesium, manganese, phosphorus, potassium, sodium, and silicon, and results show that concentrations can be measured with an uncertainty of approximately 100 parts per million using univariate calibration models and relatively few calibration samples. These results indicate that the accuracy of LIBS is comparable to that of ICP-OES methods and indicate that some acid-digestion methods for ICP-OES may not be reliable for Na and Al. These results also demonstrate that germanium can be used as an internal standard to improve the reliability and accuracy of measuring many elements of interest, and that LIBS can be used for rapid determination of total ash in biomass samples. Key benefits of LIBS include little sample preparation, no reagent consumption, and the generation of meaningful analytical data instantaneously.

  13. Rapid Analysis of Inorganic Species in Herbaceous Materials Using Laser-Induced Breakdown Spectroscopy

    PubMed Central

    Emerson, Rachel M.

    2015-01-01

    Abstract Inorganic compounds in biomass, often referred to as ash, are known to be problematic in the thermochemical conversion of biomass to bio-oil or syngas and, ultimately, hydrocarbon fuels because they negatively influence reaction pathways, contribute to fouling and corrosion, poison catalysts, and impact waste streams. The most common ash-analysis methods, such as inductively coupled plasma-optical emission spectrometry/mass spectrometry (ICP-OES/MS), require considerable time and expensive reagents. Laser-induced breakdown spectroscopy (LIBS) is emerging as a technique for rapid analysis of the inorganic constituents in a wide range of biomass materials. This study compares analytical results using LIBS data to results obtained from three separate ICP-OES/MS methods for 12 samples, including six standard reference materials. Analyzed elements include aluminum, calcium, iron, magnesium, manganese, phosphorus, potassium, sodium, and silicon, and results show that concentrations can be measured with an uncertainty of approximately 100 parts per million using univariate calibration models and relatively few calibration samples. These results indicate that the accuracy of LIBS is comparable to that of ICP-OES methods and indicate that some acid-digestion methods for ICP-OES may not be reliable for Na and Al. These results also demonstrate that germanium can be used as an internal standard to improve the reliability and accuracy of measuring many elements of interest, and that LIBS can be used for rapid determination of total ash in biomass samples. Key benefits of LIBS include little sample preparation, no reagent consumption, and the generation of meaningful analytical data instantaneously. PMID:26733765

  14. Efficient desulfurization by polymer-inorganic nanocomposite membranes fabricated in reverse microemulsion.

    PubMed

    Li, Ben; Yu, Shengnan; Jiang, Zhongyi; Liu, Wanpeng; Cao, Ruijian; Wu, Hong

    2012-04-15

    The sulfur in gasoline will convert to SO(2) after combustion under high temperature, which adversely affects human health and the environment. Membrane technique in particular pervaporation offers a number of potential advantages over conventional FCC gasoline desulfurization processes. The present study focuses on the performance enhancement of PDMS membrane by incorporating silica nanoparticles. Specifically, silica nanoparticles formed by the catalysis and templating of protamine in w/o reverse microemulsion are in situ embedded into PDMS bulk matrix, endowing the resultant oleophilic nanocomposite membranes with appropriate free volume properties and superior separation performance. Through the rational manipulation of biomimetic mineralization at water-oil interface, silica particles with uniform size are acquired. Following this protocol, by introducing organic PDMS oligomers into the oil phase, PDMS-SiO(2) nanocomposite membranes are prepared in a facile way. The resultant nanocomposite membranes display superior permeability and permselectivity in the pervaporative desulfurization using thiophene/n-octane binary mixture as model gasoline, for example, under the condition of 500 ppm sulfur in feed (40 L/h) at 30°C, an enrichment factor of 4.83-5.82 with a normalized permeation rate of 6.61-10.76 × 10(-5)kgm/m(2)h is acquired.

  15. Innovative Concepts Phase I: Inorganic Membranes for CO2/N2 Separation

    SciTech Connect

    William Desisto

    2003-09-23

    Silica membranes were prepared using a novel technique of catalyzed-atomic layer deposition of silica within a mesoporous matrix. Pyridine was used to catalyze the silicon chloride attachment to the hydroxylated silica surface at room temperature. This half-reaction was followed by the hydration of the surface with water regenerating surface hydroxyls and completing one reaction cycle. The technique resulted in the self-limited pore size reduction of the mesoporous matrix to pore sizes near 1 nm. The self-limited reaction was presumed to be the exclusion of the large catalyst molecule from the pore entrance. In addition to pore size reduction, viscous flow defects were repaired without significantly reducing overall porosity of the membrane. In addition, we investigated the ability of amine-functionalization to enhance the CO{sub 2} transport in silica membranes. Specifically, we examined three synthesis techniques for functionalizing silica membranes with amino groups that resulted in different surface chemistries of the silica membranes. These differences were correlated with changes in the CO{sub 2} facilitation characteristics. It was found that high loadings of amino groups where interaction with the silica surface was minimized promoted the highest CO{sub 2} transport.

  16. Synthesis and characterization of inorganic nanostructured materials for advanced energy storage

    NASA Astrophysics Data System (ADS)

    Xie, Jin

    to the challenges. The understanding of the synergistic effect between electrolyte decomposition and electrode decomposition, nevertheless, is conspicuously lacking. To better understand the reaction chemistries in lithium oxygen batteries, I designed, synthesized, and studied heteronanostructure-based carbon-free inorganic electrodes, as well as carbon electrodes whose surfaces protected by metal oxide thin films. The new types of electrodes prove to be highly effective in minimizing parasitic reactions, reducing operation overpotentials and boosting battery lifetimes. The improved stability and well-defined electrode morphology also enabled detailed studies on the formation and decomposition of Li2O 2. To summarize, this dissertation presented the synthesis and characterization of inorganic nanostructured materials for advanced energy storage. On a practical level, the new types of materials allow for the immediate advancement of the energy storage technology. On a fundamental level, it helped to better understand reaction chemistries and fading mechanisms of battery electrodes.

  17. Synthesis of Inorganic-Organic Hybrid Materials Designed for Radiation Detection, Luminescence, and Gas Storage

    NASA Astrophysics Data System (ADS)

    Vaughn, Shae Anne

    Materials discovery is the driving force behind the research presented herein. Basic research has been conducted in order to obtain a better understanding of coordination chemistry and structural outcomes, particularly within the area of trivalent lanthanides. Discovering new materials is one route to further advancement of technology; another one is the focus on incremental changes to already existing materials. Often the building blocks of a compound are chosen in an effort to synthesize a material that makes use of the properties of each individual component and may result in a better, more robust, applicable material. The combination of organic and inorganic components for the synthesis of novel materials with potential applications such as scintillation photoluminescence, catalysis, and gas storage are the focus of the research presented herein. The first part focuses on lanthanide organic hybrid materials, where the synthesis of a new family of potential scintillating materials was undertaken and yielded improved understanding of the control that can be achieved over the topological structure of these materials by controlling the coordinating crystallization solvents. This research has led to the synthesis of an array of unique motifs, ranging from dimeric complexes, tetrameric complexes, to 1-D chains, and most intriguing of all, catenated tetradecanuclear rings. These rings represent the largest lanthanide rings synthesized to date, the next largest multinuclear rings, until now, were dodecanuclear complexes of alkoxides. From a basic research standpoint this is an exciting new development in lanthanide coordination chemistry and illustrates the importance of steric effects upon a system. These complexes are potential scintillators, supported by their luminescence and measurements of similar compounds that demonstrate surprising scintillation efficiencies. In the second part, other hybrid materials that have also been prepared are discussed, including the

  18. Structure and magnetic properties of SiO{sub 2}/PCL novel sol–gel organic–inorganic hybrid materials

    SciTech Connect

    Catauro, Michelina; Bollino, Flavia; Cristina Mozzati, Maria; Ferrara, Chiara; Mustarelli, Piercarlo

    2013-07-15

    Organic–inorganic nanocomposite materials have been synthesized via sol–gel. They consist of an inorganic SiO{sub 2} matrix, in which different percentages of poly(ε-caprolactone) (PCL) have been incorporated. The formation of H-bonds among the carbonyl groups of the polymer chains and Si–OH group of the inorganic matrix has been proved by means of Fourier transform infrared spectroscopy (FT-IR) analysis and has been confirmed by solid-state nuclear magnetic resonance (NMR). X-Ray diffraction (XRD) analysis highlighted the amorphous nature of the synthesized materials. Scanning electron microscope (SEM) micrograph and atomic force microscope (AFM) topography showed their homogeneous morphology and nanostructure nature. Considering the opportunity to synthesize these hybrid materials under microgravity conditions by means of magnetic levitation, superconducting quantum interference device (SQUID) magnetometry has been used to quantify their magnetic susceptibility. This measure has shown that the SiO{sub 2}/PCL hybrid materials are diamagnetic and that their diamagnetic susceptibility is independent of temperature and increases with the PCL amount. - Graphical abstract: Characterization and magnetic properties of SiO{sub 2}/PCL organic–inorganic hybrid materials synthesized via sol–gel. FT-IR, Fourier transform infrared spectroscopy; solid-state NMR: solid-state nuclear magnetic resonance; SQUID: superconducting quantum interference device. - Highlights: • Sol–gel synthesis of SiO{sub 2}/PCL amorphous class I organic–inorganic hybrid materials. • FT-IR and NMR analyses show the hydrogen bonds formation between SiO{sub 2} and PCL. • AFM and SEM analyses confirm that the SiO{sub 2}/PCL are homogenous hybrid materials. • The SQUID measures show that the simples are diamagnetic. • Diamagnetic susceptibility of SiO{sub 2}/PCL materials increases with the PCL amount.

  19. A novel organic/inorganic polymer membrane based on poly(vinyl alcohol)/poly(2-acrylamido-2-methyl-1-propanesulfonic acid/3-glycidyloxypropyl trimethoxysilane polymer electrolyte membrane for direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Yang, Chun-Chen; Lue, Shingjiang Jessie; Shih, Jeng-Ywan

    2011-05-01

    Poly(vinyl alcohol)/poly(2-acrylamido-2-methyl-1-propanesulfonic acid (PAMPS)/3-glycidyloxypropyl)trimethoxysilane (PVA/PAMPS/GPTMS) organic/inorganic proton-conducting polymer membranes are prepared by a solution casting method. PAMPS is a polymeric acid commonly used as a primary proton donor, while 3-(glycidyloxypropyl)trimethoxysilane (GPTMS) is an inorganic precursor forming a semi-interpenetrating network (SIPN). Varying amounts of sulfosuccinic acid (SSA) are used as the cross-linker and secondary proton source. The characteristic properties of PVA/PAMPS/GPTMS composite membranes are investigated by thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), micro-Raman spectroscopy and the AC impedance method. Direct methanol fuel cells (DMFCs) made of PVA/PAMPS/GPTMS composite membranes are assembled and examined. Experimental results indicate that DMFCs employing an inexpensive, non-perfluorinated, organic/inorganic SIPN membrane achieve good electrochemical performance. The highest peak power density of a DMFC using PVA/PAMPS/GPTMS composite membrane with 2 M CH3OH solution fuel at ambient temperature is 23.63 mW cm-2. The proposed organic/inorganic proton-conducting membrane based on PVA/PAMPS/GPTMS appears to be a viable candidate for future DMFC applications.

  20. An intuitive thermal-induced surface zwitterionization for versatile, well-controlled haemocompatible organic and inorganic materials.

    PubMed

    Sin, Mei-Chan; Lou, Pei-Tzu; Cho, Chia-He; Chinnathambi, Arunachalam; Alharbi, Sulaiman Ali; Chang, Yung

    2015-03-01

    In this study, a facile and effective strategy is presented for the preparation of a series of zwitterionic poly(sulfobetaine methacrylate) (pSBMA)-grafted organic and inorganic biomaterials with well-controlled haemocompatibility via intuitive thermal-induced graft polymerization. The research focused on the effects of zwitterionic surface packing density on human blood compatibility by varying the SBMA monomer concentration on the silanized silicon wafer substrates. A 0.2 M SBMA monomer solution was found to not only produce Si wafer surfaces with ideal zwitterionic surface packing density and uniform, evenly distributed pSBMA grafting coverage but also yield optimal hydrophilicity and haemocompatibility. SBMA monomer concentrations lower and greater than 0.2 M yielded a zwitterionic surface with low grafting coverage. This study also demonstrated that the same, intuitive thermal-induced graft polymerization strategy could be applied to a variety of organic polymeric, inorganic ceramic and metal oxide biomaterials to improve haemocompatibility. Among the tested organic and inorganic materials, however, it was found that inorganic biomaterials demonstrated greater resistance to protein and platelet adhesions. It was hypothesized that the ozone treatment, which generated an abundance of hydroxide groups on inorganic substrate interfaces, might have given the inorganic biomaterials a more stable silanized layer yielding a preferable reaction state and resulted in sturdier and more durable pSBMA grafting. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Photoluminescence Mechanism and Photocatalytic Activity of Organic-Inorganic Hybrid Materials Formed by Sequential Vapor Infiltration.

    PubMed

    Akyildiz, Halil I; Stano, Kelly L; Roberts, Adam T; Everitt, Henry O; Jur, Jesse S

    2016-05-03

    Organic-inorganic hybrid materials formed by sequential vapor infiltration (SVI) of trimethylaluminum into polyester fibers are demonstrated, and the photoluminescence of the fibers is evaluated using a combined UV-vis and photoluminescence excitation (PLE) spectroscopy approach. The optical activity of the modified fibers depends on infiltration thermal processing conditions and is attributed to the reaction mechanisms taking place at different temperatures. At low temperatures a single excitation band and dual emission bands are observed, while, at high temperatures, two distinct absorption bands and one emission band are observed, suggesting that the physical and chemical structure of the resulting hybrid material depends on the SVI temperature. Along with enhancing the photoluminescence intensity of the PET fibers, the internal quantum efficiency also increased to 5-fold from ∼4-5% to ∼24%. SVI processing also improved the photocatalytic activity of the fibers, as demonstrated by photodeposition of Ag and Au metal particles out of an aqueous metal salt solution onto fiber surfaces via UVA light exposure. Toward applications in flexible electronics, well-defined patterning of the metallic materials is achieved by using light masking and focused laser rastering approaches.

  2. Two-dimensional materials for novel liquid separation membranes

    NASA Astrophysics Data System (ADS)

    Ying, Yulong; Yang, Yefeng; Ying, Wen; Peng, Xinsheng

    2016-08-01

    Demand for a perfect molecular-level separation membrane with ultrafast permeation and a robust mechanical property for any kind of species to be blocked in water purification and desalination is urgent. In recent years, due to their intrinsic characteristics, such as a unique mono-atom thick structure, outstanding mechanical strength and excellent flexibility, as well as facile and large-scale production, graphene and its large family of two-dimensional (2D) materials are regarded as ideal membrane materials for ultrafast molecular separation. A perfect separation membrane should be as thin as possible to maximize its flux, mechanically robust and without failure even if under high loading pressure, and have a narrow nanochannel size distribution to guarantee its selectivity. The latest breakthrough in 2D material-based membranes will be reviewed both in theories and experiments, including their current state-of-the-art fabrication, structure design, simulation and applications. Special attention will be focused on the designs and strategies employed to control microstructures to enhance permeation and selectivity for liquid separation. In addition, critical views on the separation mechanism within two-dimensional material-based membranes will be provided based on a discussion of the effects of intrinsic defects during growth, predefined nanopores and nanochannels during subsequent fabrication processes, the interlayer spacing of stacking 2D material flakes and the surface charge or functional groups. Furthermore, we will summarize the significant progress of these 2D material-based membranes for liquid separation in nanofiltration/ultrafiltration and pervaporation. Lastly, we will recall issues requiring attention, and discuss existing questionable conclusions in some articles and emerging challenges. This review will serve as a valuable platform to provide a compact source of relevant and timely information about the development of 2D material-based membranes as

  3. Pervaporation Separation of Water-Ethanol Mixtures Using Organic-Inorganic Nanocomposite Membranes

    EPA Science Inventory

    Preyssler type heteropolyacid viz., H14[NaP5W30O110] incorporated chitosan nanocomposite membranes (NCMs) were prepared by solution casting, characterized using a variety of techniques and employed in the pervaporation separation of water-ethanol mixtures as a function of feed wa...

  4. Pervaporation Separation of Water-Ethanol Mixtures Using Organic-Inorganic Nanocomposite Membranes

    EPA Science Inventory

    Preyssler type heteropolyacid viz., H14[NaP5W30O110] incorporated chitosan nanocomposite membranes (NCMs) were prepared by solution casting, characterized using a variety of techniques and employed in the pervaporation separation of water-ethanol mixtures as a function of feed wa...

  5. CHARACTERISTICS OF POROUS CELLULOSE ACETATE MEMBRANES FOR THE SEPARATION OF SOME INORGANIC SALTS IN AQUEOUS SOLUTION,

    DTIC Science & Technology

    Experimental results are presented to illustrate the effect of operating variables on the separation and flow characteristics of porous cellulose ... acetate membranes. The results are discussed from the point of view of the preferential sorption and capillary flow mechanism, together with the concept

  6. Surface ablation of inorganic transparent materials using 70W femtosecond pulses at 1MHz (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Mishchik, Konstantin; Gaudfrin, Kevin; Audouard, Eric F.; Mottay, Eric P.; Lopez, John

    2017-03-01

    Nowadays processing of transparent materials, such as glass, quartz, sapphire and others, is a subject of high interest for worldwide industry since these materials are widely used for mass markets such as consumer electronics, flat display panels manufacturing, optoelectronics or watchmaking industry. The key issue is to combine high throughput, low residual stress and good processing quality in order to avoid chipping and any post-processing step such as grinding or polishing. Complimentary to non-ablative techniques used for zero-kerf glass cutting, surface ablation of such materials is interesting for engraving, grooving as well as full ablation cutting. Indeed this technique enables to process complex parts including via or blind, open or closed, straight or small radius of curvature patterns. We report on surface ablation experiments on transparent materials using a high average power (70W) and high repetition rate (1 MHz) femtosecond laser. These experiments have been done at 1030nm and 515nm on different inorganic transparent materials, such as regular and strengthened glass, borosilicate glass or sapphire, in order to underline their different ablation behavior. Despite the heat accumulation that occurs above 100 kHz we have reached a good compromise between throughput and processing quality. The effects of fluence, pulse-to-pulse overlap and number of passes are discussed in terms of etch rate, ablation efficiency, optimum fluence, maximum achievable depth, micro cracks formation and residual stresses. These experimental results will be also compared with numerical calculations obtained owing to a simple engineering model based on the two-temperature description of the ultrafast ablation.

  7. Crystallization behavior of PA6/SiO{sub 2} organic-inorganic hybrid material

    SciTech Connect

    Wang Hualin; Shi Tiejun . E-mail: stjdean@hfut.edu.cn; Yang Shanzhong; Hang Guopei

    2006-02-02

    Poly 2-hydroxy propylmethacrylate-methyl methacrylate/SiO{sub 2} (PHPMA-MMA/SiO{sub 2}), an active composite was used to synthesize polyamide-6/SiO{sub 2} (PA6/SiO{sub 2}) organic-inorganic hybrid materials via blending method. X-ray diffraction analysis (XRD) results showed that the addition of PHPMA-MMA/SiO{sub 2} composite induced PA6 to transit from {alpha} to {gamma} crystal form. The nonisothermal crystallization kinetics of PA6 and PA6/SiO{sub 2} hybrid materials was investigated by differential scanning calorimetry (DSC). Jeziorny method derived from Avrami analysis and a method developed by Liu were employed to describe the nonisothermal crystallization process of PA6 and PA6/SiO{sub 2} hybrid materials. Based on our experimental data, if the relative degree of crystallinity was approximately 60% or more, the Jeziorny method was not valid to describe the nonisothermal crystallization process, while Liu method was successful to describe the whole nonisothermal crystallization process. When X(t) was below about 60%, the crystallization rates of PA6 and PA6/SiO{sub 2} hybrid materials were very approximate, but when X(t) was approximately 60% or more, the crystallization rate of PA6 was quicker than that of PA6/SiO{sub 2} hybrid materials. Moreover, the addition of PHPMA-MMA/SiO{sub 2} composite decreased the crystallization activation energy {delta}E calculated by Kissinger equation because of the {gamma} transition.

  8. Attenuation of landfill leachate by clay liner materials in laboratory columns: 2. Behaviour of inorganic contaminants.

    PubMed

    Thornton, S F; Lerner, D N; Tellam, J H

    2001-02-01

    The chemical attenuation of inorganic contaminants in methanogenic landfill leachate, spiked with heavy metals (Cd, Cd, Ni and Zn), by two UK clay liner materials was compared in laboratory columns over 15 months. Ammonium was attenuated by ion-exchange but this attenuation was finite and when exhausted, NH4 passed through the liners at concentrations found in the leachate. The breakthrough behaviour of NH4 could be described by a simple distribution coefficient. Heavy metals were attenuated by sorption and precipitation of metal sulphide and carbonate compounds near the top of the liner. Adequate SO4 and CaCO3 in the liner is necessary to ensure the long term retention of heavy metals, and pH buffering agents added to stabilise reactive metal fractions should be admixed with the liner. Some metals may not be chemically attenuated by clay liners due to the formation of stable complexes with organic and/or colloidal fractions in leachate. Flushing of the liners with oxygenated water after leachate caused mobilisation of attenuated contaminants. Sorbed NH4 was released by the liners but groundwater loadings were manageable. Re-oxidation of metal sulphides under these conditions resulted in the release of heavy metals from the liners when the pH buffering capacity was poor. Contaminant attenuation by the clay liners was similar and the attenuation of NH4 and heavy metals could be predicted from the geochemical properties of the liner using simple tests. A conceptual model of clay liner performance is presented. Chemical attenuation of inorganic pollutants can be included in containment liner design to produce a dual reactive-passive barrier for landfills.

  9. Organic and inorganic hazardous waste stabilization utilizing fossil fuel combustion waste materials

    SciTech Connect

    Netzel, D.A.; Lane, D.C.; Brown, M.A.; Raska, K.A.; Clark, J.A.; Rovani, J.F.

    1993-09-01

    A laboratory study was conducted at the Western Research Institute to evaluate the ability of innovative clean coal technology (ICCT) waste to stabilize organic and inorganic constituents of hazardous wastes. The four ICCT wastes used in this study were: (1) the Tennessee Valley Authority (TVA) atmospheric fluidized bed combustor (AFBC) waste, (2) the TVA spray dryer waste, (3) the Laramie River Station spray dryer waste, and (4) the Colorado-Ute AFBC waste. Four types of hazardous waste stream materials were obtained and chemically characterized for use in evaluating the ability of the ICCT wastes to stabilize hazardous organic and inorganic wastes. The wastes included an API separator sludge, mixed metal oxide-hydroxide waste, metal-plating sludge, and creosote-contaminated soil. The API separator sludge and creosote-contaminated soil are US Environmental Protection Agency (EPA)-listed hazardous wastes and contain organic contaminants. The mixed metal oxide-hydroxide waste and metal-plating sludge (also an EPA-listed waste) contain high concentrations of heavy metals. The mixed metal oxide-hydroxide waste fails the Toxicity Characteristic Leaching Procedure (TCLP) for cadmium, and the metal-plating sludge fails the TCLP for chromium. To evaluate the ability of the ICCT wastes to stabilize the hazardous wastes, mixtures involving varying amounts of each of the ICCT wastes with each of the hazardous wastes were prepared, allowed to equilibrate, and then leached with deionized, distilled water. The leachates were analyzed for the hazardous constituent(s) of interest using the Toxicity Characteristic Leaching Procedure.

  10. ALTERNATIVE MATERIALS TO PD MEMBRANES FOR HYDROGEN PURIFICATION

    SciTech Connect

    Adams, T; Paul Korinko, P

    2007-11-13

    Development of advanced hydrogen separation membranes in support of hydrogen production processes such as coal gasification and as front end gas purifiers for fuel cell based system is paramount to the successful implementation of a national hydrogen economy. Current generation metallic hydrogen separation membranes are based on Pd-alloys. Although the technology has proven successful, at issue is the high cost of palladium. Evaluation of non-noble metal based dense metallic separation membranes is currently receiving national and international attention. The focal point of the reported work was to evaluate two different classes of materials for potential replacement of conventional Pd-alloy purification/diffuser membranes. Crystalline V-Ni-Ti and Amorphous Fe- and Co-based metallic glass alloys have been evaluated using both electrochemical and gaseous hydrogen permeation testing techniques..

  11. Chitosan as a barrier membrane material in periodontal tissue regeneration.

    PubMed

    Xu, Chun; Lei, Chang; Meng, Liuyan; Wang, Changning; Song, Yaling

    2012-07-01

    Periodontal regeneration is defined as regeneration of the tooth-supporting tissues including cementum, periodontal ligament, and alveolar bone. Guided tissue regeneration (GTR) has been demonstrated to be an effective technique to achieve periodontal regeneration. In the GTR procedures, various kinds of membranes play important roles. Chitosan, a deacetylated derivative of chitin, is biocompatible, biodegradable, and antimicrobial. It acts as hydrating agent and possesses tissue healing and osteoinducing effect. Chitosan can be easily processed into membranes, gels, nanofibers, beads, nanoparticles, scaffolds, and sponges forms and can be used in drug delivery systems. Here, we review the bioproperties of chitosan and report the progress of application of chitosan as membranes in GTR and guided bone regeneration (GBR), which indicates that chitosan could be a good substrate candidate as the materials for the GTR/GBR membranes.

  12. INVESTIGATION OF INORGANIC PHOTOTROPIC MATERIALS AS A BI-OPTIC ELEMENT APPLICABLE IN HIGH DENSITY STORAGE COMPUTER MEMORIES

    DTIC Science & Technology

    A general valuation of the various types of phototropic (i.e., reversible, light induced, color producing) phenomenon is given regarding the...application of phototropic material to bioptic high density storage media for compu er memories. The inorganic ’’F’’ center type phototropic systems were

  13. Mimicking lizard-like surface structures upon ultrashort laser pulse irradiation of inorganic materials

    NASA Astrophysics Data System (ADS)

    Hermens, U.; Kirner, S. V.; Emonts, C.; Comanns, P.; Skoulas, E.; Mimidis, A.; Mescheder, H.; Winands, K.; Krüger, J.; Stratakis, E.; Bonse, J.

    2017-10-01

    Inorganic materials, such as steel, were functionalized by ultrashort laser pulse irradiation (fs- to ps-range) to modify the surface's wetting behavior. The laser processing was performed by scanning the laser beam across the surface of initially polished flat sample material. A systematic experimental study of the laser processing parameters (peak fluence, scan velocity, line overlap) allowed the identification of different regimes associated with characteristic surface morphologies (laser-induced periodic surface structures, grooves, spikes, etc.). Analyses of the surface using optical as well as scanning electron microscopy revealed morphologies providing the optimum similarity to the natural skin of lizards. For mimicking skin structures of moisture-harvesting lizards towards an optimization of the surface wetting behavior, additionally a two-step laser processing strategy was established for realizing hierarchical microstructures. In this approach, micrometer-scaled capillaries (step 1) were superimposed by a laser-generated regular array of small dimples (step 2). Optical focus variation imaging measurements finally disclosed the three dimensional topography of the laser processed surfaces derived from lizard skin structures. The functionality of these surfaces was analyzed in view of wetting properties.

  14. Litter ammonia generation: moisture content and organic versus inorganic bedding materials.

    PubMed

    Miles, D M; Rowe, D E; Cathcart, T C

    2011-06-01

    Negative impacts on the environment, bird well-being, and farm worker health indicate the need for abatement strategies for poultry litter NH(3) generation. Type of bedding affects many parameters related to poultry production including NH(3) losses. In a randomized complete block design, 3 trials compared the cumulative NH(3) volatilization for laboratory-prepared litter (4 bedding types mixed with excreta) and commercial litter (sampled from a broiler house during the second flock on reused pine wood chips). Litters were assessed at the original moisture content and 2 higher moisture contents. Broiler excrement was mixed with pine wood shavings, rice hulls, sand, and vermiculite to create litter samples. Volumetrically uniform litter samples were placed in chambers receiving humidified air where the exhaust passed through H(3)BO(3) solution, trapping litter-emitted NH(3). At the original moisture content, sand and vermiculite litters generated the most NH(3) (5.3 and 9.1 mg of N, respectively) whereas wood shavings, commercial, and rice hull litters emitted the least NH(3) (0.9-2.6 mg of N). For reducing NH(3) emissions, the results support recommendations for using wood shavings and rice hulls, already popular bedding choices in the United States and worldwide. In this research, the organic bedding materials generated the least NH(3) at the original moisture content when compared with the inorganic materials. For each bedding type, incremental increases in litter moisture content increased NH(3) volatilization. However, the effects of bedding material on NH(3) volatilization at the increased moisture levels were not clearly differentiated across the treatments. Vermiculite generated the most NH(3) (26.3 mg of N) at the highest moisture content. Vermiculite was a novel bedding choice that has a high water absorption capacity, but because of high NH(3) generation, it is not recommended for further study as broiler bedding material. Controlling unnecessary moisture

  15. External interface for trap-and-release membrane introduction mass spectrometry applied to the detection of inorganic chloramines and chlorobenzenes in water.

    PubMed

    Riter, L S; Charles, L; Turowski, M; Cooks, R G

    2001-01-01

    Construction and evaluation of an external configuration trap-and-release membrane introduction system for mass spectrometry is described. This novel interface allows independent control of the temperature of the membrane and eliminates the dependence of membrane heating efficiency on its position in the ion source. The external trap-and-release MIMS configuration is successfully applied to detection of inorganic chloramines and chlorobenzenes. The method is shown to give temporal resolution of volatile vs. semi-volatile compounds, which increases its sensitivity for semi-volatiles in the presence of volatiles and provides an additional selectivity parameter. Further selectivity is provided by tandem mass spectrometry. Copyright 2001 John Wiley & Sons, Ltd.

  16. Synthesis and characterizaton of inorganic materials for sodium-ion batteries

    NASA Astrophysics Data System (ADS)

    Shanmugam, Rengarajan

    Development of low-cost energy storage devices is critical for wide-scale implementation of intermittent renewable energy technologies and improving the electricity grid. Commercial devices remain prohibitively expensive or lack the performance specifications for a wider market reach. Na-ion batteries would perfectly suited for these large-scale applications as the raw materials (such as soda ash, salt, etc.) are plentiful, inexpensive and geographically unconstrained. However, extensive materials research on insertion electrodes is required for better understanding of the electrochemical and structural properties and engineering high performance Na-ion batteries. This thesis research involves exploratory study on new insertion materials with various crystallographic structure-types and extensive characterization of promising new inorganic compositions. Tunnel-type materials, sodium nickel phosphate-Na4Ni7(PO4)6, and sodium cobalt titanate- Na0.8Co0.4Ti1.6O4, were investigated to capitalize on the intrinsic structural stability offered by framework materials. Sol-gel and solid-state reaction synthetic techniques were employed for inorganic powder synthesis. Galvanostatic and potentiostatic testing confirm reversible sodium insertion/de-insertion reactions albeit with inadequate electrochemical characteristics (high voltage hysteresis> 1V). Subsequent efforts involved investigating layer-structured materials supporting fast ionic transport for better electrochemical performance. P2-sodium nickel titanate, Na2/3[Ni1/3Ti2/3]O2 (P2NT), with prismatic sodium co-ordination, was synthesized by solid-state technique. The 'bifunctional' oxide contains Ni2+/4+ and Ti4+/3+ redox couples with redox potentials of 3.6 V, 0.7 V vs. Na/Na+, respectively. This bifunctional approach would simplify electrode processing and provide cost reduction opportunities in battery manufacturing. The structural changes monitored using ex-situ XRD demonstrate a favorably broad solid

  17. Oxidation control of fluxes for mixed-valent inorganic oxide materials synthesis

    NASA Astrophysics Data System (ADS)

    Schrier, Marc David

    This dissertation is concerned with controlling the flux synthesis and ensuing physical properties of mixed-valence metal oxides. Molten alkali metal nitrates and hydroxides have been explored to determine and exploit their variable redox chemistries for the synthesis of mixed-valent oxide materials. Cationic and anionic additives have been utilized in these molten salts to control the relative concentrations of the redox-active species present to effectively tune and cap the electrochemical potential of the flux. Atoms like bismuth, copper, and manganese are capable of providing different numbers of electrons for bonding. With appropriate doping near the metal-insulator transition, many of these mixed-valent inorganic metal oxides exhibit extraordinary electronic and magnetic properties. Traditionally, these materials have been prepared by classical high temperature solid state routes where microscopic homogeneity is hard to attain. In these routes, the starting composition dictates the doping level, and in turn, the formal oxidation state achieved. Molten flux syntheses developed in this work have provided the potential for preparing single-phase, homogeneous, and crystalline materials. The redox-active fluxes provide a medium for enhanced doping and mixed-valency control in which the electrochemical potential adjusts the formal oxidation state, and the doping takes place to maintain charge neutrality. The two superconductor systems investigated are: (1) the potassium-doped barium bismuth oxides, and (2) the alkali metal- and alkaline earth metal-doped lanthanum copper oxides. Controlled oxidative doping has been achieved in both systems by two different approaches. The superconducting properties of these materials have been assessed, and the materials have been characterized by powder X-ray diffraction and e-beam microprobe elemental analyses. In the course of these studies, several other materials have been identified. Analysis of these materials, and the

  18. Sialic acid mediates the initial binding of positively charged inorganic particles to alveolar macrophage membranes.

    PubMed

    Gallagher, J E; George, G; Brody, A R

    1987-06-01

    Pulmonary macrophages phagocytize inhaled particles and are postulated to play a role in the development of pulmonary interstitial fibrogenesis. The basic biologic mechanisms through which inhaled particles bind to macrophage membranes and subsequently are phagocytized remain unclear. We hypothesize that positively charged particles bind to negatively charged sialic acid (SA) residues on macrophage membranes. Alveolar Macrophages (AM) were collected by saline lavage from normal rat lungs. The cells adhered to plastic coverslips in serum-free phosphate buffered saline at 37 degrees C for 45 min and then were maintained at 4 degrees C for the binding experiments. Even distribution of SA groups on AM surfaces was demonstrated by scanning electron microscopy of wheat germ agglutinin (WGA) conjugated to 50 nm gold spheres. The WGA is a lectin that binds specifically to sialic acid, and pretreatment of AM with this lectin prevented the binding of positively charged carbonyl iron (C-Fe) spheres, aluminum (Al) spheres, and chrysotile asbestos fibers to AM surfaces. Limulus protein, another lectin with binding specificity for SA, similarly blocked the binding of positively charged spheres and chrysotile asbestos fibers but not negatively charged glass spheres or crocidolite asbestos fibers. Con A and ricin, lectins that bind to mannose and galactose residues, respectively, did not block particle binding. When both positively charged iron spheres and negatively charged glass spheres were prebound to AM membranes, subsequent treatment with WGA displaced only the positively charged spheres from macrophage surfaces. Con A and ricin had no effect on prebound positively charged C-Fe and Al spheres.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Chiral Inorganic Nanostructures.

    PubMed

    Ma, Wei; Xu, Liguang; de Moura, André F; Wu, Xiaoling; Kuang, Hua; Xu, Chuanlai; Kotov, Nicholas A

    2017-06-28

    The field of chiral inorganic nanostructures is rapidly expanding. It started from the observation of strong circular dichroism during the synthesis of individual nanoparticles (NPs) and their assemblies and expanded to sophisticated synthetic protocols involving nanostructures from metals, semiconductors, ceramics, and nanocarbons. Besides the well-established chirality transfer from bioorganic molecules, other methods to impart handedness to nanoscale matter specific to inorganic materials were discovered, including three-dimentional lithography, multiphoton chirality transfer, polarization effects in nanoscale assemblies, and others. Multiple chiral geometries were observed with characteristic scales from ångströms to microns. Uniquely high values of chiral anisotropy factors that spurred the development of the field and differentiate it from chiral structures studied before, are now well understood; they originate from strong resonances of incident electromagnetic waves with plasmonic and excitonic states typical for metals and semiconductors. At the same time, distinct similarities with chiral supramolecular and biological systems also emerged. They can be seen in the synthesis and separation methods, chemical properties of individual NPs, geometries of the nanoparticle assemblies, and interactions with biological membranes. Their analysis can help us understand in greater depth the role of chiral asymmetry in nature inclusive of both earth and space. Consideration of both differences and similarities between chiral inorganic, organic, and biological nanostructures will also accelerate the development of technologies based on chiroplasmonic and chiroexcitonic effects. This review will cover both experiment and theory of chiral nanostructures starting with the origin and multiple components of mirror asymmetry of individual NPs and their assemblies. We shall consider four different types of chirality in nanostructures and related physical, chemical, and

  20. Size-controlled hydroxyapatite nanoparticles as self-organized organic-inorganic composite materials.

    PubMed

    Rusu, Viorel Marin; Ng, Chuen-How; Wilke, Max; Tiersch, Brigitte; Fratzl, Peter; Peter, Martin G

    2005-09-01

    This paper presents some results concerning the size-controlled hydroxyapatite nanoparticles obtained in aqueous media in a biopolymer matrix from soluble precursors salts. Taking the inspiration from nature, where composite materials made of a polymer matrix and inorganic fillers are often found, e.g. bone, shell of crustaceans, shell of eggs, etc., the feasibility on making composite materials containing chitosan and nanosized hydroxyapatite was investigated. A stepwise co-precipitation approach was used to obtain different types of composites by means of different ratio between components. The synthesis of hydroxyapatite was carried out in the chitosan matrix from calcium chloride and sodium dihydrogenphosphate in alkaline solutions at moderate pH of 10-11 for 24 h. Our research is focused on studying and understanding the structure of this class of composites, aiming at the development of novel materials, controlled at the nanolevel scale. The X-ray diffraction technique was employed in order to study the kinetic of hydroxyapatite formation in the chitosan matrix as well as to determine the HAp crystallite sizes in the composite samples. The hydroxyapatite synthesized using this route was found to be nano-sized (15-50 nm). Moreover, applying an original approach to analyze the (002) XRD diffraction peak profile of hydroxyapatite by using a sum of two Gauss functions, the bimodal distribution of nanosized hydroxyapatite within the chitosan matrix was revealed. Two types of size distribution domains such as cluster-like (between 200 and 400 nm), which are the habitat of ''small'' hydroxyapatite nanocrystallites and scattered-like, which are the habitat of ''large'' hydroxyapatite nanocrystallites was probed by TEM and CSLM. The structural features of composites suggest that self-assembly processes might be involved. The composites contain nanosized hydroxyapatite with structural features close to those of biological apatites that make them attractive for bone

  1. Membranes for Periodontal Regeneration--A Materials Perspective.

    PubMed

    Bottino, Marco C; Thomas, Vinoy

    2015-01-01

    Periodontitis is a chronic inflammatory disorder affecting nearly 50% of adults in the United States. If left untreated, it can lead to the destruction of both soft and mineralized tissues that constitute the periodontium. Clinical management, including but not limited to flap debridement and/or curettage, as well as regenerative-based strategies with periodontal membranes associated or not with grafting materials, has been used with distinct levels of success. Unquestionably, no single implantable biomaterial can consistently guide the coordinated growth and development of multiple tissue types, especially in very large periodontal defects. With the global aging population, it is extremely important to find novel biomaterials, particularly bioactive membranes and/or scaffolds, for guided tissue (GTR) and bone regeneration (GBR) to aid in the reestablishment of the health and function of distinct periodontal tissues. This chapter offers an update on the evolution of biomaterials (i.e. membranes and bioactive scaffolds) as well as material-based strategies applied in periodontal regeneration. The authors start by providing a brief summary of the histological characteristics and functions of the periodontium and its main pathological condition, namely periodontitis. Next, a review of commercially available GTR/GBR membranes is given, followed by a critical appraisal of the most recent advances in the development of bioactive materials that enhance the chance for clinical success of periodontal tissue regeneration.

  2. Abnormalities in the membrane material properties of hereditary spherocytes

    SciTech Connect

    Waugh, R.E.; La Celle, P.L.

    1980-08-01

    Mechanical measurements of intrinsic membrane material properties are used to characterize the defect in hereditary spherocyte membrane at a continuum level. The value of the surface elastic shear modulus is two-thirds as large as normal values, and the value of the yield shear resultant is one-third as large as normal values. The viscosity of the surface above th elastic-plastic transition appears normal. Under similar geometric conditions, the force required to fragment a hereditary spherocyte is about one-third as large as the force required to fragment a normal cell.

  3. Composite materials for polymer electrolyte membrane microbial fuel cells.

    PubMed

    Antolini, Ermete

    2015-07-15

    Recently, the feasibility of using composite metal-carbon, metal-polymer, polymer-carbon, polymer-polymer and carbon-carbon materials in microbial fuel cells (MFCs) has been investigated. These materials have been tested as MFC anode catalyst (microorganism) supports, cathode catalysts and membranes. These hybrid materials, possessing the properties of each component, or even with a synergistic effect, would present improved characteristics with respect to the bare components. In this paper we present an overview of the use of these composite materials in microbial fuel cells. The characteristics of the composite materials as well as their effect on MFC performance were compared with those of the individual component and/or the conventionally used materials.

  4. [Development and evaluation of fertilizers cemented and coated with organic-inorganic materials].

    PubMed

    Xiao, Qiang; Wang, Jia-Chen; Zuo, Qiang; Zhang, Lin; Liu, Bao-Cun; Zhao, Tong-Ke; Zou, Guo-Yuan; Xu, Qiu-Ming

    2010-01-01

    Four kinds of organic-inorganic cementing and coating materials were prepared by a coating method using water as the solvent, and the corresponding cemented and coated fertilizers (B2, PS, F2, and F2F) were produced by disc pelletizer. The tests on the properties of these fertilizers showed that the granulation rate, compression strength, and film-forming rate were B2 > PS > F2 > F2F. Soil column leaching experiment showed that the curve of accumulated nitrogen-dissolving rate was the gentlest for B2. In 48 days, the accumulated nitrogen-dissolving rate was in the order of B2, 54.65% < PS, 56.16% < F2, 59.47%, < F2F, 63.12%. Field experiment showed that compared with the same application amount of NPK, all the test fertilizers had better effects on corn yield, among which, B2 was the best, with the corn yield and fertilizer use efficiency increased by 19.72% and 20.30%, respectively. The yield-increasing effect of other test fertilizers was in the order of PS > F2 > F2F.

  5. Inorganic-organic hybrid materials based on keggin type polyoxometalates and organic polyammonium cations

    NASA Astrophysics Data System (ADS)

    Vasylyev, Maxym; Popovitz-Biro, Ronit; Shimon, Linda J. W.; Neumann, Ronny

    2003-08-01

    Co-crystallization of a tri-ammonium cation with short and somewhat flexible ‘arms', [N,N,N-tris[2-(dimethylamino)ethyl]-1,3,5-benzenetricarboxamide]3+, with a polyoxometalate trianion, PW12O403-, yielded an insoluble channeled or microporous structure. The polyoxometalate clusters are arranged in a layered and zig-zag fashion along the xy plane. Looking along the x-axis, channels of a dimension of ∼3.5×∼6.5 Å are observed. It was found that C-H⋯O bonds aided in determining the crystal packing by providing directionality to the anion-cation interaction. On the other hand the co-crystallization of a tetraammonium cation with an extended and rigid tetrahedral configuration, 1,3,5,7-tetrakis{4-[(E)-2(N-methylpyridinium-4-yl)vinyl]phenyl adamantane tetraiodide, with a polyoxometalate tetracation, SiW12O404-, yielded a lamellar structure with alternating layers with spacing of 16.6 Å of the inorganic-organic hybrid material.

  6. Electrolytic aminated carbon materials for the electrocatalytic redox reactions of inorganic and organic compounds.

    PubMed

    Hayashida, Eriko; Takahashi, Yuichi; Nishi, Hideki; Uchiyama, Shunichi

    2011-06-01

    Some kinds of amine groups can be introduced to the glassy carbon surface by the electrode oxidation of the carbon electrode surface in ammonium carbamate solution, and this amine groups modified electrode is named as an aminated glassy carbon electrode. The existences of not only primary amine but also secondary and tertially amines were confirmed by X ray photoelectron spectroscopy. The applications of the aminated carbon material for the electrocatalytic reductions of oxygen, hydrogen peroxide, and organic compounds such as quinones were carried out, and the effects of amination on the formation of electrocatalytic sites for many species were revealed. The electrocatalyzed cyclic voltammograms of metal ions and metal chelate compounds obtained by aminated glassy carbon electrodes are also discussed. Moreover, we intend to describe that the aminated carbon electrode can exhibit the large reduction waves of inorganic oxoacids such as N02- or bromide ion. The introduced functional groups containing nitrogen atom can change the distribution of the electron densities of the graphite carbon surface, and this specific electron distribution environment may generate the various electrocatalytic activities. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  7. Numerical and Experimental Analysis on Inorganic Phase Change Material Usage in Construction

    NASA Astrophysics Data System (ADS)

    Muthuvel, S.; Saravanasankar, S.; Sudhakarapandian, R.; Muthukannan, M.

    2014-12-01

    This work demonstrates the significance of Phase Change Material (PCM) in the construction of working sheds and product storage magazines in fireworks industries to maintain less temperature variation by passive cooling. The inorganic PCM, namely Calcium Chloride Hexahydrate (CCH) is selected in this study. First, the performance of two models with inbuilt CCH was analysed, using computational fluid dynamics. A significant change in the variation of inner wall temperature was observed, particularly during the working hours. This is mainly due to passive cooling, where the heat transfer from the surroundings to the room is partially used for the phase change from solid to liquid. The experiment was carried out by constructing two models, one with PCM packed in hollow brick walls and roof, and the other one as a conventional construction. The experimental results show that the temperature of the room got significantly reduced up to 7 °C. The experimental analysis results had good agreement with the numerical analysis results, and this reveals the advantage of the PCM in the fireworks industry construction.

  8. Organic/inorganic interfaced field-effect transistor properties with a novel organic semiconducting material

    NASA Astrophysics Data System (ADS)

    Demir, Ahmet; Atahan, Alparslan; Bağcı, Sadık; Aslan, Metin; Saif Islam, M.

    2016-01-01

    A novel 1,3,4-oxadiazole-substituted benzo[b]triphenylene was synthesized by three-step synthetic procedure and OFET device design was successfully designed after theoretical calculations made using Gaussian software. For investigating the field-effect properties of designed organic electronic device, a SiO2 (300 nm) was thermally grown on p-Si wafer at 1000 °C as a dielectric layer and gate, source and drain contacts have been deposited using Au metal with physical vapour deposition. 1,3,4-Oxadiazole-substituted benzo[b]triphenylene was spin coated on the source and drain electrodes of our device, forming organic/inorganic interfaced field-effect transistors. Surface morphology and thin film properties were investigated using AFM. All electrical measurements were done in air ambient. The device showed a typical p-type channel behaviour with increasing negative gate bias voltage values. Our results have surprisingly shown that the saturation regime of this device has high mobility (μFET), excellent on/off ratio (Ion/Ioff), high transconductance (gm) and a small threshold voltage (VTh). The values of μFET, Ion/Ioff, gm and VTh were found as 5.02 cm2/Vs, 0.7 × 103, 5.64 μS/mm and 1.37 V, respectively. These values show that our novel organic material could be a potential candidate for organic electronic device applications in the future.

  9. Immunity induced by a broad class of inorganic crystalline materials is directly controlled by their chemistry.

    PubMed

    Williams, Gareth R; Fierens, Kaat; Preston, Stephen G; Lunn, Daniel; Rysnik, Oliwia; De Prijck, Sofie; Kool, Mirjam; Buckley, Hannah C; Lambrecht, Bart N; O'Hare, Dermot; Austyn, Jonathan M

    2014-06-02

    There is currently no paradigm in immunology that enables an accurate prediction of how the immune system will respond to any given agent. Here we show that the immunological responses induced by members of a broad class of inorganic crystalline materials are controlled purely by their physicochemical properties in a highly predictable manner. We show that structurally and chemically homogeneous layered double hydroxides (LDHs) can elicit diverse human dendritic cell responses in vitro. Using a systems vaccinology approach, we find that every measured response can be modeled using a subset of just three physical and chemical properties for all compounds tested. This correlation can be reduced to a simple linear equation that enables the immunological responses stimulated by newly synthesized LDHs to be predicted in advance from these three parameters alone. We also show that mouse antigen-specific antibody responses in vivo and human macrophage responses in vitro are controlled by the same properties, suggesting they may control diverse responses at both individual component and global levels of immunity. This study demonstrates that immunity can be determined purely by chemistry and opens the possibility of rational manipulation of immunity for therapeutic purposes.

  10. Nano-Structured Bio-Inorganic Hybrid Material for High Performing Oxygen Reduction Catalyst.

    PubMed

    Jiang, Rongzhong; Tran, Dat T; McClure, Joshua P; Chu, Deryn

    2015-08-26

    In this study, we demonstrate a non-Pt nanostructured bioinorganic hybrid (BIH) catalyst for catalytic oxygen reduction in alkaline media. This catalyst was synthesized through biomaterial hemin, nanostructured Ag-Co alloy, and graphene nano platelets (GNP) by heat-treatment and ultrasonically processing. This hybrid catalyst has the advantages of the combined features of these bio and inorganic materials. A 10-fold improvement in catalytic activity (at 0.8 V vs RHE) is achieved in comparison of pure Ag nanoparticles (20-40 nm). The hybrid catalyst reaches 80% activity (at 0.8 V vs RHE) of the state-of-the-art catalyst (containing 40% Pt and 60% active carbon). Comparable catalytic stability for the hybrid catalyst with the Pt catalyst is observed by chronoamperometric experiment. The hybrid catalyst catalyzes 4-electron oxygen reduction to produce water with fast kinetic rate. The rate constant obtained from the hybrid catalyst (at 0.6 V vs RHE) is 4 times higher than that of pure Ag/GNP catalyst. A catalytic model is proposed to explain the oxygen reduction reaction at the BIH catalyst.

  11. Wind-blown Sand Electrification Inspired Triboelectric Energy Harvesting Based on Homogeneous Inorganic Materials Contact: A Theoretical Study and Prediction

    PubMed Central

    Hu, Wenwen; Wu, Weiwei; Zhou, Hao-miao

    2016-01-01

    Triboelectric nanogenerator (TENG) based on contact electrification between heterogeneous materials has been widely studied. Inspired from wind-blown sand electrification, we design a novel kind of TENG based on size dependent electrification using homogeneous inorganic materials. Based on the asymmetric contact theory between homogeneous material surfaces, a calculation of surface charge density has been carried out. Furthermore, the theoretical output of homogeneous material based TENG has been simulated. Therefore, this work may pave the way of fabricating TENG without the limitation of static sequence. PMID:26817411

  12. Wind-blown Sand Electrification Inspired Triboelectric Energy Harvesting Based on Homogeneous Inorganic Materials Contact: A Theoretical Study and Prediction

    NASA Astrophysics Data System (ADS)

    Hu, Wenwen; Wu, Weiwei; Zhou, Hao-Miao

    2016-01-01

    Triboelectric nanogenerator (TENG) based on contact electrification between heterogeneous materials has been widely studied. Inspired from wind-blown sand electrification, we design a novel kind of TENG based on size dependent electrification using homogeneous inorganic materials. Based on the asymmetric contact theory between homogeneous material surfaces, a calculation of surface charge density has been carried out. Furthermore, the theoretical output of homogeneous material based TENG has been simulated. Therefore, this work may pave the way of fabricating TENG without the limitation of static sequence.

  13. Effects of chemical cleaning on RO membrane inorganic, organic and microbial foulant removal in a full-scale plant for municipal wastewater reclamation.

    PubMed

    Yu, Tong; Meng, Lu; Zhao, Qing-Bo; Shi, Ye; Hu, Hong-Ying; Lu, Yun

    2017-04-15

    Of all of the strategies for controlling reverse osmosis (RO) membrane fouling, chemical cleaning is indispensable. To study the effects of chemical cleaning on membrane foulant removal, a comparative analysis of RO membranes before and after common alkaline and acid cleaning was conducted by dissecting lead and terminal RO membranes in a full-scale municipal wastewater reclamation plant. Most foulants on the membranes were removed by chemical cleaning processes. Calcium was the major inorganic component of the foulants because of its highest concentration in the feed water. Aluminum and iron were also abundant elements on the membranes due to their high deposition ratios and low removal efficiencies. Hydrophilic neutrals (HIN) and hydrophobic neutrals (HON) were the two largest dissolved organic matter (DOM) fractions on the membranes before cleaning. HIN and hydrophilic acids (HIA) were not effectively removed. Chemical cleaning removed 94% and 90% of the total bacteria on the lead and tail membranes and considerably changed the structure of the microbial communities. Bacteria excessively producing extracellular polymeric substance (EPS), such as Pseudomonas and Zoogloea, were much more resistant to the chemical cleaning process. After cleaning, the membrane microbial community structures were more similar to those in the feed water than the structures on the membranes before cleaning. These results shed light on the effects of cleaning in a full-scale RO plant, improves our understanding of the removal of foulants and provides potential research directions for cleaning methods and RO pretreatment processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Metal-organic framework templated synthesis of porous inorganic materials as novel sorbents

    DOEpatents

    Taylor-Pashow, Kathryn M. L.; Lin, Wenbin; Abney, Carter W.

    2017-03-21

    A novel metal-organic framework (MOF) templated process for the synthesis of highly porous inorganic sorbents for removing radionuclides, actinides, and heavy metals is disclosed. The highly porous nature of the MOFs leads to highly porous inorganic sorbents (such as oxides, phosphates, sulfides, etc) with accessible surface binding sites that are suitable for removing radionuclides from high level nuclear wastes, extracting uranium from acid mine drainage and seawater, and sequestering heavy metals from waste streams. In some cases, MOFs can be directly used for removing these metal ions as MOFs are converted to highly porous inorganic sorbents in situ.

  15. Supramolecularly self-organized nanomaterials: A voyage from inorganic particles to organic light-harvesting materials

    NASA Astrophysics Data System (ADS)

    Varotto, Alessandro

    In 2009 the U.S. National Science Foundation announced the realignment of the Chemistry Divisions introducing the new interdisciplinary program of "Macromolecular, Supramolecular and Nanochemistry." This statement officially recognizes a field of studies that has already seen the publication of many thousands of works in the past 20 years. Nanotechnology and supramolecular chemistry can be found in the most diverse disciplines, from biology to engineering, to physics. Furthermore, many technologies rely on nanoscale dimensions for more than one component. Nanomaterials and technologies are on the market with a range of applications from composite materials, to electronics, to medicine, to sensing and more. This thesis will introduce a variety of studies and applications of supramolecular chemistry to form nanoscale photonic materials from soft matter. We will first illustrate a method to synthesize metallic nanoparticles using plasmids DNA as a mold. The circular DNA functions as a sacrificial template to shape the particles into narrowly monodispersed nanodiscs. Secondly, we will describe the synthesis of a highly fluorinated porphyrin derivative and how the fluorines improve the formation of ultra thin films when the porphyrin is blended with fullerene C60. Finally, we will show how to increase the short-circuit current in a solar cell built with an internal parallel tandem light harvesting design. A blend of phthalocyanines, each with a decreasing optical band gap, is supramolecularly self-organized with pyridyl-C60 within thin films. The different band gaps of the single phthalocyanines capture a wider segment of the solar spectrum increasing the overall efficiency of the device. In conclusion, we have presented a number of studies for the preparation of inorganic and organic nanomaterials and their application in supramolecularly organized photonic devices.

  16. Inorganic nanotubes and fullerene-like nanoparticles at the crossroad between materials science and nanotechnology

    NASA Astrophysics Data System (ADS)

    Tenne, Reshef

    2014-03-01

    This presentation is aimed at underlying the principles, synthesis, characterization and applications of inorganic nanotubes (INT) and fullerne-like (IF) nanoparticles (NP) from 2-D layered compounds. While the high temperature synthesis and study of IF materials and INT from layered metal dichalcogenides, like WS2 and MoS2 remain a major challenge, progress with the synthesis of IF and INT structures from various other compounds has been realized, as well. Intercalation and doping of these nanostructures, which lends itself to interesting electronic properties, has been realized, too. Core-shell nanotubular structures, like PbI2@WS2 and SnS/SnS2 and PbS/NbS2 nanotubes from ``misfit'' compounds have been recently reported. Re doping of the IF and INT endow them with interesting electrical and other physio-chemical properties. Major progress has been achieved in elucidating the structure of INT and IF using advanced microscopy techniques, like aberration corrected TEM and electron tomography. Also recently, scaling up efforts in collaboration with ``NanoMaterials'' resulted in multikilogram production of (almost) pure multiwall WS2 nanotubes phases. Extensive experimental and theoretical analysis of the mechanical properties of individual INT and more recently IF NP was performed casting light on their behavior in the macroscopic world. IF-MS2 (M =W,Mo, etc) were shown to be superior solid lubricants in variety of forms, including an additive to various lubricating fluids/greases and for various self-lubricating coating. Full commercialization of products based on this technology is taking place now.

  17. Information or resolution: Which is required from an SEM to study bulk inorganic materials?

    PubMed

    Xing, Q

    2016-11-01

    Significant technological advances in scanning electron microscopy (SEM) have been achieved over the past years. Different SEMs can have significant differences in functionality and performance. This work presents the perspectives on selecting an SEM for research on bulk inorganic materials. Understanding materials demands quantitative composition and orientation information, and informative and interpretable images that reveal subtle differences in chemistry, orientation/structure, topography, and electronic structure. The capability to yield informative and interpretable images with high signal-to-noise ratios and spatial resolutions is an overall result of the SEM system as a whole, from the electron optical column to the detection system. The electron optical column determines probe performance. The roles of the detection system are to capture, filter or discriminate, and convert signal electrons to imaging information. The capability to control practical operating parameters including electron probe size and current, acceleration voltage or landing voltage, working distance, detector selection, and signal filtration is inherently determined by the SEM itself. As a platform for various accessories, e.g. an energy-dispersive spectrometer and an electron backscatter diffraction detector, the properties of the electron optical column, specimen chamber, and stage greatly affect the performance of accessories. Ease-of-use and ease-of-maintenance are of practical importance. It is practically important to select appropriate test specimens, design suitable imaging conditions, and analyze the specimen chamber geometry and dimensions to assess the overall functionality and performance of an SEM. For an SEM that is controlled/operated with a computer, the stable software and user-friendly interface significantly improve the usability of the SEM. SCANNING 38:864-879, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  18. Effect of inorganic carbon concentration on the stability and nitrite-oxidizing bacteria community structure of the CANON process in a membrane bioreactor.

    PubMed

    Zhang, Xiaojing; Zhou, Yue; Ma, Yongpeng; Zhang, Nan; Zhao, Siyu; Zhang, Rongrong; Zhang, Jun; Zhang, Hongzhong

    2017-03-30

    In the completely autotrophic nitrogen removal over nitrite (CANON) process, the nitrite-oxidizing bacteria (NOB) should be effectively suppressed or thoroughly washed out. In this study, the nitrate production and the structure of NOB community under different inorganic carbon (IC) concentrations were investigated using denaturing gradient gel electrophoresis (DGGE) in a membrane bioreactor (MBR). Results showed that IC decrease correspondingly lowered the nitrogen removal, and simultaneously induced the nitrate production by NOB. DGGE results indicated the IC deficit led to the biodiversity increasing of both Nitrobacter-like NOB and Nitrospira-like NOB. An equation fitted between the ratio of nitrate production to ammonia consumption ([Formula: see text]) and the ratio of influent IC to ammonia concentration ([Formula: see text]) indicated the influent [Formula: see text] should be controlled between 1.6 and 2.3 to ensure the stable operation of the CANON process. A small amount addition of organic material could be used as an effective strategy to suppress NOB when the [Formula: see text] ratio was not appropriate.

  19. Flexible anodized aluminum oxide membranes with customizable back contact materials

    NASA Astrophysics Data System (ADS)

    Nadimpally, B.; Jarro, C. A.; Mangu, R.; Rajaputra, S.; Singh, V. P.

    2016-12-01

    Anodized aluminum oxide (AAO) membranes were fabricated using flexible substrate/carrier material. This method facilitates the use of AAO templates with many different materials as substrates that are otherwise incompatible with most anodization techniques. Thin titanium (Ti) and tungsten (W) layers were employed as interlayer materials. Titanium enhances adhesion. Tungsten not only helps eliminate the barrier layer but also plays a critical role in enabling the use of flexible substrates. The resulting flexible templates provide new, exciting opportunities in photovoltaic and other device applications. CuInSe2 nanowires were electrochemically deposited into porous AAO templates with molybdenum (Mo) as the back contact material. The feasibility of using any material to form a contact with semiconductor nanowires has been demonstrated for the first time enabling new avenues in photovoltaic applications.

  20. Influence of membrane structure on the operating current densities of non-aqueous redox flow batteries: Organic-inorganic composite membranes based on a semi-interpenetrating polymer network

    NASA Astrophysics Data System (ADS)

    Shin, Sung-Hee; Kim, Yekyung; Yun, Sung-Hyun; Maurya, Sandip; Moon, Seung-Hyeon

    2015-11-01

    We develop three types of organic-inorganic composite membranes based on a semi-interpenetrating polymer network (SIPN) to explore the effects of membrane structure on the possible operating current densities of a non-aqueous redox flow battery (RFB) system. Poly(vinylidene fluoride) (PVdF) is selected as a supporting polymer matrix for improving the chemical and thermal stability of the organic-inorganic composite membranes. We also introduce silica nanoparticles (5 wt% of PVdF) into the membranes to ensure the low crossover of active species. The fabrication of SIPN through the addition of glycidyl methacrylate, 4-vinylpyridine, or N-vinylcarbazole enables control of the membrane structure. Depending on monomer type, the membrane structure is determined to be either aliphatic or aromatic in terms of chemical properties and either dense or porous in terms of physical properties. These chemical and physical structures affect the electrochemical properties that correspond to charge/discharge performance and to the range of possible operating current densities. An important requirement is to examine charge/discharge performance at the possible range of operating current densities by using various membrane structures. This requirement is discussed in relation to a proposed design strategy for non-aqueous RFB membranes.

  1. Effect of inorganic carbon on nitrogen removal and microbial communities of CANON process in a membrane bioreactor.

    PubMed

    Zhang, Xiaojing; Yu, Boyang; Zhang, Nan; Zhang, Haojing; Wang, Chaonan; Zhang, Hongzhong

    2016-02-01

    In this study, a membrane bioreactor (MBR) was adopted for completely autotrophic nitrogen removal over nitrite (CANON) process. Inorganic carbon (IC) was step-wise decreased to analyze the IC influence on nitrogen removal and microbial communities, finally IC was elevated to study its recovery capability. The bioactivities of functional organisms were detected by batch experiments. Results showed that the bioactivity and biodiversity of aerobic ammonia-oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing bacteria (AAOB) both decreased due to the IC shortage, while nitrite-oxidizing bacteria bioactivity showed a contrary result. When the concentration ratio of IC to nitrogen (IC/N) decreased to 1.0, the nitrogen removal sharply deteriorated, which then recovered when the ratio increased to 2.5. Denaturing gradient gel electrophoresis results showed that Nitrosomonas sp. of AOB and Candidatus Brocadia fulgida of AAOB could survive in the condition of IC deficit. The prominent IC/N ratio for high-rate and stable CANON was between 1.5-2.0. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. The liquid-liquid interface as a medium to generate nanocrystalline films of inorganic materials.

    PubMed

    Rao, C N R; Kalyanikutty, K P

    2008-04-01

    Unlike the air-water interface, the organic-aqueous (liquid-liquid) interface has not been exploited sufficiently for materials synthesis. In this Account, we demonstrate how ultrathin nanocrystalline films of metals such as gold and silver as well as of inorganic materials such as semiconducting metal chalcogenides (e.g., CdS, CuS, CdSe) and oxides are readily generated at the liquid-liquid interface. What is particularly noteworthy is that single-crystalline films of certain metal chalcogenides are also obtained by this method. The as-prepared gold films at the toluene-water interface comprise fairly monodisperse nanocrystals that are closely packed, the nature and properties of the films being influenced by various reaction parameters such as reaction temperature, time, reactant concentrations, mechanical vibrations, and the viscosity of the medium. The surface plasmon band of gold is markedly red-shifted in the films due to electronic coupling between the particles. The shift of the surface plasmon band of the Au film toward higher wavelengths with an accompanying increase in intensity as a function of reaction time marks the growth of the film. Depending on the reaction temperature, the Au films show interesting electrical transport properties. Films of metals such as gold are disintegrated by the addition of alkanethiols, the effectiveness depending on the alkane chain length, clearly evidenced by shifts of the surface plasmon bands. A time evolution study of the polycrystalline Au and CdS films as well as the single-crystalline CuS films is carried out by employing atomic force microscopy. X-ray reflectivity studies reveal the formation of a monolayer of capped clusters having 13 gold atoms each, arranged in a hexagonal manner at the toluene-water interface. The measurements also reveal an extremely small value of the interfacial tension. Besides describing features of such nanocrystalline films and their mode of formation, their rheological properties have

  3. Novel approaches to the synthesis and cooperative assembly of inorganic materials utilizing block copolypeptides

    NASA Astrophysics Data System (ADS)

    Euliss, Larken E.

    Biominerals and biocomposites are highly ornate and functional materials. Nature controls the properties of these materials by organizing their organic and inorganic constituents on the atomic, molecular, nano, and micron scales. The remarkable precision and complexity of this organization is accomplished using a combination of electrostatics, hydrogen bonding, disulfide bonding, and other molecular-level interactions. The goal of the work described in this dissertation was to use the principles employed by Nature in the biological assembly of biomaterials as inspiration for developing (1) completely synthetic and novel composite materials, and (2) new general methods for the synthesis of composite materials. Specifically, block copolypeptides were used as structure-directing agents in several successful applications of this approach. One application involves the rational design of an organic polymer molecule to direct the crystallization of calcium carbonate into microspheres. I have shown that the doubly-hydrophilic block copolypeptide poly{Nepsilon-2[2-(2 methoxy-ethoxy)ethoxy]acetyl-L-lysine}100-block-poly(L-aspartate sodium salt)30 can act as the structure-directing agent in this process. In addition, control over the morphology of calcium carbonate crystals can be exerted using anionic, amphiphilic block copolypeptides, such as poly(L-aspartate sodium salt)100-block-poly(L-phenylalanine- random-L-leucine)50 and poly(L-glutamate sodium salt) 100-block-poly(L-phenylalanine-random-L-leucine) 50. I have demonstrated that microspheres of calcium carbonate can be prepared by introducing the polymer additive during crystallization. These self-assembling polymers control the precipitation of the microspheres by acting as templates for sphere formation. Another application involves the organization of magnetic nanoparticles into well-defined, soluble nanoclusters. First, I have demonstrated that highly crystalline, monodisperse maghemite (gamma-Fe2O3) nanoparticles

  4. Microbial mediated retention/transformation of organic and inorganic materials in freshwater and marine ecosystems

    EPA Science Inventory

    Aquatic ecosystems are globally connected by hydrological and biogeochemical cycles. Microorganisms inhabiting aquatic ecosystems form the basis of food webs, mediate essential element cycles, decompose natural organic matter, transform inorganic nutrients and metals, and degrad...

  5. Microbial mediated retention/transformation of organic and inorganic materials in freshwater and marine ecosystems

    EPA Science Inventory

    Aquatic ecosystems are globally connected by hydrological and biogeochemical cycles. Microorganisms inhabiting aquatic ecosystems form the basis of food webs, mediate essential element cycles, decompose natural organic matter, transform inorganic nutrients and metals, and degrad...

  6. Graphene-based structure, method of suspending graphene membrane, and method of depositing material onto graphene membrane

    DOEpatents

    Zettl, Alexander K.; Meyer, Jannik Christian

    2013-04-02

    An embodiment of a method of suspending a graphene membrane across a gap in a support structure includes attaching graphene to a substrate. A pre-fabricated support structure having the gap is attached to the graphene. The graphene and the pre-fabricated support structure are then separated from the substrate which leaves the graphene membrane suspended across the gap in the pre-fabricated support structure. An embodiment of a method of depositing material includes placing a support structure having a graphene membrane suspended across a gap under vacuum. A precursor is adsorbed to a surface of the graphene membrane. A portion of the graphene membrane is exposed to a focused electron beam which deposits a material from the precursor onto the graphene membrane. An embodiment of a graphene-based structure includes a support structure having a gap, a graphene membrane suspended across the gap, and a material deposited in a pattern on the graphene membrane.

  7. Selection and Manufacturing of Membrane Materials for Solar Sails

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G.; Seaman, Shane T.; Wilkie, W. Keats; Miyaucchi, Masahiko; Working, Dennis C.

    2013-01-01

    Commercial metallized polyimide or polyester films and hand-assembly techniques are acceptable for small solar sail technology demonstrations, although scaling this approach to large sail areas is impractical. Opportunities now exist to use new polymeric materials specifically designed for solar sailing applications, and take advantage of integrated sail manufacturing to enable large-scale solar sail construction. This approach has, in part, been demonstrated on the JAXA IKAROS solar sail demonstrator, and NASA Langley Research Center is now developing capabilities to produce ultrathin membranes for solar sails by integrating resin synthesis with film forming and sail manufacturing processes. This paper will discuss the selection and development of polymer material systems for space, and these new processes for producing ultrathin high-performance solar sail membrane films.

  8. Differential mechanisms of inorganic pyrophosphate production by plasma cell membrane glycoprotein-1 and B10 in chondrocytes.

    PubMed

    Johnson, K; Vaingankar, S; Chen, Y; Moffa, A; Goldring, M B; Sano, K; Jin-Hua, P; Sali, A; Goding, J; Terkeltaub, R

    1999-09-01

    Increased nucleoside triphosphate pyrophosphohydrolase (NTPPPH) activity in chondrocytes is associated with cartilage matrix inorganic pyrophosphate (PPi) supersaturation in chondrocalcinosis. This study compared the roles of the transforming growth factor beta (TGFbeta)-inducible plasma cell membrane glycoprotein-1 (PC-1) and the closely related B10 NTPPPH activities in chondrocyte PPi metabolism. NTPPPH expression was studied using reverse transcriptase-polymerase chain reaction and Western blotting. Transmembrane PC-1 (tmPC-1), water-soluble secretory PC-1 (secPC-1), and transmembrane B10 were expressed by adenoviral gene transfer or plasmid transfection, and expression of PPi was assessed in cultured articular chondrocytes and immortalized NTPPPH-deficient costal chondrocytes (TC28 cells). PC-1 and B10 messenger RNA were demonstrated in articular cartilages in situ, in untreated cultured normal articular chondrocytes, and in TC28 cells. Expression of tmPC-1 and secPC-1, but not B10, rendered the NTPPPH-deficient TC28 cells able to increase expression of extracellular PPi, with or without addition of TGFbeta (10 ng/ml) to the media. More plasma membrane NTPPPH activity was detected in cells transfected with tmPC-1 than in cells transfected with B10. Furthermore, confocal microscopy with immunofluorescent staining of articular chondrocytes confirmed preferential plasma membrane localization of PC-1, relative to B10. Finally, both PC-1 and B10 increased the levels of intracellular PPi, but PC-1 and B10 appeared to act principally in different intracellular compartments (Golgi and post-Golgi versus pre-Golgi, respectively). PC-1 and B10 NTPPPH activities were not redundant in chondrocytes. Although increased PC-1 and B10 expression caused elevations in intracellular PPi, the major effects of PC-1 and B10 were exerted in distinct subcellular compartments. Moreover, PC-1 (transmembrane and secreted), but not B10, increased the levels of extracellular PPi

  9. The Features of Self-Assembling Organic Bilayers Important to the Formation of Anisotropic Inorganic Materials in Microgravity Conditions

    NASA Technical Reports Server (NTRS)

    Talham, Daniel R.; Adair, James H.

    1999-01-01

    There is a growing need for inorganic anisotropic particles in a variety of materials science applications. Structural, optical, and electrical properties can be greatly augmented by the fabrication of composite materials with anisotropic microstructures or with anisotropic particles uniformly dispersed in an isotropic matrix. Examples include structural composites, magnetic and optical recording media, photographic film, certain metal and ceramic alloys, and display technologies including flat panel displays. While considerable progress has been made toward developing an understanding of the synthesis of powders composed of monodispersed, spherical particles, these efforts have not been transferred to the synthesis of anisotropic nanoparticles. The major objective of the program is to develop a fundamental understanding of the growth of anisotropic particles at organic templates, with emphasis on the chemical and structural aspects of layered organic assemblies that contribute to the formation of anisotropic inorganic particles.

  10. [Pollution prevention and control of aqueous extract of astragali radix processed with ZrO2 inorganic ceramic membrane micro-filtration].

    PubMed

    Pan, Lin-Men; Huang, Min-Yan; Guo, Li-Wei

    2012-11-01

    To study the measures for preventing and controlling the pollution of aqueous extract of Astragali Radix proceeded with inorganic ceramic membrane micro-filtration, in order to find effective measures for preventing and controlling the membrane pollution. The resistance distribution, polymer removal and changes in physical and chemical parameters of the zirconium oxide film of different pore diameters were determined to analyze the state or location of pollutants as well as the regularity of formation. Meanwhile, recoil and ultrasonic physical measures were adopted to strengthen the membrane process, in order to explore the methods for preventing and controlling the membrane pollution. When 0.2 microm of ZrO2 micro-filtrated aqueous extract of Astragali Radix, the rate of pollution was as high as 44.9%. The hole blocking resistance and the concentration polarization resistance were the main filtration resistances, while the surface deposit resistance decreased with the increase in the membrane's hold diameter; after micro-filtration, the liquid turbidity significantly reduced, with slight changes in both pH and viscosity. The 0.2 microm ZrO2 micro-filtration membrane performed better than the 0.05 microm pore size membrane in terms of conductivity. The 0. 2 microm and 0.05 microm pore diameter membranes showed better performance in the removal of pectin. The ultrasonic measure to strengthen membranes is more suitable to this system, with a flux rate up by 41.7%. The membrane optimization process adopts appropriate measures for preventing and controlling the membrane pollution, in order to reduce the membrane pollution, recover membrane performance and increase filtration efficiency.

  11. Novel organic polymer-inorganic hybrid material zinc poly(styrene-phenylvinylphosphonate)-phosphate prepared with a simple method

    SciTech Connect

    Huang Jing; Fu Xiangkai; Wang Gang; Miao Qiang

    2011-09-15

    A novel type of organic polymer-inorganic hybrid material layered crystalline zinc poly(styrene-phenylvinylphosphonate)-phosphate (ZnPS-PVPP) was synthesized under mild conditions in the absence of any template. And the ZnPS-PVPP were characterized by FT-IR, diffusion reflection UV-vis, AAS, N{sub 2} volumetric adsorption, SEM, TEM and TG. Notably, this method was entirely different from the traditional means used for preparing other zinc phosphonate. Moreover, it could be deduced that ZnPS-PVPP possessed the potential applications for catalyst supports. In the initial catalytic tests, the catalysts immobilized onto ZnPS-PVPP showed comparable or higher activity and enantioselectivity with that of catalysts reported by our group in the asymmetric epoxidation of unfunctional olefins. - Graphical Abstract: Zinc poly(styrene-phenylvinylphosphonate)-phosphate was a novel type of layered crystalline organic polymer-inorganic hybrid material prepared under mild conditions without addition of any template and could be used as heterogeneous catalyst supports. Highlights: > New types of layered crystalline inorganic-organic polymer hybrid materials zinc poly(styrene-phenylvinylphosphonate-phosphate(ZnPS-PVPP)). > ZnPS-PVPP prepared under mild condition without adding of any template. > Immobilized chiral salen Mn (III) catalysts on ZnPS-PVPP supports show comparative activity and enantioselectivity with that of on ZSPP or ZPS-PVPA.

  12. Insights into the Interactions of Amino Acids and Peptides with Inorganic Materials Using Single-Molecule Force Spectroscopy.

    PubMed

    Das, Priyadip; Duanias-Assaf, Tal; Reches, Meital

    2017-03-06

    The interactions between proteins or peptides and inorganic materials lead to several interesting processes. For example, combining proteins with minerals leads to the formation of composite materials with unique properties. In addition, the undesirable process of biofouling is initiated by the adsorption of biomolecules, mainly proteins, on surfaces. This organic layer is an adhesion layer for bacteria and allows them to interact with the surface. Understanding the fundamental forces that govern the interactions at the organic-inorganic interface is therefore important for many areas of research and could lead to the design of new materials for optical, mechanical and biomedical applications. This paper demonstrates a single-molecule force spectroscopy technique that utilizes an AFM to measure the adhesion force between either peptides or amino acids and well-defined inorganic surfaces. This technique involves a protocol for attaching the biomolecule to the AFM tip through a covalent flexible linker and single-molecule force spectroscopy measurements by atomic force microscope. In addition, an analysis of these measurements is included.

  13. Block copolymers for alkaline fuel cell membrane materials

    NASA Astrophysics Data System (ADS)

    Li, Yifan

    Alkaline fuel cells (AFCs) using anion exchange membranes (AEMs) as electrolyte have recently received considerable attention. AFCs offer some advantages over proton exchange membrane fuel cells, including the potential of non-noble metal (e.g. nickel, silver) catalyst on the cathode, which can dramatically lower the fuel cell cost. The main drawback of traditional AFCs is the use of liquid electrolyte (e.g. aqueous potassium hydroxide), which can result in the formation of carbonate precipitates by reaction with carbon dioxide. AEMs with tethered cations can overcome the precipitates formed in traditional AFCs. Our current research focuses on developing different polymer systems (blend, block, grafted, and crosslinked polymers) in order to understand alkaline fuel cell membrane in many aspects and design optimized anion exchange membranes with better alkaline stability, mechanical integrity and ionic conductivity. A number of distinct materials have been produced and characterized. A polymer blend system comprised of poly(vinylbenzyl chloride)-b-polystyrene (PVBC-b-PS) diblock copolymer, prepared by nitroxide mediated polymerization (NMP), with poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) or brominated PPO was studied for conversion into a blend membrane for AEM. The formation of a miscible blend matrix improved mechanical properties while maintaining high ionic conductivity through formation of phase separated ionic domains. Using anionic polymerization, a polyethylene based block copolymer was designed where the polyethylene-based block copolymer formed bicontinuous morphological structures to enhance the hydroxide conductivity (up to 94 mS/cm at 80 °C) while excellent mechanical properties (strain up to 205%) of the polyethylene block copolymer membrane was observed. A polymer system was designed and characterized with monomethoxy polyethylene glycol (mPEG) as a hydrophilic polymer grafted through substitution of pendent benzyl chloride groups of a PVBC

  14. A new method for synthesizing fluid inclusions in fused silica capillaries containing organic and inorganic material

    USGS Publications Warehouse

    Chou, I.-Ming; Song, Y.; Burruss, R.C.

    2008-01-01

    Considerable advances in our understanding of physicochemical properties of geological fluids and their roles in many geological processes have been achieved by the use of synthetic fluid inclusions. We have developed a new method to synthesize fluid inclusions containing organic and inorganic material in fused silica capillary tubing. We have used both round (0.3 mm OD and 0.05 or 0.1 mm ID) and square cross-section tubing (0.3 ?? 0.3 mm with 0.05 ?? 0.05 mm or 0.1 ?? 0.1 mm cavities). For microthermometric measurements in a USGS-type heating-cooling stage, sample capsules must be less than 25 mm in length. The square-sectioned capsules have the advantage of providing images without optical distortion. However, the maximum internal pressure (P; about 100 MPa at 22 ??C) and temperature (T; about 500 ??C) maintained by the square-sectioned capsules are less than those held by the round-sectioned capsules (about 300 MPa at room T, and T up to 650 ??C). The fused silica capsules can be applied to a wide range of problems of interest in fluid inclusion and hydrothermal research, such as creating standards for the calibration of thermocouples in heating-cooling stages and frequency shifts in Raman spectrometers. The fused silica capsules can also be used as containers for hydrothermal reactions, especially for organic samples, including individual hydrocarbons, crude oils, and gases, such as cracking of C18H38 between 350 and 400 ??C, isotopic exchanges between C18H38 and D2O and between C19D40 and H2O at similar temperatures. Results of these types of studies provide information on the kinetics of oil cracking and the changes of oil composition under thermal stress. When compared with synthesis of fluid inclusions formed by healing fractures in quartz or other minerals or by overgrowth of quartz at elevated P-T conditions, the new fused-silica method has the following advantages: (1) it is simple; (2) fluid inclusions without the presence of water can be formed; (3

  15. A new method for synthesizing fluid inclusions in fused silica capillaries containing organic and inorganic material

    NASA Astrophysics Data System (ADS)

    Chou, I.-Ming; Song, Yucai; Burruss, R. C.

    2008-11-01

    Considerable advances in our understanding of physicochemical properties of geological fluids and their roles in many geological processes have been achieved by the use of synthetic fluid inclusions. We have developed a new method to synthesize fluid inclusions containing organic and inorganic material in fused silica capillary tubing. We have used both round (0.3 mm OD and 0.05 or 0.1 mm ID) and square cross-section tubing (0.3 × 0.3 mm with 0.05 × 0.05 mm or 0.1 × 0.1 mm cavities). For microthermometric measurements in a USGS-type heating-cooling stage, sample capsules must be less than 25 mm in length. The square-sectioned capsules have the advantage of providing images without optical distortion. However, the maximum internal pressure ( P; about 100 MPa at 22 °C) and temperature ( T; about 500 °C) maintained by the square-sectioned capsules are less than those held by the round-sectioned capsules (about 300 MPa at room T, and T up to 650 °C). The fused silica capsules can be applied to a wide range of problems of interest in fluid inclusion and hydrothermal research, such as creating standards for the calibration of thermocouples in heating-cooling stages and frequency shifts in Raman spectrometers. The fused silica capsules can also be used as containers for hydrothermal reactions, especially for organic samples, including individual hydrocarbons, crude oils, and gases, such as cracking of C 18H 38 between 350 and 400 °C, isotopic exchanges between C 18H 38 and D 2O and between C 19D 40 and H 2O at similar temperatures. Results of these types of studies provide information on the kinetics of oil cracking and the changes of oil composition under thermal stress. When compared with synthesis of fluid inclusions formed by healing fractures in quartz or other minerals or by overgrowth of quartz at elevated P- T conditions, the new fused-silica method has the following advantages: (1) it is simple; (2) fluid inclusions without the presence of water can be

  16. Breath Figures of Nanoscale Bricks: A Universal Method for Creating Hierarchic Porous Materials from Inorganic Nanoparticles Stabilized with Mussel-Inspired Copolymers.

    PubMed

    Saito, Yuta; Shimomura, Masatsugu; Yabu, Hiroshi

    2014-09-01

    High-performance catalysts and photovoltaics are required for building an environmentally sustainable society. Because catalytic and photovoltaic reactions occur at the interfaces between reactants and surfaces, the chemical, physical, and structural properties of interfaces have been the focus of much research. To improve the performance of these materials further, inorganic porous materials with hierarchic porous architectures have been fabricated. The breath figure technique allows preparing porous films by using water droplets as templates. In this study, a valuable preparation method for hierarchic porous inorganic materials is shown. Hierarchic porous materials are prepared from surface-coated inorganic nanoparticles with amphiphilic copolymers having catechol moieties followed by sintering. Micron-scale pores are prepared by using water droplets as templates, and nanoscale pores are formed between the nanoparticles. The fabrication method allows the preparation of hierarchic porous films from inorganic nanoparticles of various shapes and materials.

  17. Ecosustainable Development of Novel Bio-inorganic Hybrid Materials as UV Protection Systems for Potential Cosmetic Applications.

    PubMed

    Villa, Carla; Lacapra, Chiara; Rosa, Roberto; Veronesi, Paolo; Leonelli, Cristina

    2015-01-01

    A new organoclay, bio-inorganic hybrid material, was successfully prepared following the "green chemistry" principles, exploiting microwave irradiation (as an alternative energetic source) in both the solvent-free synthesis of the organic filler (UVB filter) and in its hydrothermal intercalation in a sodium Bentonite clay (renewable natural inorganic source at low temperature). The organic filler is a benzylidene camphor derivative with the same cationic moiety as the well- known UV filter camphor benzalkonium methosulfate. The aim of the research was the ecosustainable development of a new UV protection model, suitable for use in cosmetic and pharmaceutical products, with potential advantages of stability, efficiency and safety compared to the commercially available UVB sunscreens. The organically modified clay was thoroughly investigated using X-ray diffraction (XRD), infrared spectroscopy (IR), thermo gravimetric analysis and differential thermal analysis (DTA). Results confirmed the complete intercalation of the organic filler in the interlayer region of the smectite clay, leading to a new bio-inorganic hybrid material with potential for cosmetic and pharmaceutical applications in the UV protection field, as confirmed by preliminary photochemical studies. This work represents the first example in the use of Na-Bentonite cationic clay (usually employed as rheological additive) as hosting agent of the synthesized quaternary UVB filter, as well as in the complete MW-assisted preparation of the organoclay, starting from the synthesis of the organic UV sunscreen to its hydrothermal intercalation.

  18. Reliable measurement of the Seebeck coefficient of organic and inorganic materials between 260 K and 460 K

    SciTech Connect

    Beretta, D.; Lanzani, G.; Bruno, P.; Caironi, M.

    2015-07-15

    A new experimental setup for reliable measurement of the in-plane Seebeck coefficient of organic and inorganic thin films and bulk materials is reported. The system is based on the “Quasi-Static” approach and can measure the thermopower in the range of temperature between 260 K and 460 K. The system has been tested on a pure nickel bulk sample and on a thin film of commercially available PEDOT:PSS deposited by spin coating on glass. Repeatability within 1.5% for the nickel sample is demonstrated, while accuracy in the measurement of both organic and inorganic samples is guaranteed by time interpolation of data and by operating with a temperature difference over the sample of less than 1 K.

  19. Remote Raman Spectroscopic Detection of Inorganic, Organic and Biological Materials to 100 m and More

    NASA Astrophysics Data System (ADS)

    Sharma, Shiv K.; Misra, Anupam K.

    2008-11-01

    We have designed and tested a portable gated-Raman system that is capable of detecting organic and inorganic bulk chemicals over stand-off distances of 100 m and more during day and night time. Utilizing a 532 nm laser pulse (~35 mJ/pulse), Raman spectra of several organic and inorganic compounds have been measured with the portable Raman instrument over a distance of 100 m. Remote Raman spectra, obtained with a very short gate (2 micro second), from a variety of inorganic minerals such as calcite (CaCO3), α-quartz (α-SiO2), barite (BaSO4), and FeSO4.7H2O, and organic compounds such as acetone, methanol, 2-propanol and naphthalene showed all major bands required for unambiguous chemical identification. We also measured the Raman and fluorescence spectra of plant leaves, tomato, and chicken eggshell excited with a 532 nm, 20 Hz pulsed laser and accumulated over 200 laser shots (10-s integration time) at 110 m with good signal-to-noise ratio. The results of these investigations show that remote Raman spectroscopy over a distance of 100 m can be used to identify Raman fingerprints of both inorganic, organic, and some biological compounds on planetary surfaces and could be useful for environmental monitoring.

  20. Simulations of inorganic-bioorganic interfaces to discover new materials: insights, comparisons to experiment, challenges, and opportunities.

    PubMed

    Heinz, Hendrik; Ramezani-Dakhel, Hadi

    2016-01-21

    Natural and man-made materials often rely on functional interfaces between inorganic and organic compounds. Examples include skeletal tissues and biominerals, drug delivery systems, catalysts, sensors, separation media, energy conversion devices, and polymer nanocomposites. Current laboratory techniques are limited to monitor and manipulate assembly on the 1 to 100 nm scale, time-consuming, and costly. Computational methods have become increasingly reliable to understand materials assembly and performance. This review explores the merit of simulations in comparison to experiment at the 1 to 100 nm scale, including connections to smaller length scales of quantum mechanics and larger length scales of coarse-grain models. First, current simulation methods, advances in the understanding of chemical bonding, in the development of force fields, and in the development of chemically realistic models are described. Then, the recognition mechanisms of biomolecules on nanostructured metals, semimetals, oxides, phosphates, carbonates, sulfides, and other inorganic materials are explained, including extensive comparisons between modeling and laboratory measurements. Depending on the substrate, the role of soft epitaxial binding mechanisms, ion pairing, hydrogen bonds, hydrophobic interactions, and conformation effects is described. Applications of the knowledge from simulation to predict binding of ligands and drug molecules to the inorganic surfaces, crystal growth and shape development, catalyst performance, as well as electrical properties at interfaces are examined. The quality of estimates from molecular dynamics and Monte Carlo simulations is validated in comparison to measurements and design rules described where available. The review further describes applications of simulation methods to polymer composite materials, surface modification of nanofillers, and interfacial interactions in building materials. The complexity of functional multiphase materials creates

  1. A new anionic exchange stir bar sorptive extraction coating based on monolithic material for the extraction of inorganic anion.

    PubMed

    Huang, Xiaojia; Lin, Jianbing; Yuan, Dongxing

    2010-07-23

    A novel anionic exchange stir bar sorptive extraction (SBSE) coating based on poly(2-(methacryloyloxy)ethyltrimethylammonium chloride-co-divinylbenzene) monolithic material for the extraction of inorganic anion was prepared. The effect of preparation conditions such as ratio of functional monomer to cross-linker, content of porogenic solvent on the extraction efficiencies were investigated in detailed. The monolithic material was characterized by elemental analysis, scanning electron microscopy and infrared spectroscopy. In order to investigate the extraction capacity of the new coating for inorganic anion, the new SBSE was combined with ionic chromatography with conductivity detection, Br-, NO3-, PO4(3-) and SO4(2-) were selected as detected solutes. Several extractive parameters, including pH value and ionic strength in sample matrix, desorption solvent, extraction and desorption time were optimized. The results showed that strongly ionic strength did not favor the extraction of anlaytes. Under the optimum experimental conditions, low detection limits (S/N=3) and quantification limits (S/N=10) of the proposed method for the target anions were achieved within the range of 0.92-2.62 and 3.03-9.25 microg/L, respectively. The method also showed good linearity, simplicity, practicality and low cost for the extraction inorganic anions. Finally, the proposed method was successfully used to detect the two different trademarks of commercial purified water with satisfactory recovery in the range of 70.0-92.6%. To the best of our knowledge, this is the first to use SBSE to enrich inorganic anions.

  2. Organic-inorganic crosslinked and hybrid membranes derived from sulfonated poly(arylene ether sulfone)/silica via sol-gel process

    NASA Astrophysics Data System (ADS)

    Feng, Shaoguang; Shang, Yuming; Wang, Yingzi; Xie, Xiaofeng; Mathur, V. K.; Xu, Jingming

    A series of covalently crosslinkable organic-inorganic hybrid membranes have been prepared from sulfonated poly(arylene ether sulfone) (SPAES) with pendant propenyl moiety and various amounts of vinyl substituted silica via sol-gel process which are then thermally crosslinked in the presence of benzoyl peroxide (BPO) initiator. The obtained membranes are characterized in terms of oxidative stability, thermal property, ion exchange capacity (IEC), water uptake, swelling ratio in methanol aqueous solution, proton conductivity, and methanol permeability coefficient. The results indicate that the oxidative stability and thermal stability of the hybrid membranes are improved. Moreover, introduction of silica reduces the water uptake and methanol swelling of membranes. The swelling ratio of membranes in 2 mol L -1 methanol aqueous solution at 80 °C slowly decreases from 26 to 19% with the increase of SiO 2 content from 0 to 12 wt.%. Furthermore, with the increase in silica content, the methanol permeability coefficient of the hybrid membranes decreases at first and then increases. When the silica content reaches 8 wt.%, the methanol permeability coefficient is at the minimum of 6.02 × 10 -7 cm 2 s -1, a 2.64-fold decrease compared with that of the pristine SPAES membrane. Moreover, the proton conductivity is found to be at about 95% of that of pristine polymer at that silica content.

  3. Phase transfer membrane supported liquid-liquid-liquid microextraction combined with large volume sample injection capillary electrophoresis-ultraviolet detection for the speciation of inorganic and organic mercury.

    PubMed

    Li, Pingjing; Zhang, Xing; Hu, Bin

    2011-12-30

    In this paper, a novel sample pretreatment technique termed phase transfer based liquid-liquid-liquid microextraction (PT-LLLME) was proposed for the simultaneous extraction of inorganic and organic mercury species. In PT-LLLME, an intermediate solvent (acetonitrile) was added into the donor phase to improve the contacting between target mercury species and complexing reagent. Meanwhile, a membrane supported (MS)-LLLME unit was designed to realize the PT-LLLME procedure. By using nylon membrane as supporting carrier, larger than 50 μL of acceptor solution could be hung up. Following PT/MS-LLLME, the acceptor solutions were directly analyzed by large volume sample stacking capillary electrophoresis/ultraviolet detection (LVSS-CE/UV). Accordingly, a new method of PT/MS-LLLME combined with LVSS-CE/UV was developed for the simultaneous speciation of inorganic and organic mercury species. Parameters affecting the extraction efficiency of PT/MS-LLLME were investigated in details. Under the optimized conditions, enrichment factors (EFs) ranging from 160- to 478-fold were obtained for the extraction of target mercury species by PT/MS-LLLME. By combining PT/MS-LLLME with LVSS-CE/UV, EFs were magnified up to 12,138-fold and the limits of detection (at a signal-to-noise ratio of 3) were at sub ppb level. The established approach of PT/MS-LLLME-LVSS-CE/UV was successfully applied to simultaneous determination of inorganic and organic mercury species in biological samples and environmental water samples.

  4. Microwave-assisted Synthesis and Biomedical Applications of Inorganic Nanostructured Materials

    NASA Astrophysics Data System (ADS)

    Jia, Juncai

    Inorganic nanostrucured materials have attracted much attention owing to their unique features and important applications in biomedicine. This thesis describes the development of rapid and efficient approaches to synthesize inorganic nanostructures, and introduces some potential applications. Magnetic nanostructures, such as necklace-like FeNi3 magnetic nanochains and magnetite nanoclusters, were synthesized by an efficient microwave-hydrothermal process. They were used as magnetic resonance imaging (MRI) contrast agents. Magnetic FeNi3 nanochains were synthesized by reducing iron(III) acetylacetonate and nickel(II) acetylacetonate with hydrazine in ethylene glycol solution without any template under microwave irradiation. This was a rapid and economical route based on an efficient microwave-hydrothermal process which significantly shortened the synthesis time to mins. The morphologies and size of the materials could be effectively controlled by adjusting the reaction conditions, such as, the reaction time, temperature and concentrations of reactants. The morphology and composition of the as-prepared products were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The size of the aligned nanospheres in the magnetic FeNi 3 chains could be adjusted from 150nm to 550nm by increasing the amounts of the precursors. Magnetic measurements revealed that the FeNi3 nanochains showed enhanced coercivity and saturation magnetization. Toxicity tests by exposure of FeNi3 nanochains to the zebrafish larvae showed that the as-prepared nanochains were biocompatible. In vitro magnetic resonance imaging (MRI) confirms the effectiveness of the FeNi 3 nanochains as sensitive MRI probes. Magnetite nanoclusters were synthesized by reducing iron(III) acetylacetonate with hydrazine in ethylene glycol under microwave irradiation. The nanoclusters showed enhanced T2

  5. Structural direction of hybrid organic-inorganic materials: Synthesis of vanadium oxyfluoride, copper vanadate, and copper molybdate solid state materials through solvuthermal and solution methods

    NASA Astrophysics Data System (ADS)

    Deburgomaster, Paul

    The vast structural complexity of inorganic oxides with structure directing organocations, nitrogen containing ligands and organophosphonate ligands was explored. The hydrothermal reaction conditions utilized herein include the variables of temperature, pH, fill volume and stoichiometry. The systems studied included: (1) the complex materials rendered from reactions of organoamine cations on the structure of vanadium oxides, oxyfluorides and fluorides. As with other systems, the influence of the mineralizer HF was not limited to pH as fluorine incorporation was not uncommon. In specific cases this coincided with reduction of vanadium sites. (2) The copper-organonitrogen ligand/vanadium oxide/aromatic phosphonate system has been studied. The rigid aromatic di- and tri-phosphonate tethers have provided a series of materials which are structurally distinct from the previously investigated aliphatic series. The inclusion of copper-coordinated nitrogen bi- and tri-dentate ligands also provided structural diversity. Product composition was highly influenced by the HF/V ratio. A similar study was conducted with the ligand 1,4-carboxy-phenylphosphonic acid. (3) The preparation of a series of bimetallic organic-inorganic hybrid materials of the M(II)/VxOy/organonitrogen ligand class was further evidence of the utility of thermodynamically driven hydrothermal synthesis. (4) While decomposition of the spherical Keplerate molybdenum clusters is encountered under hydrothermal conditions, this highly soluble form of molybdate was investigated for the development of hybrid organic-inorganic room temperature solution synthesis.

  6. A Statistical Learning Framework for Materials Science: Application to Elastic Moduli of k-nary Inorganic Polycrystalline Compounds

    NASA Astrophysics Data System (ADS)

    de Jong, Maarten; Chen, Wei; Notestine, Randy; Persson, Kristin; Ceder, Gerbrand; Jain, Anubhav; Asta, Mark; Gamst, Anthony

    2016-10-01

    Materials scientists increasingly employ machine or statistical learning (SL) techniques to accelerate materials discovery and design. Such pursuits benefit from pooling training data across, and thus being able to generalize predictions over, k-nary compounds of diverse chemistries and structures. This work presents a SL framework that addresses challenges in materials science applications, where datasets are diverse but of modest size, and extreme values are often of interest. Our advances include the application of power or Hölder means to construct descriptors that generalize over chemistry and crystal structure, and the incorporation of multivariate local regression within a gradient boosting framework. The approach is demonstrated by developing SL models to predict bulk and shear moduli (K and G, respectively) for polycrystalline inorganic compounds, using 1,940 compounds from a growing database of calculated elastic moduli for metals, semiconductors and insulators. The usefulness of the models is illustrated by screening for superhard materials.

  7. A Statistical Learning Framework for Materials Science: Application to Elastic Moduli of k-nary Inorganic Polycrystalline Compounds

    SciTech Connect

    de Jong, Maarten; Chen, Wei; Notestine, Randy; Persson, Kristin; Ceder, Gerbrand; Jain, Anubhav; Asta, Mark; Gamst, Anthony

    2016-10-03

    Materials scientists increasingly employ machine or statistical learning (SL) techniques to accelerate materials discovery and design. Such pursuits benefit from pooling training data across, and thus being able to generalize predictions over, k-nary compounds of diverse chemistries and structures. This work presents a SL framework that addresses challenges in materials science applications, where datasets are diverse but of modest size, and extreme values are often of interest. Our advances include the application of power or Hölder means to construct descriptors that generalize over chemistry and crystal structure, and the incorporation of multivariate local regression within a gradient boosting framework. The approach is demonstrated by developing SL models to predict bulk and shear moduli (K and G, respectively) for polycrystalline inorganic compounds, using 1,940 compounds from a growing database of calculated elastic moduli for metals, semiconductors and insulators. The usefulness of the models is illustrated by screening for superhard materials.

  8. A Statistical Learning Framework for Materials Science: Application to Elastic Moduli of k-nary Inorganic Polycrystalline Compounds

    PubMed Central

    de Jong, Maarten; Chen, Wei; Notestine, Randy; Persson, Kristin; Ceder, Gerbrand; Jain, Anubhav; Asta, Mark; Gamst, Anthony

    2016-01-01

    Materials scientists increasingly employ machine or statistical learning (SL) techniques to accelerate materials discovery and design. Such pursuits benefit from pooling training data across, and thus being able to generalize predictions over, k-nary compounds of diverse chemistries and structures. This work presents a SL framework that addresses challenges in materials science applications, where datasets are diverse but of modest size, and extreme values are often of interest. Our advances include the application of power or Hölder means to construct descriptors that generalize over chemistry and crystal structure, and the incorporation of multivariate local regression within a gradient boosting framework. The approach is demonstrated by developing SL models to predict bulk and shear moduli (K and G, respectively) for polycrystalline inorganic compounds, using 1,940 compounds from a growing database of calculated elastic moduli for metals, semiconductors and insulators. The usefulness of the models is illustrated by screening for superhard materials. PMID:27694824

  9. A Statistical Learning Framework for Materials Science: Application to Elastic Moduli of k-nary Inorganic Polycrystalline Compounds.

    PubMed

    de Jong, Maarten; Chen, Wei; Notestine, Randy; Persson, Kristin; Ceder, Gerbrand; Jain, Anubhav; Asta, Mark; Gamst, Anthony

    2016-10-03

    Materials scientists increasingly employ machine or statistical learning (SL) techniques to accelerate materials discovery and design. Such pursuits benefit from pooling training data across, and thus being able to generalize predictions over, k-nary compounds of diverse chemistries and structures. This work presents a SL framework that addresses challenges in materials science applications, where datasets are diverse but of modest size, and extreme values are often of interest. Our advances include the application of power or Hölder means to construct descriptors that generalize over chemistry and crystal structure, and the incorporation of multivariate local regression within a gradient boosting framework. The approach is demonstrated by developing SL models to predict bulk and shear moduli (K and G, respectively) for polycrystalline inorganic compounds, using 1,940 compounds from a growing database of calculated elastic moduli for metals, semiconductors and insulators. The usefulness of the models is illustrated by screening for superhard materials.

  10. A Statistical Learning Framework for Materials Science: Application to Elastic Moduli of k-nary Inorganic Polycrystalline Compounds

    DOE PAGES

    de Jong, Maarten; Chen, Wei; Notestine, Randy; ...

    2016-10-03

    Materials scientists increasingly employ machine or statistical learning (SL) techniques to accelerate materials discovery and design. Such pursuits benefit from pooling training data across, and thus being able to generalize predictions over, k-nary compounds of diverse chemistries and structures. This work presents a SL framework that addresses challenges in materials science applications, where datasets are diverse but of modest size, and extreme values are often of interest. Our advances include the application of power or Hölder means to construct descriptors that generalize over chemistry and crystal structure, and the incorporation of multivariate local regression within a gradient boosting framework. Themore » approach is demonstrated by developing SL models to predict bulk and shear moduli (K and G, respectively) for polycrystalline inorganic compounds, using 1,940 compounds from a growing database of calculated elastic moduli for metals, semiconductors and insulators. The usefulness of the models is illustrated by screening for superhard materials.« less

  11. Laser-induced breakdown spectroscopy (LIBS) technique for the determination of the chemical composition of complex inorganic materials

    NASA Astrophysics Data System (ADS)

    Łazarek, Łukasz; Antończak, Arkadiusz J.; Wójcik, Michał R.; Kozioł, Paweł E.; Stepak, Bogusz; Abramski, Krzysztof M.

    2014-08-01

    Laser-induced breakdown spectroscopy (LIBS) is a fast, fully optical method, that needs little or no sample preparation. In this technique qualitative and quantitative analysis is based on comparison. The determination of composition is generally based on the construction of a calibration curve namely the LIBS signal versus the concentration of the analyte. Typically, to calibrate the system, certified reference materials with known elemental composition are used. Nevertheless, such samples due to differences in the overall composition with respect to the used complex inorganic materials can influence significantly on the accuracy. There are also some intermediate factors which can cause imprecision in measurements, such as optical absorption, surface structure, thermal conductivity etc. This paper presents the calibration procedure performed with especially prepared pellets from the tested materials, which composition was previously defined. We also proposed methods of post-processing which allowed for mitigation of the matrix effects and for a reliable and accurate analysis. This technique was implemented for determination of trace elements in industrial copper concentrates standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for contents of three elements, that is silver, cobalt and vanadium. It has been shown that the described technique can be used to qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates.

  12. Recycling of inorganic waste in monolithic and cellular glass-based materials for structural and functional applications.

    PubMed

    Rincón, Acacio; Marangoni, Mauro; Cetin, Suna; Bernardo, Enrico

    2016-07-01

    The stabilization of inorganic waste of various nature and origin, in glasses, has been a key strategy for environmental protection for the last decades. When properly formulated, glasses may retain many inorganic contaminants permanently, but it must be acknowledged that some criticism remains, mainly concerning costs and energy use. As a consequence, the sustainability of vitrification largely relies on the conversion of waste glasses into new, usable and marketable glass-based materials, in the form of monolithic and cellular glass-ceramics. The effective conversion in turn depends on the simultaneous control of both starting materials and manufacturing processes. While silica-rich waste favours the obtainment of glass, iron-rich wastes affect the functionalities, influencing the porosity in cellular glass-based materials as well as catalytic, magnetic, optical and electrical properties. Engineered formulations may lead to important reductions of processing times and temperatures, in the transformation of waste-derived glasses into glass-ceramics, or even bring interesting shortcuts. Direct sintering of wastes, combined with recycled glasses, as an example, has been proven as a valid low-cost alternative for glass-ceramic manufacturing, for wastes with limited hazardousness. The present paper is aimed at providing an up-to-date overview of the correlation between formulations, manufacturing technologies and properties of most recent waste-derived, glass-based materials. © 2016 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  13. Recycling of inorganic waste in monolithic and cellular glass‐based materials for structural and functional applications

    PubMed Central

    Rincón, Acacio; Marangoni, Mauro; Cetin, Suna

    2016-01-01

    Abstract The stabilization of inorganic waste of various nature and origin, in glasses, has been a key strategy for environmental protection for the last decades. When properly formulated, glasses may retain many inorganic contaminants permanently, but it must be acknowledged that some criticism remains, mainly concerning costs and energy use. As a consequence, the sustainability of vitrification largely relies on the conversion of waste glasses into new, usable and marketable glass‐based materials, in the form of monolithic and cellular glass‐ceramics. The effective conversion in turn depends on the simultaneous control of both starting materials and manufacturing processes. While silica‐rich waste favours the obtainment of glass, iron‐rich wastes affect the functionalities, influencing the porosity in cellular glass‐based materials as well as catalytic, magnetic, optical and electrical properties. Engineered formulations may lead to important reductions of processing times and temperatures, in the transformation of waste‐derived glasses into glass‐ceramics, or even bring interesting shortcuts. Direct sintering of wastes, combined with recycled glasses, as an example, has been proven as a valid low‐cost alternative for glass‐ceramic manufacturing, for wastes with limited hazardousness. The present paper is aimed at providing an up‐to‐date overview of the correlation between formulations, manufacturing technologies and properties of most recent waste‐derived, glass‐based materials. © 2016 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:27818564

  14. PREFACE: International Scientific Conference on Radiation-Thermal Effects and Processes in Inorganic Materials 2015 (RTEP2015)

    NASA Astrophysics Data System (ADS)

    2016-02-01

    The International Scientific Conference "Radiation-Thermal Effects and Processes in Inorganic Materials" is a traditional representative forum devoted to the discussion of fundamental problems of radiation physics and its technical applications. The first nine conferences were held fourfold in Tomsk, Ulan-Ude (Russia), Bishkek (Kyrgyzstan), Tashkent (Uzbekistan), Sharm El Sheikh (Egypt), the island of Cyprus. The XI conference was held in Tomsk, Russia. The program of the Conference covers a wide range of technical areas and modern aspects of radiation physics, its applications and related matters. Topics of interest include, but are not limited to: • Physical and chemical phenomena in inorganic materials in radiation, electrical and thermal fields; • Research methods and equipment modification states and properties of materials; • Technologies and equipment for their implementation; • The use of radiation-thermal processes in nanotechnology; • Adjacent to the main theme of the conference issues The conference was attended by leading scientists from countries near and far abroad who work in the field of radiation physics of solid state and of radiation material science. The School-Conference of Young Scientists was also held during the conference. The event was held with the financial support of the Russian Foundation for Basic Research, projects No. 15-02-20616.

  15. Morphology and properties of organic-inorganic hybrid materials involving TiO2 and poly(epsilon-caprolactone), a biodegradable aliphatic polyester.

    PubMed

    Li, Rui; Nie, Kangming; Pang, Wenmin; Zhu, Qingren

    2007-10-01

    The novel biodegradable poly(epsilon-caprolactone)/titanium dioxide hybrid materials were prepared via in situ sol-gel process of tetrabutyl titanate (TBT) as inorganic precursor in the presence of PCL. The relationships between morphology, microphase separation, crystalline structure, and properties were investigated by means of XPS, SEM, XRD, DSC, and in vitro degradation test. The microstructures of the bulk hybrids display two-phase microscopic separation on the nanometer scale, which domain is 20-80 nm. The surface morphology and intermolecular bonding interaction are significantly dependent on inorganic component. The relative crystalline degrees of PCL/TiO(2) hybrid nanocomposite materials were controlled by both inorganic component and hydrogen bonding special interaction. The hybrid nanocomposite materials with TiO(2) showed faster biodegradation rate than that of pure PCL itself, and the transparency corresponding to microstructure increase with increase of inorganic component content.

  16. Investigations of inorganic and organic fouling behaviors, antifouling and cleaning strategies for pressure retarded osmosis (PRO) membrane using seawater desalination brine and wastewater.

    PubMed

    Han, Gang; Zhou, Jieliang; Wan, Chunfeng; Yang, Tianshi; Chung, Tai-Shung

    2016-10-15

    By employing seawater desalination brine (SWBr) and wastewater brine (WWBr) as the feed pair, membrane fouling behaviors as well as antifouling and cleaning strategies for the state-of-the-art thin-film composite polyethersulfone (TFC-PES) hollow fiber membrane have been systematically investigated under pressure retarded osmosis (PRO) operations. Fouling on the polyamide selective layer induced by the SWBr draw solution is relatively mild because of the outstanding membrane rejection and the hydration antifouling layer formed by the permeating water. However, using WWBr as the feed causes fast and severe internal concentration polarization (ICP) and fouling within the porous PES substrate, which result in dramatic flux and power density declines. In addition, the PRO fouling upon and within the porous substrate is highly irreversible. Experimental data show that both anti-scalant pretreatment and pH adjustment of WWBr could effectively mitigate inorganic fouling, while increasing feed flow velocity along the substrate surface is ineffective for fouling control. To clean the fouled membranes, hydraulic-pressure induced backwash and flushing with alkaline and NaOCl solutions on the fouled surface are effective strategies to remove foulants and regenerate membranes with a flux recovery of 83-90%. However, osmotic backwash shows low cleaning efficiency in PRO. In summary, a proper combination of feed pretreatment and membrane cleaning strategies has been demonstrated in this study to sustain PRO operations with a high water flux and power density. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Protective effect of Premna tomentosa (L. Verbenaceae) extract on membrane-bound phosphatases and inorganic cations transport in acetaminophen-induced hepatotoxicity rats.

    PubMed

    Devi, K Pandima; Sreepriya, M; Balakrishna, K; Devaki, T

    2004-08-01

    Hepatic injury elicits intracellular stress that leads to peroxidation of membrane lipids accompanied by alteration of structural and functional characteristics of membrane, which affect the activities of membrane-bound ATPases. The present study appraised the membrane protective effect of Premna tomentosa, a hepatoprotective drug used in Indian traditional medicine. Wistar strain rats were pre-treated with Premna tomentosa extract (750 mg/kg, orally) for 15 days, 24 h prior to administration of acetaminophen (640 mg/kg, orally). During acetaminophen intoxication, the levels of membrane-bound enzymes were significantly decreased, total ATPase (1.63-fold), Mg(2+)ATPase (1.9-fold), Ca(2+)ATPase (1.33-fold) and Na(+)K(+)ATPase (1.73-fold) which was accompanied by changes in the levels of inorganic cations N+, K+ and Ca2+. These alterations were prevented by Premna tomentosa extract pre-treatment, which shows that Premna tomentosa supplementation could exert a beneficial effect against liver injury-induced membrane damage. The potential of the plant might be credited to the presence of antioxidant compound limonene in the plant.

  18. Interconnected porosity analysis by 3D X-ray microtomography and mechanical behavior of biomimetic organic-inorganic composite materials.

    PubMed

    Alonso-Sierra, S; Velázquez-Castillo, R; Millán-Malo, B; Nava, R; Bucio, L; Manzano-Ramírez, A; Cid-Luna, H; Rivera-Muñoz, E M

    2017-11-01

    Hydroxyapatite-based materials have been used for dental and biomedical applications. They are commonly studied due to their favorable response presented when used for replacement of bone tissue. Those materials should be porous enough to allow cell penetration, internal tissue growth, vascular incursion and nutrient supply. Furthermore, their morphology should be designed to guide the growth of new bone tissue in anatomically applicable ways. In this work, the mechanical performance and 3D X-ray microtomography (X-ray μCT) study of a biomimetic, organic-inorganic composite material, based on hydroxyapatite, with physicochemical, structural, morphological and mechanical properties very similar to those of natural bone tissue is reported. Ceramic pieces in different shapes and several porous sizes were produced using a Modified Gel Casting Method. Pieces with a controlled and 3D hierarchical interconnected porous structure were molded by adding polymethylmethacrylate microspheres. Subsequently, they were subject to a thermal treatment to remove polymers and to promote a sinterization of the ceramic particles, obtaining a HAp scaffold with controlled porosity. Then, two different organic phases were used to generate an organic-inorganic composite material, so gelatin and collagen, which was extracted from bovine tail, were used. The biomimetic organic-inorganic composite material was characterized by Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, X-ray Diffraction, Fourier Transform Infrared Spectroscopy and 3D X-ray microtomography techniques. Mechanical properties were characterized in compression tests, obtaining a dramatic and synergic increment in the mechanical properties due to the chemical and physical interactions between the two phases and to the open-cell cellular behavior of the final composite material; the maximum compressive strength obtained corresponds to about 3 times higher than that reported for natural cancellous bone. The

  19. Thin films and assemblies of photosensitive membrane proteins and colloidal nanocrystals for engineering of hybrid materials with advanced properties.

    PubMed

    Zaitsev, Sergei Yu; Solovyeva, Daria O; Nabiev, Igor

    2012-11-15

    The development and study of nano-bio hybrid materials engineered from membrane proteins (the key functional elements of various biomembranes) and nanoheterostructures (inorganic colloidal nanoparticles, transparent electrodes, and films) is a rapidly growing field at the interface of materials and life sciences. The mainspring of the development of bioinspired materials and devices is the fact that biological evolution has solved many problems similar to those that humans are attempting to solve in the field of light-harvesting and energy-transferring inorganic compounds. Along this way, bioelectronics and biophotonics have shown considerable promise. A number of proteins have been explored in terms of bioelectronic device applications, but bacteriorhodopsin (bR, a photosensitive membrane protein from purple membranes of the bacterium Halobacterium salinarum) and bacterial photosynthetic reaction centres have received the most attention. The energy harvesting in plants has a maximum efficiency of 5%, whereas bR, in the absence of a specific light-harvesting system, allows bacteria to utilize only 0.1-0.5% of the solar light. Recent nano-bioengineering approaches employing colloidal semiconductor and metal nanoparticles conjugated with biosystems permit the enhancement of the light-harvesting capacity of photosensitive proteins, thus providing a strong impetus to protein-based device optimisation. Fabrication of ultrathin and highly oriented films from biological membranes and photosensitive proteins is the key task for prospective bioelectronic and biophotonic applications. In this review, the main advances in techniques of preparation of such films are analyzed. Comparison of the techniques for obtaining thin films leads to the conclusion that the homogeneity and orientation of biomembrane fragments or proteins in these films depend on the method of their fabrication and increase in the following order: electrophoretic sedimentation < Langmuir-Blodgett and

  20. Two inorganic-organic hybrid materials based on polyoxometalate anions and methylene blue: Preparations, crystal structures and properties

    SciTech Connect

    Nie Shanshan; Zhang Yaobin; Liu Bin; Li Zuoxi; Hu Huaiming; Xue Ganglin; Fu Feng; Wang Jiwu

    2010-12-15

    Two novel inorganic-organic hybrid materials based on an organic dye cation methylene blue (MB) and Lindqvist-type POM polyanions, [C{sub 22}H{sub 18}N{sub 3}S]{sub 2}Mo{sub 6}O{sub 19} 2DMF (1) and [C{sub 22}H{sub 18}N{sub 3}S]{sub 2}W{sub 6}O{sub 19} 2DMF (2) were synthesized under ambient conditions and characterized by CV, IR spectroscopy, solid diffuse reflectance spectrum, UV-vis spectra in DMF solution, luminescent spectrum and single crystal X-ray diffraction. Crystallographic data reveal that compounds 1 and 2 are isostructural and both crystallize in the triclinic space group P1-bar . Their crystal structures present that the layers of organic molecules and inorganic anions array alternatively, and there exist strong {pi}...{pi} stacking interactions between dimeric MB cations and near distance interactions among organic dye cations, Lindqvist-type POM polyanions and DMF molecules. The solid diffuse reflectance spectra and UV-vis spectra in DMF solution appear new absorption bands ascribed to the charge-transfer transition between the cationic MB donor and the POM acceptors. Studies of the photoluminescent properties show that the formation of 1 and 2 lead to the fluorescence quenching of starting materials. -- Graphical abstract: Their crystal structures present that the layers of organic molecules and inorganic anions array alternatively, and there exist strong {pi}...{pi} stacking interactions between dimeric MB cations. Display Omitted

  1. [Study on spectroscopic characterization and property of PES/ micro-nano cellulose composite membrane material].

    PubMed

    Tang, Huan-Wei; Zhang, Li-Ping; Li, Shuai; Zhao, Guang-Jie; Qin, Zhu; Sun, Su-Qin

    2010-03-01

    In the present paper, the functional groups of PES/micro-nano cellulose composite membrane materials were characterized by Fourier transform infrared spectroscopy (FTIR). Also, changes in crystallinity in composite membrane materials were analyzed using X-ray diffraction (XRD). The effects of micro-nano cellulose content on hydrophilic property of composite membrane material were studied by measuring hydrophilic angle. The images of support layer structure of pure PES membrane material and composite membrane material were showed with scanning electron microscope (SEM). These results indicated that in the infrared spectrogram, the composite membrane material had characteristic peaks of both PES and micro-nano cellulose without appearance of other new characteristics peaks. It revealed that there were no new functional groups in the composite membrane material, and the level of molecular compatibility was achieved, which was based on the existence of inter-molecular hydrogen bond association between PES and micro-nano cellulose. Due to the existence of micro-nano cellulose, the crystallinity of composite membrane material was increased from 37.7% to 47.9%. The more the increase in micro-nano cellulose mass fraction, the better the van de Waal force and hydrogen bond force between composite membrane material and water were enhanced. The hydrophilic angle of composite membrane material was decreased from 55.8 degrees to 45.8 degrees and the surface energy was raised from 113.7 to 123.5 mN x m(-2). Consequently, the hydrophilic property of composite membrane material was improved. The number of pores in the support layer of composite membrane material was lager than that of pure PES membrane. Apparently, pores were more uniformly distributed.

  2. Dual cross-linked organic-inorganic hybrid polymer electrolyte membranes based on quaternized poly(ether ether ketone) and (3-aminopropyl)triethoxysilane

    NASA Astrophysics Data System (ADS)

    Zhang, Na; Wang, Baolong; Zhao, Chengji; Zhang, Yurong; Bu, Fanzhe; Cui, Ying; Li, Xuefeng; Na, Hui

    2015-02-01

    Quaternized poly(ether ether ketone)s (QPEEKs) are synthesized to absorb phosphoric acid (PA) and used as high temperature proton exchange membranes (HTPEMs). In order to improve their oxidative and mechanical stability without sacrificing proton conductivities, a series of dual cross-linked organic-inorganic hybrid membranes are prepared using (3-aminopropyl)triethoxysilane (APTES) as a cross-linker. The amine of APTES reacts with two benzyl bromide groups to build the primary cross-linking network. The Si-O-Si network generated by the hydrolysis of triethoxysilane in APTES is the secondary cross-linking network. The dual cross-linking hybrid networks improve the mechanical and oxidative stability of PA doped membranes. They can endure up to 15.3 h in 3 wt.% H2O2, 4 ppm Fe2+ Fenton solution at 80 °C. During the hydrolysis of triethoxysilane, the release of small molecules (H2O and C2H5OH) forms many pores in surfaces and interior of membranes. These pores and the resulted Si-OH groups corporately enhance the PA absorbing ability and proton conductivity. The highest proton conductivity is 61.7 mS cm-1 for PA-QPEEK-10%APTES at 200 °C under anhydrous condition. These membranes show great potential to be used in HTPEM fuel cell.

  3. Nano-Ablation of Inorganic Materials Using Laser Plasma Soft X-rays at around 10 nm

    NASA Astrophysics Data System (ADS)

    Makimura, Tetsuya; Miyamoto, Hisao; Uchida, Satoshi; Fujimori, Takashige; Niino, Hiroyuki; Murakami, Kouichi

    2006-06-01

    We have investigated the direct nanomachining of inorganic materials using laser plasma soft X-rays (LPSXs). LPSXs were generated by the irradiation of Ta targets with Q-switched 532 nm Nd:YAG laser light at an energy density of ˜104 J/cm2. Under this condition, Ta plasma emits soft X-rays at around 10 nm. The LPSXs were focused on the surfaces of inorganic materials, using an ellipsoidal mirror that we desined so as to focus LPSXs at around 10 nm efficiently. We found that synthetic quartz glass, fused silica, Pyrex, LiF, CaF2, Al2O3, and LiNbO3 can be machined. Typically, silica glass is ablated at 47 nm/shot, and it has a surface roughness less than 10 nm after 10 shots. To demonstrate lateral resolution, we fabricated a WSi contact mask with 200-nm-pitch line-and-space patterns on quartz glass. After soft X-ray irradiation, trench structures with a width of 70 nm were clearly observed.

  4. Two inorganic-organic hybrid materials based on polyoxometalate anions and methylene blue: Preparations, crystal structures and properties

    NASA Astrophysics Data System (ADS)

    Nie, Shanshan; Zhang, Yaobin; Liu, Bin; Li, Zuoxi; Hu, Huaiming; Xue, Ganglin; Fu, Feng; Wang, Jiwu

    2010-12-01

    Two novel inorganic-organic hybrid materials based on an organic dye cation methylene blue (MB) and Lindqvist-type POM polyanions, [C 22H 18N 3S] 2Mo 6O 19 2DMF (1) and [C 22H 18N 3S] 2W 6O 19 2DMF (2) were synthesized under ambient conditions and characterized by CV, IR spectroscopy, solid diffuse reflectance spectrum, UV-vis spectra in DMF solution, luminescent spectrum and single crystal X-ray diffraction. Crystallographic data reveal that compounds 1 and 2 are isostructural and both crystallize in the triclinic space group P1¯. Their crystal structures present that the layers of organic molecules and inorganic anions array alternatively, and there exist strong π···π stacking interactions between dimeric MB cations and near distance interactions among organic dye cations, Lindqvist-type POM polyanions and DMF molecules. The solid diffuse reflectance spectra and UV-vis spectra in DMF solution appear new absorption bands ascribed to the charge-transfer transition between the cationic MB donor and the POM acceptors. Studies of the photoluminescent properties show that the formation of 1 and 2 lead to the fluorescence quenching of starting materials.

  5. Large pore volume mesoporous copper particles and scaffold microporous carbon material obtained from an inorganic-organic nanohybrid material, copper-succinate-layered hydroxide.

    PubMed

    Ghotbi, Mohammad Yeganeh; Bagheri, Narjes; Sadrnezhaad, S K

    2011-10-01

    Copper-succinate-layered hydroxide (CSLH), a new nanohybrid material, was synthesized as an inorganic-organic nanohybrid, in which organic moiety was intercalated between the layers of a single cation layered material, copper hydroxide nitrate. Microporous scaffold carbon material was obtained by thermal decomposition of the nanohybrid at 500 °C under argon atmosphere followed by acid washing process. Furthermore, the heat-treated product of the nanohybrid at 600 °C was ultrafine mesoporous metallic copper particles. The results of this study confirmed the great potential of CSLH to produce the carbon material with large surface area (580 m(2)/g) and high pore volume copper powder (2.04 cm(3)/g).

  6. Distribution of inorganic mercury in Sacramento River water and suspended colloidal sediment material

    USGS Publications Warehouse

    Roth, D.A.; Taylor, H.E.; Domagalski, J.; Dileanis, P.; Peart, D.B.; Antweiler, R.C.; Alpers, C.N.

    2001-01-01

    The concentration and distribution of inorganic Hg was measured using cold-vapor atomic fluorescence spectrometry in samples collected at selected sites on the Sacramento River from below Shasta Dam to Freeport, CA, at six separate times between 1996 and 1997. Dissolved (ultrafiltered, 0.005 ??m equivalent pore size) Hg concentrations remained relatively constant throughout the system, ranging from the detection limit (< 0.4 ng/L) to 2.4 ng/L. Total Hg (dissolved plus colloidal suspended sediment) concentrations ranged from the detection limit at the site below Shasta Dam in September 1996 to 81 ng/L at the Colusa site in January 1997, demonstrating that colloidal sediment plays an important role in the downriver Hg transport. Sequential extractions of colloid concentrates indicate that the greatest amount of Hg associated with sediment Was found in the "residual" (mineral) phase with a significant quantity also occurring in the "oxidizable" phase. Only a minor amount of Hg was observed in the "reducible" phase. Dissolved Hg loads remained constant or increased slightly in the downstream direction through the study area, whereas the total inorganic Hg load increased significantly downstream especially in the reach of the fiver between Bend Bridge and Colusa. Analysis of temporal variations showed that Hg loading was positively correlated to discharge.

  7. Intercalation compound of diclofenac sodium with layered inorganic compounds as a new drug material.

    PubMed

    Tajima, Tomoko; Suzuki, Noriko; Watanabe, Yoshiteru; Kanzaki, Yasushi

    2005-11-01

    The intercalation reaction of diclofenac sodium (DFS) with layered inorganic compounds, gamma-titanium phosphate (gamma-TiP), proton type titanium oxide (H-TiO2) and sodium type synthetic mica (Na-TSM), was examined on. The direct reaction of DFS in ethanol-water mixed solvent resulted in the large amount accommodation of DFS. The amount of intercalated DFS was the order of gamma-TiP>H-TiO2>Na-TSM corresponding to the order of acidity. The intercalation using phospholiopids was also examined to assist the intercalation reaction. However, the amount of intercalated DFS was rather small in comparison with those in the direct reaction. DFS accommodated in gamma-TiP dissolved into neutral and basic buffer solution stoichiometry while scarcely dissolved in the acidic solution. The mechanism of the intercalation and reverse dissolution was successfully accounted according to the ion-exchange mechanism between Na+ in DFS and H+ in gamma-TiP. The dissolution from tablet of DFS/gamma-TiP intercalation compound was examined by using a disintegrator. It was found that the dissolution rate appropriately controlled by mixing the disintegrator. The present results suggested the different possibilities in the clinical field to use layered inorganic compounds such as drug delivery system (DDS).

  8. Organic free decavanadate based materials: Inorganic linkers to obtain extended structures

    NASA Astrophysics Data System (ADS)

    Yerra, Sridevi; Das, Samar K.

    2017-10-01

    Decavanadate based extended structures containing compounds [{Na3(H2O)8(μ2-H2O)6Ag2}HV10O28]n·6nH2O (1), [Co(H2O)6]n[{Na2(H2O)6(μ2-H2O)4Co(H2O)2}V10O28]n·4nH2O (2) and [Zn(H2O)6]n[{Na2(H2O)6(μ2-H2O)4Zn(H2O)2}V10O28]n·4nH2O (3) have been synthesized from respective aqueous solutions of sodium metavanadate. Compounds 1, 2 and 3 crystallize in a triclinic space group P-1. Compound 1 is a three-dimensional inorganic solid, whereas compounds 2 and 3 are isomorphous one-dimensional inorganic polymers. In the crystal structure of compound 1, the silver (I) cation is coordinated to the terminal oxygen as well as bridging oxygen atoms of decavanadate anion and it is also connected to bridging oxygen atom of trimeric sodium aqua cluster cation. In the crystals of compound 2, one hexa-hydrated cobalt cation is present as a counter cation and one ;di-sodium cobalt aqua-complex; cation is supported on the [V10O28]6- cluster anion by coordinate covalent bond. Compound 3 is isomorphous with compound 2, with Zn2+ present (in compound 3) in the place of Co2+ (in compound 2). Compounds 1, 2 and 3 are characterized by routine elemental analyses, FT-IR spectroscopy and unambiguously by single crystal X-ray crystallography. In the crystal structure of compound 1, an unusual silver dimer is observed.

  9. The chemical composition of inorganic and carbonaceous materials in PM 2.5 in Nanjing, China

    NASA Astrophysics Data System (ADS)

    Yang, Hong; Yu, Jian Zhen; Ho, Steven Sai Hang; Xu, Jinhui; Wu, Wai-Shing; Wan, Chun Hong; Wang, Xiaodong; Wang, Xiaorong; Wang, Liansheng

    PM 2.5 samples were collected at an urban and a suburban site in Nanjing, China in 2001. They were analyzed for inorganic ions, elemental carbon, organic carbon (OC), water-soluble organic carbon (WSOC), and individual WSOC and nonpolar organic species. Sulfate and organic matter were the two most abundant constituents in these samples. Sulfate accounted for an average of 23% (urban site) and 30% (suburban site) of the identified aerosol mass. Organic matter accounted for an average of 37% (urban) and 28% (suburban) of the identified aerosol mass. WSOC was a significant portion of OC, accounting for about one-third of OC at the urban site and 45% of OC at the suburban site. The suburban-urban gradient in the WSOC/OC ratio also reflected that the aerosol OC was more aged at the suburban location. The correlations of WSOC with sulfate and nitrate suggest that the WSOC fraction was dominated by secondary organics. More than 30 individual WSOC species in the compound classes of organic anions, amino acids, aliphatic amines, and carbohydrates were quantified, accounting for approximately 8% of the WSOC on a carbon mass basis. In addition, 46 individual nonpolar organic compounds in the compound classes of n-alkanes, hopanes, and polycyclic aromatic hydrocarbons were quantified using an in-injection port thermal desorption technique. These nonpolar organic species accounted for less than 7% of the OC on a carbon mass basis. The quantification of individual compounds allowed the identification of major aerosol sources through principal component analysis. Coal combustion, vehicular emissions, secondary inorganic and organic aerosols, and road/sea salt were the major contributing sources to the identified PM 2.5 aerosol mass.

  10. Synthesis and morphogenesis of organic and inorganic polymers by means of biominerals and biomimetic materials.

    PubMed

    Kijima, Misako; Oaki, Yuya; Munekawa, Yurika; Imai, Hiroaki

    2013-02-11

    We have studied the simultaneous synthesis and morphogenesis of polymer materials with hierarchical structures from nanoscopic to macroscopic scales. The morphologies of the original materials can be replicated to the polymer materials. In general, it is not easy to achieve the simultaneous synthesis and morphogenesis of polymer material even using host materials. In the present work, four biominerals and three biomimetic mesocrystal structures are used as the host materials or templates and polypyrrole, poly(3-hexylthiopehene), and silica were used as the precursors for the simultaneous syntheses and morphogenesis of polymer materials. The host materials with the hierarchical structure possess the nanospace for the incorporation of the monomers. After the incorporation of the monomers, the polymerization reaction proceeds in the nanospace with addition of the initiator agents. Then, the dissolution of the host materials leads to the formation and morphogenesis of the polymer materials. The scheme of the replication can be classified into the three types based on the structures of the host materials (types I-III). The type I template facilitates the hierarchical replication of the whole host material, type II mediates the hierarchical surface replication, and type III induces the formation of the two-dimensional nanosheets. Based on these results, the approach for the coupled synthesis and morphogenesis can be applied to a variety of combinations of the templates and polymer materials.

  11. Materials issues in polymer electrolyte membrane fuel cells.

    SciTech Connect

    Garland, N. L.; Benjamin, T. G.; Kopasz, J. P.; Chemical Sciences and Engineering Division; DOE

    2008-11-01

    Fuel cells have the potential to reduce the nation's energy use through increased energy conversion efficiency and dependence on imported petroleum by the use of hydrogen from renewable resources. The US DOE Fuel Cell subprogram emphasizes polymer electrolyte membrane (PEM) fuel cells as replacements for internal combustion engines in light-duty vehicles to support the goal of reducing oil use in the transportation sector. PEM fuel cells are the focus for light-duty vehicles because they are capable of rapid start-up, demonstrate high operating efficiency, and can operate at low temperatures. The program also supports fuel cells for stationary power, portable power, and auxiliary power applications where earlier market entry would assist in the development of a fuel cell manufacturing and supplier base. The technical focus is on developing materials and components that enable fuel cells to achieve the fuel cell subprogram objectives, primarily related to system cost and durability. For transportation applications, the performance and cost of a fuel cell vehicle must be comparable or superior to today's gasoline vehicles to achieve widespread penetration into the market and achieve the desired reduction in petroleum consumption. By translating vehicle performance requirements into fuel cell system needs, DOE has defined technical targets for 2010 and 2015. These targets are based on competitiveness with current internal combustion engine vehicles in terms of vehicle performance and cost, while providing improvements in efficiency of a factor of 2.5 to 3. The overall system targets are: a 60% peak-efficient, durable, direct hydrogen fuel cell power system for transportation at a cost of $45/kW by 2010 and $30/kW by 2015. DOE's approach to achieving these technical and cost targets is to improve existing materials and to identify and qualify new materials.

  12. New organic-inorganic hybrid molecular systems and highly organized materials in catalysis

    NASA Astrophysics Data System (ADS)

    Kustov, L. M.

    2015-11-01

    Definitions of hybrid materials are suggested, and applications of these materials are considered. Particular attention is focused on the application of hybrid materials in hydrogenation, partial oxidation, plant biomass conversion, and natural gas reforming, primarily on the use of core-shell nanoparticles and decorated metal nanoparticles in these reactions. Application prospects of various hybrid materials, particularly those of metal-organic frameworks, are discussed.

  13. Phosphomolybdate clusters as molecular building blocks in the design of one-, two- and three-dimensional organic inorganic hybrid materials

    NASA Astrophysics Data System (ADS)

    Gabriel Armatas, N.; Burkholder, Eric; Zubieta, Jon

    2005-08-01

    An attractive approach to the design of inorganic solids exploits the tethering of inorganic clusters through organic spacers to produce hybrid materials with composite properties. We have recently described a modified strategy in which polyoxometalate clusters are linked through organic subunits to give an anionic hybrid substructure which may be further modified through the introduction of secondary metal-ligand complex (SMLC) cations, serving as a third component building block. In this application, the molybdophosphonate cluster {Mo 5O 15(O 3PR) 2} 4- serves as a secondary building unit (SBU) with alkyl (CH 2) n or aromatic -(C 6H 4) n- tethers providing one-dimensional structural expansion. A binucleating ligand such as tetrapyridylpyrazine (tpyprz) is used to bridge secondary metal sites into a binuclear {Cu 2(tpyprz)} 4+ SBU which may link phosphomolybdate clusters into two- or three-dimensional structures. The influence of a variety of structural determinants is discussed, including the tether length of the diphosphonate ligand, the coordination preferences of the secondary metal, expansion of the ligand component of the SMLC, and substitution of As for P in the oxide SBU.

  14. Three iodometalate organic-inorganic hybrid materials based on methylene blue cation: Syntheses, structures, properties and DFT calculations

    NASA Astrophysics Data System (ADS)

    Chai, Wen-Xiang; Lin, Jian; Song, Li; Qin, Lai-Shun; Shi, Hong-Sheng; Guo, Jia-Yu; Shu, Kang-Ying

    2012-08-01

    The functional dye of methylene blue (MB) has been employed for seeking new organic-inorganic hybrid photochromic materials. Although the photochromism has not been observed yet, three iodometalate compounds, namely (MB) (PbI3) (DMF) (1), (MB)4(Cu2I4)2 (2), and (MB)3(Bi2I9) (DMF)2 (3), have been synthesized and characterized. The iodometalate anion features as a [PbI3]∞- chain in 1, a dinuclear unit of Cu2I42- in 2, and a dinuclear unit of Bi2I93- in 3. Due to the synergy of cations and anions, the MB+ cations present supramolecular column stacks in 1 and 3, but a novel supramolecular octamer structure in 2. Their thermogravimetric analyses reveal that the polymeric inorganic anion structure is helpful to increase the stability of cation whereas the discrete structure is adverse. For seeking some clues which is significant to searching new photochromic systems, the density functional theory (DFT) studies have been performed on 1, in which the electronic structure analyses suggests that the stacking mode of cations and anions could be also an important factor influencing the charge transfer between them. In addition, dielectric hysteresis loop testing has been performed on 1 due to its polar space group of Cc.

  15. The structures and properties of the new two-dimensional inorganic-organic hybrid materials based on the molybdate chains

    NASA Astrophysics Data System (ADS)

    Li, Na; Mu, Bao; Cao, Xinyu; Huang, Rudan

    2014-09-01

    A series of inorganic organic hybrid materials based on polyoxometalates(POMs), namely, [MII(HL)2(H2O)2][MoVI6O20] [M=Co (1), Ni (2), Cu (3), Zn (4)], [MnIVL2(H2O)2][MoVI6O20] (5), and (HL)3PMO12O40 (6) [L=3-(4-pyridyl)pyrazole], have been synthesized. The compounds have been characterized by elemental analysis, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. The results from single-crystal X-ray diffraction indicate that 1-5 are isostructural. It is worth noting that the polyanions are bridged by Mo-O-Mo to form 1D inorganic chains, which are further connected via M ions to form 2D nets. In compound 6, the ligands are used as the positive ions to balance the charge of the compound. Moreover, the magnetic properties of compound 5 have also been investigated in detail.

  16. Ionic liquid-based materials: a platform to design engineered CO2 separation membranes.

    PubMed

    Tomé, Liliana C; Marrucho, Isabel M

    2016-05-21

    During the past decade, significant advances in ionic liquid-based materials for the development of CO2 separation membranes have been accomplished. This review presents a perspective on different strategies that use ionic liquid-based materials as a unique tuneable platform to design task-specific advanced materials for CO2 separation membranes. Based on compilation and analysis of the data hitherto reported, we provide a judicious assessment of the CO2 separation efficiency of different membranes, and highlight breakthroughs and key challenges in this field. In particular, configurations such as supported ionic liquid membranes, polymer/ionic liquid composite membranes, gelled ionic liquid membranes and poly(ionic liquid)-based membranes are detailed, discussed and evaluated in terms of their efficiency, which is attributed to their chemical and structural features. Finally, an integrated perspective on technology, economy and sustainability is provided.

  17. DEVELOPMENT OF MESOPOROUS MEMBRANE MATERIALS FOR CO2 SEPARATION

    SciTech Connect

    Wei-Heng Shih; Tejas Patil; Qiang Zhao

    2003-03-25

    The huge emissions of carbon dioxide from fossil fuel fired power plants and industrial plants over the last century have resulted in an increase of the atmospheric carbon dioxide concentration. Climatological modeling work has predicted severe climate disruption as a result of the trapping of heat due to CO{sub 2}. As an attempt to address this global warming effect, DOE has initiated the Vision 21 concept for future power plants. We first synthesized mesoporous aluminosilicates that have high surface area and parallel pore channels for membrane support materials. Later we synthesized microporous aluminosilicates as the potential thin membrane materials for selective CO{sub 2} adsorption. The pore size is controlled to be less that 1 nm so that the adsorption of CO{sub 2} on the pore wall will block the passage of N{sub 2}. Mesoporous and precipitated alumina were synthesized as the base material for CO{sub 2} adsorbent. The porous alumina is doped with Ba to enhance its CO{sub 2} affinity due to the basicity of Ba. It is shown by gas chromatograph (GC) that the addition of Ba enhances the separation CO{sub 2} from N{sub 2}. It was found that mesoporous alumina has larger specific surface area and better selectivity of CO{sub 2} than precipitated alumina. Ba improves the affinity of mesoporous alumina with CO{sub 2}. Phase may play an important role in selective adsorption of CO{sub 2}. It is speculated that mesoporous alumina is more reactive than precipitated alumina creating the xBaO {center_dot}Al{sub 2}O{sub 3} phase that may be more affinitive to CO{sub 2} than N{sub 2}. On the other hand, the barium aluminates phase (Ba{sub 3}Al{sub 2}O{sub 6}) in the mesoporous sample does not help the adsorption of CO{sub 2}. Microporous aluminosilicate was chosen as a suitable candidate for CO{sub 2}/N{sub 2} separation because the pore size is less than 10 {angstrom}. If a CO{sub 2} adsorbent is added to the microporous silica, the adsorption of CO{sub 2} can block the

  18. Organic adlayer on inorganic materials: XPS analysis selectivity to cope with adventitious contamination

    NASA Astrophysics Data System (ADS)

    Landoulsi, Jessem; Genet, Michel J.; Fleith, Sandrine; Touré, Yetioman; Liascukiene, Irma; Méthivier, Christophe; Rouxhet, Paul G.

    2016-10-01

    This work addresses the ubiquitous presence of organic contaminants at inorganic solid surfaces and the improvement of XPS analysis selectivity to cope with it. Water contact angle measurements showed that the adsorption of organic contaminants occurs readily in ambient air, and faster and more extensively under high vacuum. It is stronger on stainless steel (SS) compared to silica and is significantly reduced when SS is sterilized by autoclaving. The reliability of XPS data was evaluated (selectivity, precision, accuracy) by correlations between spectral data incorporating a large amount of results obtained with different XPS spectrometers on SS and glass samples cleaned in different ways and conditioned with several biomacromolecules. The methodology used allows a discrimination to be made between contaminants and deliberately adsorbed biomacromolecules, and offers perspectives for tracking the source of contamination. Furthermore, a discrimination can be made between oxygen from the organic adlayer and oxygen from the substrate, and the O 1s component above 532.0 eV observed for SS is shown to be due to organic contaminants rather than adsorbed water. This approach offers new perspectives to examine the interactions (displacement or not) between contaminants and compounds of interest, e.g. proteins, at the stage of the adsorption process.

  19. Activation and splitting of carbon dioxide on the surface of an inorganic electride material.

    PubMed

    Toda, Yoshitake; Hirayama, Hiroyuki; Kuganathan, Navaratnarajah; Torrisi, Antonio; Sushko, Peter V; Hosono, Hideo

    2013-01-01

    Activation of carbon dioxide is the most important step in its conversion into valuable chemicals. Surfaces of stable oxide with a low work function may be promising for this purpose. Here we report that the surfaces of the inorganic electride [Ca24Al28O64](4+)(e(-))4 activate and split carbon dioxide at room temperature. This behaviour is attributed to a high concentration of localized electrons in the near-surface region and a corrugation of the surface that can trap oxygen atoms and strained carbon monoxide and carbon dioxide molecules. The [Ca24Al28O64](4+)(e(-))4 surface exposed to carbon dioxide is studied using temperature-programmed desorption, and spectroscopic methods. The results of these measurements, corroborated with ab initio simulations, show that both carbon monoxide and carbon dioxide adsorb on the [Ca24Al28O64](4+)(e(-))4 surface at RT and above and adopt unusual configurations that result in desorption of molecular carbon monoxide and atomic oxygen upon heating.

  20. Activation and splitting of carbon dioxide on the surface of an inorganic electride material

    PubMed Central

    Toda, Yoshitake; Hirayama, Hiroyuki; Kuganathan, Navaratnarajah; Torrisi, Antonio; Sushko, Peter V.; Hosono, Hideo

    2013-01-01

    Activation of carbon dioxide is the most important step in its conversion into valuable chemicals. Surfaces of stable oxide with a low work function may be promising for this purpose. Here we report that the surfaces of the inorganic electride [Ca24Al28O64]4+(e−)4 activate and split carbon dioxide at room temperature. This behaviour is attributed to a high concentration of localized electrons in the near-surface region and a corrugation of the surface that can trap oxygen atoms and strained carbon monoxide and carbon dioxide molecules. The [Ca24Al28O64]4+(e−)4 surface exposed to carbon dioxide is studied using temperature-programmed desorption, and spectroscopic methods. The results of these measurements, corroborated with ab initio simulations, show that both carbon monoxide and carbon dioxide adsorb on the [Ca24Al28O64]4+(e−)4 surface at RT and above and adopt unusual configurations that result in desorption of molecular carbon monoxide and atomic oxygen upon heating. PMID:23986101

  1. Morphological structure of Gluconacetobacter xylinus cellulose and cellulose-based organic-inorganic composite materials

    NASA Astrophysics Data System (ADS)

    Smyslov, R. Yu; Ezdakova, K. V.; Kopitsa, G. P.; Khripunov, A. K.; Bugrov, A. N.; Tkachenko, A. A.; Angelov, B.; Pipich, V.; Szekely, N. K.; Baranchikov, A. E.; Latysheva, E.; Chetverikov, Yu O.; Haramus, V.

    2017-05-01

    Scanning electron microscopy, ultra-small-angle neutron scattering (USANS), small-angle neutron and X-ray scattering (SANS and SAXS), as well as low-temperature nitrogen adsorption, were used in the studies of micro- and mesostructure of polymer matrix prepared from air-dry preliminarily disintegrated cellulose nano-gel film (synthesized by Gluconacetobacter xylinus) and the composites based on this bacterial cellulose. The composites included ZrO2 nanoparticles, Tb3+ in the form of low molecular weight salt and of metal-polymer complex with poly(vinylpyrrolydone)-poly(methacryloyl-o-aminobenzoic acid) copolymer. The combined analysis of the data obtained allowed revealing three levels of fractal organization in mesostructure of G. xylinus cellulose and its composites. It was shown that both the composition and an aggregation state of dopants have a significant impact on the structural characteristics of the organic-inorganic composites. The composites containing Tb3+ ions demonstrate efficient luminescence; its intensity is an order of magnitude higher in the case of the composites with the metal-polymer complex. It was found that there is the optimal content of ZrO2 nanoparticles in composites resulting in increased Tb3+ luminescence.

  2. Photochromic hybrid organic-inorganic liquid-crystalline materials built from nonionic surfactants and polyoxometalates: elaboration and structural study.

    PubMed

    Poulos, Andreas S; Constantin, Doru; Davidson, Patrick; Impéror, Marianne; Pansu, Brigitte; Panine, Pierre; Nicole, Lionel; Sanchez, Clément

    2008-06-17

    This work reports the elaboration and structural study of new hybrid organic-inorganic materials constructed via the coupling of liquid-crystalline nonionic surfactants and polyoxometalates (POMs). X-ray scattering and polarized light microscopy demonstrate that these hybrid materials, highly loaded with POMs (up to 18 wt %), are nanocomposites of liquid-crystalline lamellar structure (Lalpha), with viscoelastic properties close to those of gels. The interpretation of X-ray scattering data strongly suggests that the POMs are located close to the terminal -OH groups of the nonionic surfactants, within the aqueous sublayers. Moreover, these materials exhibit a reversible photochromism associated to the photoreduction of the polyanion. The photoinduced mixed-valence behavior has been characterized through ESR and UV-visible-near-IR spectroscopies that demonstrate the presence of W(V) metal cations and of the characteristic intervalence charge transfer band in the near-IR region, respectively. These hybrid nanocomposites exhibit optical properties that may be useful for applications involving UV-light-sensitive coatings or liquid-crystal-based photochromic switches. From a more fundamental point of view, these hybrid materials should be very helpful models for the study of both the static and dynamic properties of nano-objects confined within soft lamellar structures.

  3. Ti/Au Cathode for Electronic transport material-free organic-inorganic hybrid perovskite solar cells

    PubMed Central

    Shi, Tongfei; Chen, Jian; Zheng, Jianqiang; Li, Xinhua; Zhou, Bukang; Cao, Huaxiang; Wang, Yuqi

    2016-01-01

    We have fabricated organic-inorganic hybrid perovskite solar cell that uses a Ti/Au multilayer as cathode and does not use electron transport materials, and achieved the highest power conversion efficiency close to 13% with high reproducibility and hysteresis-free photocurrent curves. Our cell has a Schottky planar heterojunction structure (ITO/PEDOT:PSS/perovskite/Ti/Au), in which the Ti insertion layer isolate the perovskite and Au layers, thus proving good contact between the Au and perovskite and increasing the cells’ shunt resistance greatly. Moreover, the Ti/Au cathode in direct contact with hybrid perovskite showed no reaction for a long-term exposure to the air, and can provide sufficient protection and avoid the perovskite and PEDOT:PSS layers contact with moisture. Hence, the Ti/Au based devices retain about 70% of their original efficiency after 300 h storage in the ambient environment. PMID:27995951

  4. Ti/Au Cathode for Electronic transport material-free organic-inorganic hybrid perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Shi, Tongfei; Chen, Jian; Zheng, Jianqiang; Li, Xinhua; Zhou, Bukang; Cao, Huaxiang; Wang, Yuqi

    2016-12-01

    We have fabricated organic-inorganic hybrid perovskite solar cell that uses a Ti/Au multilayer as cathode and does not use electron transport materials, and achieved the highest power conversion efficiency close to 13% with high reproducibility and hysteresis-free photocurrent curves. Our cell has a Schottky planar heterojunction structure (ITO/PEDOT:PSS/perovskite/Ti/Au), in which the Ti insertion layer isolate the perovskite and Au layers, thus proving good contact between the Au and perovskite and increasing the cells’ shunt resistance greatly. Moreover, the Ti/Au cathode in direct contact with hybrid perovskite showed no reaction for a long-term exposure to the air, and can provide sufficient protection and avoid the perovskite and PEDOT:PSS layers contact with moisture. Hence, the Ti/Au based devices retain about 70% of their original efficiency after 300 h storage in the ambient environment.

  5. Colloidal CuInS2 Quantum Dots as Inorganic Hole-Transporting Material in Perovskite Solar Cells.

    PubMed

    Lv, Mei; Zhu, Jun; Huang, Yang; Li, Yi; Shao, Zhipeng; Xu, Yafeng; Dai, Songyuan

    2015-08-12

    To develop novel hole-transporting materials (HTMs) is an important issue of perovskite solar cells (PSCs), especially favoring the stability improvement and the cost reduction. Herein, we use ternary quantum dots (QDs) as HTM in mesoporous TiO2/CH3NH3PbI3/HTM/Au solar cell, and modify the surface of CuInS2 QDs by cation exchange to improve the carrier transport. The device efficiency using CuInS2 QDs with a ZnS shell layer as HTM is 8.38% under AM 1.5, 100 mW cm(-2). The electrochemical impedance spectroscopy suggested that the significantly enhanced performance is mainly attributed to the reduced charge recombination between TiO2 and HTM. It paves a new pathway for the future development of cheap inorganic HTMs for the high efficiency PSCs.

  6. Hydrophilic solid-phase extraction of melamine with ampholine-modified hybrid organic-inorganic silica material.

    PubMed

    Wang, Tingting; Zhu, Yiming; Ma, Junfeng; Xuan, Rongrong; Gao, Haoqi; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2015-01-01

    In this work, an ampholine-functionalized hybrid organic-inorganic silica sorbent was successfully used to extract melamine from a milk formula sample by a hydrophilic interaction solid-phase extraction protocol. Primary factors affecting the extraction efficiency of the material such as extraction solvent, elution solvent, sample loading volume, and elution volume have been thoroughly optimized. Under the optimized hydrophilic solid-phase extraction conditions, the recoveries of melamine spiked in milk formula samples ranged from 86.2 to 101.8% with relative standard deviations of 4.1-9.4% (n = 3). The limit of detection (S/N = 3) was 0.32 μg/g. The adsorption capacity toward melamine was 30 μg of melamine per grams of sorbent. Due to its simplicity, rapidity and cost effectiveness, the newly developed hydrophilic solid-phase extraction method should provide a promising tool for daily monitoring of doped melamine in milk formula.

  7. TRANSPORT OF INORGANIC COLLOIDS THROUGH NATURAL AQUIFER MATERIAL: IMPLICATIONS FOR CONTAMINANT TRANSPORT

    EPA Science Inventory

    The stability and transport of radiolabeled Fe2O3 particles were studied using laboratory batch and column techniques. Core material collected from a shallow sand and gravel aquifer was used as the immobile column matrix material. Variables in the study incl...

  8. LABORATORY STUDIES ON THE STABILITY AND TRANSPORT OF INORGANIC COLLOIDS THROUGH NATURAL AQUIFER MATERIAL

    EPA Science Inventory

    The stability and transport of radio-labeled Fe2O3 particles were studied using laboratory batch and column techniques. Core material collected from shallow sand and gravel aquifer was used as the immobile column matrix material. Variables in the study included flow rate, pH, i...

  9. TRANSPORT OF INORGANIC COLLOIDS THROUGH NATURAL AQUIFER MATERIAL: IMPLICATIONS FOR CONTAMINANT TRANSPORT

    EPA Science Inventory

    The stability and transport of radiolabeled Fe2O3 particles were studied using laboratory batch and column techniques. Core material collected from a shallow sand and gravel aquifer was used as the immobile column matrix material. Variables in the study incl...

  10. LABORATORY STUDIES ON THE STABILITY AND TRANSPORT OF INORGANIC COLLOIDS THROUGH NATURAL AQUIFER MATERIAL

    EPA Science Inventory

    The stability and transport of radio-labeled Fe2O3 particles were studied using laboratory batch and column techniques. Core material collected from shallow sand and gravel aquifer was used as the immobile column matrix material. Variables in the study included flow rate, pH, i...

  11. Synthesis of hybrid organic-inorganic nanocomposite materials based on CdS nanocrystals for energy conversion applications

    NASA Astrophysics Data System (ADS)

    Laera, A. M.; Resta, V.; Ferrara, M. C.; Schioppa, M.; Piscopiello, E.; Tapfer, L.

    2011-11-01

    Efficient solar energy conversion is strongly related to the development of new materials with enhanced functional properties. In this context, a wide variety of inorganic, organic, or hybrid nanostructured materials have been investigated. In particular, in hybrid organic-inorganic nanocomposites are combined the convenient properties of organic polymers, such as easy manipulation and mechanical flexibility, and the unique size-dependent properties of nanocrystals (NCs). However, applications of hybrid nanocomposites in photovoltaic devices require a homogeneous and highly dense dispersion of NCs in polymer in order to guarantee not only an efficient charge separation, but also an efficient transport of the carriers to the electrodes without recombination. In previous works, we demonstrated that cadmium thiolate complexes are suitable precursors for the in situ synthesis of nanocrystalline CdS. Here, we show that the soluble [Cd(SBz)2]2·(1-methyl imidazole) complex can be efficiently annealed in a conjugated polymer obtaining a nanocomposite with a regular and compact network of NCs. The proposed synthetic strategies require annealing temperatures well below 200 °C and short time for the thermal treatment, i.e., less than 30 min. We also show that the same complex can be used to synthesize CdS NCs in mesoporous TiO2. The adsorption of cadmium thiolate molecule in TiO2 matrix can be obtained by using chemical bath deposition technique and subsequent thermal annealing. The use of NCs, quantum dots, as sensitizers of TiO2 matrices represents a very promising alternative to common dye-sensitized solar cells and an interesting solution for heterogeneous photocatalysis.

  12. Terahertz and infrared transmission of an organic/inorganic hybrid thermoelectric material

    SciTech Connect

    Heyman, J. N. Alebachew, B. A.; Kaminski, Z. S.; Nguyen, M. D.; Coates, N. E.; Urban, J. J.

    2014-04-07

    We report terahertz and infrared transmission measurements of a high-performance thermoelectric material containing tellurium nanowires in a conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) matrix. The DC electrical conductivity of the hybrid material (41 S/cm) is approximately one hundred times that of pure PEDOT:PSS and more than 400 times that of a film of pure tellurium nanowires, while the terahertz-frequency (THz) conductivity of PEDOT:PSS and the hybrid material are comparable at f ∼ 2THz. A frequency-dependent conductivity model indicates that the increased DC conductivity of the hybrid material results from an increase in the DC charge mobility rather than in the free charge density. We suggest that the increased DC conductivity of the hybrid material results from an increase in linkage between PEDOT domains by the tellurium nanowires.

  13. Superhydrophobic and superhydrophilic surface-enhanced separation performance of porous inorganic membranes for biomass-to-biofuel conversion applications

    SciTech Connect

    Hu, Michael Z.; Engtrakul, Chaiwat; Bischoff, Brian L.; Jang, Gyoung G.; Theiss, Timothy J.; Davis, Mark F.

    2016-11-14

    A new class of porous membranes is introduced to provide unique separation mechanisms by surface interactions and capillary condensation. High-performance architectural surface selective (HiPAS) membranes were designed for high perm-selective flux and high-temperature tolerance for hot vapor processing and liquid processing Due to surface-enhanced selectivity, larger-fluxes were achieved by utilizing larger pore sizes (~8 nm for vapor phase and micron-sized pores for liquid phase separations). This paper describes a membrane-based separation concept for biomass conversion pathways and demonstrates the initial data for selective permeation of toluene-water and toluene-phenol-water relevant to biofuel processing.

  14. Survey of inorganic arsenic in marine animals and marine certified reference materials by anion exchange high-performance liquid chromatography-inductively coupled plasma mass spectrometry.

    PubMed

    Sloth, Jens J; Larsen, Erik H; Julshamn, Kåre

    2005-07-27

    A method for the determination of inorganic arsenic in seafood samples using high-performance liquid chromatography-inductively coupled plasma mass spectrometry is described. The principle of the method relied on microwave-assisted alkaline dissolution of the sample, which at the same time oxidized arsenite [As(III)] to arsenate [As(V)], whereby inorganic arsenic could be determined as the single species As(V). Anion exchange chromatography using isocratic elution with aqueous ammonium carbonate as the mobile phase was used for the separation of As(V) from other coextracted organoarsenic compounds, including arsenobetaine. The stability of organoarsenic compounds during the sample pretreatment was investigated, and no degradation/conversion to inorganic arsenic was detected. The method was employed for the determination of inorganic arsenic in a variety of seafood samples including fish, crustaceans, bivalves, and marine mammals as well as a range of marine certified reference materials, and the results were compared to values published in the literature. For fish and marine mammals, the results were in most cases below the limit of detection. For other sample types, inorganic arsenic concentrations up to 0.060 mg kg(-)(1) were found. In all samples, the inorganic arsenic content constituted less than 1% of the total arsenic content.

  15. Colloidal Inorganic Nanocrystal Based Nanocomposites: Functional Materials for Micro and Nanofabrication

    PubMed Central

    Ingrosso, Chiara; Panniello, AnnaMaria; Comparelli, Roberto; Curri, Maria Lucia; Striccoli, Marinella

    2010-01-01

    The unique size- and shape-dependent electronic properties of nanocrystals (NCs) make them extremely attractive as novel structural building blocks for constructing a new generation of innovative materials and solid-state devices. Recent advances in material chemistry has allowed the synthesis of colloidal NCs with a wide range of compositions, with a precise control on size, shape and uniformity as well as specific surface chemistry. By incorporating such nanostructures in polymers, mesoscopic materials can be achieved and their properties engineered by choosing NCs differing in size and/or composition, properly tuning the interaction between NCs and surrounding environment. In this contribution, different approaches will be presented as effective opportunities for conveying colloidal NC properties to nanocomposite materials for micro and nanofabrication. Patterning of such nanocomposites either by conventional lithographic techniques and emerging patterning tools, such as ink jet printing and nanoimprint lithography, will be illustrated, pointing out their technological impact on developing new optoelectronic and sensing devices.

  16. High-throughput screening of inorganic compounds for the discovery of novel dielectric and optical materials

    NASA Astrophysics Data System (ADS)

    Petousis, Ioannis; Mrdjenovich, David; Ballouz, Eric; Liu, Miao; Winston, Donald; Chen, Wei; Graf, Tanja; Schladt, Thomas D.; Persson, Kristin A.; Prinz, Fritz B.

    2017-01-01

    Dielectrics are an important class of materials that are ubiquitous in modern electronic applications. Even though their properties are important for the performance of devices, the number of compounds with known dielectric constant is on the order of a few hundred. Here, we use Density Functional Perturbation Theory as a way to screen for the dielectric constant and refractive index of materials in a fast and computationally efficient way. Our results constitute the largest dielectric tensors database to date, containing 1,056 compounds. Details regarding the computational methodology and technical validation are presented along with the format of our publicly available data. In addition, we integrate our dataset with the Materials Project allowing users easy access to material properties. Finally, we explain how our dataset and calculation methodology can be used in the search for novel dielectric compounds.

  17. Physicochemical properties affect the synthesis, controlled delivery, degradation and pharmacokinetics of inorganic nanoporous materials.

    PubMed

    Yazdi, Iman K; Ziemys, Arturas; Evangelopoulos, Michael; Martinez, Jonathan O; Kojic, Milos; Tasciotti, Ennio

    2015-10-01

    Controlling size, shape and uniformity of porous constructs remains a major focus of the development of porous materials. Over the past two decades, we have seen significant developments in the fabrication of new, porous-ordered structures using a wide range of materials, resulting in properties well beyond their traditional use. Porous materials have been considered appealing, due to attractive properties such as pore size length, morphology and surface chemistry. Furthermore, their utilization within the life sciences and medicine has resulted in significant developments in pharmaceutics and medical diagnosis. This article focuses on various classes of porous materials, providing an overview of principle concepts with regard to design and fabrication, surface chemistry and loading and release kinetics. Furthermore, predictions from a multiscale mathematical model revealed the role pore length and diameter could have on payload release kinetics.

  18. High-throughput screening of inorganic compounds for the discovery of novel dielectric and optical materials

    PubMed Central

    Petousis, Ioannis; Mrdjenovich, David; Ballouz, Eric; Liu, Miao; Winston, Donald; Chen, Wei; Graf, Tanja; Schladt, Thomas D.; Persson, Kristin A.; Prinz, Fritz B.

    2017-01-01

    Dielectrics are an important class of materials that are ubiquitous in modern electronic applications. Even though their properties are important for the performance of devices, the number of compounds with known dielectric constant is on the order of a few hundred. Here, we use Density Functional Perturbation Theory as a way to screen for the dielectric constant and refractive index of materials in a fast and computationally efficient way. Our results constitute the largest dielectric tensors database to date, containing 1,056 compounds. Details regarding the computational methodology and technical validation are presented along with the format of our publicly available data. In addition, we integrate our dataset with the Materials Project allowing users easy access to material properties. Finally, we explain how our dataset and calculation methodology can be used in the search for novel dielectric compounds. PMID:28140408

  19. High-throughput screening of inorganic compounds for the discovery of novel dielectric and optical materials.

    PubMed

    Petousis, Ioannis; Mrdjenovich, David; Ballouz, Eric; Liu, Miao; Winston, Donald; Chen, Wei; Graf, Tanja; Schladt, Thomas D; Persson, Kristin A; Prinz, Fritz B

    2017-01-31

    Dielectrics are an important class of materials that are ubiquitous in modern electronic applications. Even though their properties are important for the performance of devices, the number of compounds with known dielectric constant is on the order of a few hundred. Here, we use Density Functional Perturbation Theory as a way to screen for the dielectric constant and refractive index of materials in a fast and computationally efficient way. Our results constitute the largest dielectric tensors database to date, containing 1,056 compounds. Details regarding the computational methodology and technical validation are presented along with the format of our publicly available data. In addition, we integrate our dataset with the Materials Project allowing users easy access to material properties. Finally, we explain how our dataset and calculation methodology can be used in the search for novel dielectric compounds.

  20. High-throughput screening of inorganic compounds for the discovery of novel dielectric and optical materials

    DOE PAGES

    Petousis, Ioannis; Mrdjenovich, David; Ballouz, Eric; ...

    2017-01-31

    Dielectrics are an important class of materials that are ubiquitous in modern electronic applications. Even though their properties are important for the performance of devices, the number of compounds with known dielectric constant is on the order of a few hundred. Here, we use Density Functional Perturbation Theory as a way to screen for the dielectric constant and refractive index of materials in a fast and computationally efficient way. Our results constitute the largest dielectric tensors database to date, containing 1,056 compounds. Details regarding the computational methodology and technical validation are presented along with the format of our publicly availablemore » data. In addition, we integrate our dataset with the Materials Project allowing users easy access to material properties. Finally, we explain how our dataset and calculation methodology can be used in the search for novel dielectric compounds.« less

  1. Inorganic Fe2+ formation upon Fe-S protein thermodestruction in the membranes of thermophilic cyanobacteria: Mössbauer spectroscopy study.

    PubMed

    Kaurov YuN; Novakova, A A; Davletshina, L N; Aleksandrov AYu; Khval'kovskaya, E A; Semin, B K; Belevich, N P; Ivanov, I I; Rubin, A B

    1999-04-30

    A model description of the Mössbauer spectrum (80 K) of native membranes of the thermophilic cyanobacterium Synechococcus elongatus is suggested on the basis of the known values of quadrupole splitting (deltaE(Q)) and isomer shift (deltaFe) for the iron-containing components of the photosynthetic apparatus. Using this approach, we found that heating the membranes at 70-80 K results in a decrease of doublet amplitudes belonging to F(X), F(A), F(B) and ferredoxin and simultaneous formation of a new doublet with deltaE(Q) = 3.10 mm/s and delta-Fe = 1.28 mm/s, typical of inorganic hydrated forms of Fe2+. The inhibition of electron transfer via photosystem I to oxygen, catalyzed by ferredoxin, occurs within the same range of temperatures. The data demonstrate that the processes of thermoinduced Fe2+ formation and distortions in the photosystem I electron transport in the membranes are interrelated and caused mainly by the degradation of ferredoxin. The possible role of Fe2+ formation in the damage of the photosynthetic apparatus resulting from heating and the action of other extreme factors is discussed.

  2. A new strategy for designing high-performance sulfonated poly(ether ether ketone) polymer electrolyte membranes using inorganic proton conductor-functionalized carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Gong, Chunli; Zheng, Xuan; Liu, Hai; Wang, Guangjin; Cheng, Fan; Zheng, Genwen; Wen, Sheng; Law, Wing-Cheung; Tsui, Chi-Pong; Tang, Chak-Yin

    2016-09-01

    Remarkable progress has been made on the use of polymer electrolyte membranes (PEMs) for renewable-energy-related research. In particular, carbon nanotubes (CNTs) have emerged as versatile nanomaterials to modify PEMs. However, the inert ionic conduction ability and possible short-circuiting risk are the two major obstacles to their further development. In this work, CNTs are firstly functionalized with an inorganic proton conductor, boron phosphate (BPO4), using a facile polydopamine-assisted sol-gel method to yield BPO4@CNTs. This new additive is then used to modify sulfonated poly(ether ether ketone) (SPEEK). Polydopamine coating layer can act as an extraordinary glue to homogeneously adhere BPO4 nanoparticles on CNTs, thereby not only reducing the risk of short-circuiting, but also fabricating new proton-conducting pathways in the composite membranes. A comprehensive characterization reveals that the thermal stability, tensile properties, and dimensional stability of PEMs are significantly improved. Compared with pure SPEEK, the proton conductivity of SPEEK/BPO4@CNTs-2 is improved by 45% and 150% at 20 °C and at 80 °C, respectively. Furthermore, the H2/O2 cell performance of SPEEK/BPO4@CNTs-2 membrane exhibits a peak power density of 340.7 mW cm-2 at 70 °C, which is significantly better than that of pure SPEEK (254.2 mW cm-2), demonstrating the great potential of proton conductors-functionalized CNTs in PEMs.

  3. All-inorganic nanocrystals as a glue for BiSbTe grains: design of interfaces in mesostructured thermoelectric materials.

    PubMed

    Son, Jae Sung; Zhang, Hao; Jang, Jaeyoung; Poudel, Bed; Waring, Al; Nally, Luke; Talapin, Dmitri V

    2014-07-14

    Nano- and mesostructuring is widely used in thermoelectric (TE) materials. It introduces numerous interfaces and grain boundaries that scatter phonons and decrease thermal conductivity. A new approach has been developed for the rational design of the interfaces in TE materials by using all-inorganic nanocrystals (NCs) that serve as a "glue" for mesoscopic grains. For example, circa 10 nm Bi NCs capped with (N2H5)4Sb2Te7 chalcogenidometallate ligands can be used as an additive to BiSbTe particles. During heat treatment, NCs fill up the voids between particles and act as a "glue", joining grains in hot-pressed pellets or solution-processed films. The chemical design of NC glue allowed the selective enhancement or decrease of the majority-carrier concentration near the grain boundaries, and thus resulted in doped or de-doped interfaces in granular TE material. Chemically engineered interfaces can be used as to optimize power factor and thermal conductivity.

  4. Inorganic contents of peats

    SciTech Connect

    Raymond, R. Jr.; Bish, D.L.; Cohen, A.D.

    1988-02-01

    Peat, the precursor of coal, is composed primarily of plant components and secondarily of inorganic matter derived from a variety of sources. The elemental, mineralogic, and petrographic composition of a peat is controlled by a combination of both its botanical and depositional environment. Inorganic contents of peats can vary greatly between geographically separated peat bogs as well as vertially and horizontally within an individual bog. Predicting the form and distribution of inorganic matter in a coal deposit requires understanding the distribution and preservation of inorganic matter in peat-forming environments and diagenetic alterations affecting such material during late-stage peatification and coalification processes. 43 refs., 4 figs., 3 tabs.

  5. Layered inorganic materials as redox agents: ferrocenium-intercalated zirconium phosphate.

    PubMed

    Santiago, Mitk'El B; Declet-Flores, Chasterie; Díaz, Agustín; Vélez, Meredith M; Bosques, Myrna Zoé; Sanakis, Yannis; Colón, Jorge L

    2007-07-03

    The direct intercalation reaction of ferrocene (bis(eta5-cyclopentadienyl)iron(II), Fc) with a highly hydrated layered zirconium phosphate (ZrP) resulted in the formation of the ferrocenium ion (Fc+) within the ZrP material. The Fc+-intercalated ZrP material has an interlayer distance of 10.7 A. The intercalated material was used as an electron acceptor for the oxidation of both ferro-cytochrome c and the excited state of tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)3]2+). Upon contact of the material with a 1.5 x 10(-5) M solution of ferro-cytochrome c, the UV-vis absorption spectrum shows the successful formation of ferri-cytochrome c. Luminescence spectroscopy shows that the Fc+-intercalated ZrP material quenches the luminescence of [Ru(bpy)3]2+. The excited-state quenching mechanism of [Ru(bpy)3]2+* by Fc+-intercalated ZrP follows a dynamic plus sphere of action model. The second-order dynamic quenching rate constant kq is 2.2 x 10(8) M(-1) s(-1).

  6. Flagellar filament bio-templated inorganic oxide materials - towards an efficient lithium battery anode

    NASA Astrophysics Data System (ADS)

    Beznosov, Sergei N.; Veluri, Pavan S.; Pyatibratov, Mikhail G.; Chatterjee, Abhijit; Macfarlane, Douglas R.; Fedorov, Oleg V.; Mitra, Sagar

    2015-01-01

    Designing a new generation of energy-intensive and sustainable electrode materials for batteries to power a variety of applications is an imperative task. The use of biomaterials as a nanosized structural template for these materials has the potential to produce hitherto unachievable structures. In this report, we have used genetically modified flagellar filaments of the extremely halophilic archaea species Halobacterium salinarum to synthesize nanostructured iron oxide composites for use as a lithium-ion battery anode. The electrode demonstrated a superior electrochemical performance compared to existing literature results, with good capacity retention of 1032 mAh g-1 after 50 cycles and with high rate capability, delivering 770 mAh g-1 at 5 A g-1 (~5 C) discharge rate. This unique flagellar filament based template has the potential to provide access to other highly structured advanced energy materials in the future.

  7. Flagellar filament bio-templated inorganic oxide materials - towards an efficient lithium battery anode.

    PubMed

    Beznosov, Sergei N; Veluri, Pavan S; Pyatibratov, Mikhail G; Chatterjee, Abhijit; MacFarlane, Douglas R; Fedorov, Oleg V; Mitra, Sagar

    2015-01-13

    Designing a new generation of energy-intensive and sustainable electrode materials for batteries to power a variety of applications is an imperative task. The use of biomaterials as a nanosized structural template for these materials has the potential to produce hitherto unachievable structures. In this report, we have used genetically modified flagellar filaments of the extremely halophilic archaea species Halobacterium salinarum to synthesize nanostructured iron oxide composites for use as a lithium-ion battery anode. The electrode demonstrated a superior electrochemical performance compared to existing literature results, with good capacity retention of 1032 mAh g(-1) after 50 cycles and with high rate capability, delivering 770 mAh g(-1) at 5 A g(-1) (~5 C) discharge rate. This unique flagellar filament based template has the potential to provide access to other highly structured advanced energy materials in the future.

  8. Alkylene-bridged polygerm- and polygermsilsesqui-oxanes: New hybrid organic-inorganic materials

    SciTech Connect

    Jamison, G.M.; Loy, D.A.; Zender, G.; Shea, K.J.

    1993-12-31

    Alkylene-bridge polygerm- and polygermsilsequioxanes have been formed by hydrolysis-condensation of their corresponding (EtO){sub 3}M(CH{sub 2}){sub n}Ge(OEt){sub 3} monomers under HCl- and NEt{sub 3}-catalyzed conditions in ethanol. Solid state {sup 13}C and {sup 29}Si NMR indicate the retention of the alkylene bridging moiety during polymerization. The resulting aerogels are mesoporous materials with high surface areas. Incorporation of the short ethylene bridging unit results in higher surface areas than when heylene bridges are present. The porous nature of hexylene-bridged hybrid network [Si(CH{sub 2}){sub 6}GeO{sub 3}]{sub n} appears insensitive to the acidic or basic nature of the catalyst employed in it formation, in contrast to its polysilsesquioxane counterpart. Work is underway to determine the origin of porosity in these materials, and to characterize xerogel materials generated from these monomers.

  9. Flagellar filament bio-templated inorganic oxide materials – towards an efficient lithium battery anode

    PubMed Central

    Beznosov, Sergei N.; Veluri, Pavan S.; Pyatibratov, Mikhail G.; Chatterjee, Abhijit; MacFarlane, Douglas R.; Fedorov, Oleg V.; Mitra, Sagar

    2015-01-01

    Designing a new generation of energy-intensive and sustainable electrode materials for batteries to power a variety of applications is an imperative task. The use of biomaterials as a nanosized structural template for these materials has the potential to produce hitherto unachievable structures. In this report, we have used genetically modified flagellar filaments of the extremely halophilic archaea species Halobacterium salinarum to synthesize nanostructured iron oxide composites for use as a lithium-ion battery anode. The electrode demonstrated a superior electrochemical performance compared to existing literature results, with good capacity retention of 1032 mAh g−1 after 50 cycles and with high rate capability, delivering 770 mAh g−1 at 5 A g−1 (~5 C) discharge rate. This unique flagellar filament based template has the potential to provide access to other highly structured advanced energy materials in the future. PMID:25583370

  10. Ability of organic and inorganic bedding materials to promote growth of environmental bacteria.

    PubMed

    Godden, S; Bey, R; Lorch, K; Farnsworth, R; Rapnicki, P

    2008-01-01

    The major objective of this study was to contrast the ability of 4 commonly utilized bedding materials to promote growth of environmental bacteria under controlled conditions. A second objective was to describe the relationship between bacterial growth and specific biochemical or nutritional properties of these bedding materials. Unused samples of clean sand (CS; n = 20), recycled sand (RS; n = 21), digested manure solids (DS; n = 15), and shavings (SH; n = 15) were collected from bedding storage areas on 49 commercial Minnesota and Wisconsin dairy farms. Sterilized bedding samples were inoculated with Klebsiella pneumoniae and Enterococcus faecium then incubated, in triplicate, for 72 h at 37 degrees C. Subsamples were collected after 0, 24, 48, and 72 h of incubation for culture and enumeration of bacteria. Subsamples of bedding were also tested for pH, total C content (%), and total N content (%). If bacterial growth occurred, peak levels were typically achieved within 24 h. Digested manure solids promoted the greatest amounts of growth of K. pneumoniae, followed by RS and then SH, whereas CS promoted the least. There would seem to be a tradeoff in selecting SH as a bedding material, because it supported moderate growth of K. pneumoniae but caused a rapid decline in the numbers of E. faecium. However, RS, CS, and DS each only supported relatively small amounts of growth of E. faecium, so the benefit of SH relative to other bedding materials is limited. High bedding pH may partially explain why some bedding materials supported growth of E. faecium (e.g., DS and RS). Both high bedding pH (e.g., as for DS or RS) and high total C (%) content (e.g., as for DS and SH) may partially explain why some bedding materials supported growth of K. pneumoniae.

  11. Research Update: Triblock copolymers as templates to synthesize inorganic nanoporous materials

    NASA Astrophysics Data System (ADS)

    Li, Yunqi; Bastakoti, Bishnu Prasad; Yamauchi, Yusuke

    2016-04-01

    This review focuses on the application of triblock copolymers as designed templates to synthesize nanoporous materials with various compositions. Asymmetric triblock copolymers have several advantages compared with symmetric triblock copolymers and diblock copolymers, because the presence of three distinct domains can provide more functional features to direct the resultant nanoporous materials. Here we clearly describe significant contributions of asymmetric triblock copolymers, especially polystyrene-block-poly(2-vinylpyridine)-block-poly(ethylene oxide) (abbreviated as PS-b-P2VP-b-PEO).

  12. The presence and distribution of polycyclic aromatic hydrocarbons and inorganic elements in water and lakebed materials and the potential for bioconcentration in biota at established sampling sites on Lake Powell, Utah and Arizona

    USGS Publications Warehouse

    Schonauer, Kurt T.; Hart, Robert J.; Antweiler, Ronald C.

    2014-01-01

    The National Park Service is responsible for monitoring the effects of visitor use on the quality of water, lakebed material (bottom sediments), and biota, in Lake Powell, Utah and Arizona. A sampling program was begun in 2010 to assess the presence, distribution, and concentrations of organic and inorganic compounds in the water column and bottom sediment. In response to an Environmental Impact Statement regarding personal watercraft and as a continuation from previous studies by the U.S. Geological Survey and the National Park Service, Glen Canyon National Recreation Area, water samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) using semipermeable membrane devices and inorganic elements using a fixed-bottle sampler deployed at established monitoring sites during 2010 and 2011. Lakebed material samples were also analyzed for polycyclic aromatic hydrocarbons and inorganic elements, some of which could be harmful to aquatic biota if present at concentrations above established aquatic life criteria. Of the 44 PAH compounds analyzed, 26 individual compounds were detected above the censoring limit in the water column by semipermeable membrane devices. The highest number of compounds detected were at Lone Rock Beach, Wahweap Marina, Rainbow Bridge National Monument, and Antelope Marina which are all located in the southern part of Lake Powell where visitation and boat use is high. Because PAHs can remain near their source, the potential for bioconcentration is highest near these sites. The PAH compound found in the highest concentration was phenol (5,902 nanograms per liter), which is included in the U.S. Environmental Protection Agency’s priority pollutants list. The dissolved inorganic chemistry of water samples measured at the sampling sites in Lake Powell defined three different patterns of elements: (1) concentrations were similar between sites in the upper part of the lake near Farley Canyon downstream to Halls Crossing Marina, a

  13. Layered and Pb-Free Organic-Inorganic Perovskite Materials for Ultraviolet Photoresponse: (010)-Oriented (CH3NH3)2MnCl4 Thin Film.

    PubMed

    Nie, Zhonghao; Yin, Jie; Zhou, Huawei; Chai, Ning; Chen, Baoli; Zhang, Yingtian; Qu, Konggang; Shen, Guodong; Ma, Huiyan; Li, Yuchao; Zhao, Jinsheng; Zhang, Xianxi

    2016-10-07

    Organic-inorganic lead perovskite materials show impressive performance in photovoltaics, photodetectors, light-emitting diodes, lasers, sensors, medical imaging devices, and other applications. Although organic-inorganic lead perovskites have shown good performance in numerous fields, they contain toxic Pb, which is expected to cause environmental pollution in future large-scale applications. Thus, the photoelectric properties of Pb-free organic-inorganic perovskite materials should be developed and studied. In this paper, we report on the photoresponse of Pb-free organic-inorganic hybrid manganese perovskite (CH3NH3)2MnCl4. To the best of our knowledge, this study demonstrates the first time that organic-inorganic hybrid manganese perovskites are used for this type of application. We found that the solution-processed MA2MnCl4 thin film tends to be oriented along the b-axis direction on the TiO2 surface. The evident photoresponse of the FTO/TiO2/MA2MnCl4/carbon electrode devices was observed under 10-30 Hz flashlight frequencies and a 330 nm light beam. This simple, green, and low-cost photoresponsive device is beneficial for the future industrial production of optical recorders and optical memory devices.

  14. DFT-chemical pressure analysis: visualizing the role of atomic size in shaping the structures of inorganic materials.

    PubMed

    Fredrickson, Daniel C

    2012-04-04

    Atomic size effects have long played a role in our empirical understanding of inorganic crystal structures. At the level of electronic structure calculations, however, the contribution of atomic size remains difficult to analyze, both alone and relative to other influences. In this paper, we extend the concepts outlined in a recent communication to develop a theoretical method for revealing the impact of the space requirements of atoms: the density functional theory-chemical pressure (DFT-CP) analysis. The influence of atomic size is most pronounced when the optimization of bonding contacts is impeded by steric repulsion at other contacts, resulting in nonideal interatomic distances. Such contacts are associated with chemical pressures (CPs) acting upon the atoms involved. The DFT-CP analysis allows for the calculation and interpretation of the CP distributions within crystal structures using DFT results. The method is demonstrated using the stability of the Ca(2)Ag(7) structure over the simpler CaCu(5)-type alternative adopted by its Sr-analogue, SrAg(5). A hypothetical CaCu(5)-type CaAg(5) phase is found to exhibit large negative pressures on each Ca atom, which are concentrated in two symmetry-related interstitial spaces on opposite sides of the Ca nucleus. In moving to the Ca(2)Ag(7) structure, relief comes to each Ca atom as a defect plane is introduced into one of these two negative-pressure regions, breaking the symmetry equivalence of the two sides and yielding a more compact Ca coordination environment. These results illustrate how the DFT-CP analysis can visually and intuitively portray how atomic size interacts with electronics in determining structure, and bridge theoretical and experimental approaches toward understanding the structural chemistry of inorganic materials.

  15. Protein micropatterning on bifunctional organic-inorganic sol-gel hybrid materials.

    PubMed

    Kim, Woo-Soo; Kim, Min-Gon; Ahn, Jun-Hyeong; Bae, Byeong-Soo; Park, Chan Beum

    2007-04-24

    Active protein micropatterns and microarrays made by selective localization are popular candidates for medical diagnostics, such as biosensors, bioMEMS, and basic protein studies. In this paper, we present a simple fabrication process of thick (approximately 20 microm) protein micropatterning using capillary force lithography with bifunctional sol-gel hybrid materials. Because bifunctional sol-gel hybrid material can have both an amine function for linking with protein and a methacryl function for photocuring, proteins such as streptavidin can be immobilized directly on thick bifunctional sol-gel hybrid micropatterns. Another advantage of the bifunctional sol-gel hybrid materials is the high selective stability of the amine group on bifunctional sol-gel hybrid patterns. Because amine function is regularly contained in each siloxane oligomers, immobilizing sites for streptavidin are widely distributed on the surface of thick hybrid micropatterns. The micropatterning processes of active proteins using efficient bifunctional sol-gel hybrid materials will be useful for the development of future bioengineered systems because they can save several processing steps and reduce costs.

  16. Immobilization of rhodium complexes in chiral organic-inorganic hybrid materials.

    PubMed

    Adima, A; Moreau, J J; Wong Chi Man, M

    2000-06-01

    Two new alkoxysilylated derivatives of (-)-(1R,2R)-1, 2-diaminocyclohexane: M = N-[(triethoxysilyl)propyl]-(-)-(1R,2R)-1, 2-diaminocyclohexane and B = N, N'-bis[(triethoxysilyl)propyl]-(-)-(1R,2R)-1,2-diaminocyclohexane have been synthesized. Their complexation with [Rh(cod)Cl]2 in the presence of TEOS = Si(OEt)4, followed by sol-gel hydrolysis-condensation, afforded new catalytic chiral hybrid materials. Evidence for the presence of the organic moieties complexed by rhodium in these solids was obtained by UV-visible spectroscopy, FT-IR studies, solid state 13C and 29Si CP-MAS NMR analysis, energy-dispersive X-ray (EDX) techniques, and elemental analysis. The nitrogen sorption studies and BET analyses ranged these solid gels from nonporous to highly porous materials. The catalytic activities and selectivities of the solid materials have been studied in the asymmetric hydrogen-transfer reduction of prochiral ketones and compared to that of the homogeneous rhodium complexes of the ligands M and B. The hybrid materials appeared interesting supports for enantioselective heterogeneous catalysis leading to chiral alcohols with ee up to 58% in the reduction of acetophenone and up to 98% in the case of the more hindered related ketones. The catalytic properties as a function of the nature of chiral hybrid solid are discussed.

  17. Geochemical and mineralogical interpretation of the Viking inorganic chemical results. [for Martian surface materials

    NASA Technical Reports Server (NTRS)

    Toulmin, P., III; Rose, H. J., Jr.; Christian, R. P.; Baird, A. K.; Evans, P. H.; Clark, B. C.; Keil, K.; Kelliher, W. C.

    1977-01-01

    The current status of geochemical, mineralogical, petrological interpretation of refined Viking Lander data is reviewed, and inferences that can be drawn from data on the composition of Martian surface materials are presented. The materials are dominantly fine silicate particles admixed with, or including, iron oxide particles. Both major element and trace element abundances in all samples are indicative of mafic source rocks (rather than more highly differentiated salic materials). The surface fines are nearly identical in composition at the two widely separated Lander sites, except for some lithologic diversity at the 100-m scale. This implies that some agency (presumably aeolian processes) has thoroughly homogenized them on a planetary scale. The most plausible model for the mineralogical constitution of the fine-grained surface materials at the two Lander sites is a fine-grained mixture dominated by iron-rich smectites, or their degradation products, with ferric oxides, probably including maghemite and carbonates (such as calcite), but not such less stable phases as magnesite or siderite.

  18. Optical transmission radiation damage and recovery stimulation of DSB: Ce3+ inorganic scintillation material

    NASA Astrophysics Data System (ADS)

    Borisevich, A.; Dormenev, V.; Korjik, M.; Kozlov, D.; Mechinsky, V.; Novotny, R. W.

    2015-02-01

    Recently, a new scintillation material DSB: Ce3+ was announced. It can be produced in a form of glass or nano-structured glass ceramics with application of standard glass production technology with successive thermal annealing. When doped with Ce3+, material can be applied as scintillator. Light yield of scintillation is near 100 phe/MeV. Un-doped material has a wide optical window from 4.5eV and can be applied to detect Cherenkov light. Temperature dependence of the light yield LY(T) is 0.05% which is 40 times less than in case of PWO. It can be used for detectors tolerant to a temperature variation between -20° to +20°C. Several samples with dimensions of 15x15x7 mm3 have been tested for damage effects on the optical transmission under irradiation with γ-quanta. It was found that the induced absorption in the scintillation range depends on the doping concentration and varies in range of 0.5-7 m-1. Spontaneous recovery of induced absorption has fast initial component. Up to 25% of the damaged transmission is recuperated in 6 hours. Afterwards it remains practically constant if the samples are kept in the dark. However, induced absorption is reduced by a factor of 2 by annealing at 50°C and completely removed in a short time when annealing at 100°C. A significant acceleration of the induced absorption recovery is observed by illumination with visible and IR light. This effect is observed for the first time in a Ce-doped scintillation material. It indicates, that radiation induced absorption in DSB: Ce scintillation material can be retained at the acceptable level by stimulation with light in a strong irradiation environment of collider experiments.

  19. Workshop on Measurement Needs for Local-Structure Determination in Inorganic Materials

    PubMed Central

    Levin, Igor; Vanderah, Terrell

    2008-01-01

    The functional responses (e.g., dielectric, magnetic, catalytic, etc.) of many industrially-relevant materials are controlled by their local structure—a term that refers to the atomic arrangements on a scale ranging from atomic (sub-nanometer) to several nanometers. Thus, accurate knowledge of local structure is central to understanding the properties of nanostructured materials, thereby placing the problem of determining atomic positions on the nanoscale—the so-called “nanostructure problem”—at the center of modern materials development. Today, multiple experimental techniques exist for probing local atomic arrangements; nonetheless, finding accurate comprehensive, and robust structural solutions for the nanostructured materials still remains a formidable challenge because any one of these methods yields only a partial view of the local structure. The primary goal of this 2-day NIST-sponsored workshop was to bring together experts in the key experimental and theoretical areas relevant to local-structure determination to devise a strategy for the collaborative effort required to develop a comprehensive measurement solution on the local scale. The participants unanimously agreed that solving the nanostructure problem—an ultimate frontier in materials characterization—necessitates a coordinated interdisciplinary effort that transcends the existing capabilities of any single institution, including national laboratories, centers, and user facilities. The discussions converged on an institute dedicated to local structure determination as the most viable organizational platform for successfully addressing the nanostructure problem. The proposed “institute” would provide an intellectual infrastructure for local structure determination by (1) developing and maintaining relevant computer software integrated in an open-source global optimization framework (Fig. 2), (2) connecting industrial and academic users with experts in measurement techniques, (3

  20. Optical and thermal characterization of membrane reflector materials for solar orbit transfer vehicles

    NASA Astrophysics Data System (ADS)

    Farmer, Gregory D.; McGee, Jennie K.; Partch, Russell; Lester, Dean M.

    2002-01-01

    The Air Force Research Laboratory (AFRL), is advancing technologies to enable greater mobility for future AF spacecraft. The Solar Orbit Transfer Vehicle (SOTV) program is developing components for a concept based on a solar thermal rocket and solar thermal power generation. The program is performing ground testing of a thin film membrane concentrator concept. To better understand system performance, a series of optical characterization tests of the membrane material were performed. The objective was to quantify the relationship between membrane optical properties and the concentrator on-orbit transmission performance and thermal profile. During testing we collected reflectivity, absorptivity, transmissivity, and emissivity data for un-coated and coated membrane material. The membrane material tested was fabricated using a flight-qualified polyimide material and proven manufacturing processes. The test results, and system thermal analysis are presented in this paper. The results of this research will be used to refine hardware performance predictions and improve sizing for flight demonstration. .

  1. Meeting Materials for the 4th NRC Meeting on the Guidance for and the Review of EPA's Toxicological Assessment of Inorganic Arsenic

    EPA Science Inventory

    On December 2-3, 2015, the National Research Council (NRC) hosted the 4th meeting of the committee formed to peer review the draft IRIS assessment of inorganic arsenic. EPA presented background and overview materials during the public session on December 2nd. This information co...

  2. Meeting Materials for the 4th NRC Meeting on the Guidance for and the Review of EPA's Toxicological Assessment of Inorganic Arsenic

    EPA Science Inventory

    On December 2-3, 2015, the National Research Council (NRC) hosted the 4th meeting of the committee formed to peer review the draft IRIS assessment of inorganic arsenic. EPA presented background and overview materials during the public session on December 2nd. This information co...

  3. Role of Organic Anion and Amino Acid Carriers in Transport of Inorganic Mercury in Rat Renal Basolateral Membrane Vesicles: Influence of Compensatory Renal Growth

    PubMed Central

    Lash, Lawrence H.; Hueni, Sarah E.; Putt, David A.; Zalups, Rudolfs K.

    2006-01-01

    Susceptibility to renal injury induced by inorganic mercury (Hg2+) increases significantly as a result of compensatory renal growth (following reductions of renal mass). We hypothesize that this phenomenon is related in part to increased basolateral uptake of Hg2+ by proximal tubular cells. To determine the mechanistic roles of various transporters, we studied uptake of Hg2+, in the form of biologically relevant Hg2+-thiol conjugates, using baso-lateral membrane (BLM) vesicles isolated from the kidney(s) of control and uninephrectomized (NPX) rats. Binding of Hg2+ to membranes, accounted for 52–86% of total Hg2+ associated with membrane vesicles exposed to HgCl2, decreased with increasing concentrations of HgCl2, and decreased slightly in the presence of sodium ions. Conjugation of Hg2+ with thiols (glutathione, l-cysteine (Cys), N-acetyl-l-cysteine) reduced binding by more than 50%. Under all conditions, BLM vesicles from NPX rats exhibited a markedly lower proportion of binding. Of the Hg2+-thiol conjugates studied, transport of Hg-(Cys)2 was fastest. Selective inhibition of BLM carriers implicated the involvement of organic anion transporter(s) (Oat1 and/or Oat3; Slc22a6 and Slc22a8), amino acid transporter system ASC (Slc7a10), the dibasic amino acid transporter (Slc3a1), and the sodium-dicarboxylate carrier (SDCT2 or NADC3; Slc13a3). Uptake of each mercuric conjugate, when factored by membrane protein content, was higher in BLM vesicles from uninephrectomized (NPX) rats, with specific increases in transport by the carriers noted above. These results support the hypothesis that compensatory renal growth is associated with increased uptake of Hg2+ in proximal tubular cells and we have identified specific transporters involved in the process. PMID:16162843

  4. Analysis of the inorganic component of autogenous tooth bone graft material.

    PubMed

    Kim, Young-Kyun; Kim, Su-Gwan; Oh, Ji-Su; Jin, Seung-Chan; Son, Jun-Sik; Kim, Suk-Young; Lim, Soo-Young

    2011-08-01

    This study was performed to identify the calcium phosphate minerals, chemical element and Ca/P ratio and to examine the surface structure of autogenous tooth bone grafting material (AutoBT) which recently developed and applied clinically as a bone graft materials. The analytical results showed that AutoBT is composed of low-crystalline hydroxyapatite (HA) and possibly other calcium phosphate minerals, which is similar to the minerals of human bone tissues. And the dental crown portion was composed of high-crystalline calcium phosphate minerals (mainly HA) with higher Ca/P ratio while the root portion was mainly composed of low-crystalline calcium phosphates with relatively low Ca/P ratio.

  5. Optical properties of LaF3:Er,Yb nanoparticle-doped organic-inorganic hybrid material.

    PubMed

    Li, Tong; Zhang, Dan; Chen, Cong; Bo, Shuhui; Zhang, Daming

    2010-03-01

    Oleic acid (OA)-modified LaF3:Er,Yb nanoparticle-doped organic-inorganic hybrid material (OIHM) was prepared. The absorption spectrum and photoluminescence spectrum were analyzed. The full width at half maximum (FWHM) of the photoluminescence spectrum was about 83 nm. The Judd-Ofelt theory was used to analyze the absorption spectrum of Er3+ and obtain the intensity parameters: omega2 = 2.11 x 10(-20) cm2, omega4 = 0.78 x 10(-200 cm2, omega6 = 0.56 x 10(-20)cm2. The line strengths predict spontaneous transition probabilities, and the radiative lifetimes are calculated with the Judd-Ofelt intensity parameters. The calculated radiative lifetime of the excited 4I13/2 state of Er3+ is 13.34 ms. Based on the parameters we calculated, OA-modified LaF3:Er,Yb nanoparticle-doped OIHM is a potential material for polymeric optical waveguide amplifiers.

  6. Organic-inorganic hybrid polyionic liquid based polyoxometalate as nano porous material for selective oxidation of sulfides

    NASA Astrophysics Data System (ADS)

    Rafiee, Ezzat; Shahebrahimi, Shabnam

    2017-07-01

    Organic-inorganic hybrid nano porous materials based on poly(ionic liquid)-polyoxometalate (PIL-POM) were reported. These hybrid materials were synthesized by the reaction of 4-vinyl pyridine with 1,3-propanesultone, followed by the polymerization and also sulfonate-functionalized cross-linked poly(4-vinylpyridine) and combining these polymers with H5PMo10V2O40 (PMo10V2). Activity of prepared PIL-PMo10V2 hybrids were investigated as catalysts for oxidation of sulfides with H2O2 as oxidant. For understanding catalytic activities of the PIL-PMo10V2 hybrids in oxidation of sulfides, effect of catalyst composition, substrate, and reaction conditions were studied. The results show that the PIL-PMo10V2 hybrids are active as selective heterogeneous catalysts for oxidation of sulfides and can be recovered and reused. The catalyst was characterized by FT-IR, TGA-DSC, XRD, SEM/EDX, BET, CV and zeta potential measurement. Also, average molecular weight of prepared catalysts were measured.

  7. Final Report: Photo-Directed Molecular Assembly of Multifunctional Inorganic Materials

    SciTech Connect

    B.G. Potter, Jr.

    2010-10-15

    This final report details results, conclusions, and opportunities for future effort derived from the study. The work involved combining the molecular engineering of photoactive Ti-alkoxide systems and the optical excitation of hydrolysis and condensation reactions to influence the development of the metal-oxygen-metal network at the onset of material formation. Selective excitation of the heteroleptic alkoxides, coupled with control of alkoxide local chemical environment, enabled network connectivity to be influenced and formed the basis for direct deposition and patterning of Ti-oxide-based materials. The research provided new insights into the intrinsic photoresponse and assembly of these complex, alkoxide molecules. Using a suite of electronic, vibrational, and nuclear spectroscopic probes, coupled with quantum chemical computation, the excitation wavelength and fluence dependence of molecular photoresponse and the nature of subsequent hydrolysis and condensation processes were probed in pyridine-carbinol-based Ti-alkoxides with varied counter ligand groups. Several methods for the patterning of oxide material formation were demonstrated, including the integration of this photoprocessing approach with conventional, dip-coating methodologies.

  8. Adsorption of transition metal ions from aqueous solutions onto a novel silica gel matrix inorganic-organic composite material.

    PubMed

    Yin, Ping; Xu, Qiang; Qu, Rongjun; Zhao, Guifang; Sun, Yanzhi

    2010-01-15

    A novel inorganic-organic composite material silica gel microspheres encapsulated by imidazole functionalized polystyrene (SG-PS-azo-IM) has been synthesized and characterized. This composite material was used to investigate the adsorption of Cr(III), Mn(II), Fe(III), Ni(II), Cu(II), Zn(II), Hg(II), Pb(II), Pd(II), Pt(II), Ag(I), and Au(III) from aqueous solutions, and the research results displayed that SG-PS-azo-IM has the highest adsorption capacity for Au(III). Langmuir and Freundlich isotherm models were applied to analyze the experimental data, the best interpretation for the experimental data was given by the Langmuir isotherm equation, and the maximum adsorption capacity for Au(III) is 1.700 mmol/g. The adsorption selectivity, the dynamic adsorption and desorption properties of SG-PS-azo-IM for Au(III) have also been studied. The results showed that SG-PS-azo-IM had excellent adsorption for Au(III) in four binary ions system, especially in the systems of Au(III)-Zn(II) and Au(III)-Cu(II), and almost Au(III) could be desorbed with the eluent solution of 0.5% thiourea in 1 mol/L HCl. Moreover, this novel composite material was used to preconcentrate Au(III) before its determination by flame atomic adsorption spectrometry. In the initial concentration range of 0.10-0.20 microg/mL, multiple of enrichment could reach 5.28. Thus, silica gel encapsulated by polystyrene coupling with imidazole (SG-PS-azo-IM) is favorable and useful for the removal of transition metal ions, and the high adsorption capacity makes it a good promising candidate material for Au(III) removal.

  9. Interfacial Engineering of Inorganic Materials for Energy Storage and Conversion Applications

    NASA Astrophysics Data System (ADS)

    Samiee, Mojtaba

    Since the micrometer-sized bulk materials have reached their inherent limits, development of new materials with high performance is essential for low cost and environmentally friendly electrochemical energy storage and conversion devices. One approach is to take advantage of interfacial engineering in order to modify currently developed materials, thus improving their properties for specific applications. The advantage of interfacial engineering is that it can also be applied to newly developed materials to further improve their properties for the specific applications. In first part of this dissertation, a systematic study is performed to investigate the effect of annealing in reducing atmospheres with different oxygen partial pressures and presence of other species (Ar, H2, N2, vacuum or hydrocarbon) on visible-light photocatalytic activity of TiO2. In second part, a facile nitridation method is used to improve the rate capability of TiO 2 as anode material for Li ion batteries. The enhanced high-rate capacities are attributed to moderate surface nitridation with less-disordered nitridated regions, which may enhance the surface electronic conductivity without forming discrete, nanoscale, and surface amorphous films to block the lithium transport. In third part, pseudocapacitive properties of V2O5-based adsorbates supported on TiO2 nanoparticles is systematically measured. Surface amorphous films (SAFs), which form naturally at thermodynamic equilibria at 550-600 °C with self-regulating or "equilibrium" thicknesses on the order of 1 nm, exhibit superior electrochemical performance at moderate and high scan rates (20-500 mV/s) that are of prime importance for supercapacitor applications, as compared with submonolayer and monolayer adsorbates formed at lower equilibration temperatures. In fourth part, we perform a combined experimental and computational investigation into the effects of aliovalent doping in NASICON on both bulk and grain boundary ionic conductivity

  10. Synthesis and Characterization of Organic-Inorganic Nanocomposite Poly-o-anisidine Sn(IV) Arsenophosphate: Its Analytical Applications as Pb(II) Ion-Selective Membrane Electrode

    PubMed Central

    Khan, Asif Ali; Habiba, Umme; Khan, Anish

    2009-01-01

    Poly-o-anisidine Sn(IV) arsenophosphate is a newly synthesized nanocomposite material and has been characterized on the basis of its chemical composition, ion exchange capacity, TGA-DTA, FTIR, X-RAY, SEM, and TEM studies. On the basis of distribution studies, the exchanger was found to be highly selective for lead that is an environmental pollutant. For the detection of lead in water a heterogeneous precipitate based ion-selective membrane electrode was developed by means of this composite cation exchanger as electroactive material. The membrane electrode is mechanically stable, with a quick response time, and can be operated over a wide pH range. The selectivity coefficients were determined by mixed solution method and revealed that the electrode is sensitive for Pb(II) in presence of interfering cations. The practical utility of this membrane electrode has been established by employing it as an indicator electrode in the potentiometric titration of Pb(II). PMID:20140082

  11. Fouling of ceramic filters and thin-film composite reverse osmosis membranes by inorganic and bacteriological constituents

    SciTech Connect

    Siler, J.L.; Poirier, M.R.; McCabe, D.J.; Hazen, T.C.

    1991-12-31

    Two significant problems have been identified during the first three years of operating the Savannah River Site Effluent Treatment Facility. These problems encompass two of the facility`s major processing areas: the microfiltration and reverse osmosis steps. The microfilters (crossflow ceramic filters {minus}0.2{mu} nominal pore size) have been prone to pluggage problems. The presence of bacteria and bacteria byproducts in the microfilter feed, along with small quantities of colloidal iron, silica, and aluminum, results in a filter foulant that rapidly deteriorates filter performance and is difficult to remove by chemical cleaning. Processing rates through the filters have dropped from the design flow rate of 300 gpm after cleaning to 60 gpm within minutes. The combination of bacteria (from internal sources) and low concentrations of inorganic species resulted in substantial reductions in the reverse osmosis system performance. The salt rejection has been found to decrease from 99+% to 97%, along with a 50% loss in throughput, within a few hours of cleaning. Experimental work has led to implementation of several changes to plant operation and to planned upgrades of existing equipment. It has been shown that biological control in the influent is necessary to achieve design flowrates. Experiments have also shown that the filter performance can be optimized by the use of efficient filter backpulsing and the addition of aluminum nitrate (15 to 30 mg/L Al{sup 3+}) to the filter feed. The aluminum nitrate assists by controlling adsorption of colloidal inorganic precipitates and biological contaminants. In addition, improved cleaning procedures have been identified for the reverse osmosis units. This paper provides a summary of the plant problems and the experimental work that has been completed to understand and correct these problems.

  12. Fouling of ceramic filters and thin-film composite reverse osmosis membranes by inorganic and bacteriological constituents

    SciTech Connect

    Siler, J.L.; Poirier, M.R.; McCabe, D.J.; Hazen, T.C.

    1991-01-01

    Two significant problems have been identified during the first three years of operating the Savannah River Site Effluent Treatment Facility. These problems encompass two of the facility's major processing areas: the microfiltration and reverse osmosis steps. The microfilters (crossflow ceramic filters {minus}0.2{mu} nominal pore size) have been prone to pluggage problems. The presence of bacteria and bacteria byproducts in the microfilter feed, along with small quantities of colloidal iron, silica, and aluminum, results in a filter foulant that rapidly deteriorates filter performance and is difficult to remove by chemical cleaning. Processing rates through the filters have dropped from the design flow rate of 300 gpm after cleaning to 60 gpm within minutes. The combination of bacteria (from internal sources) and low concentrations of inorganic species resulted in substantial reductions in the reverse osmosis system performance. The salt rejection has been found to decrease from 99+% to 97%, along with a 50% loss in throughput, within a few hours of cleaning. Experimental work has led to implementation of several changes to plant operation and to planned upgrades of existing equipment. It has been shown that biological control in the influent is necessary to achieve design flowrates. Experiments have also shown that the filter performance can be optimized by the use of efficient filter backpulsing and the addition of aluminum nitrate (15 to 30 mg/L Al{sup 3+}) to the filter feed. The aluminum nitrate assists by controlling adsorption of colloidal inorganic precipitates and biological contaminants. In addition, improved cleaning procedures have been identified for the reverse osmosis units. This paper provides a summary of the plant problems and the experimental work that has been completed to understand and correct these problems.

  13. Inorganic-organic solar cells based on quaternary sulfide as absorber materials.

    PubMed

    Hong, Tiantian; Liu, Zhifeng; Yan, Weiguo; Liu, Junqi; Zhang, Xueqi

    2015-12-14

    We report a novel promising quaternary sulfide (CuAgInS) to serve as a semiconductor sensitizer material in the photoelectrochemical field. In this study, CuAgInS (CAIS) sulfide sensitized ZnO nanorods were fabricated on ITO substrates through a facile and low-cost hydrothermal chemical method and applied on photoanodes for solar cells for the first time. The component and stoichiometry were key factors in determining the photoelectric performance of CAIS sulfide, which were controlled by modulating their reaction time. ZnO/Cu0.7Ag0.3InS2 nanoarrays exhibit an enhanced optical and photoelectric performance and the power conversion efficiency of ITO/ZnO/Cu0.7Ag0.3InS2/P3HT/Pt solid-state solar cell was up to 1.80%. The remarkable performance stems from improved electron transfer, a higher efficiency of light-harvesting and appropriate band gap alignment at the interface of the ZnO/Cu0.7Ag0.3InS2 NTs. The research indicates that CAIS as an absorbing material has enormous potential in solar cell systems.

  14. Quantum dot-based organic-inorganic hybrid materials for optoelectronic applications (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Lee, Kwang-Sup

    2016-10-01

    Our recent research involves the design, characterization and testing of devices constituting low bandgap conjugated polymers, surface-engineered quantum dots (QDs), carbon nanotube (CNT)-QDs, QDs decorated nanowires, and QD coupled conjugated polymers. The resulting hybrid materials can be used for facilitating the charge/energy transfer and enhancing the charge carrier mobility in highly efficient optoelectronic and photonic devices. Exploiting the full potential of quantum dots (QDs) in optoelectronic devices require efficient mechanisms for transfer of energy or electrons produced in the optically excited QDs. We propose semiconducting π-conjugated molecules as ligands to achieve energy or charge transfer. The hybridization of p-type π-conjugated molecules to the surface of n-type QDs can induce distinct luminescence and charge transport characteristics due to energy and/or charge transfer effects. QDs and π-conjugated molecule hybrids with controlled luminescent properties can be used for new active materials for light-emitting diodes and flexible displays. In addition, such hybrid systems with enhanced charge transfer efficiency can be used for nanoscale photovoltaic devices. We have also explored single nanoparticle based electronics using QDs and π-conjugated molecule hybrids with molecular-scale n-p or n-insulating (ins)-p-heterojunction structures.

  15. Effect of geometrical dimension, shape, thickness, material & applied pressure on nanopore thin filtration membrane strength

    NASA Astrophysics Data System (ADS)

    Mustafa, Kamarul Asyikin; Yunas, Jumril; Hamzah, Azrul Azlan; Majlis, Burhanuddin Yeop

    2017-09-01

    Filtration membrane is an essential part in an artificial kidney device functioning as a channel to pass through all wastes from blood. This paper focuses on the effect of dimension, shape, thickness, material and applied pressure on the artificial filtration membrane to be used in terms of its mechanical strength. Studied parameters important for consideration of an actual filtration membrane design for the artificial kidney. The stress and deflection at the center of the membrane is studied using COMSOL Multiphysics simulation tool using "Solid Mechanics" physics module. The results shows that maximum deflection happens at the center of the membrane. Higher applied pressure causes more membrane deflection from the initial state while thicker membrane shows a better withstand towards applied pressure. Circle shape pores has lower stress and deflection compared to slit pores whereas filtration pore size does not give much impact on the stress and deflection of the membrane. Silicon Nitride filtration membrane is the most robust compared to Silicon and Silicon Dioxide membrane evaluated. To conclude, thicker Silicon Nitride membrane with arrays of uniform circle pores will result to a more stable filtration membrane that would be able to withstand simulated blood stream pressure of 10 until 55 mmHg in an artificial kidney.

  16. Designing and nanoscale engineering of organic/inorganic electronic materials for organic light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Cui, Ji

    2001-07-01

    Organic light-emitting diodes (OLEDs) have been intensively studied due to their emerging applications in flat panel display technologies. The motivation of the present research has been the desire to (a) explore new routes to OLED functional layers with rigorous control of layer properties; (b) probe the effects of OLED anode-hole transport layer interfacial energetics on charge injection, luminous efficiency; (c) acquire micron-scale multicolor OLED pixels for potential high resolution OLED display application; (d) better understand and further improve charge injection into molecular and macromolecular solids by designing and implementing novel OLED anode materials. In the first part, a spin-coating/siloxane cross-linking approach has been applied to OLED charge transport layers which provides a high throughput route to robust, pinhole-free, adherent thin films with covalently interlinked, glassy structures (Chapter 2). In anode-hole transport layer contact study (Chapter 3), it is shown that integrity of electrode/organic interfacial contact is crucial to the performance and stability of organic light emitting diodes (OLEDs). It is demonstrated that self-assembled or spincoated nm-scale thick silane derived hole transport layer on ITO can effectively prevent de-wetting of the vapor deposited TPD hole transport layers (Chapter 3), leading to significantly enhanced light output (15,000 cd/m2), luminous efficiency (1.2%), and thermal stability (up to 110°C). In applying soft lithography techniques to OLED micro-patterning, we designed and implemented high temperature micro-contact printing, which readily affords pixel features down to 1.0 micron dimensions, and which, by virtue of the length scale-dependent carrier tunneling through SAM structures, affords tenability in luminescence patterns (Chapter 4). To facilitate hole injection at anode side of OLED, MOCVD derived, highly transparent, high work function thin film TCO materials is synthesized and employed as

  17. Tungsten hydride complex as a template in organic inorganic hybrid materials

    NASA Astrophysics Data System (ADS)

    Montinho, Isilda; Boev, Victor; Fonseca, António M.; Silva, Carlos J. R.; Neves, Isabel C.

    2003-03-01

    A tungsten hydride complex, [WH 2( η2-OOCCH 3)(Ph 2PCH 2CH 2PPh 2) 2][BPh 4], was dispersed in a hybrid matrix synthesized by a sol-gel process. The host matrix of the so-called ureasil is a network of silica to which oligopolyoxyethylene chains [POE, (OCH 2CH 2) n] are grafted by means of urea cross-links. The free complex and sol-gel materials were characterized by thermal analysis (DSC) and spectroscopic methods (FT-IR and UV/Vis). The data gathered indicate that the tungsten(IV) complex is immobilized in the host matrix, and it exhibits structural properties different from those of the free form. These differences could arise either from distortions caused by steric effects imposed by the structure of hybrid matrix or by interactions with the matrix.

  18. Solvothermal synthesis and characterization of two inorganic-organic hybrid materials based on barium.

    PubMed

    Abdollahian, Yashar; Hauser, Jesse L; Rogow, David L; Oliver, Allen G; Oliver, Scott R J

    2012-10-28

    Two metal-organic frameworks containing barium were synthesized hydrothermally and investigated for their catalytic properties. Ba(2)F(2)[O(3)SC(2)H(4)SO(3)] has barium fluoride layers linked by organic 1,2-ethanedisulfonate molecules. Ba[O(3)SC(2)H(4)SO(3)] has discrete barium centers arranged in layers and connected covalently by ethanedisulfonate bridges. Thermogravimetric analysis showed that Ba(2)F(2)[O(3)SC(2)H(4)SO(3)] is stable to ca. 325 °C and Ba[O(3)SC(2)H(4)SO(3)] to ca. 375 °C. These materials expand the metal-organic frameworks available for group II metals bound to organodisulfonate linkers and are potentially useful for a range of heterogeneous acid catalysis reactions.

  19. Vertically Aligned Nanostructured Arrays of Inorganic Materials: Synthesis, Distinctive Physical Phenomena, and Device Integration

    NASA Astrophysics Data System (ADS)

    Velazquez, Jesus Manuel

    The manifestation of novel physical phenomena upon scaling materials to finite size has inspired new device concepts that take advantage of the distinctive electrical, mechanical, and optical, properties of nanostructures. The development of fabrication approaches for the preparation of their 1D nanostructured form, such as nanowires and nanotubes, has contributed greatly to advancing fundamental understanding of these systems, and has spurred the integration of these materials in novel electronics, photonic devices, power sources, and energy scavenging constructs. Significant progress has been achieved over the last decade in the preparation of ordered arrays of carbon nanotubes, II---VI and III---V semiconductors, and some binary oxides such as ZnO. In contrast, relatively less attention has been focused on layered materials with potential for electrochemical energy storage. Here, we describe the catalyzed vapor transport growth of vertical arrays of orthorhombic V2O 5 nanowires. In addition, near-edge X-ray absorption fine structure (NEXAFS) spectroscopy is used to precisely probe the alignment, uniformity in crystal growth direction, and electronic structure of single-crystalline V2O5 nanowire arrays prepared by a cobalt-catalyzed vapor transport process. The dipole selection rules operational for core-level electron spectroscopy enable angle-dependant NEXAFS spectroscopy to be used as a sensitive probe of the anisotropy of these systems and provides detailed insight into bond orientation and the symmetry of the frontier orbital states. The experimental spectra are matched to previous theoretical predictions and allow experimental verification of features such as the origin of the split-off conduction band responsible for the n-type conductivity of V2O5 and the strongly anisotropic nature of vanadyl-oxygen-derived (V=O) states thought to be involved in catalysis. We have also invested substantial effort in obtaining shape and size control of metal oxide

  20. Gigantic swelling of inorganic layered materials: a bridge to molecularly thin two-dimensional nanosheets.

    PubMed

    Geng, Fengxia; Ma, Renzhi; Ebina, Yasuo; Yamauchi, Yusuke; Miyamoto, Nobuyoshi; Sasaki, Takayoshi

    2014-04-09

    Platy microcrystals of a typical layered material, protonated titanate, have been shown to undergo an enormous degree of swelling in aqueous solutions of various amines, including tertiary amines, quaternary ammonium hydroxides, and primary amines. Introducing these solutions expanded the crystal gallery height by up to ~100-fold. Through systematic analysis, we determined that ammonium ion intercalation is predominantly affected by the acid-base equilibrium and that the degree of swelling or inflow of H2O is controlled by the osmotic pressure balance between the gallery and the solution environment, both of which are relatively independent of electrolyte identity but substantially dependent on molarity. In solutions of tertiary amines and quaternary ammonium hydroxides, the uptake of ammonium ions increases nearly linearly with increasing external concentration before reaching a saturation plateau, i.e., ~40% relative to the cation-exchange capacity of the crystals used. The only exception is tetrabutylammonium ions, which yield a lower saturation value, ~30%, owing to steric effects. The swelling behaviors in some primary amine solutions differ as a result of the effect of attractive forces between amine solute molecules on the solution osmotic pressure. Although the swelling is essentially colligative in nature, the stability of the resultant swollen structure is heavily dependent on the chemical nature of the guest ions. Intercalated ions of higher polarity and smaller size help stabilize the swollen structure, whereas ions of lower polarity and larger size lead readily to exfoliation. The insight gained from this study sheds new light on both the incorporation of guest molecules into a gallery of layered structures in general and the exfoliation of materials into elementary single-layer nanosheets.

  1. Mixed anion materials and compounds for novel proton conducting membranes

    DOEpatents

    Poling, Steven Andrew; Nelson, Carly R.; Martin, Steve W.

    2006-09-05

    The present invention provides new amorphous or partially crystalline mixed anion chalcogenide compounds for use in proton exchange membranes which are able to operate over a wide variety of temperature ranges, including in the intermediate temperature range of about 100 .degree. C. to 300.degree. C., and new uses for crystalline mixed anion chalcogenide compounds in such proton exchange membranes. In one embodiment, the proton conductivity of the compounds is between about 10.sup.-8 S/cm and 10.sup.-1 S/cm within a temperature range of between about -60 and 300.degree. C. and a relative humidity of less than about 12%..

  2. Maximum yields of microsomal-type membranes from small amounts of plant material without requiring ultracentrifugation.

    PubMed

    Abas, Lindy; Luschnig, Christian

    2010-06-15

    Isolation of a microsomal membrane fraction is a common procedure in studies involving membrane proteins. By conventional definition, microsomal membranes are collected by centrifugation of a postmitochondrial fraction at 100,000g in an ultracentrifuge, a method originally developed for large amounts of mammalian tissue. We present a method for isolating microsomal-type membranes from small amounts of Arabidopsis thaliana plant material that does not rely on ultracentrifugation but instead uses the lower relative centrifugal force (21,000g) of a microcentrifuge. We show that the 21,000g pellet is equivalent to that obtained at 100,000g and that it contains all of the membrane fractions expected in a conventional microsomal fraction. Our method incorporates specific manipulation of sample density throughout the procedure, with minimal preclearance, minimal volumes of extraction buffer, and minimal sedimentation pathlength. These features allow maximal membrane yields, enabling membrane isolation from limited amounts of material. We further demonstrate that conventional ultracentrifuge-based protocols give submaximal yields due to losses during early stages of the procedure; that is, extensive amounts of microsomal-type membranes can sediment prematurely during the typical preclearance steps. Our protocol avoids such losses, thereby ensuring maximal yield and a representative total membrane fraction. The principles of our method can be adapted for nonplant material. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  3. Static adsorptive fouling of extracellular polymeric substances with different membrane materials.

    PubMed

    Su, Xinying; Tian, Yu; Zuo, Wei; Zhang, Jun; Li, Hui; Pan, Xiaoyue

    2014-03-01

    Adsorptive fouling of microbial extracellular polymeric substances (EPS) greatly influences the fouling behavior and membrane characteristics in a membrane bioreactor (MBR). In this study, adsorptive fouling of the EPS on different membrane materials was compared and adsorptive mechanism between membranes and EPS was investigated by thermodynamic analysis. The results suggested that both the absolute and relative changes of hydraulic resistances should be considered to evaluate fouling of membranes with different materials, and Sips isotherm was the most suitable model to describe the EPS carbohydrate and protein adsorptions on membranes. Thermodynamic analysis showed that both EPS carbohydrate and protein adsorptions were spontaneous (ΔrG(θ) < 0), endothermic (ΔrH(θ) > 0), and entropy driven (ΔrS(θ) > 0). Decreasing ΔrG(θ) values with temperature suggested that EPS adsorptive fouling can be limited by reducing temperature. In addition, physisorption processes and hydrogen bonding interactions between EPS and membranes might play a relatively major role in the adsorption mechanism of EPS on the membrane surface. Atomic force microscopy (AFM) and contact angle analysis confirmed that the adsorptive fouling modified the membrane surface, making the membrane surface more heterogeneous and more hydrophobic.

  4. Study of high resistance inorganic coatings on graphite fibers. [for graphite-epoxy composite materials

    NASA Technical Reports Server (NTRS)

    Galasso, F. S.; Veltri, R. D.; Scola, D. A.

    1979-01-01

    Coatings made of boron, silicon carbide, silica, and silica-like materials were studied to determine their ability to increase resistance of graphite fibers. The most promising results were attained by chemical vapor depositing silicon carbide on graphite fiber followed by oxidation, and drawing graphite fiber through ethyl silicate followed by appropriate heat treatments. In the silicon carbide coating studies, no degradation of the graphite fibers was observed and resistance values as high as three orders of magnitude higher than that of the uncoated fiber was attained. The strength of a composite fabricated from the coated fiber had a strength which compared favorably with those of composites prepared from uncoated fiber. For the silica-like coated fiber prepared by drawing the graphite fiber through an ethyl silicate solution followed by heating, coated fiber resistances about an order of magnitude greater than that of the uncoated fiber were attained. Composites prepared using these fibers had flexural strengths comparable with those prepared using uncoated fibers, but the shear strengths were lower.

  5. Metal-Organic-Inorganic Nanocomposite Thermal Interface Materials with Ultralow Thermal Resistances.

    PubMed

    Yegin, Cengiz; Nagabandi, Nirup; Feng, Xuhui; King, Charles; Catalano, Massimo; Oh, Jun Kyun; Talib, Ansam J; Scholar, Ethan A; Verkhoturov, Stanislav V; Cagin, Tahir; Sokolov, Alexei V; Kim, Moon J; Matin, Kaiser; Narumanchi, Sreekant; Akbulut, Mustafa

    2017-03-22

    As electronic devices get smaller and more powerful, energy density of energy storage devices increases continuously, and moving components of machinery operate at higher speeds, the need for better thermal management strategies is becoming increasingly important. The removal of heat dissipated during the operation of electronic, electrochemical, and mechanical devices is facilitated by high-performance thermal interface materials (TIMs) which are utilized to couple devices to heat sinks. Herein, we report a new class of TIMs involving the chemical integration of boron nitride nanosheets (BNNS), soft organic linkers, and a copper matrix-which are prepared by the chemisorption-coupled electrodeposition approach. These hybrid nanocomposites demonstrate bulk thermal conductivities ranging from 211 to 277 W/(m K), which are very high considering their relatively low elastic modulus values on the order of 21.2-28.5 GPa. The synergistic combination of these properties led to the ultralow total thermal resistivity values in the range of 0.38-0.56 mm(2) K/W for a typical bond-line thickness of 30-50 μm, advancing the current state-of-art transformatively. Moreover, its coefficient of thermal expansion (CTE) is 11 ppm/K, forming a mediation zone with a low thermally induced axial stress due to its close proximity to the CTE of most coupling surfaces needing thermal management.

  6. Structural versus electrical properties of an organic-inorganic hybrid material based on sulfate

    NASA Astrophysics Data System (ADS)

    Ben Rached, Asma; Guionneau, Philippe; Lebraud, Eric; Mhiri, Tahar; Elaoud, Zakaria

    2017-01-01

    A new organo-sulfate compound is obtained by slow evaporation at room temperature and is characterized by powder and single-crystal X-ray diffraction (XRD) at variable temperatures. The benzylammonium monohydrogenosulfate of formula C6H5CH2NH3+. HSO4-, denoted (BAS), crystallizes in the monoclinic system P21/c space group with the following parameters at room temperature: a=5.623(5)Å, b=20.239(5) Å, c=8.188(5)Å, β=94.104(5)°. The crystal structure consists of infinite parallel two-dimensional planes built by HSO4- anions and C6H5CH2NH3+ cations interconnected by strong O-H….. O and N-H….. O hydrogen bonds. A phase transition is detected at 350 K by differential scanning calorimetry (DSC) and confirmed by powder XRD. Conductivity measurements using the impedance spectroscopy technique allow to determine the conductivity relaxation parameters associated with the H+ conduction from an analysis of the M"/M"max spectrum measured in a wide temperature range. Transport properties of this material appear to be due to an H+ ion hopping mechanism.

  7. Metal–Organic–Inorganic Nanocomposite Thermal Interface Materials with Ultralow Thermal Resistances

    DOE PAGES

    Yegin, Cengiz; Nagabandi, Nirup; Feng, Xuhui; ...

    2017-02-27

    As electronic devices get smaller and more powerful, energy density of energy storage devices increases continuously, and moving components of machinery operate at higher speeds, the need for better thermal management strategies is becoming increasingly important. The removal of heat dissipated during the operation of electronic, electrochemical, and mechanical devices is facilitated by high-performance thermal interface materials (TIMs) which are utilized to couple devices to heat sinks. Here in this paper, we report a new class of TIMs involving the chemical integration of boron nitride nanosheets (BNNS), soft organic linkers, and a copper matrix -- which are prepared by chemisorption-coupledmore » electrodeposition approach. These hybrid nanocomposites demonstrate bulk thermal conductivities ranging from 211 to 277 W/(m.K), which are very high considering their relatively low elastic modulus values on the order of 21.2 to 28.5 GPa. The synergistic combination of these properties lead to the ultra-low total thermal resistivity values in the range of 0.38 to 0.56 mm2.K/W for a typical bondline thickness of 30-50 um, advancing the current state-of-art transformatively. Moreover, its coefficient of thermal expansion (CTE) is 11 ppm/K, forming a mediation zone with a low thermally-induced axial stress due to its close proximity to the CTE of most coupling surfaces needing thermal management.« less

  8. Inorganic nanotubes reinforced polyvinylidene fluoride composites as low-cost electromagnetic interference shielding materials

    PubMed Central

    2011-01-01

    Novel polymer nanocomposites comprising of MnO2 nanotubes (MNTs), functionalized multiwalled carbon nanotubes (f-MWCNTs), and polyvinylidene fluoride (PVDF) were synthesized. Homogeneous distribution of f-MWCNTs and MNTs in PVDF matrix were confirmed by field emission scanning electron microscopy. Electrical conductivity measurements were performed on these polymer composites using four probe technique. The addition of 2 wt.% of MNTs (2 wt.%, f-MWCNTs) to PVDF matrix results in an increase in the electrical conductivity from 10-16S/m to 4.5 × 10-5S/m (3.2 × 10-1S/m). Electromagnetic interference shielding effectiveness (EMI SE) was measured with vector network analyzer using waveguide sample holder in X-band frequency range. EMI SE of approximately 20 dB has been obtained with the addition of 5 wt.% MNTs-1 wt.% f-MWCNTs to PVDF in comparison with EMI SE of approximately 18 dB for 7 wt.% of f-MWCNTs indicating the potential use of the present MNT/f-MWCNT/PVDF composite as low-cost EMI shielding materials in X-band region. PMID:21711633

  9. Materials Suitable for preparing Inorganic Nanocasts of butterflies and other insects

    NASA Astrophysics Data System (ADS)

    Silver, J.; Fern, G. R.; Ireland, T. G.

    2015-06-01

    Replication of 3D-structures, in particular those that have a periodic modulation of a dielectric material at optical wavelengths and below have proven very difficult to fabricate. The majority of such replication techniques are complex or use moisture sensitive precursors requiring the use of for example a glove box. Here we demonstrate how an air stable supersaturated europium-doped yttrium nitrate phosphor precursor solution has the ability to easily impregnate a structure or produce a cast yielding faithful replicas composed of Y2O:Eu3+ after a final short annealing step. New replicas of Lepidoptera (moth) wing scales using field emission scanning electron microscopy, structures down to 10 nm have been imaged. Moreover as these replicas are made of phosphors, their luminescence in some cases may be modulated by the internal periodic modulation built into their structures. In this work we will discuss more recent results on the use of the phosphors for making nanocasts of moth wing scales and show a range of beautiful pictures to show what the method can achieve.

  10. Block Copolymers for Alkaline Fuel Cell Membrane Materials

    DTIC Science & Technology

    2014-07-30

    113 CHAPTER 5 MONO METHOXY POLY( ETHYLENE GLYCOL) GRAFTED BLOCK COPOLYMERS FOR ALKALINE EXCHANGE MEMBRANE...polystyrene-poly( ethylene -co-butylene)-polystyrene (SEBS) copolymer.[37, 42] Chloromethylation of the polystyrene block and trimethylamine...temperature. The same graft and functionalization strategy was applied to poly( ethylene -co- tetrafluoroethylene) (ETFE) film leading to a promising

  11. Monoolein lipid phases as incorporation and enrichment materials for membrane protein crystallization.

    SciTech Connect

    Wallace, E.; Dranow, D.; Laible, P. D.; Christensen, J.; Nollert, P.

    2011-01-01

    The crystallization of membrane proteins in amphiphile-rich materials such as lipidic cubic phases is an established methodology in many structural biology laboratories. The standard procedure employed with this methodology requires the generation of a highly viscous lipidic material by mixing lipid, for instance monoolein, with a solution of the detergent solubilized membrane protein. This preparation is often carried out with specialized mixing tools that allow handling of the highly viscous materials while minimizing dead volume to save precious membrane protein sample. The processes that occur during the initial mixing of the lipid with the membrane protein are not well understood. Here we show that the formation of the lipidic phases and the incorporation of the membrane protein into such materials can be separated experimentally. Specifically, we have investigated the effect of different initial monoolein-based lipid phase states on the crystallization behavior of the colored photosynthetic reaction center from Rhodobacter sphaeroides. We find that the detergent solubilized photosynthetic reaction center spontaneously inserts into and concentrates in the lipid matrix without any mixing, and that the initial lipid material phase state is irrelevant for productive crystallization. A substantial in-situ enrichment of the membrane protein to concentration levels that are otherwise unobtainable occurs in a thin layer on the surface of the lipidic material. These results have important practical applications and hence we suggest a simplified protocol for membrane protein crystallization within amphiphile rich materials, eliminating any specialized mixing tools to prepare crystallization experiments within lipidic cubic phases. Furthermore, by virtue of sampling a membrane protein concentration gradient within a single crystallization experiment, this crystallization technique is more robust and increases the efficiency of identifying productive crystallization

  12. Monoolein Lipid Phases as Incorporation and Enrichment Materials for Membrane Protein Crystallization

    PubMed Central

    Wallace, Ellen; Dranow, David; Laible, Philip D.; Christensen, Jeff; Nollert, Peter

    2011-01-01

    The crystallization of membrane proteins in amphiphile-rich materials such as lipidic cubic phases is an established methodology in many structural biology laboratories. The standard procedure employed with this methodology requires the generation of a highly viscous lipidic material by mixing lipid, for instance monoolein, with a solution of the detergent solubilized membrane protein. This preparation is often carried out with specialized mixing tools that allow handling of the highly viscous materials while minimizing dead volume to save precious membrane protein sample. The processes that occur during the initial mixing of the lipid with the membrane protein are not well understood. Here we show that the formation of the lipidic phases and the incorporation of the membrane protein into such materials can be separated experimentally. Specifically, we have investigated the effect of different initial monoolein-based lipid phase states on the crystallization behavior of the colored photosynthetic reaction center from Rhodobacter sphaeroides. We find that the detergent solubilized photosynthetic reaction center spontaneously inserts into and concentrates in the lipid matrix without any mixing, and that the initial lipid material phase state is irrelevant for productive crystallization. A substantial in-situ enrichment of the membrane protein to concentration levels that are otherwise unobtainable occurs in a thin layer on the surface of the lipidic material. These results have important practical applications and hence we suggest a simplified protocol for membrane protein crystallization within amphiphile rich materials, eliminating any specialized mixing tools to prepare crystallization experiments within lipidic cubic phases. Furthermore, by virtue of sampling a membrane protein concentration gradient within a single crystallization experiment, this crystallization technique is more robust and increases the efficiency of identifying productive crystallization

  13. Physical state and acidity of inorganic sulfate can regulate the production of secondary organic material from isoprene photooxidation products.

    PubMed

    Kuwata, Mikinori; Liu, Yingjun; McKinney, Karena; Martin, Scot T

    2015-02-28

    The production of secondary organic material (SOM) by the reactive uptake of isoprene photooxidation products was investigated using partially to wholly neutralized sulfuric acid particles. The experiments were performed at a relative humidity (RH) of <5% and a temperature of 20 °C. The extent X of neutralization was adjusted from that of sulfuric acid (X = 0) to that of ammonium sulfate (X = 1). Significant SOM production was observed only for X < 0.7. The threshold of 0.7 corresponded to the transition point of the sulfate particles from aqueous to solid for <5% RH. The phase transition of inorganic sulfate therefore regulated the particle-phase reactions that produce isoprene SOM, at least for the investigated conditions. For aqueous particles, a decreasing extent of neutralization was associated with increasing production of SOM, including increased production of oligomers and organosulfates. These results can underpin treatments of phase-dependent SOM production within chemical transport models, thereby improving the accuracy of simulations of biogenic-anthropogenic interactions in the atmosphere and the associated impacts of aerosol particles on climate and air quality.

  14. Effects of crystalline structures and surface functional groups on the adsorption of haloacetic acids by inorganic materials.

    PubMed

    Punyapalakul, Patiparn; Soonglerdsongpha, Suwat; Kanlayaprasit, Chutima; Ngamcharussrivichai, Chawalit; Khaodhiar, Sutha

    2009-11-15

    The effects of the crystalline structure and surface functional groups of porous inorganic materials on the adsorption of dichloroacetic acid (DCAA) were evaluated by using hexagonal mesoporous silicates (HMS), two surface functional group (3-aminopropyltriethoxy- and 3-mercaptopropyl-) modified HMSs, faujasite Y zeolite and activated alumina as adsorbents, and compared with powdered activated carbon (PAC). Selective adsorption of HAA(5) group was studied by comparing single and multiple-solute solution, including effect of common electrolytes in tap water. Adsorption capacities were significantly affected by the crystalline structure. Hydrogen bonding is suggested to be the most important attractive force. Decreasing the pH lower than the pH(zpc) increased the DCAA adsorption capacities of these adsorbents due to electrostatic interaction and hydrogen bonding caused by protonation of the hydronium ion. Adsorption capacities of HAA(5) on HMS did not relate to molecular structure of HAA(5). Common electrolytes did not affect the adsorption capacities and selectivity of HMS for HAA5, while they affected those of PAC.

  15. Dissolution improvement of solid self-emulsifying drug delivery systems of fenofibrate using an inorganic high surface adsorption material.

    PubMed

    Shazly, Gamal; Mohsin, Kazi

    2015-03-01

    Solidification of lipid formulations using adsorbents is a recent technique attracting great interest due to its favourable properties including flexibility in dose division, reduction of intra-subject and inter-subject variability, improvement in efficacy/safety profile and enhancement of physical/ chemical stability. The current study aims to convert liquid self-emulsifying/nanoemulsifying drug delivery systems (SEDDS/SNEDDS) into solid SEDDS/SNEDDS and to assess how adsorption of the drug onto an inorganic high surface area material, NeusilinR grade US2 (NUS2), affects its in vitro dissolution performance. Lipid formulation classification systems (LFCS) Type III formulations were designed for the model anti-cholesterol drug fenofibrate. NUS2 was used to solidify the SEDDS/SNEDDS. Particle size and SEM analyses of solid SEDDS/SNEDDS powder were carried out to investigate the adsorption efficiency. In vitro dissolution studies were conducted to compare the developed formulations with the marketed product. The results of characterization studies showed that the use of 50% (m/m) adsorbent resulted in superior flowability and kept the drug stable is amorphous state. Dissolution studies allow the conclusion that the formulation containing a surfactant of higher water solubility (particularly, Type IIIB SNEDDS) has comparably faster and higher release profiles than Type IIIA (SEDDS) and marketed product.

  16. Three-dimensional visualization of electron- and nuclear-density distributions in inorganic materials by MEM-based technology

    NASA Astrophysics Data System (ADS)

    Izumi, F.; Momma, K.

    2011-03-01

    The analysis of observed structure factors estimated after Rietveld analysis by the maximum-entropy method (MEM) gives electron or nuclear densities in the unit cell. The resultant densities are, more or less, biased toward a structural model in the Rietveld analysis. To overcome such a problem, we devised a sophisticated technique named MEM-based pattern fitting (MPF). For this purpose, a pattern-fitting system, RIETAN-FP, and a MEM analysis programs, PRIMA or its successor called Dysnomia, were virtually integrated into a structure-refinement system, whereby the pattern calculated from structure factors obtained by MEM is fit to the whole observed pattern. The resulting observed structure factors are analyzed again by MEM. In this way, whole-pattern fitting and MEM analysis are alternately repeated until R factors in the former no longer decrease. MPF virtually represents the crystal structure by electron or nuclear densities. MPF is, therefore, very effective in visualizing positional, occupational, and orientational disorder, chemical bonding, and anharmonic thermal motion. New programs, MPF_multi and VESTA 3, used in MPF are briefly introduced, and two representative applications of MPF to inorganic materials containing highly disordered chemical species are demonstrated.

  17. Regulation of responsiveness of phosphorescence toward dissolved oxygen concentration by modulating polymer contents in organic-inorganic hybrid materials.

    PubMed

    Okada, Hiroshi; Tanaka, Kazuo; Chujo, Yoshiki

    2014-06-15

    Platinum(II) octaethylporphyrin (PtOEP)-loaded organic-inorganic hybrids were obtained via the microwave-assisted sol-gel condensation with methyltrimethoxysilane and poly(vinylpyrrolidone). From transparent and homogeneous hybrid films, the strong phosphorescence from PtOEP was observed. Next, the resulting hybrids were immersed in the aqueous buffer, and the emission intensity was monitored by changing the dissolved oxygen level in the buffer. When the hybrid with relatively-higher amount of the silica element, the strong phosphorescence was observed even under the aerobic conditions. In contrast, the emission from the hybrids with lower amounts of the silica element was quenched under the hypoxic conditions. This is, to the best of our knowledge, the first example to demonstrate that the responsiveness of the phosphorescence intensity of PtOEP in hybrid films to the dissolved oxygen concentration in water can be modulated by changing the percentage of the contents in the material. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Assembly of three organic–inorganic hybrid supramolecular materials based on reduced molybdenum(V) phosphates

    SciTech Connect

    Zhang, He; Yu, Kai; Lv, Jing-Hua; Wang, Chun-Mei; Wang, Chun-Xiao; Zhou, Bai-Bin

    2014-09-15

    Three supramolecular materials based on (P{sub 4}Mo{sub 6}) polyoxoanions, (Hbbi){sub 2}(H{sub 2}bbi)[Cu{sub 3}Mo{sub 12}{sup V}O{sub 24}(OH){sub 6}(H{sub 2}O){sub 6}(HPO{sub 4}){sub 4}(H{sub 2}PO{sub 4}){sub 2}(PO{sub 4}){sub 2}]·3H{sub 2}O (1), (Hbbi){sub 2}(H{sub 2}bbi)[Ni{sub 3}Mo{sub 12}{sup V}O{sub 24}(OH){sub 6}(H{sub 2}O){sub 2}(HPO{sub 4}){sub 4}(H{sub 2}PO{sub 4}){sub 2}(PO{sub 4}){sub 2}]·9H{sub 2}O (2), (Hbpy)(bpy){sub 3}[Ni{sub 2}(H{sub 2}O){sub 10}Na(PCA){sub 2}][NiMo{sub 12}{sup V}O{sub 24}(OH){sub 6}(H{sub 2}PO{sub 4}){sub 6}(PO{sub 4}){sub 2}]·6H{sub 2}O (3) (bbi=1,1′-(1,4-butanediyl)bis(imidazole), bpy=4,4′-bipyridine, PCA=pyridine-4-carboxylic acid), have been hydrothermally synthesized and structurally characterized by the elemental analysis, TG, IR, UV–vis, PXRD and the single-crystal X-ray diffraction. Compounds 1 and 2 exhibit covalent 1-D chains constructed from M[P{sub 4}Mo{sub 6}]{sub 2} dimeric cluster and (M(H{sub 2}O){sub n}) (M=Cu, n=3 for 1 and M=Ni, n=1 for 2) linker. Compound 3 possesses an unusual POMMOF supramolecular layers based on [Ni(P{sub 4}Mo{sub 6})]{sub 2} dimeric units and 1-D metal–organic strings [Ni(H{sub 2}O){sub 5}Na(PCA)]{sub n}, in which an in situ ligand of PCA from 1,3-bis(4-pyridyl)propane (bpp) precursor was observed. Furthermore, the electrochemical behavior of 1–3-CPE and magnetic properties of 1–3 have been investigated in detail. - Graphical abstract: As new linking unit, Cu(H{sub 2}O){sub 3}, Ni(H{sub 2}O), and (Ni{sub 2}(H{sub 2}O){sub 10}Na(PCA){sub 2}) are introduced into (TM(P{sub 4}Mo{sub 6}){sub 2}) reaction systems to assemble three supramolecular materials under hydrothermal conditions via changing organic ligand and transition metal. - Highlights: • Tree new supramolecular hybrids based on (P{sub 4}Mo{sub 6}) cluster are reported. • Cu(H{sub 2}O){sub 3} and Ni(H{sub 2}O) as linker are introduced into the (TM(P{sub 4}Mo{sub 6}){sub 2}) systems. • 3 shows unusual layers based on

  19. Aripiprazole-montmorillonite: a new organic-inorganic nanohybrid material for biomedical applications.

    PubMed

    Oh, Yeon-Ji; Choi, Goeun; Choy, Young Bin; Park, Je Won; Park, Jung Hyun; Lee, Hwa Jeong; Yoon, Yeo Joon; Chang, Hee Chul; Choy, Jin-Ho

    2013-04-08

    Poor aqueous solubility and the unpleasant taste of aripiprazole (APZ) have been recurring problems, owing to its low bioavailability and low patient tolerance, respectively. Herein, we prepared a nanohybrid system that was based on a bentonite clay material, montmorillonite (MMT), which could both mask the taste and enhance the solubility of APZ (i.e., APZ-MMT). To further improve the efficacy of this taste masking and drug solubility, APZ-MMT was also coated with a cationic polymer, polyvinylacetal diethylamino acetate (AEA). In vitro dissolution tests at neutral pH showed that the amount of drug that was released from the AEA-coated APZ-MMT was greatly suppressed (<1%) for the first 3 min, thus suggesting that AEA-coated APZ-MMT has strong potential for the taste masking of APZ. Notably, in simulated gastric juice at pH 1.2, the total percentage of APZ that was released within the first 2 h increased up to 95% for AEA-coated APZ-MMT. Furthermore, this in vitro release profile was also similar to that of Abilify®, a commercially available medication. In vivo experiments by using Sprague-Dawley rats were also performed to compare the pharmacokinetics of AEA-coated APZ-MMT and Abilify®. AEA-coated APZ-MMT exhibited about 20% higher systemic exposure of APZ and its metabolite, dehydro-APZ, compared with Abilify®. Therefore, a new MMT-based nanovehicle, which is coated with a cationic polymer, can act as a promising delivery system for both taste masking and for enhancing the bioavailability of APZ. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Responses of organic and inorganic materials to intense EUV radiation from laser-produced plasmas

    NASA Astrophysics Data System (ADS)

    Makimura, Tetsuya; Torii, Shuichi; Nakamura, Daisuke; Takahashi, Akihiko; Okada, Tatsuo; Niino, Hiroyuki; Murakami, Kouichi

    2013-05-01

    We have investigated responses of polymers to EUV radiation from laser-produced plasmas beyond ablation thresholds and micromachining. We concentrated on fabricate precise 3D micro-structures of PDMS, PMMA, acrylic block copolymers (BCP), and silica. The micromachining technique can be applied to three-dimensional micro-fluidic and bio-medical devices. The EUV processing is a promising to realize a practical micromachining technique. In the present work, we used two EUV radiation sources; (a) Wide band EUV light in a range of 10{300 eV was generated by irradiation of Ta targets with Nd:YAG laser light at 500 mJ/pulse. (b) Narrow band EUV light at 11 and 13 nm was generated by irradiation of solid Xe and Sn targets, respectively, with pulsed TEA CO2 laser light. The generated EUV light was condensed onto the materials at high power density beyond the ablation thresholds, using ellipsoidal mirrors. We found that through-holes with a diameter of one micrometer an be fabricated in PMMA and PDMS sheets with thicknesses of 4-10 micrometers, at 250 and 230 nm/shot, respectively. The effective ablation of PMMA sheets can be applied to a LIGA-like process for fabricating micro-structures of metals for micro- and nano-molds. PDMS sheets are ablated if it is irradiated with EUV light beyond a distinct threshold power density, while PDMS surfaces were modified at lower power densities. Furthermore, BCP sheets were ablated to have 1-micrometer structures. Thus, we have developed a practical technique for micromachining of PMMA, PDMS and BCP sheets in a micrometer scale.

  1. Design of hybrid conjugated polymer materials: 1) Novel inorganic/organic hybrid semiconductors and 2) Surface modification via grafting approaches

    NASA Astrophysics Data System (ADS)

    Peterson, Joseph J.

    The research presented in this dissertation focuses on the design and synthesis of novel hybrid conjugated polymer materials using two different approaches: (1) inorganic/organic hybrid semiconductors through the incorporation of carboranes into the polymer structure and (2) the modification of surfaces with conjugated polymers via grafting approaches. Hybrid conjugated polymeric materials, which are materials or systems in which conjugated polymers are chemically integrated with non-traditional structures or surfaces, have the potential to harness useful properties from both components of the material to help overcome hurdles in their practical realization in polymer-based devices. This work is centered around the synthetic challenges of creating new hybrid conjugated systems and their potential for advancing the field of polymer-based electronics through both greater understanding of the behavior of hybrid systems, and access to improved performance and new applications. Chapter 1 highlights the potential applications and advantages for these hybrid systems, and provides some historical perspective, along with relevant background materials, to illustrate the rationale behind this work. Chapter 2 explores the synthesis of poly(fluorene)s with pendant carborane cages. The Ni(0) dehalogenative polymerization of a dibromofluorene with pendant carborane cages tethered to the bridging 9-position produced hybrid polymers produced polymers which combined the useful emissive characteristics of poly(fluorene) with the thermal and chemical stability of carborane cages. The materials were found to display increased glass transition temperatures and showed improved emission color stability after annealing at high temperatures relative to the non-hybrid polymer. The design and synthesis of a poly(fluorene)-based hybrid material with carborane cages in the backbone, rather than as pendant groups, begins in chapter 3. Poly(fluorene) with p-carborane in the backbone is

  2. Influence of surface chemistry of carbon materials on their interactions with inorganic nitrogen contaminants in soil and water.

    PubMed

    Sumaraj; Padhye, Lokesh P

    2017-10-01

    Inorganic nitrogen contaminants (INC) (NH4(+), NO3(-), NO2(-), NH3, NO, NO2, and N2O) pose a growing risk to the environment, and their remediation methods are highly sought after. Application of carbon materials (CM), such as biochar and activated carbon, to remediate INC from agricultural fields and wastewater treatment plants has gained a significant interest since past few years. Understanding the role of surface chemistry of CM in adsorption of various INC is highly critical to increase adsorption efficiency as well as to assess the long term impact of using these highly recalcitrant CM for remediation of INC. Critical reviews of adsorption studies related to INC have revealed that carbon surface chemistry (surface functional groups, pH, Eh, elemental composition, and mineral content) has significant influence on adsorption of INC. Compared to basic functional groups, oxygen containing surface functional groups have been found to be more influential for adsorption of INC. However, basic sites on carbon materials still play an important role in chemisorption of anionic INC. Apart from surface functional groups, pH, Eh and pHzpc of CM and elemental and mineral composition of its surface are important properties capable of altering INC interactions with CM. This review summarizes our current understanding of INC interactions with CM's surface through the known chemisorption mechanisms: electrostatic interaction, hydrogen bonding, electron donor-acceptor mechanism, hydrophobic and hydrophilic interaction, chemisorption aided by minerals, and interactions influenced by pH and elemental composition. Change in surface chemistry of CM in soil during aging is also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Information or resolution: Which is required from an SEM to study bulk inorganic materials?: Evaluate SEMs’ practical performance

    DOE PAGES

    Xing, Q.

    2016-07-11

    Significant technological advances in scanning electron microscopy (SEM) have been achieved over the past years. Different SEMs can have significant differences in functionality and performance. This work presents the perspectives on selecting an SEM for research on bulk inorganic materials. Understanding materials demands quantitative composition and orientation information, and informative and interpretable images that reveal subtle differences in chemistry, orientation/structure, topography, and electronic structure. The capability to yield informative and interpretable images with high signal-to-noise ratios and spatial resolutions is an overall result of the SEM system as a whole, from the electron optical column to the detection system. Themore » electron optical column determines probe performance. The roles of the detection system are to capture, filter or discriminate, and convert signal electrons to imaging information. The capability to control practical operating parameters including electron probe size and current, acceleration voltage or landing voltage, working distance, detector selection, and signal filtration is inherently determined by the SEM itself. As a platform for various accessories, e.g. an energydispersive spectrometer and an electron backscatter diffraction detector, the properties of the electron optical column, specimen chamber, and stage greatly affect the performance of accessories. Ease-of-use and ease-of-maintenance are of practical importance. It is practically important to select appropriate test specimens, design suitable imaging conditions, and analyze the specimen chamber geometry and dimensions to assess the overall functionality and performance of an SEM. Finally, for an SEM that is controlled/operated with a computer, the stable software and user-friendly interface significantly affect the usability of the SEM.« less

  4. Information or resolution: Which is required from an SEM to study bulk inorganic materials?: Evaluate SEMs’ practical performance

    SciTech Connect

    Xing, Q.

    2016-07-11

    Significant technological advances in scanning electron microscopy (SEM) have been achieved over the past years. Different SEMs can have significant differences in functionality and performance. This work presents the perspectives on selecting an SEM for research on bulk inorganic materials. Understanding materials demands quantitative composition and orientation information, and informative and interpretable images that reveal subtle differences in chemistry, orientation/structure, topography, and electronic structure. The capability to yield informative and interpretable images with high signal-to-noise ratios and spatial resolutions is an overall result of the SEM system as a whole, from the electron optical column to the detection system. The electron optical column determines probe performance. The roles of the detection system are to capture, filter or discriminate, and convert signal electrons to imaging information. The capability to control practical operating parameters including electron probe size and current, acceleration voltage or landing voltage, working distance, detector selection, and signal filtration is inherently determined by the SEM itself. As a platform for various accessories, e.g. an energydispersive spectrometer and an electron backscatter diffraction detector, the properties of the electron optical column, specimen chamber, and stage greatly affect the performance of accessories. Ease-of-use and ease-of-maintenance are of practical importance. It is practically important to select appropriate test specimens, design suitable imaging conditions, and analyze the specimen chamber geometry and dimensions to assess the overall functionality and performance of an SEM. Finally, for an SEM that is controlled/operated with a computer, the stable software and user-friendly interface significantly affect the usability of the SEM.

  5. Information or resolution: Which is required from an SEM to study bulk inorganic materials?: Evaluate SEMs’ practical performance

    SciTech Connect

    Xing, Q.

    2016-07-11

    Significant technological advances in scanning electron microscopy (SEM) have been achieved over the past years. Different SEMs can have significant differences in functionality and performance. This work presents the perspectives on selecting an SEM for research on bulk inorganic materials. Understanding materials demands quantitative composition and orientation information, and informative and interpretable images that reveal subtle differences in chemistry, orientation/structure, topography, and electronic structure. The capability to yield informative and interpretable images with high signal-to-noise ratios and spatial resolutions is an overall result of the SEM system as a whole, from the electron optical column to the detection system. The electron optical column determines probe performance. The roles of the detection system are to capture, filter or discriminate, and convert signal electrons to imaging information. The capability to control practical operating parameters including electron probe size and current, acceleration voltage or landing voltage, working distance, detector selection, and signal filtration is inherently determined by the SEM itself. As a platform for various accessories, e.g. an energydispersive spectrometer and an electron backscatter diffraction detector, the properties of the electron optical column, specimen chamber, and stage greatly affect the performance of accessories. Ease-of-use and ease-of-maintenance are of practical importance. It is practically important to select appropriate test specimens, design suitable imaging conditions, and analyze the specimen chamber geometry and dimensions to assess the overall functionality and performance of an SEM. Finally, for an SEM that is controlled/operated with a computer, the stable software and user-friendly interface significantly affect the usability of the SEM.

  6. A mechanistic study of molecular sieving inorganic membranes for gas separations. Final report, [August 1, 1992--July 31, 1993

    SciTech Connect

    Way, J.D.

    1993-05-03

    The permeability of gases with kinetic diameters of 2.89 {Angstrom} to 3.9 {Angstrom} were measured through microporous silica hollow fiber membranes at 298 K to 473 K at 20 atm feed gas pressure. Permeabilities ranged from 0.01 Barrer to 1000 Barrer and were inversely proportional to the kinetic diameter of the penetrant. Linear Arrhenius plots were obtained from permeability data activation energies ranged from 7.5 to 13.5 kcal/mole. The activation energies for the hollow Tiber membranes were consistent with literature data for diffusion of hydrocarbons in zeolites. High separation factors were obtained for O{sub 2}/N{sub 2} and CO{sub 2}/CH{sub 2} mixtures. The mixture separation factors for O{sub 2}/N{sub 2} decreased from 11.5 at 298 K to 4.6 at 423 K. Over the same temperature range, CO{sub 2}/CH{sub 2} separation factors decreased from 186 to 22.3. Separation factors for O{sub 2}/N{sub 2} mixtures were up to 20% larger than the values obtained from pure gas measurements below 373 K. A similar effect was seen for CO{sub 2}/CH{sub 2} mixtures after the membrane had been heated to at least 398 K and then cooled in inert gas flow. Differences between separation factors and ideal gas values is attributed to a competitive adsorption effect where the more strongly interacting gases (O{sub 2}, CO{sub 2}) saturate the surface and block the transport of weakly interacting gases (N{sub 2}, CH{sub 4}).

  7. Membrane materials for addressing energy and environmental challenges.

    PubMed

    Drioli, Enrico; Fontananova, Enrica

    2012-01-01

    Our modern society must solve various severe problems to maintain and increase our quality of life: from water stress to global warming, to fossil fuel depletion, to environmental pollution. The process intensification (PI) strategy is expected to contribute to overcoming many of these issues by facilitating the transition from a resource-intensive to a knowledge-intensive industrial system that will guarantee sustainable growth. Membrane operations, which respond efficiently to the requirements of the PI strategy, have the potential to replace conventional energy-intensive separation techniques, which will boost the efficiency and reduce the environmental impact of separations as well as conversion processes. This work critically reviews the current status and emerging applications of (integrated) membrane operations with a special focus on energy and environmental applications.

  8. High-Performance Water Filtration Membranes using Surface Modification and New Materials

    NASA Astrophysics Data System (ADS)

    Huang, Xinwei

    Water scarcity is one of the most critical challenges faced by mankind and it is only getting worse due to source pollution and rising population. There is critical need for the development of water filtration membranes in order to treat polluted water and turn water from non-potable sources such as waste waster and ocean water into freshwater for human consumption and agricultural irrigation. Filtration Membranes are generally classified into four categories: microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO), with decreasing pore size for rejecting different sized substances. Commercial filtration membranes are able to provide decent flux and rejection for their targeted applications. However, most of them suffer from fouling issues when the microorganisms and organic matter such as proteins and polysaccharides in the water source deposit onto the membrane surface, impeding the permeation of water and lowering the flux. Therefore, it is of high demand to develop membranes that are anti-fouling. Foulants such as protein particles adhere to the membrane surface via hydrophobic interactions. In order to minimize such effects, a typical way is to increase the hydrophilicity of the membrane by surface modification or by utilizing hydrophilic membrane materials. Foulants also tend to get trapped in the open "pores" on a rough membrane surface with ridges and valleys. It is then expected that a smoother membrane surface tend to lessen such effects. Incorporating antimicrobial properties into the membrane is also an effective way to reduce fouling as this inhibits the growth of microorganisms on the membrane surfaces. New materials are also used to fabricate membranes with improved performance. Conducting polymers have recently been discovered as a new category of membrane-making materials that are hydrophilic and low-fouling. A new type of polyaniline derivative has been used to fabricate UF membranes that demonstrate chlorine

  9. Membrane materials for storing biological samples intended for comparative nanotoxicological testing

    NASA Astrophysics Data System (ADS)

    Metelkin, A.; Kuznetsov, D.; Kolesnikov, E.; Chuprunov, K.; Kondakov, S.; Osipov, A.; Samsonova, J.

    2015-11-01

    The study is aimed at identifying the samples of most promising membrane materials for storing dry specimens of biological fluids (Dried Blood Spots, DBS technology). Existing sampling systems using cellulose fiber filter paper have a number of drawbacks such as uneven distribution of the sample spot, dependence of the spot spreading area on the individual biosample properties, incomplete washing-off of the sample due to partially inconvertible sorption of blood components on cellulose fibers, etc. Samples of membrane materials based on cellulose, polymers and glass fiber with applied biosamples were studied using methods of scanning electron microscopy, FT-IR spectroscopy and surface-wetting measurement. It was discovered that cellulose-based membrane materials sorb components of biological fluids inside their structure, while membranes based on glass fiber display almost no interaction with the samples and biological fluid components dry to films in the membrane pores between the structural fibers. This characteristic, together with the fact that membrane materials based on glass fiber possess sufficient strength, high wetting properties and good storage capacity, attests them as promising material for dry samples of biological fluids storage systems.

  10. Solution-Processed CuS NPs as an Inorganic Hole-Selective Contact Material for Inverted Planar Perovskite Solar Cells.

    PubMed

    Rao, Haixia; Sun, Weihai; Ye, Senyun; Yan, Weibo; Li, Yunlong; Peng, Haitao; Liu, Zhiwei; Bian, Zuqiang; Huang, Chunhui

    2016-03-01

    Organic-inorganic hybrid perovskite solar cells (PSCs) have drawn worldwide intense research in recent years. Herein, we have first applied another p-type inorganic hole-selective contact material, CuS nanoparticles (CuS NPs), in an inverted planar heterojunction (PHJ) perovskite solar cell. The CuS NP-modification of indium tin oxide (ITO) has successfully tuned the surface work function from 4.9 to 5.1 eV but not affect the surface roughness and transmittance, which can effectively reduce the interfacial carrier injection barrier and facilitate high hole extraction efficiency between the perovskite and ITO layers. After optimization, the maximum power conversion efficiency (PCE) has been over 16% with low J-V hysteresis and excellent stability. Therefore, the low-cost solution-processed and stable CuS NPs would be an alternative interfacial modification material for industrial production in perovskite solar cells.

  11. Hybrid organic/inorganic reverse osmosis (RO) membrane for bactericidal anti-fouling. 1. Preparation and characterization of TiO2 nanoparticle self-assembled aromatic polyamide thin-film-composite (TFC) membrane.

    PubMed

    Kwak, S Y; Kim, S H; Kim, S S

    2001-06-01

    Hybrid organic/inorganic reverse osmosis (RO) membranes composed of aromatic polyamide thin films underneath titanium dioxide (TiO2) nanosized particles have been fabricated by a self-assembly process, aiming at breakthrough of biofouling problems. First, positively charged particles of the colloidal TiO2 were synthesized by a sol-gel process, and the diameter of the resulting particles in acidic aqueous solution was estimated to be approximately 2 nm by analyzing the UV-visible absorption characteristics with a quantum mechanical model developed by Brus. Transmission electron microscopy (TEM) further confirmed the formation of the quantum-sized TiO2 particles (approximately 10 nm or less). The TiO2 particles appeared to exist in the crystallographic form of anatase as observed with the X-ray diffraction (XRD) pattern in comparison with those of commercial 100% rutile and commercial 70:30% anatase-to-rutile mixture. The hybrid thin-film-composite (TFC) aromatic polyamide membranes were prepared by self-assembly of the TiO2 nanoparticles on the polymer chains with COOH groups along the surface. They showed improved RO performance in which the water flux even increased, though slightly. Field-emission scanning electron microscopy (FESEM) exhibited the TiO2 nanoparticles well adsorbed onto the surface. X-ray photoelectron spectroscopy (XPS) demonstrated quantitatively that a considerable amount of the adsorbed particles were tightly self-assembled at the expense of the initial loss of those that were loosely bound, and became stabilized even after exposure to the various washing and harsh RO operating conditions. The antibacterial fouling potential of the TiO2 hybrid membrane was examined and verified by measuring the viable numbers and determining the survival ratios of the Escherichia coli (E. coli) as a model bacterium, both with and without UV light illumination. The photocatalytic bactericidal efficiency was remarkably higher for the TiO2 hybrid membrane under UV

  12. DEVELOPMENT OF MESOPOROUS MEMBRANE MATERIALS FOR CO2 SEPARATION

    SciTech Connect

    Wei-Heng Shih; Qiang Zhao; Tejas Patil

    2002-05-01

    The authors propose to use microporous silica as a suitable candidate for CO{sub 2}/N{sub 2} separation because the pore size is less than 10 {angstrom}. If a CO{sub 2}adsorbent is added to the microporous silica, the adsorption of CO{sub 2} can block the passage of N{sub 2} and an effective CO{sub 2}/N{sub 2} separator will be found. It was first demonstrated that microporous silica could be synthesized. The microporous silica was then impregnated with Ba(OH){sub 2}. The results of GC study showed that at temperatures between 50 C and 90 C, Ba-doped microporous silica can separate CO{sub 2} from N{sub 2} and the idea of a microporous membrane for CO{sub 2}/N{sub 2} separation is feasible. The new result gives strong support to the proposed research that was outlined in the Phase II proposal. They hope to be able to continue the research and build an effective CO{sub 2}/N{sub 2} membrane separator in the Phase II of this project.

  13. Effects of Membrane Material Properties on the Deformation of Elastic Capsules in a Shear Flow

    NASA Astrophysics Data System (ADS)

    Chan, Kit Yan; Eggleton, Charles

    2006-03-01

    The deformation process of elastic capsules in a simple shear flow is studied numerically using the immersed boundary method to probe the influence of membrane material properties. Membrane models that are representative of linear elastic membrane (Hookean law), strain hardening membrane (Skalak), and strain softening membrane (Mooney-Rivlin, neo-Hookean) and the Evans-Skalak model developed from thermodynamic principles to represent the behavior of a lipid bilayer and a cytoskeletal network, are used to study the effects of membrane material properties on the response of the capsule at various shear rates. Simulation results indicate that both the time to reach steady state and the final steady shape of the capsule are sensitive to the choice of the membrane model and parameter values used. These experimentally measurable quantities may be compared with computations for determining suitable model of a particular capsule of interest, and the associated material properties. Local strain and energy distributions computed also provide additional information that is not easily accessible experimentally.

  14. Imidazolium-Based Polymeric Materials as Alkaline Anion-Exchange Fuel Cell Membranes

    NASA Technical Reports Server (NTRS)

    Narayan, Sri R.; Yen, Shiao-Ping S.; Reddy, Prakash V.; Nair, Nanditha

    2012-01-01

    Polymer electrolyte membranes that conduct hydroxide ions have potential use in fuel cells. A variety of polystyrene-based quaternary ammonium hydroxides have been reported as anion exchange fuel cell membranes. However, the hydrolytic stability and conductivity of the commercially available membranes are not adequate to meet the requirements of fuel cell applications. When compared with commercially available membranes, polystyrene-imidazolium alkaline membrane electrolytes are more stable and more highly conducting. At the time of this reporting, this has been the first such usage for imidazolium-based polymeric materials for fuel cells. Imidazolium salts are known to be electrochemically stable over wide potential ranges. By controlling the relative ratio of imidazolium groups in polystyrene-imidazolium salts, their physiochemical properties could be modulated. Alkaline anion exchange membranes based on polystyrene-imidazolium hydroxide materials have been developed. The first step was to synthesize the poly(styrene-co-(1-((4-vinyl)methyl)-3- methylimidazolium) chloride through a free-radical polymerization. Casting of this material followed by in situ treatment of the membranes with sodium hydroxide solutions provided the corresponding hydroxide salts. Various ratios of the monomers 4-chloromoethylvinylbenzine (CMVB) and vinylbenzine (VB) provided various compositions of the polymer. The preferred material, due to the relative ease of casting the film, and its relatively low hygroscopic nature, was a 2:1 ratio of CMVB to VB. Testing confirmed that at room temperature, the new membranes outperformed commercially available membranes by a large margin. With fuel cells now in use at NASA and in transportation, and with defense potential, any improvement to fuel cell efficiency is a significant development.

  15. Synthesis, Multinuclear NMR Characterization and Dynamic Property of Organic–Inorganic Hybrid Electrolyte Membrane Based on Alkoxysilane and Poly(oxyalkylene) Diamine

    PubMed Central

    Saikia, Diganta; Pan, Yu-Chi; Kao, Hsien-Ming

    2012-01-01

    Organic–inorganic hybrid electrolyte membranes based on poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether) complexed with LiClO4 via the co-condensation of tetraethoxysilane (TEOS) and 3-(triethoxysilyl)propyl isocyanate have been prepared and characterized. A variety of techniques such as differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, alternating current (AC) impedance and solid-state nuclear magnetic resonance (NMR) spectroscopy are performed to elucidate the relationship between the structural and dynamic properties of the hybrid electrolyte and the ion mobility. A VTF (Vogel-Tamman-Fulcher)-like temperature dependence of ionic conductivity is observed for all the compositions studied, implying that the diffusion of charge carriers is assisted by the segmental motions of the polymer chains. A maximum ionic conductivity value of 5.3 × 10−5 Scm−1 is obtained at 30 °C. Solid-state NMR results provide a microscopic view of the effects of salt concentrations on the dynamic behavior of the polymer chains. PMID:24958176

  16. Synthesis, Multinuclear NMR Characterization and Dynamic Property of Organic-Inorganic Hybrid Electrolyte Membrane Based on Alkoxysilane and Poly(oxyalkylene) Diamine.

    PubMed

    Saikia, Diganta; Pan, Yu-Chi; Kao, Hsien-Ming

    2012-06-13

    Organic-inorganic hybrid electrolyte membranes based on poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether) complexed with LiClO4 via the co-condensation of tetraethoxysilane (TEOS) and 3-(triethoxysilyl)propyl isocyanate have been prepared and characterized. A variety of techniques such as differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, alternating current (AC) impedance and solid-state nuclear magnetic resonance (NMR) spectroscopy are performed to elucidate the relationship between the structural and dynamic properties of the hybrid electrolyte and the ion mobility. A VTF (Vogel-Tamman-Fulcher)-like temperature dependence of ionic conductivity is observed for all the compositions studied, implying that the diffusion of charge carriers is assisted by the segmental motions of the polymer chains. A maximum ionic conductivity value of 5.3 × 10-5 Scm-1 is obtained at 30 °C. Solid-state NMR results provide a microscopic view of the effects of salt concentrations on the dynamic behavior of the polymer chains.

  17. A review on the application of inorganic nano-structured materials in the modification of textiles: focus on anti-microbial properties.

    PubMed

    Dastjerdi, Roya; Montazer, Majid

    2010-08-01

    Textiles can provide a suitable substrate to grow micro-organisms especially at appropriate humidity and temperature in contact to human body. Recently, increasing public concern about hygiene has been driving many investigations for anti-microbial modification of textiles. However, using many anti-microbial agents has been avoided because of their possible harmful or toxic effects. Application of inorganic nano-particles and their nano-composites would be a good alternative. This review paper has focused on the properties and applications of inorganic nano-structured materials with good anti-microbial activity potential for textile modification. The discussed nano-structured anti-microbial agents include TiO(2) nano-particles, metallic and non-metallic TiO(2) nano-composites, titania nanotubes (TNTs), silver nano-particles, silver-based nano-structured materials, gold nano-particles, zinc oxide nano-particles and nano-rods, copper nano-particles, carbon nanotubes (CNTs), nano-clay and its modified forms, gallium, liposomes loaded nano-particles, metallic and inorganic dendrimers nano-composite, nano-capsules and cyclodextrins containing nano-particles. This review is also concerned with the application methods for the modification of textiles using nano-structured materials.

  18. Synthesis and characterizations of anion exchange organic-inorganic hybrid materials based on poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)

    SciTech Connect

    Zhang Shaoling; Wu Cuiming; Xu Tongwen . E-mail: twxu@ustc.edu.cn; Gong Ming; Xu Xiaolong

    2005-07-15

    A series of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)-based organic-inorganic hybrid materials for anion exchange were prepared through sol-gel process of polymer precursors PPO-Si(OCH{sub 3}){sub 3}. PPO-Si(OCH{sub 3}){sub 3} were obtained from the reaction of bromomethylated PPO with 3-aminopropyl-trimethoxysilane (A1110). These polymer precursors then underwent hydrolysis and condensation with additional A1110 to generate hybrid materials. The reaction to produce polymer precursors was identified by FTIR; while FTIR, TGA, XRD, SEM, as well as conventional ion exchange capacity (IEC) measurements were conducted for the structures and properties of the prepared hybrids. TGA results show that this series of hybrid materials possess high thermal stability; XRD and SEM indicate that the prepared hybrid materials are amorphous and the inorganic and organic contents show good compatibility if the ratio between them is proper. The IEC values of the hybrid materials due to the amine groups range from 1.13 mmol/gBPPO (material i) to 4.80 mmol/gBPPO (material iv)

  19. Cathode and electrolyte materials for solid oxide fuel cells and ion transport membranes

    DOEpatents

    Jacobson, Allan J; Wang, Shuangyan; Kim, Gun Tae

    2014-01-28

    Novel cathode, electrolyte and oxygen separation materials are disclosed that operate at intermediate temperatures for use in solid oxide fuel cells and ion transport membranes based on oxides with perovskite related structures and an ordered arrangement of A site cations. The materials have significantly faster oxygen kinetics than in corresponding disordered perovskites.

  20. Characterization of commercial proton exchange membrane materials after exposure to beta and gamma radiation

    SciTech Connect

    Thomson, S.N.; Carson, R.; Muirhead, C.; Li, H.; Castillo, I.; Boniface, H.; Suppiah, S.; Ratnayake, A.; Robinson, J.

    2015-03-15

    Proton Exchange Membrane (PEM) type electrolysis cells have a potential use for tritium removal and heavy water upgrading. AECL is currently exposing various commercial PEM materials to both gamma (Cobalt-60 source) and beta (tritiated water) radiation to study the effects of radiation on these materials. This paper summarizes the testing methods and results that have been collected to date. The PEM materials that are or have been exposed to radiation are: Nafion 112, 212, 117 and 1110. Membrane characterization pre- and post- exposure consists of non-destructive inspection (FTIR, SEM/XPS), mechanical (tensile strength, percentage elongation, and modulus), electrical (resistance), or chemical (ion-exchange capacity - IEC). It has appeared that the best characterization techniques to compare exposed versus unexposed membranes were IEC, ultimate tensile strength and percent elongation. These testing techniques are easy and cheap to perform. The non-destructive tests, such as SEM and FTIR did not provide particularly useful information on radiation-induced degradation. Where changes in material properties were measured after radiation exposure, they would be expected to result in poorer cell performance. However, for modest γ-radiation exposure, all membranes showed a slight decrease in cell voltage (better performance). In contrast, the one β-radiation exposed membrane did show the expected increase in cell voltage. The counterintuitive trend for γ-radiation exposed membranes is not yet understood. Based on these preliminary results, it appears that γ- and β-radiation exposures have different effects.

  1. Materials for use as proton conducting membranes for fuel cells

    DOEpatents

    Einsla, Brian R.; McGrath, James E.

    2009-01-06

    A family of polymers having pendent sulfonate moieties connected to polymeric main chain phenyl groups are described. These polymers are prepared by the steps of polymerization (using a monomer with a phenyl with an alkoxy substitution), deportation by converting the alkoxy to a hydroxyl, and functionalization of the polymer with a pendant sulfonate group. As an example, sulfonated poly(arylene ether sulfone) copolymers with pendent sulfonic acid groups are synthesized by the direct copolymerization of methoxy-containing poly(arylene ether sulfone)s, then converting the methoxy groups to the reactive hydroxyl form, and finally functionalizing the hydroxyl form with proton-conducting sites through nucleophilic substitution. The family of polymers may have application in proton exchange membranes and in other applications.

  2. Purple membrane-polyacrilamide films as holographic recording materials

    NASA Astrophysics Data System (ADS)

    Fimia, Antonio; Acebal, P.; Murciano, A.; Blaya, S.; Carretero, L.; Ulibarrena, M.; Aleman, R.; Gomariz, M.; Meseguer, I.

    2003-12-01

    The holographic parameters of purple membrane-polyacrylamide films obtained from a mutant form of Halobacterium salinarum (originally Halobacterium halobium) were measured. The synthesized films have an absorption of around 2.5 at 532 nm and a pH of 8.65. The results show that diffraction efficiencies of about 1.2 % (measured at 633 nm) can be achieved with writing intensities in the range of 200-400 mW/cm2 (532 nm), and these values remain constant after saturation. Pump-probe experiments were also used to measure the M state lifetime and our PM films were found to have the lowest M state lifetime described at this pH.

  3. Sorption of pure N2O to biochars and other organic and inorganic materials under anhydrous conditions

    USGS Publications Warehouse

    Cornelissen, Gerard; Rutherford, David W.; Arp, Hans Peter H.; Dorsch, Peter; Kelly, Charlene N.; Rostad, Colleen E.

    2013-01-01

    Suppression of nitrous oxide (N2O) emissions from soil is commonly observed after amendment with biochar. The mechanisms accounting for this suppression are not yet understood. One possible contributing mechanism is N2O sorption to biochar. The sorption of N2O and carbon dioxide (CO2) to four biochars was measured in an anhydrous system with pure N2O. The biochar data were compared to those for two activated carbons and other components potentially present in soils—uncharred pine wood and peat—and five inorganic metal oxides with variable surface areas. Langmuir maximum sorption capacities (Qmax) for N2O on the pine wood biochars (generated between 250 and 500 °C) and activated carbons were 17–73 cm3 g–1 at 20 °C (median 51 cm3 g–1), with Langmuir affinities (b) of 2–5 atm–1 (median 3.4 atm–1). Both Qmaxand b of the charred materials were substantially higher than those for peat, uncharred wood, and metal oxides [Qmax 1–34 cm3 g–1 (median 7 cm3 g–1); b 0.4–1.7 atm–1 (median 0.7 atm–1)]. This indicates that biochar can bind N2O more strongly than both mineral and organic soil materials. Qmax and b for CO2 were comparable to those for N2O. Modeled sorption coefficients obtained with an independent polyparameter—linear free-energy relationship matched measured data within a factor 2 for mineral surfaces but underestimated by a factor of 5–24 for biochar and carbonaceous surfaces. Isosteric enthalpies of sorption of N2O were mostly between −20 and −30 kJ mol–1, slightly more exothermic than enthalpies of condensation (−16.1 kJ mol–1). Qmax of N2O on biochar (50000–130000 μg g–1 biochar at 20 °C) exceeded the N2O emission suppressions observed in the literature (range 0.5–960 μg g–1 biochar; median 16 μg g–1) by several orders of magnitude. Thus, the hypothesis could not be falsified that sorption of N2O to biochar is a mechanism of N2O emission suppression.

  4. Synthetic Two-Dimensional Materials: A New Paradigm of Membranes for Ultimate Separation.

    PubMed

    Zheng, Zhikun; Grünker, Ronny; Feng, Xinliang

    2016-08-01

    Microporous membranes act as selective barriers and play an important role in industrial gas separation and water purification. The permeability of such membranes is inversely proportional to their thickness. Synthetic two-dimensional materials (2DMs), with a thickness of one to a few atoms or monomer units are ideal candidates for developing separation membranes. Here, groundbreaking advances in the design, synthesis, processing, and application of 2DMs for gas and ion separations, as well as water desalination are presented. This report describes the syntheses, structures, and mechanical properties of 2DMs. The established methods for processing 2DMs into selective permeation membranes are also discussed and the separation mechanism and their performances addressed. Current challenges and emerging research directions, which need to be addressed for developing next-generation separation membranes, are summarized.

  5. Fabrication of nanoporous arrays from photosensitive organic-inorganic hybrid materials by using an UV soft nanoimprint technique.

    PubMed

    Zhang, Xuehua; Que, Wenxiu; Hu, Jiaxing; Chen, Jin; Zhang, Jin; Liu, Weiguo

    2013-02-01

    A honeycomb-like regular nanoporous pattern built in the photosensitive organic-inorganic hybrid film was fabricated by an UV soft nanoimprint technique. Polydimethylsiloxane (PDMS) soft mold was firstly replicated from an anodic aluminum oxide (AAO) template obtained by using a two-step anodization method. Scanning electron microscopy images show that the AAO template has a regular honeycomb-like nanoporous structure, while the PDMS soft mold has a relief structure of nanopillar arrays. Photosensitive TiO2-contained organic-inorganic hybrid films, which were prepared by combining a low temperature sol-gel process with a spin-coating technique, were used as the imprinted layer. Thus, a honeycomb-like regular nanoporous pattern built in the hybrid film can be easily obtained by imprinting the PDMS soft mold into the photosensitive hybrid film under an UV-irradiation. The as-fabricated organic-inorganic regular nonporous arrays have potential applications in two-dimensional photonic crystal.

  6. Impact of colloidal and soluble organic material on membrane performance in membrane bioreactors for municipal wastewater treatment.

    PubMed

    Rosenberger, S; Laabs, C; Lesjean, B; Gnirss, R; Amy, G; Jekel, M; Schrotter, J-C

    2006-02-01

    Two parallel membrane bioreactors (2 m3 each) were operated over a period of 2 years. Both pilots were optimised for nitrification, denitrification, and enhanced biological phosphorous elimination, treating identical municipal wastewater under comparable operating conditions. The only constructional difference between the pilots was the position of the denitrification zone (pre-denitrification in pilot 1 and post-denitrification in pilot 2). Despite identical modules and conditions, the two MBRs showed different permeabilities and fouling rates. The differences were not related to the denitrification scheme. In order to find an explanation for the different membrane performances, a one-year investigation was initiated and the membrane performance as well as the operating regime and characteristics of the activated sludge were closely studied. MLSS concentrations, solid retention time, loading rates, and filtration flux were found not to be responsible for the different performance of the submerged modules. These parameters were kept identical in the two pilot plants. Instead, the non-settable fraction of the sludges (soluble and colloidal material, i.e. polysaccharides, proteins and organic colloids) was found to impact fouling and to cause the difference in membrane performance between the two MBR. This fraction was analysed by spectrophotometric and size exclusion chromatography (SEC) methods. In a second step, the origin of these substances was investigated. The results point to microbiologically produced substances such as extracellular polymeric substances (EPS) or soluble microbial products (SMP).

  7. Inorganic separator technology program

    NASA Technical Reports Server (NTRS)

    Smatko, J. S.; Weaver, R. D.; Kalhammer, F. R.

    1973-01-01

    Testing and failure analyses of silver zinc cells with largely inorganic separators were performed. The results showed that the wet stand and cycle life objective of the silver-zinc cell development program were essentially accomplished and led to recommendations for cell composition, design, and operation that should yield further improvement in wet and cycle life. A series of advanced inorganic materials was successfully developed and formulated into rigid and semiflexible separator samples. Suitable screening tests for evaluation of largely inorganic separators were selected and modified for application to the separator materials. The results showed that many of these formulations are potentially superior to previously used materials and permitted selection of three promising materials for further evaluation in silver-zinc cells.

  8. Gold nanoparticles-induced enhancement of the analytical response of an electrochemical biosensor based on an organic-inorganic hybrid composite material.

    PubMed

    Barbadillo, M; Casero, E; Petit-Domínguez, M D; Vázquez, L; Pariente, F; Lorenzo, E

    2009-12-15

    The design and characterization of a new organic-inorganic hybrid composite material for glucose electrochemical sensing are described. This material is based on the entrapment of both gold nanoparticles (AuNPs) and glucose oxidase, which was chosen as a model, into a sol-gel matrix. The addition of spectroscopic grade graphite to this system, which confers conductivity, leads to the development of a material particularly attractive for electrochemical biosensor fabrication. The characterization of the hybrid composite material was performed using atomic force microscopy and scanning electron microscopy techniques. This composite material was applied to the determination of glucose in presence of hydroxymethylferrocene as a redox mediator. The system exhibits a clear electrocatalytic activity towards glucose, allowing its determination at 250 mV vs Ag/AgCl. The performance of the resulting enzyme biosensor was evaluated in terms of sensitivity, detection limit, linear response range, stability and accuracy. Finally, the enhancement of the analytical response of the resulting biosensor induced by the presence of gold nanoparticles was evaluated by comparison with a similar organic-inorganic hybrid composite material without AuNPs.

  9. Comparing graphene, carbon nanotubes, and superfine powdered activated carbon as adsorptive coating materials for microfiltration membranes.

    PubMed

    Ellerie, Jaclyn R; Apul, Onur G; Karanfil, Tanju; Ladner, David A

    2013-10-15

    Multi-walled carbon nanotubes (MWCNTs), nano-graphene platelets (NGPs), and superfine powdered activated carbon (S-PAC) were comparatively evaluated for their applicability as adsorptive coatings on microfiltration membranes. The objective was to determine which materials were capable of contaminant removal while causing minimal flux reduction. Methylene blue and atrazine were the model contaminants. When applied as membrane coatings, MWCNTs had minimal retention capabilities for the model contaminants, and S-PAC had the fastest removal. The membrane coating approach was also compared with a stirred vessel configuration, in which the adsorbent was added to a stirred flask preceding the membrane cell. Direct application of the adsorbent to the membrane constituted a greater initial reduction in permeate concentrations of the model contaminants than with the stirred flask setup. All adsorbents except S-PAC showed flux reductions less than 5% after application as thin-layer membrane coatings, and flux recovery after membrane backwashing was greater than 90% for all materials and masses tested.

  10. Polypropylene track membranes as a promising material for targets with polarized protons

    NASA Astrophysics Data System (ADS)

    Barashkova, I. I.; Bunyatova, E. I.; Kravets, L. I.

    2014-01-01

    Polypropylene track membranes made by irradiation of polypropylene films with a beam of high-energy heavy ions followed by chemical etching of latent ion tracks are proposed for being used as a polarized target material. To give membranes paramagnetic properties needed for allowing dynamic polarization of nuclei, the nitroxyl radical 2,2,6,6-tetramethylpiperidine-1-oxyl was introduced in the samples by the thermal diffusion technique. Using the electron paramagnetic resonance method, we obtained information on paramagnetic centers in the polymer matrix of the membranes and determined the nitroxyl radical concentration and rotational mobility of the spin probe in them.

  11. Self-Repair and Patterning of 2D Membrane-Like Peptoid Materials

    SciTech Connect

    Jiao, Fang; Chen, Yulin; Jin, Haibao; He, Pingang; Chen, Chun-Long; De Yoreo, James J.

    2016-08-31

    Two-dimensional materials are of increasing interest for use in filtration, sensing, nanoelectronics, and biomedical devices. Peptoids are a class of biomimetic sequence-defined polymers for which certain amphiphillic sequences self-assemble into 2D crystalline materials with properties that mimic those of cell membranes. Using in situ AFM to both dissect these membrane-like materials and image their subsequent behavior, we explore their ability to self-repair on a range of solid substrates. We show that, in a suitable range of pH, self-repair occurs on both negatively and positively charged substrates and can even occur in the absence of an underlying surface. Following dissection of pre-assembled peptoid membranes and upon introduction of a peptoid monomer solution, peptoids repair the damage by assembling at the newly created edges. The speed of the advancing edge depends on the edge orientation, reflecting the two-fold symmetry of the underlying peptoid lattice. Moreover, because the membranes are stabilized by hydrophobic interactions, if the solution contains peptoids possessing an identical sequence in the hydrophobic block but a distinct hydrophilic block, filling of the defects creates membranes that are patterned at the nanoscale. Consequently, we can utilize this ability to create nm-sized patterns of distinct functional groups within a single coherent membrane.

  12. Synthesis, structural and optical characterization of APbX{sub 3} (A=methylammonium, dimethylammonium, trimethylammonium; X=I, Br, Cl) hybrid organic-inorganic materials

    SciTech Connect

    Mancini, Alessandro; Quadrelli, Paolo; Amoroso, Giuseppe; Milanese, Chiara; Boiocchi, Massimo; Sironi, Angelo; Patrini, Maddalena; Guizzetti, Giorgio; Malavasi, Lorenzo

    2016-08-15

    In this paper we report the synthesis, the crystal structure and the optical response of APbX{sub 3} (A=MA, DMA, and TMA; X=I, Br) hybrid organic-inorganic materials including some new phases. We observe that as the cation group increases in size, the optical absorption edge shifts to higher energies with energy steps which are systematic and independent on the anion. A linear correlation between the optical bad gap and the tolerance factor has been shown for the series of samples investigated. - Graphical abstract: The crystal structure and the optical response of the two series of hybrid organic-inorganic materials APbX{sub 3} (A=MA, DMA, and TMA; X=I, Br), which include some new phases, are reported. A dependence of crystal structure and band-gap with tolerance factor is shown. Display Omitted - Highlights: • DMAPbI{sub 3}, TMAPbI{sub 3} and TMAPbBr{sub 3} are reported as new hybrid organic-inorganic compounds. • Crystal structure and optical properties as a function of the number of methyl groups are provided. • Correlation between structure and optical properties are given as a function of tolerance factor.

  13. Friction properties of biological functional materials: PVDF membranes.

    PubMed

    Chen, Long; Di, Changan; Chen, Xuguang; Li, Zhengzhi; Luo, Jia

    2017-01-02

    Touch is produced by sensations that include approaching, sliding, pressing, and temperature. This concept has become a target of research in biotechnology, especially in the field of bionic biology. This study measured sliding and pressing with traditional tactile sensors in order to improve a machine operator's judgment of surface roughness. Based on the theory of acoustic emission, this study combined polyvinylidene fluoride (PVDF) with a sonic transducer to produce tactile sensors that can detect surface roughness. Friction between PVDF films and experimental materials generated tiny acoustic signals that were transferred into electrical signals through a sonic transducer. The characteristics of the acoustic signals for the various materials were then analyzed. The results suggest that this device can effectively distinguish among different objects based on roughness. Tactile sensors designed using this principle and structure function very similarly to the human body in recognizing the surface of an object.

  14. Some Characteristics of the Outer Membrane Material Released by Growing Enterotoxigenic Escherichia coli

    PubMed Central

    Gankema, Henk; Wensink, Jan; Guinée, Pieter A. M.; Jansen, Wim H.; Witholt, Bernard

    1980-01-01

    The high-molecular-weight material released into the medium by Escherichia coli AP1, an enterotoxigenic strain of porcine origin, has been isolated and resolved into two clearly distinct fractions, based on sucrose density gradient and differential centrifugation, chemical analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and freeze-fracture electron microscopy. These two fractions, referred to as “medium vesicles” and “medium lipopolysaccharides”, were compared with the cellular outer and cytoplasmic membranes, the periplasmic fraction, and the cytoplasmic fraction. The medium vesicles closely resembled outer membrane and accounted for 3 to 5% of the total cellular outer membrane. They contained most of the heat-labile enterotoxin (LT) activity released into the medium by E. coli AP1. The medium lipopolysaccharide consisted mostly of lipopolysaccharide and a small amount of outer membrane and contained relatively little LT activity. Based on experiments with E. coli K-12 strains, in which about 5% of the newly synthesized outer membrane is lost from areas of outer membrane synthesis, it is proposed that enterotoxigenic E. coli strains release LT as part of such newly synthesized outer membrane fragments and that released outer membrane fragments may function as physiologically significant LT carriers. ImagesFig. 4Fig. 1Fig. 2Fig. 2Fig. 3 PMID:7011982

  15. Ion-Conducting Organic/Inorganic Polymers

    NASA Technical Reports Server (NTRS)

    Kinder, James D.; Meador, Mary Ann B.

    2007-01-01

    Ion-conducting polymers that are hybrids of organic and inorganic moieties and that are suitable for forming into solid-electrolyte membranes have been invented in an effort to improve upon the polymeric materials that have been used previously for such membranes. Examples of the prior materials include perfluorosulfonic acid-based formulations, polybenzimidazoles, sulfonated polyetherketone, sulfonated naphthalenic polyimides, and polyethylene oxide (PEO)-based formulations. Relative to the prior materials, the polymers of the present invention offer greater dimensional stability, greater ease of formation into mechanically resilient films, and acceptably high ionic conductivities over wider temperature ranges. Devices in which films made of these ion-conducting organic/inorganic polymers could be used include fuel cells, lithium batteries, chemical sensors, electrochemical capacitors, electrochromic windows and display devices, and analog memory devices. The synthesis of a polymer of this type (see Figure 1) starts with a reaction between an epoxide-functionalized alkoxysilane and a diamine. The product of this reaction is polymerized by hydrolysis and condensation of the alkoxysilane group, producing a molecular network that contains both organic and inorganic (silica) links. The silica in the network contributes to the ionic conductivity and to the desired thermal and mechanical properties. Examples of other diamines that have been used in the reaction sequence of Figure 1 are shown in Figure 2. One can use any of these diamines or any combination of them in proportions chosen to impart desired properties to the finished product. Alternatively or in addition, one could similarly vary the functionality of the alkoxysilane to obtain desired properties. The variety of available alkoxysilanes and diamines thus affords flexibility to optimize the organic/inorganic polymer for a given application.

  16. NOVEL CERAMIC MEMBRANE FOR HIGH TEMPERATURE CARBON DIOXIDE SEPARATION

    SciTech Connect

    Jerry Y.S. Lin; Jun-ichi Ida

    2001-03-01

    This project is aimed at demonstrating technical feasibility for a lithium zirconate based dense ceramic membrane for separation of carbon dioxide from flue gas at high temperature. The research work conducted in this reporting period was focused on several fundamental issues of lithium zirconate important to the development of the dense inorganic membrane. These fundamental issues include material synthesis of lithium zirconate, phases and microstructure of lithium zirconate and structure change of lithium zirconate during sorption/desorption process. The results show difficulty to prepare the dense ceramic membrane from pure lithium zirconate, but indicate a possibility to prepare the dense inorganic membrane for carbon dioxide separation from a composite lithium zirconate.