Sample records for functional inorganic materials

  1. Crystallization and functionality of inorganic materials

    SciTech Connect

    Xue, Dongfeng, E-mail: dongfeng@ciac.jl.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China) [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Li, Keyan [School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China)] [School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Liu, Jun [Key Laboratory of Low Dimensional Materials and Application Technology, Ministry of Education, Faculty of Materials, Optoelectronics and Physics, Xiangtan University, 411105 (China)] [Key Laboratory of Low Dimensional Materials and Application Technology, Ministry of Education, Faculty of Materials, Optoelectronics and Physics, Xiangtan University, 411105 (China); Sun, Congting; Chen, Kunfeng [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China) [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China)

    2012-10-15

    In this article, we briefly summarized our recent work on the studies of crystallization and functionality of inorganic materials. On the basis of the chemical bonding theory of single crystal growth, we can quantitatively simulate Cu{sub 2}O crystallization processes in solution system. We also kinetically controlled Cu{sub 2}O crystallization process in the reduction solution route. Lithium ion battery and supercapacitor performances of some oxides such as Co{sub 3}O{sub 4} and MnO{sub 2} were shown to elucidate the important effect of crystallization on functionality of inorganic materials. This work encourages us to create novel functionalities through the study of crystallization of inorganic materials, which warrants more chances in the field of functional materials.

  2. Inorganic Materials

    NASA Astrophysics Data System (ADS)

    ?erný, Radovan

    The separation of compounds by inorganic/organic boundary is of less importance for the structure determination by diffraction methods. More important for the diffraction is how the atoms build up larger building units and the crystal itself. A molecular/non-molecular boundary is therefore relevant for the choice of a structure determination method. Non-molecular compounds - also called extended solids - are constructed by bonds that extend "infinitely" in three dimensions through a crystal. These non-molecular crystals usually crystallize with higher symmetries, and atoms often occupy special Wyckoff positions. A review of actual methodology is given first, and then highlights and pitfalls of structure determination from powder diffraction, its problems and their solutions are shown and discussed using selected examples.

  3. New inorganic materials

    SciTech Connect

    Birchall, J.D. (Imperial Chemical Industries, Ltd., London, Great Britain); 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.

  4. 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.…

  5. 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.

  6. 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 described in Chapter 3. The devices are prepared via the layer-by-layer deposition technique and characterized by voltammetry and transmission spectroscopy. Contrast ratios between yellow and violet states were 45-50% with switching times of 3-3.5 seconds. Finally, Appendix I describes the resolution of racemic 3,3.3',3'-Tetramethyl-1,1"-spirobisindane-5,5',6,6'-tetrol by diastereomeric complex formation with (8S,9R)-(-)-N-benzylcinchonidinium chloride. Enantiomerically pure bisspirocatechol is used to prepare a chiral polymer, which exhibits differences in solid state packing from polymer made with the racemic monomer. Preliminary results on the use of the chiral polymer in enantioselective membrane separations technology are described.

  7. Bio-functional inorganic materials: an attractive branch of gene-based nano-medicine delivery for 21st century.

    PubMed

    Chowdhury, Ezharul H; Akaike, Toshihiro

    2005-12-01

    Treatment of a physiological disorder in the genetic level (gene therapy) and induction of a specific immunity by means of a genetic material (genetic vaccination), are considered two revolutionary approaches for clinical medicine. The implementation strategies for these basic concepts demand a vehicle for nucleic acid delivery. Viral delivery systems, although highly efficient, possess severe limitations in terms of life safety and thus non-viral synthetic systems have become increasingly desirable. Intensive efforts for the last 3 decades enabled the development of a lot of synthetic devices, most of which belong to cationic lipids, peptides and other polymers, but comparatively little attention was paid to inorganic materials. This is the first article aimed at reviewing the dramatic progress of non-viral gene delivery research focusing on the functional inorganic materials. Both biodegradable and non-biodegradable inorganic particles have been fabricated in the nano-scale with the attributes of binding DNA, internalizing across the plasma membrane and finally releasing it in the cytoplasm for final expression of a protein. Some in vivo trials also brought highly satisfactory results demonstrating their potential applications in the clinical medicine. PMID:16457655

  8. Inorganic immobilisation of waste materials

    Microsoft Academic Search

    F. Felix; A. L. A. Fraaji; Ch. F. Hendriks

    1997-01-01

    Inorganic immobilisation uses cement to solidify certain waste materials. Water is added to the cement in a ratio between 0.4 and 0.6. The calcium-silicates of the cement react with the water to a calcium-silicate-hydrate-gel (CSH-gel), lime and heat. This gel is able to cling aggregates together. The result is a hardened product, including some pores. Pores larger than 20 nm

  9. 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.

  10. RETROSPECTIVE MONITORING OF INORGANIC MATERIALS

    EPA Science Inventory

    The development of chronological reference points to which present levels of inorganic pollutants can be compared is increasingly needed. The requirements for retrospective monitoring methods are discussed in relation to their attainability. The literature has been reviewed for b...

  11. 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. PMID:25302345

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

    PubMed

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

    2015-05-01

    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. PMID:25533589

  13. Engineering living functional materials.

    PubMed

    Chen, Allen Y; Zhong, Chao; Lu, Timothy K

    2015-01-16

    Natural materials, such as bone, integrate living cells composed of organic molecules together with inorganic components. This enables combinations of functionalities, such as mechanical strength and the ability to regenerate and remodel, which are not present in existing synthetic materials. Taking a cue from nature, we propose that engineered 'living functional materials' and 'living materials synthesis platforms' that incorporate both living systems and inorganic components could transform the performance and the manufacturing of materials. As a proof-of-concept, we recently demonstrated that synthetic gene circuits in Escherichia coli enabled biofilms to be both a functional material in its own right and a materials-synthesis platform. To demonstrate the former, we engineered E. coli biofilms into a chemical-inducer-responsive electrical switch. To demonstrate the latter, we engineered E. coli biofilms to dynamically organize biotic-abiotic materials across multiple length scales, template gold nanorods, gold nanowires, and metal/semiconductor heterostructures, and synthesize semiconductor nanoparticles (Chen, A. Y. et al. (2014) Synthesis and patterning of tunable multiscale materials with engineered cells. Nat. Mater. 13, 515-523.). Thus, tools from synthetic biology, such as those for artificial gene regulation, can be used to engineer the spatiotemporal characteristics of living systems and to interface living systems with inorganic materials. Such hybrids can possess novel properties enabled by living cells while retaining desirable functionalities of inorganic systems. These systems, as living functional materials and as living materials foundries, would provide a radically different paradigm of materials performance and synthesis-materials possessing multifunctional, self-healing, adaptable, and evolvable properties that are created and organized in a distributed, bottom-up, autonomously assembled, and environmentally sustainable manner. PMID:25592034

  14. A Zn2+\\/ UV-inspired molecular logic function based on an organic\\/inorganic hybrid materials

    Microsoft Academic Search

    Shichao Wang; Guangwen Men; Liyan Zhao; Ying Wu; Yue Wang; Shimei Jiang

    2009-01-01

    In this paper, one simple binaphthyl-bridged salicylidene Schiff base (2,2'-bis(3,5-dichloro-2-hydroxybenzylideneamino)-1,1'-binaphthyl (BCHB)) was successfully modified into the channel of mesoporous molecular sieve SBA-15. Detailed characterizations demonstrated that the inner channel of SBA-15 was firstly functionalized with 3-aminapropyltriethoxysilane, then the functional molecule BCHB was anchored through the hydrogen bond assembly. During these processes the hexagonally ordered mesoporous structure of SBA-15 has not

  15. REVIEW ARTICLE Mechanics of stretchable inorganic electronic materials

    E-print Network

    Rogers, John A.

    REVIEW ARTICLE Mechanics of stretchable inorganic electronic materials J. Songa Department-Champaign, Urbana, Illinois 61801 Received 2 June 2009; accepted 8 June 2009; published 31 July 2009 Electronic-based technologies. This article reviews the mechanics of stretchable inorganic materials on compliant substrates

  16. Processing and optimization of functional ceramic coatings and inorganic nanomaterials

    Microsoft Academic Search

    Edward Kennedy G. Nyutu

    2008-01-01

    Processing of functional inorganic materials including zero (0-D) dimensional (e.g. nanoparticles), 1-D (nanorods, nanofibers), and 2-D (films\\/coating) structures is of fundamental and technological interest. This research will have two major sections. The first part of section one focuses on the deposition of silicon dioxide onto a pre-deposited molybdenum disilicide coating on molybdenum substrates for both high (>1000 °C) and moderate

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

    PubMed

    Wang, Hailiang; Dai, Hongjie

    2013-04-01

    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-hybrid materials for high performance lithium ion batteries, rechargeable Li-S and Li-O2 batteries, supercapacitors and ultrafast Ni-Fe batteries, and new electrocatalysts for oxygen reduction, oxygen evolution and hydrogen evolution reactions. PMID:23361617

  18. Identifying Affinity Classes of Inorganic Materials Binding Sequences via a Graph-based Model

    E-print Network

    Zhang, Aidong

    ], which are of great interest for applications in tech- nology and medicine. Inorganic material binding1 Identifying Affinity Classes of Inorganic Materials Binding Sequences via a Graph-based Model Nan to inorganic materials and classifying them based on their inorganic material affinities. However

  19. Generalized synthesis of periodic surfactant/inorganic composite materials

    NASA Astrophysics Data System (ADS)

    Huo, Qisheng; Margolese, David I.; Ciesla, Ulrike; Feng, Pingyun; Gier, Thurman E.; Sieger, Peter; Leon, Rosa; Petroff, Pierre M.; Schüth, Ferdi; Stucky, Galen D.

    1994-03-01

    THE recent synthesis of silica-based mesoporous materials1,2 by the cooperative assembly of periodic inorganic and surfactant-based structures has attracted great interest because it extends the range of molecular-sieve materials into the very-large-pore regime. If the synthetic approach can be generalized to transition-metal oxide mesostructures, the resulting nanocomposite materials might find applications in electrochromic or solid-electrolyte devices3,4, as high-surface-area redox catalysts5 and as substrates for biochemical separations. We have proposed recently6 that the matching of charge density at the surfactant/inorganic interfaces governs the assembly process; such co-organization of organic and inorganic phases is thought to be a key aspect of biomineralization7. Here we report a generalized approach to the synthesis of periodic mesophases of metal oxides and cationic or anionic surfactants under a range of pH conditions. We suggest that the assembly process is controlled by electrostatic complementarity between the inorganic ions in solution, the charged surfactant head groups and-when these charges both have the same sign-inorganic counterions. We identify a number of different general strategies for obtaining a variety of ordered composite materials.

  20. 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.

  1. Solution Processable Hybrid Polymer-Inorganic Thermoelectric Materials

    Microsoft Academic Search

    Shannon Yee; Nelson Coates; Kevin See; Jeffrey Urban; Rachel Segalman

    2011-01-01

    In the last decade thermoelectric material improvements have largely been attributed to a reduction in thermal conductivity due to nanostructuring. An alternative approach is to decouple and optimize the power factor using the unique properties of organic-inorganic interfaces. One method to do this could rely on the electrical properties of a conducting polymer in combination with the thermoelectrical proprieties of

  2. STABILITY AND TRANSPORT OF INORGANIC COLLOIDS THROUGH CONTAMINATED AQUIFER MATERIAL

    EPA Science Inventory

    Laboratory columns using contaminated natural aquifer material from Globe, Arizona, were used to investigate the transport of inorganic colloids under saturated flow conditions. e2O3 radio-labeled spherical colloids of various diameters were synthesized and introduced into the co...

  3. Combinatorial Measurement Methods for Inorganic Materials

    E-print Network

    ) devices, or the Seebeck coefficients of thermoelectric materials for vehicular waste heat recovery devices such as Intel and Micron, as well as GM and Honda for the use of thermoelectrics for vehicular waste heat recovery applications. We are very active in promoting the use of combinatorial methodologies with our

  4. Conceptual inorganic materials discovery - a road map.

    PubMed

    Jansen, Martin

    2015-06-01

    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. PMID:25899476

  5. Superhydrofobic effect of hybrid organo-inorganic materials

    Microsoft Academic Search

    V. V. VinogradovA; A. V. Agafonov; Alexander Valentinovich Vinogradov

    2010-01-01

    Superhydrophobic films were obtained on the basis of sol–gel-derived titania or alumina\\/dodecylamine hybrid materials. It\\u000a has been shown that wettability of surfaces of the inorganic oxides changes from superhydrophilic to superhydrophobic. For\\u000a superhydrophobic materials, the surface roughness of the hybrid films on the basis of titania and alumina is 39 and 55 ?m,\\u000a respectively, and water contact angle is about 150°.

  6. Identification of tunnels in proteins, nucleic acids, inorganic materials and molecular ensembles

    Microsoft Academic Search

    Ji?í Damborský; Martin Pet?ek; Pavel Banáš; Michal Otyepka

    2007-01-01

    The knowledge of the access paths connecting interior of molecular systems with surrounding en- vironment is important for the understanding of structure function relationships and engineering of molecules for biotechnological applications. CAVER is a computer program developed for cal- culations of tunnels, channels or pores in the biomolecules, inorganic materials and molecular en- sembles. The algorithm performs a skeleton search

  7. Combinatorial Screening Of Inorganic And Organometallic Materials

    DOEpatents

    Li, Yi (Miami, FL), Li, Jing (Miami, FL), Britton, Ted W. (Sunrise, FL)

    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.

  8. Inorganic electroluminescent displays: the impact of new materials

    Microsoft Academic Search

    A. J. Steckl; J. C. Heikenfeld; C. Munasinghe; D. S. Lee; Y. Q. Wang; R. Jones

    2003-01-01

    An overview of inorganic EL (iEL) flat panel displays (FPD) is presented. This includes a summary of the key points of iEL device operation and on overview of the impact of new phosphors and dielectric materials critical in EL device operation. This is followed by in-depth review of iEL devices and displays utilizing rare-earth-doped GaN and transition-metal-doped ZnS, in conjunction

  9. Bioinspired, functional nanoscale materials

    NASA Astrophysics Data System (ADS)

    Jun, In-Kook

    Functional nanomaterials in nature exhibit many unique functions and optical and mechanical properties. Examples of this include the dry adhesion of a gecko's foot, the reduced drag on a shark's skin, the high strength and toughness of nacre, and the superhydrophobic self-cleaning of a lotus leaf. This dissertation is devoted to creating unique and enhanced properties by mimicking such functional materials. We have developed a novel self-pumping membrane, which does not require an applied voltage. The self-pumping membrane harvests chemical energy from a surrounding fluid and uses it for accelerated mass transport across the membrane. A device such as this has promising applications in implantable or remotely operating autonomous devices and membrane-based purification systems. Reproducible and highly active surface enhanced Raman scattering (SERS) substrates were developed using a bottom-up self-assembly technology. With their high sensitivity and good reproducibility, the developed nanostructures (gold nanoparticle and nanohole arrays) as SERS substrates are very promising for applications such as ultra-sensitive detectors for chemicals and reproducible sensors for chemical and biological molecules. Binary colloidal crystals were created using a simple, fast, and scalable spin-coating technology. Although further investigation of the procedure is needed to improve the ordering of particles in the individual layers, the developed assembly technology has a promising outlook in applications such as optical integrated circuits and high-speed optical computing. Inorganic-organic nanocomposites were realized by assembling synthesized gibbsite nanoplatelets using the electrophoretic deposition and infiltration of a monomer followed by polymerization. Via surface modifications of gibbsite nanoplatelets, nanocomposites were further reinforced with covalent linkages between the inorganic platelets and organic matrix.

  10. 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. PMID:24411829

  11. 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. Metallic 3DOM products were examined by TEM. Images of 3DOM cobalt and nickel produced by calcination in flowing nitrogen showed grains surrounded by layers of carbon. Next, a potentially useful sensor material is introduced: the 3DOM oxides of silicon, aluminum, and zirconium were used to demonstrate a predictable and tailorable color change when saturated with fluids of various refractive indices. Finally, some future uses of 3DOM materials are considered.

  12. Hybrid inorganic–organic materials: a new family in condensed matter physics

    Microsoft Academic Search

    C N R Rao; A K Cheetham; A Thirumurugan

    2008-01-01

    We review some recent trends in an emerging field at the interface between classical inorganic and organic materials. Hybrid inorganic–organic framework materials are crystalline systems in which both inorganic and organic structural elements co-exist within a single phase. Much of the focus in this area during the last few years has been on porous hybrid frameworks, which are of interest

  13. TOPICAL REVIEW: Hybrid inorganic organic materials: a new family in condensed matter physics

    Microsoft Academic Search

    C. N. R. Rao; A. K. Cheetham; A. Thirumurugan

    2008-01-01

    We review some recent trends in an emerging field at the interface between classical inorganic and organic materials. Hybrid inorganic-organic framework materials are crystalline systems in which both inorganic and organic structural elements co-exist within a single phase. Much of the focus in this area during the last few years has been on porous hybrid frameworks, which are of interest

  14. 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).

  15. Novel inorganic materials for polymer electrolyte and alkaline fuel cells

    NASA Astrophysics Data System (ADS)

    Tadanaga, Kiyoharu

    2012-06-01

    Inorganic materials with high ionic conductivity must have big advantages for the thermal and long term stability when the materials are used as the electrolyte of fuel cells. In the present paper, novel ionic conductive inorganic materials for polymer electrolyte fuel cells (PEFCs) and all solid state alkaline fuel cells (AFCs) that have been developed by our group have been reviewed. PEFCs which can operate in temperature range from 100 to 200 °C are intensively studied because of some advantages such as reduction of CO poisoning of Pt catalyst and acceleration of electrode reactions. We showed that the fuel cells using the composite membranes prepared from phosphosilicate gel powder and polyimide precursor can operate in the temperature range from 30 to 180 °C. We also found that the inorganic-organic hybrid membranes with acid-base pairs from 3-aminopropyl triethoxy silane and H2SO4 or H3PO4 show high proton conductivity under dry atmosphere, and the membranes are thermally stable at intermediate temperatures. On the other hand, because the use of noble platinum is the serious problem for the commercialization of PEFCs and because oxidation reactions are usually faster than those of acid-type fuel cells, alkaline type fuel cells, in which a nonplatinum catalyst can be used, are attractive. Recently, we have proposed an alkaline-type direct ethanol fuel cell (DEFC) using a natural clay electrolyte with non-platinum catalysts. So-called hydrotalcite clay, Mg-Al layered double hydroxide intercalated with CO32- (Mg-Al CO32- LDH), has been proved to be a hydroxide ion conductor. An alkalinetype DEFC using Mg-Al CO32- LDH as the electrolyte and aqueous solution of ethanol and potassium hydroxide as a source of fuel exhibited excellent electrochemical performance.

  16. Hybrid exciton recombination dynamics in inorganic-organic materials

    SciTech Connect

    Mastour, N., E-mail: mastounouha@yahoo.fr; Bouchriha, H., E-mail: mastounouha@yahoo.fr [Laboratoire : Matériaux avancés et phénomènes quantiques, Faculté des Sciences de Tunis, Université de Tunis El Manar, Campus Universitaire, 2092 Tunis (Tunisia)

    2013-12-16

    A systematic analysis of hybrid Frenkel–Wannier–Mott excitons recombination dynamics in nanocomposite material (organic–inorganic) is performed. A theoretical model based on the rate equation is used in the calculation of the light intensity and relative quantum efficiency. Numerical results have been presented for low and high concentration of quantum dots (Qds). Our results show that the light emission and relative quantum efficiency are significantly enhanced by incorporation of Qds in polymer matrix. Moreover our calculations were found to be in good agreement with the experimental data.

  17. Heterogeneous Catalyst Design by Multiple Functional Group Positioning in Organic-Inorganic Materials: On the Route to Analogs of Multifunctional Enzymes

    NASA Astrophysics Data System (ADS)

    Margelefsky, Eric L.; Zeidan, Ryan K.; Davis, Mark E.

    Enzymes catalyze reactions with high rates and selectivities through the sophisticated use of cooperative interactions between neighboring functional groups within an active site. For example, the “catalytic triad” in proteases is capable of accelerating the cleavage of amides by 1011 through neighboring interactions between carboxylic acid, imidazole, and alcohol sites. Guided by these principles, heterogeneous catalysts having two different types of functional groups have been prepared, and the cooperative behavior have been demonstrated with catalytic reactions in the liquid phase. Cooperative interactions between thiols and sulfonic acids and between incompatible acid and base groups are achievable with rates and selectivities that are superior to homogeneous systems, especially for the latter case wherein there is no reactivity.

  18. Functionalized inorganic membranes for gas separation

    DOEpatents

    Ku, Anthony Yu-Chung (Rexford, NY); Ruud, James Anthony (Delmar, NY); Molaison, Jennifer Lynn (Marietta, GA); Schick, Louis Andrew ,(Delmar, NY); Ramaswamy, Vidya (Niskayuna, NY)

    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.

  19. A review on helium mobility in inorganic materials

    NASA Astrophysics Data System (ADS)

    Trocellier, P.; Agarwal, S.; Miro, S.

    2014-02-01

    The presence and migration of helium can have a strong influence on microstructural, physical and thermo-mechanical properties of natural or manufactured inorganic solids. A lot of scientific domains are involved from geo-materials to nuclear materials. This paper presents the results of an extensive review of the literature related to the study of helium migration in a wide range of solids. The most useful experimental techniques are briefly described. Experimental and theoretical works devoted to pure metals, alloys, binary and more complex crystalline oxides, carbides and common minerals are successively considered. Relevant results concerning migration mechanisms and diffusion parameters obtained for metallic and non-metallic solids are outlined. New trends mainly developed for future nuclear applications are also reviewed.

  20. 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 deeper percolation. This ongoing research will clarify the processes involved in SIC formation and identify the situations where it is an atmospheric source or sink.

  1. Dense organic-inorganic framework materials containing transition metal ions

    NASA Astrophysics Data System (ADS)

    Feller, Russell Kenneth

    2008-10-01

    Hybrid inorganic-organic framework materials built upon metal cations and polyfunctional anionic ligands have arrived at the forefront of chemical research, boasting unique properties that derive from their diverse structures. The majority of these compounds are prepared through mild hydrothermal or solvothermal synthesis, at temperatures below 225°C. There has been a great deal of emphasis on porous coordination polymers, or "metal-organic frameworks" (MOFs), which exhibit a wide range of useful sorption and catalytic properties, but there is growing interest in a second class of hybrid frameworks which are denser and often have extended inorganic connectivity, which may be thought of as hybrid metal oxides. These denser compounds provide access to more oxide-like properties such as magnetism, along with improved thermal stability. The flourishing diversity of structures and dimensionalities seen in these materials has led to their growth into a major field of research. Here, the hydrothermal syntheses and crystal structures of fourteen new hybrid framework materials are reported, and additional properties are measured for several of them. The terminology used to describe this class of materials is laid out, and a classification scheme is introduced based on the dimensionalities of their structures. While a combinatorial approach for new compound discovery is often used, strategies for rational synthesis are also discussed. A family of isostructural 3,4,5-trihydroxybenzoate (gallate) hybrid frameworks of the first-row transition metals is produced, with chiral structures imparted by helical packing arrangements. Complex magnetic behavior is characterized in a pillared layered cobalt ethanedisulfonate, the structure of which features intricate metal-oxygen-metal connectivity. Frameworks of new, sometimes unreported, ligand molecules are created through the reactivities of aspartic acid and 5-hydroxyisophthalic acid under hydrothermal conditions. A family of two-ligand frameworks are created using 5-hydroxyisophthalic acid and 4,4'-bipyridyl, which form very different structures when reacted with Mn, Ni, Cu and Zn. Finally, reactions of Cu and Zn together with these two ligands lead to a family of four- and five-component hybrid frameworks showing even greater degrees of structural complexity.

  2. Design and synthesis of inorganic/organic hybrid electrochemical materials

    NASA Astrophysics Data System (ADS)

    Harreld, John H.

    An ambient pressure method for drying sol-gel materials is developed to synthesize high porosity (80--90%), high surface area vanadium oxide and silica aerogel materials (150--300 and 1000 m2/g for vanadium pentoxide and silica, respectively). The synthesis approach uses liquid exchange to replace the pore fluid with a low surface tension, nonpolar solvent which reduces the capillary pressures developed during drying. The Good-Girifalco interaction parameter is used to calculate pore stresses resulting from drying silica gels from various liquids. Vanadium oxide/polypyrrole hybrid aerogels are prepared using three strategies. These approaches focus on either sequential or consecutive polymerization of the inorganic and organic networks. Microcomposite aerogels are synthesized by encapsulating a dispersion of preformed polypyrrole in a vanadium pentoxide gel. In the second approach, pyrrole is polymerized and doped within the pore volume of preformed vanadium pentoxide gel. When the inorganic and organic precursors are polymerized simultaneously, the resulting gels exhibited a nanometer scaled microstructure with homogeneous distributions of either phases. Through this route, a suitable microstructure and composition for a lithium secondary battery cathode is obtained. Lithiated aerogels of hydrated nickel, cobalt, and mixed nickel-cobalt oxides are synthesized from lithium hydroxide and transition metal acetate precursors. The XRD analyses indicate that the nickel containing gels exhibit a lithium deficiency (less than 1 Li/transition metal. By increasing the concentration of the lithium precursor the lithium content in nickel oxides is increased, and additional base solution is no longer required to catalyze gelation. A non-hydrolytic sol-gel approach is utilized to create tin oxide and tin-aluminum binary oxide aerogels with high porosity (90%) and high surface area (300 m2/g). XRD data from single phase tin oxide aerogel indicates the growth of SnO2 crystallites between 150--400°C in air, accompanied by a reduction in surface area (30 m2/g). Heated tin oxide aerogel exhibits comparable reversible specific capacity (390 mAh/g) as that of commercial SnO2 (420 mAh/g). Amorphous tin oxide aerogel is stabilized to higher temperatures when aluminum oxide is incorporated into the structure. The tin oxide phase remains electrochemically active towards lithium insertion and exhibits excellent reversibility during cycling.

  3. Inorganic-organic electrolyte materials for energy applications

    NASA Astrophysics Data System (ADS)

    Fei, Shih-To

    This thesis research is devoted to the development of phosphazene-based electrolyte materials for use in various energy applications. Phosphazenes are inorganic-organic materials that provide unusal synthetic advantages and unique process features that make them useful in energy research. This particular thesis consists of six chapters and is focused on four specific aspects: lithium battery, solar cell, and fuel cell electrolytes, and artificial muscles. Chapter 1 is written as an introduction and review of phosphazene electrolytes used in energy applications. In this introduction the basic history and characteristics of the phosphazenes are discussed briefly, followed by examples of current and future applications of phosphazene electrolytes related to energy. Notes are included on how the rest of the chapters relate to previous work. Chapters 2 and 3 discuss the conductivity and fire safety of ethyleneoxy phosphazene gel electrolytes. The current highly flammable configurations for rechargeable lithium batteries generate serious safety concerns. Although commercial fire retardant additives have been investigated, they tend to decrease the overall efficiency of the battery. In these two chapters the discussion is focused on ionically conductive, non-halogenated lithium battery additives based on a methoxyethoxyethoxyphosphazene oligomer and the corresponding high polymer, both of which can increase the fire resistance of a battery while retaining a high energy efficiency. Conductivities in the range of 10 -4 Scm-1 have been obtained for self-extinguishing, ion-conductive methoxyethoxyethoxyphosphazene oligomers. The addition of 25 wt% high polymeric poly[bis(methoxyethoxyethoxy)phosphazene] to propylene carbonate electrolytes lowers the flammability by 90% while maintaining a good ionic conductivity of 2.5x10--3 Scm -1 Chapter 2 is focused more on the electrochemical properties of the electrolytes and how they compare to other similar materials, while Chapter 3 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 commercially available materials such as Nafion. However the average methanol permeability was aro

  4. Inorganic arsenic impairs differentiation and functions of human dendritic cells

    SciTech Connect

    Macoch, Mélinda; Morzadec, Claudie [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)] [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Fardel, Olivier [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France) [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Pôle Biologie, Centre Hospitalier Universitaire (CHU) Rennes, 2 rue Henri Le Guilloux, 35033 Rennes (France); Vernhet, Laurent, E-mail: laurent.vernhet@univ-rennes1.fr [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)] [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)

    2013-01-15

    Experimental studies have demonstrated that the antileukemic trivalent inorganic arsenic prevents the development of severe pro-inflammatory diseases mediated by excessive Th1 and Th17 cell responses. Differentiation of Th1 and Th17 subsets is mainly regulated by interleukins (ILs) secreted from dendritic cells (DCs) and the ability of inorganic arsenic to impair interferon-? and IL-17 secretion by interfering with the physiology of DCs is unknown. In the present study, we demonstrate that high concentrations of sodium arsenite (As(III), 1–2 ?M) clinically achievable in plasma of arsenic-treated patients, block differentiation of human peripheral blood monocytes into immature DCs (iDCs) by inducing their necrosis. Differentiation of monocytes in the presence of non-cytotoxic concentrations of As(III) (0.1 to 0.5 ?M) only slightly impacts endocytotic activity of iDCs or expression of co-stimulatory molecules in cells activated with lipopolysaccharide. However, this differentiation in the presence of As(III) strongly represses secretion of IL-12p70 and IL-23, two major regulators of Th1 and Th17 activities, from iDCs stimulated with different toll-like receptor (TLR) agonists in metalloid-free medium. Such As(III)-exposed DCs also exhibit reduced mRNA levels of IL12A and/or IL12B genes when activated with TLR agonists. Finally, differentiation of monocytes with non-cytotoxic concentrations of As(III) subsequently reduces the ability of activated DCs to stimulate the release of interferon-? and IL-17 from Th cells. In conclusion, our results demonstrate that clinically relevant concentrations of inorganic arsenic markedly impair in vitro differentiation and functions of DCs, which may contribute to the putative beneficial effects of the metalloid towards inflammatory autoimmune diseases. Highlights: ? Inorganic arsenic impairs differentiation and functions of human dendritic cells (DCs) ? Arsenite (> 1 ?M) blocks differentiation of dendritic cells by inducing necrosis ? Arsenite (0.1 to 0.5 ?M) slightly reduces endocytotic activity of immature DCs ? Arsenite (0.1 to 0.5 ?M) represses expression of IL-12p70 and IL-23 in activated DCs ? Arsenite (0.1 to 0.5 ?M) reduces the ability of DCs to activate human T lymphocytes.

  5. 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 °C in 27 nm films was evidenced, indicating changes in molecular conformations with respect to the temperature. pCBAA and pEGMA brushes displayed no thermal transitions, suggesting that the molecular conformations of these systems were insensitive to temperature in the investigated regime. The surface energy of a dimensionally constrained inorganic system, graphene is studied via local Hamaker constant determination from a single graphene layer to bulk graphite. Intrinsic friction scattering analysis of dipolar fluctuations of the Van der Waals interactions between an atomic force microscopy tip and graphene layers revealed a four-fold reduction in the surface energy from bulk HOPG to graphene. A numerical analysis based on electron energy loss spectroscopy confirms quantitatively the results.

  6. Inorganic–organic hybrid materials with zirconium oxoclusters as protective coatings on aluminium alloys

    Microsoft Academic Search

    Fabrizio Girardi; Francesco Graziola; Paolo Aldighieri; Lorenzo Fedrizzi; Silvia Gross; Rosa Di Maggio

    2008-01-01

    Inorganic–organic hybrid materials are attracting a strong scientific interest mainly for their outstanding inherent mechanical and thermal properties, which can be traced back to the intimate coupling of both inorganic and organic components. By carefully choosing the experimental parameters used for their synthesis, chemically and thermally stable acrylate-based hybrid material embedding the zirconium oxocluster Zr4O4(OMc)12, where OMcCH2C(CH3)C(O)O, can be deposited

  7. Precession electron diffraction: application to organic crystals and hybrid inorganic-organic materials

    Microsoft Academic Search

    E. G. Bithell; M. D. Eddleston; C. A. Merrill; W. Jones; P. A. Midgley

    It is now accepted that precession electron diffraction (PED) [1, 2] has a significant contribution to make to the nanoscale\\u000a characterisation of materials. In this presentation we explore the extent to which data may be derived from acutely beam sensitive\\u000a materials, specifically organic materials and hybrid inorganic-organic frameworks.

  8. Genetically engineered polypeptides for inorganics: A utility in biological materials science and engineering

    Microsoft Academic Search

    Candan Tamerler; Turgay Kacar; Deniz Sahin; Hanson Fong; Mehmet Sarikaya

    2007-01-01

    Adapting molecular biology to materials science we developed peptide-based protocols for the assembly and formation of hybrid materials and systems. In this approach of generating molecular scale biomimetic materials, peptides are designed, synthesized, genetically tailored and, finally, utilized as potential molecular linkers in self-assembly, ordered organization, and fabrication of inorganics for specific technological applications. The potential areas range from molecular

  9. Effect of modified organic–inorganic hybrid materials on thermal properties of cotton fabrics

    Microsoft Academic Search

    Shuang HuYuan; Yuan Hu; Lei Song; Hongdian Lu

    2011-01-01

    Phosphorus-modified siloxanes monomer DOPO-IPDI-AMEO (DIA) was synthesized and characterized by 1H nuclear magnetic resonance (H NMR), 31P NMR, and Fourier transform infrared spectra (FTIR). It hydrolyzed and grew an organic–inorganic hybrid coating on the surface\\u000a of cotton fabrics via sol–gel process. The conversion of gel reaction was characterized by solid-state 29Si NMR. The effect of the modified organic–inorganic hybrid materials

  10. Study of cure kinetics of epoxy-silica organic–inorganic hybrid materials

    Microsoft Academic Search

    J. Macan; H. Ivankovi?; M. Ivankovi?; H. J. Mencer

    2004-01-01

    Cure kinetics of organic–inorganic hybrids based on epoxy resin was investigated, using differential scanning calorimetry (DSC). Thermoset hybrid materials were prepared from diglycidyl ether of bisphenol A (DGEBA) as organic precursor, and 3-glycidyloxypropyltrimethoxysilane (GLYMO) as inorganic precursor. Precursors were polymerised simultaneously using poly(oxypropylene)diamine (Jeffamine D230) as a curing agent. Isothermal DSC characterisation of DGEBA\\/Jeffamine system and two hybrid DGEBA\\/GLYMO\\/Jeffamine systems,

  11. 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 presence of an external electric field are reported. While all materials of the MoWSeS family share the same qualitative properties, their individual values can differ strongly, for example, the spin-orbit splitting in WSe2 reaches the value of 428 meV, nearly three times that of MoS2. Further, we discuss the effect of strain on the electronic properties (straintronics). While MoWSeS single layers are very robust against external electric fields, bilayers show a linear reduction of the band gap, even reaching a semiconductor-metal phase transition, and an increase of the spin-orbit splitting from zero to the monolayer value at rather small fields. Strain is yet another possibility to control the band gap in a linear way, and MoWSeS monolayers become metallic at strain values of ?10%. The density-functional based tight-binding model is a useful tool to investigate the electronic and structural properties, including electron conductance, of large MoS2 structures, which show spontaneous rippling in finite-temperature molecular dynamics simulations. Structural defects in MoS2 result in anisotropy of the electric conductivity. Finally, DFT predictions on the properties of noble metal dichalcogenides are presented. Most strikingly, 1T PdS2 is an indirect band gap semiconductor in its monolayer form but becomes metallic as a bilayer. PMID:25489917

  12. Strategies for the synthesis of thermoplastic polymer nanocomposite materials with high inorganic filling fraction.

    PubMed

    Ojha, Satyajeet; Dang, Alei; Hui, Chin Ming; Mahoney, Clare; Matyjaszewski, Krzysztof; Bockstaller, Michael R

    2013-07-16

    The governing parameters controlling the miscibility of particle additives within polymeric host media are analyzed for the particular case of silica particle fillers embedded within a poly(methyl methacrylate) (PMMA) matrix. For athermal polymer-graft modification of particles (corresponding to equal chemical composition of graft and matrix polymer), compatibility is found to be a sensitive function of the degree of polymerization of graft and host polymer chains as well as the particle radius. In agreement with theoretical predictions, uniform particle dispersion is observed if the degree of polymerization of grafted chains is comparable to (or exceeds) the corresponding value of the polymer matrix. The resulting restriction to high degree of polymerization limits the accessible inorganic fraction that is attainable in athermal particle/polymer blends. In contrast, favorable interaction between grafted polymer chains and the polymeric host (as realized in the case of poly(styrene-r-acrylonitrile)-grafted particles embedded within PMMA matrix) is shown to facilitate thermodynamically stable and uniform particle dispersion across the entire compositional range even in the limit of large particle size, short grafted chains, and high molecular matrix chains. The synthesis of thermoplastic composite materials with inorganic fraction exceeding 50 vol % combining quantitative optical limiting within the UV frequency range and polymer-like mechanical properties is demonstrated. PMID:23786358

  13. Nanoscale Structure of Self-Assembling Hybrid Materials of Inorganic and Electronically Active Organic Phases

    SciTech Connect

    Sofos, M.; Goswami, D.A. Stone D.K.; Okasinski, J.S.; Jin, H.; Bedzyk, M.J.; Stupp, S.I. (NWU)

    2008-10-06

    Hybrid materials with nanoscale structure that incorporates inorganic and organic phases with electronic properties offer potential in an extensive functional space that includes photovoltaics, light emission, and sensing. This work describes the nanoscale structure of model hybrid materials with phases of silica and electronically active bola-amphiphile assemblies containing either oligo(p-phenylene vinylene) or oligo(thiophene) segments. The hybrid materials studied here were synthesized by evaporation-induced self-assembly and characterized by X-ray scattering techniques. Grazing-incidence X-ray scattering studies of these materials revealed the formation of two-dimensional hexagonally packed cylindrical micelles of the organic molecules with diameters between 3.1 and 3.6 nm and cylindrical axes parallel to the surface. During the self-assembly process at low pH, the cylindrical aggregates of conjugated molecules become surrounded by silica giving rise to a hybrid structure with long-range order. Specular X-ray reflectivity confirmed the long-range periodicity of the hybrid films within a specific range of molar ratios of tetraethyl orthosilicate to cationic amphiphile. We did not observe any long-range ordering in fully organic analogues unless quaternary ammonium groups were replaced by tertiary amines. These observations suggest that charge screening in these biscationic conjugated molecules by the mineral phase is a key factor in the evolution of long range order in the self-assembling hybrids.

  14. Adsorption of transition metal ions from aqueous solutions onto a novel silica gel matrix inorganic–organic composite material

    Microsoft Academic Search

    Ping Yin; Qiang Xu; Rongjun Qu; Guifang Zhao; Yanzhi Sun

    2010-01-01

    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

  15. Luminescent Organic–Inorganic Hybrids of Functionalized Mesoporous Silica SBA-15 by Thio-Salicylidene Schiff Base

    PubMed Central

    2010-01-01

    Novel organic–inorganic mesoporous luminescent hybrid material N, N?-bis(salicylidene)-thiocarbohydrazide (BSTC-SBA-15) has been obtained by co-condensation of tetraethyl orthosilicate and the organosilane in the presence of Pluronic P123 surfactant as a template. N,N?-bis(salicylidene)-thiocarbohydrazide (BSTC) grafted to the coupling agent 3-(triethoxysilyl)-propyl isocyanate (TESPIC) was used as the precursor for the preparation of mesoporous materials. In addition, for comparison, SBA-15 doped with organic ligand BSTC was also synthesized, denoted as BSTC/SBA-15. This organic–inorganic hybrid material was well-characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy (HRTEM), and photoluminescence spectra, which reveals that they all have high surface area, uniformity in the mesostructure. The resulting materials (BSTC-SBA-15 and BSTC/SBA-15) exhibit regular uniform microstructures, and no phase separation happened for the organic and the inorganic compounds was covalently linked through Si–O bonds via a self-assemble process. Furthermore, the two materials have different luminescence range: BSTC/SBA-15 presents the strong dominant green luminescence, while BSTC-functionalized material BSTC-SBA-15 shows the dominant blue emission. PMID:20672102

  16. Recent progress and problems in high field electroluminescence of inorganic materials

    Microsoft Academic Search

    Hiroshi Kobayashi

    1993-01-01

    High-field electroluminescence (EL) of inorganic materials are of basic and practical interest. There are two types of the high field EL; one is a thin film EL (TFEL) and the other is a powder type. Recent researches are mainly on TFEL. In this paper, recent progress on TFEL will be discussed and reviewed. Features of high field TFEL are as

  17. Functioning of inorganic/organic battery separators in silver-zinc cells

    NASA Technical Reports Server (NTRS)

    Philipp, W. H.; May, C. E.

    1976-01-01

    The results of three experimental studies related to the inorganic/organic battery separator operating mechanism are described: saponification of the plasticizer, resistivity of the simulated separators, and zincate diffusion through the separators. The inorganic/organic separator appears to be a particular example of a general class of ionic conducting films composed of inorganic fillers and/or substrates bonded together by an organic polymer containing an incompatible plasticizer that may be leached by the electrolyte. The I/O separator functions as a microporous film of varying tortuosity with essentially no specific chemical inhibition to zincate diffusion.

  18. A study of the interaction of thioindigo dye, with several inorganic host materials

    NASA Astrophysics Data System (ADS)

    Ramirez, Alejandra

    Maya Blue has been the focus of numerous studies and is believed to be a mixture of palygorskite clay and indigo dye.1,2 Several derivatives of this pigment have been developed with intriguing properties. For instance, the dye thioindigo reacts with the palygorskite clay to exhibit a broad range of colors from red to blue under UV-Vis excitation. Based on FT-Raman and computer simulation, previous work performed in our group could relate indigo and thioindigo interaction to the aluminum sites in the framework. 3,4 The work performed with other inorganic host materials such as, layer structures and zeolites have displayed reversible acid indicator properties, similar to the ones observed in concentrated sulfuric acid. Spectroscopic analyses and computer modeling of the above mentioned interactions have been evaluated. Results obtained by these techniques showed that in dehydrated materials a disturbance of thioindigo C=O at 1655 cm-1 to lower frequencies occurs, due to the C=O---Lewis acid sites (LAS) interaction. In the presence of water, a smaller C=O shift due to C=O---HO(H)LAS was observed. Moreover, displacement of the 001 plane in some layer materials confirmed the effect of water on the color changes displayed by UV-Vis spectroscopy. Based on these premises, it was concluded that weak electron donor-acceptor interactions took place between thioindigo functional groups (electron donors) and LAS of the aluminum silicate framework (electron acceptor). LAS (extra-framework aluminum and exchangeable cations) high hydration enthalpy made them extremely susceptible to water molecules (electron donors); generating a hydrogen bond between the two sites. The reversibility of these chromatic hybrid materials could have potential applications as water sensors and charge transfer photosensitizers in nanocrystalline TiO2-based solar cells.

  19. Inorganic compounds for passive solar energy storage. Solid-state dehydration materials and high specific heat materials. Progress report

    Microsoft Academic Search

    L. J. Struble; P. W. Brown

    1986-01-01

    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-AlâOâ-SOâ-HâO 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

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

    Microsoft Academic Search

    L. J. Struble; P. W. Brown

    1986-01-01

    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

  1. Dark inorganic carbon fixation sustains the functioning of benthic deep-sea ecosystems

    NASA Astrophysics Data System (ADS)

    Molari, Massimiliano; Manini, Elena; Dell'Anno, Antonio

    2013-01-01

    studies have provided evidence that dark inorganic carbon fixation is an important process for the functioning of the ocean interior. However, its quantitative relevance and ecological significance in benthic deep-sea ecosystems remain unknown. We investigated the rates of inorganic carbon fixation together with prokaryotic abundance, biomass, assemblage composition, and heterotrophic carbon production in surface sediments of different benthic deep-sea systems along the Iberian margin (northeastern Atlantic Ocean) and in the Mediterranean Sea. Inorganic carbon fixation rates in these surface deep-sea sediments did not show clear depth-related patterns, and, on average, they accounted for 19% of the total heterotrophic biomass production. The incorporation rates of inorganic carbon were significantly related to the abundance of total Archaea (as determined by catalyzed reporter deposition fluorescence in situ hybridization) and completely inhibited using an inhibitor of archaeal metabolism, N1-guanyl-1,7-diaminoheptane. This suggests a major role of the archaeal assemblages in inorganic carbon fixation. We also show that benthic archaeal assemblages contribute approximately 25% of the total 3H-leucine incorporation. Inorganic carbon fixation in surface deep-sea sediments appears to be dependent not only upon chemosynthetic processes but also on heterotrophic/mixotrophic metabolism, as suggested by estimates of the chemolithotrophic energy requirements and the enhanced inorganic carbon fixation due to the increase in the availability of organic trophic resources. Overall, our data suggest that archaeal assemblages of surface deep-sea sediments are responsible for the high rates of inorganic carbon incorporation and thereby sustain the functioning of the food webs as well as influence the carbon cycling of benthic deep-sea ecosystems.

  2. 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). The solid samples were characterized by inductively coupled plasma-optical emission (ICP-OES) spectrometry, scanning electron microscopy (SEM), simultaneous thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), and X-ray powder diffraction (XRD). The solid had a plate-like morphology. The preliminary electrochemical results showed that MgxMnO2?yH2O had a very good cycliability and the capacity retention in 20 discharge-charge cycles. When the sample was dried at 100°C after collection, the discharge capacity would increase from 80 mAh/g to 155 mAh/g in the first discharge process in cycling test. Silver vanadium phosphorous oxide (SVPO, Ag2VO2PO 4) was prepared in various reaction temperatures. It was the first time that Ag2VO2PO4 was synthesized successfully at room temperature. The solid was characterized by Brunauer-Emmitt-Teller surface area (BET), inductively coupled plasma-optical emission (ICP-OES) spectroscopy, differential scanning calorimetry (DSC), magnetic susceptibility measurement, scanning electron microscope (SEM) and x-ray powder diffraction (XRD). Ag2VO2PO4 crystallite sizes showed a strong linear correlation with reaction temperature. The BET surface area was decreased as the crystallite size increased linearly. In addition, the acicular morphology started to develop at 50°C. The impact of silver deposition loading on the silver-polypyrrole composite electrode was studied using cyclic voltammetry. The minimum Ag loading of 0.08 mg/cm2 was determined to maximize the oxygen reduction activity for the Ag/Ppy composite catalyst. In addition, the Ag/Ppy coated carbon electrode showed higher oxygen reduction activities in both air and oxygen compared to the uncoated carbon electrode.

  3. 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 tissue engineering applications. PMID:15814140

  4. Tissue conditioning materials as functional impression materials.

    PubMed

    Chander, Satinder; Hill, Mark; Moore, Derek; Morrow, Leean

    2007-06-01

    There has been much written on the subject of tissue conditioner materials. In the context of functional impressions however there exists a lack of consensus opinion. In this article various aspects of functional impression materials have been considered. These include the effects of powder to liquid mixing ratio (P/L) on the visco elastic properties, effects on the surface hardness of dental stone when these materials are cast, undercut reproducibility, compressibility and dimensional stability. Definitive conclusions are difficult to draw however it seems the evidence supports the use of tissue conditioners as functional impression materials. PMID:17645067

  5. PEGylated Inorganic Nanoparticles

    SciTech Connect

    Karakoti, Ajay S.; Das, Soumya; Thevuthasan, Suntharampillai; Seal, Sudipta

    2011-02-25

    Application of inorganic nanoparticles in diagnosis and therapy has become a critical component in targeted treatment of diseases. The surface modification of inorganic oxides is important for providing diversity in size, shape, solubility, long term stability and attachment of selective functional groups. PEGylation of surfaces is a key strategic approach for providing stealth characteristics to nanomaterials otherwise identified as foreign materials by human body. The current review describes the role of surface modification of oxides by polyethylene glycol (PEG) in providing versatile characteristics to inorganic oxide nanoparticles with a focus on their biomedical applications. The role of PEG as structure directing agent in synthesis of oxides is also captured in this short review.

  6. Exponentially Modified Gaussian Function. An Empirical Equation for Description of the Band Emission of Inorganic Phosphors

    Microsoft Academic Search

    D. Nötzold

    1997-01-01

    The empirically found, exponentially modified Gaussian function is used for the description of the band emission of inorganic phosphors. The function includes the two parameters, the intensity of the maximum (I0) and its spectral position (-0), and besides two parameters for the slope of the flanks of the emission band (k1, k2) and two parameters for their deviation from the

  7. Guidance of growth mode and structural character in organic-inorganic hybrid materials - a comparative study.

    PubMed

    Klepper, K B; Nilsen, O; Francis, S; Fjellvåg, H

    2014-03-01

    A main goal in the construction of thin films is to control film growth in all aspects. Accurate control of the building blocks and their reaction sites is one way to achieve that. This is a key feature of the atomic layer deposition (ALD) technique. The aim of this study is to achieve such growth control of organic-inorganic thin films. The organic building blocks consist of the linear carboxylic acids: glutaric, tricarballylic, and trans-aconitic acid and the amino acid l-glutamic acid. All of these are based on five carbon long backbones. The acids were linked by aluminium using trimethylaluminum (TMA). These precursors made it possible to study the effect of the functionality of the organic acid backbone on growth rate, reaction modes, and the material properties of the deposited materials. The growth dynamics were investigated by in situ characterization using a quartz crystal microbalance (QCM). QCM revealed that all systems are of a self-limiting ALD-type. Ideal ALD growth was found for the tricarballylic acid-TMA system. For the other systems, the growth rate decreased with increasing temperature. The growth rates ranged from 0.05 to 2 nm per cycle. Analysis by Fourier transform infrared spectroscopy (FTIR) verified the hybrid character of the films and the presence of two different growth modes. The films were X-ray amorphous as deposited, with the exception of the l-glutamic-TMA system. Surface roughness and topography of the films was investigated by atomic force microscopy (AFM). Optical and surface wetting properties of the films were investigated by UV-Vis spectroscopy and the goniometer method for sessile drops, respectively. All films were stable in contact with water and generally had very low surface roughness. The present work has shown that the ALD technique can offer controlled growth of functionalized hybrid materials. It is likely that specifically chosen functionalized precursors can be employed to obtain specific structural designs and properties. The first sign of this was found for the l-glutamic-TMA system. The diffraction features of the as-deposited films of this system indicate the presence of sheet-like ordering within the material. This is one of the first observations of this kind by ALD. PMID:24424246

  8. Ethylene Glycol-Citric Acid-Silica Hybrid Organic-Inorganic Materials Obtained by the Sol-Gel Method

    Microsoft Academic Search

    A. Campero; Judith Cardoso; S. Pacheco

    1997-01-01

    The combination of inorganic polymeric networks with organic molecules leads to hybrid materials. Tetraethoxysilane (TEOS) was used as the precursor for the inorganic component, covalently bonded to ethylene glycol (EG) and citric acid (CA) molecules, whose esterification provides the in situ water for hydrolysis of TEOS. Ethanol was added in various amounts to the TEOS-EG-CA mixtures in order to induce

  9. 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 ?-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. PMID:21644557

  10. 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. PMID:16233018

  11. Stabilization of Nanoscale Quasi-Liquid Interfacial Films in Inorganic Materials: A Review and Critical Assessment

    Microsoft Academic Search

    Jian Luo

    2007-01-01

    Recent observations of three classes of nanometer-thick, disordered, interfacial films in multicomponent inorganic materials are reviewed and critically assessed. The three classes of films are equilibrium-thickness intergranular films (IGFs) in ceramics, their free-surface counterparts, that is, surficial amorphous films (SAFs), and their metallic counterparts. Also briefly reviewed are several related wetting and adsorption phenomena in simpler systems, including premelting in

  12. 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. PMID:16233011

  13. 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.

  14. 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.

  15. High yield production of inorganic graphene-like materials (MoS?, WS?, BN) through liquid exfoliation testing key parameters

    E-print Network

    Pu, Fei, S.B. Massachusetts Institute of Technology

    2012-01-01

    Inorganic graphene-like materials such as molybdenum disulfide (MoS?), tungsten sulfide (WS?), and boron nitride (BN) are known to have electronic properties. When exfoliated into layers and casted onto carbon nanofilms, ...

  16. 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, synthesized in organic solvents, can be transferred effectively into an aqueous medium using an ammonium salt. The nanoparticles remain monodisperse, as characterized by TEM and XRD, as well as superparamagnetic, as determined by SQUID magnetometry. Then when the aqueous maghemite is combined with the biologically-inspired block copolypeptide poly(EG2-L-lys) 100-block-poly(L-asp)30, the nanoparticles assemble into uniform clusters of approximately twenty nanoparticles. These water-soluble, block copolypeptide-nanoparticle structures have been characterized by TEM, SQUID, and XRD. Furthermore, I have shown that it is possible to tag the polypeptides with folate molecules (cell-targeting ligands) to produce magnetic microshells with potential applications in the biological imaging and drug delivery fields.

  17. Growth and assembly of functionalized nanomaterials: Using organic-inorganic polymer hybrid systems

    NASA Astrophysics Data System (ADS)

    Goel, Divya

    Precise positioning of metallic nanostructures on semiconductor surfaces is important for applications such as photovoltaics, metal interconnects, sensing platforms, and many others. The rising cost and complexity with lithographically defined structures demands a parallel fabrication process that enables easy scale up. Surface patterns formed by block copolymers are considered as a promising means to create functional nanoscopic structures needed for the fabrication of miniaturized devices. The integration of polymers with inorganic nano-materials could find widespread applications in scientific research because it provides a strategy to combine the use of polymers as hosts, and the optical, electronic, and catalytic properties of nanoparticles. This thesis explores a technique that employs patterns in block copolymers as a template for the directed self-assembly of the nanocrystals. One area investigated was the preparation of thermally stable nanoparticles that could be intercalated into block copolymers. Nanoparticles of various materials were synthesized in spherical and rod shapes with different aspect ratios. These particles were characterized by optical absorption measurements, scanning electron microscopy, high-resolution transmission electorn microscopy, and fluorescence spectroscopy. Methods were developed to functionalize these nanoparticles with thermally stable surface coatings using emulsion polymerization. A new method to control the size and spatial distribution of vertically aligned carbon nanofibers was developed, by intercalating nickel into a polymer film. Nanofibers were subsequently grown using plasma-enhanced chemical vapor deposition, and the properties of the nanofibers were characterized using TEM and electrochemical methods. The alignment of block copolymers normal to a dielectric thin film was demonstrated using AC electric fields. These studies demonstrated the underlying mechanism by which nanoscopic structure in thin films can be manipulated, without requiring balancing the interfacial energies of the components, by the interplay of effective fields across the block copolymer film as a function of frequency.

  18. 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

  19. Ethylene glycol-citric acid-silica hybrid organic-inorganic materials obtained by the sol-gel method

    Microsoft Academic Search

    A. Campero; Judith Cardoso; S. Pacheco

    1997-01-01

    The combination of inorganic polymeric networks with organic molecules leads to hybrid materials. Tetraethoxysilane (TEOS)\\u000a was used as the precursor for the inorganic component, covalently bonded to ethylene glycol (EG) and citric acid (CA) molecules,\\u000a whose esterification provides the in situ water for hydrolysis of TEOS. Ethanol was added in various amounts to the TEOS-EG-CA\\u000a mixtures in order to induce

  20. PYP-1, inorganic pyrophosphatase, is required for larval development and intestinal function in C. elegans.

    PubMed

    Ko, Kyung Min; Lee, Wonhae; Yu, Jae-Ran; Ahnn, Joohong

    2007-11-27

    Inorganic pyrophosphatase (PPase) catalyzes the hydrolysis of inorganic pyrophosphate (PPi) into phosphate (Pi), which provides a thermodynamic driving force for important biosynthetic reactions. The nematode Caenorhabditis elegans gene C47E12.4 encodes a PPase (PYP-1) which shows 54% amino acid identity with human PPase. PYP-1 exhibits specific enzyme activity and is mainly expressed in the intestinal and nervous system. A null mutant of pyp-1 reveals a developmental arrest at early larval stages and exhibits gross defects in intestinal morphology and function. The larval arrest phenotype was successfully rescued by reintroduction of the pyp-1 gene, suggesting that PYP-1 is required for larval development and intestinal function in C. elegans. PMID:17981157

  1. Self-aligned optical couplings by self-organized waveguides toward luminescent targets in organic/inorganic hybrid materials.

    PubMed

    Yoshimura, Tetsuzo; Iida, Makoto; Nawata, Hideyuki

    2014-06-15

    Self-organization of optical waveguides is observed between two opposed optical fibers placed in a photosensitive organic/inorganic hybrid material, Sunconnect. A luminescent target containing coumarin 481 was deposited onto the edge of one of the two fibers at the core. When a 448-nm write beam was introduced from the other fiber, the write beam and the luminescence from the photoexcited target increased the refractive index of Sunconnect to induce self-focusing. Traces of waveguides were seen to grow from the cores of both fibers and merged into a single self-aligned optical coupling between the fibers. This optical solder functionality enabled increases in both coupling efficiency and tolerance to lateral misalignment of the fibers. PMID:24978520

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

    SciTech Connect

    Manias, Evangelos [Pennsylvania State University; Randall, Clive [Pennsylvania State University; Tomer, Vivek [Pennsylvania State University; Polyzos, Georgios [ORNL

    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.

  3. Nanocrystal-Based Polymer Composites as Novel Functional Materials

    Microsoft Academic Search

    M. Striccoli; M. L. Curri; R. Comparelli

    \\u000a This chapter provides an overall picture of nanocrystal-polymer based composites and describes the key properties of these\\u000a original functional materials, particularly suited for advanced applications in photonic, optoelectronic as well as in sensing.\\u000a Here, we aim at pointing out the relevance of the incorporation of inorganic colloidal nanocrystals with size-dependent properties\\u000a in highly processable polymers. Due to the countless different

  4. a Comparative Study of Laser Cleaning of Archaeological Inorganic Materials with Traditional Methods

    NASA Astrophysics Data System (ADS)

    Imam, Hisham; Elsayed, Khaled; Madkour, Fatma

    2011-06-01

    Ancient artifacts excavated from archaeological site were covered with different soil contaminates and stains which changed their chemical composition and aesthetic appearance. Ancient inorganic materials such as bronze, glass and pottery covered with different contaminates such as corrosion products, soil deposits, organic stains and gray white encrustations. Lasers are currently being tested for a wide range of conservation applications. Since they are highly controllable and can be selectively applied, lasers can be used to achieve more effective and safer cleaning of archaeological artifacts and protect their surface details. In the present work we investigated in a general way the laser cleaning of bronze corrosion products, glass, and pottery by Q-switched Nd:YAG Lasers. The results were compared with conventional methods. The artifact samples were examined by Light Optical Microscope (LOM) and showed no noticeable damage.

  5. Reconstruction strategies for structure solution using precession electron diffraction data from hybrid inorganic-organic framework materials

    Microsoft Academic Search

    E G Bithell; C A Merrill; P A Midgley

    2010-01-01

    Precession electron diffraction has received significant recent attention, and has the potential to complement x-ray structure solution methods in situations where the latter are difficult to apply. Certain materials systems may nevertheless present challenges for solution by electron diffraction, and this is particularly true when the unit cell includes light element components. Drawing specifically on our work with hybrid inorganic-organic

  6. 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.

  7. 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. PMID:11525477

  8. Inorganic nanotubes: One contribution of 12 to a Theme 'Nanotechnology of carbon and related materials'

    Microsoft Academic Search

    Reshef Tenne; C. N. R. Rao

    2004-01-01

    Following the discovery of carbon fullerenes and carbon nanotubes, it was hypothesized that nanoparticles of inorganic compounds with layered (two-dimensional) structure, such as MoS2, will not be stable against folding and form nanotubes and fullerene-like structures: IF. The synthesis of numerous other inorganic nanotubes has been reported in recent years. Various techniques for the synthesis of inorganic nanotubes, including high-temperature

  9. MOST CITED SPANISH (CONDENSED MATTER PHYSICS, PHYSICAL CHEMISTRY, MATERIALS SCIENCE MULTIDISCIPLINARY, APPLIED PHYSICS, INORGANIC CHEMISTRY,

    E-print Network

    . WSXM: A software for scanning probe microscopy and a tool for nanotechnology Horcas, I; Fernandez, R MULTIDISCIPLINARY, APPLIED PHYSICS, INORGANIC CHEMISTRY, NANOSCIENCE AND NANOTECHNOLOGY) ARTICLES 1. The SIESTA

  10. Lanthanide-centered organic-inorganic hybrids through a functionalized aza-crown ether bridge: coordination bonding assembly, microstructure and multicolor luminescence.

    PubMed

    Liu, Jin-Liang; Yan, Bing

    2011-03-01

    This work focuses on the synthesis of a series of chemically bonded lanthanide/inorganic/organic hybrid materials (CE-15-Si-Ln, CE-16-Si-Ln, CE-18-Si-Ln) containing a novel aza-crown ether organic component. The materials show red emission (Ln = Eu), green emission (Ln = Tb) and near-infrared (NIR) luminescence (Ln = Nd). Three functional molecular precursors (denoted as CE-15-Si, CE-16-Si, CE-18-Si) have been synthesized with two or three N-substituted pendant arms containing chelating groups which can not only fulfill the high coordination numbers of Ln(3+) ions but also form an inorganic Si-O-Si network with tetraethoxysilane (TEOS). The resulting amorphous materials exhibit regular uniform microstructures for the organic and the inorganic components which are covalently linked through Si-O bonds via a self-assembly process. These hybrids present strong luminescent intensities in red, green and NIR ranges by embedding selected Ln(3+) ions into the hybrid system, which may lead to potential applications in organic electroluminescence displays, light emitting devices, functional membranes or chemical/biomedical sensors. PMID:21283861

  11. Characterization of the photosensitive response in polysilane-based organic\\/inorganic hybrid materials

    Microsoft Academic Search

    Haripin Chandra

    2007-01-01

    The motivation for the current work stems from a unique application, i.e. the photopatterning of optical functionality in a photosensitive material immediately prior to use. In this case, optical devices such as diffraction gratings and optical interconnects are produced in thin films using integrated photonic sources under relatively uncontrolled environmental conditions. The compatibility of the material photoexcitation mechanism with wavelength

  12. A novel carbon nanotubes/Fe 3O 4 inorganic hybrid material: Synthesis, characterization and microwave electromagnetic properties

    NASA Astrophysics Data System (ADS)

    Zhan, Yingqing; Zhao, Rui; Lei, Yajie; Meng, Fanbin; Zhong, Jiachun; Liu, Xiaobo

    2011-04-01

    Magnetite particles with nanoscale sizes were self-assembled along multiwalled carbon nanotubes through a simple, effective and reproducible solvothermal method. The morphology, composition and phase structure of as-prepared hybrid materials were characterized by scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The results showed that denseness, size and crystallinity of magnetite can be altered by controlling the reaction parameters. Magnetization measurement indicated that both coercivity and saturation magnetization increased linearly with increasing magnetite concentration in the hybrid materials. Electromagnetic properties of the carbon nanotubes/magnetite inorganic hybrid materials were measured at 1?18 GHz. The magnetic loss was caused mainly by ferromagnetic natural resonance, which is in agreement with the Kittel equation. The as-prepared inorganic hybrid materials are believed to have potential applications in the microwave absorbing area.

  13. 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 inputs to broiler litter is a key to controlling NH(3) emissions. PMID:21597054

  14. Designer materials: Retrosynthesis of new inorganic solids, nanomaterials, and thin films with controlled structures and morphologies

    NASA Astrophysics Data System (ADS)

    Schaak, Raymond Edward

    2001-07-01

    Solid-state inorganic chemistry is dominated by high-temperature syntheses. As chemists seek to synthesize new materials with superior properties, subtle structural features become increasingly difficult to control thermodynamically. This thesis presents alternative low-temperature strategies for synthesizing inorganic solids and thin films. Layered perovskite tantalates that exhibit ion exchange were synthesized by direct solid-state reactions, and their proton forms topochemically dehydrate to form A-site defective perovskites. A topochemical reduction reaction was developed to convert layered perovskites into non-defective three-dimensional perovskites. The A-site cations either disorder or remain ordered, depending on the layer charge. The anisotropic morphology of the precursors is retained. Topochemical reduction can also form layered products. CaEu2Ti 2O8, formed by divalent ion exchange of the single-layer phase NaEuTiO4, forms the non-defective double-layer phase Eu 2CaTi2O7 upon reduction in hydrogen. Na2 Ln2Ti3-xMnxO 10 (0 ? x ? 1) was synthesized by direct solid-state reaction, and A2Ln2Ti3-xMn xO10 (A = Li, NH4) and AIIGd 2Ti3-xMnxO10 (AII = Mg, Ca) are formed by ion exchange. Temperature-dependent magnetic susceptibility data suggest that most of the Na2Ln2Ti 3-xMnxO10 phases order magnetically at low temperatures. The single-layer phases KLnTiO4 (Ln = lanthanide), which readily hydrate, were formed by ion exchange of HLnTiO4 in aqueous KOH. Protonated Dion-Jacobson phases exfoliate into nanoscale colloidal sheets upon reaction with tetra(n-butyl)ammonium hydroxide. These sheets self-assemble to form tiled monolayer and multilayer thin films on a polycation-derivatized Si/SiO2 surface. Protonated Ruddlesden-Popper tantalates and titanotantalates exfoliate into nanoscale colloidal sheets, scrolls, and fibers, which can be used as building blocks for perovskite thin films. When we combine the low-temperature reactions of perovskites that have been developed in the past few years, a powerful toolbox of solid-state reactions emerges. Using this toolbox, we can retrosynthetically synthesize a wide range of new layered and three-dimensional perovskites with controlled structures and morphologies. Colloidal crystals are large-scale analogues of inorganic crystals, and they have interesting applications as photonic materials. We proposed two retrosynthetic approaches for synthesizing new colloidal crystals with controlled structures and morphologies. A layer-by-layer approach was studied for assembling colloidal crystals with non-close-packed structures. A lithographic approach was studied for forming controlled defects in colloidal crystal waveguides.

  15. 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 synthesized and characterized, and the material is found to be a high MW, soluble blue emitter which shows a higher glass transition temperature and greater stability than a non-hybrid polymer. UV absorbance and fluorescence spectroscopy indicated some electronic interaction between the conjugated polymer and the cages, but they did not appear to be fully conjugated in the traditional sense. Chapter 4 describes the design, synthesis, and characterization of poly(fluorene) with o-carborane in the backbone. Profound changes in the behavior of the polymer, from its polymerization behavior to its emission characteristics, were observed and their origins are discussed. Experiments to explore the nature of the cage/polymer interactions were performed and possible applications which take advantage of the unique nature of the o-carborane hybrid polymer are explored and discussed. Hybrid conjugated polymer materials via grafting approaches to surfaces and surface modification are discussed starting in chapter 5. The synthesis of a dibromofluorene-based silane coupling agent for the surface functionalization of oxide surfaces is presented, and the surface directed Ni(0) dehalogenative polymerization of poly(dihexylfluorene) is explored. Chapter 6 focuses on the exploration of conjugated polymer/cellulose hybrid materials. Surface medication of cellulose materials with monomer-like anchor points is discussed. Grafting of the modified cellulose with conjugated polymers was explored and the grafting of three different repeat structures based on fluorene-, fluorenevinylene-, and fluoreneethynylene motifs were optimized to provide a general route to cellulose/conjugated polymer hybrid materials. Characterization and possible applications of such hybrid materials are discussed. Finally, chapter 7 is devoted to the simultaneous surface patterning and functionalization of poly(2-hydroxyethylmethacrylate) thin films using a silane infusion-based wrinkling technique. While not a conjugated polymer system, the spontaneous patterning and functionalization methods explored in this chapter prod

  16. 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.

  17. 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

  18. Structure and magnetic properties of SiO2/PCL novel sol-gel organic-inorganic hybrid materials

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    Organic-inorganic nanocomposite materials have been synthesized via sol-gel. They consist of an inorganic SiO2 matrix, in which different percentages of poly(?-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 SiO2/PCL hybrid materials are diamagnetic and that their diamagnetic susceptibility is independent of temperature and increases with the PCL amount.

  19. 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...

  20. 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.

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

    SciTech Connect

    Huang Jing [College of Chemistry and Chemical Engineering Southwest University, Research Institute of Applied Chemistry Southwest University, Key Laboratory of Applied Chemistry of Chongqing Municipality, Key Laboratory of Eco-environments in Three Gorges Reservoir Region Ministry of Education, Chongqing 400715 (China); Fu Xiangkai, E-mail: fxk@swu.edu.cn [College of Chemistry and Chemical Engineering Southwest University, Research Institute of Applied Chemistry Southwest University, Key Laboratory of Applied Chemistry of Chongqing Municipality, Key Laboratory of Eco-environments in Three Gorges Reservoir Region Ministry of Education, Chongqing 400715 (China); Wang Gang; Miao Qiang [College of Chemistry and Chemical Engineering Southwest University, Research Institute of Applied Chemistry Southwest University, Key Laboratory of Applied Chemistry of Chongqing Municipality, Key Laboratory of Eco-environments in Three Gorges Reservoir Region Ministry of Education, Chongqing 400715 (China)

    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.

  2. Removal of Radioactive Nuclides by Multi-Functional Microcapsules Enclosing Inorganic Ion-Exchangers and Organic Extractants

    SciTech Connect

    Mimura, H.; Akiba, K.; Onodera, Y.

    2002-02-26

    The microcapsules enclosing two kinds of functional materials, inorganic ion-exchangers and organic extractants, were prepared by taking advantage of the high immobilization ability of alginate gel polymer. The fine powders of inorganic ion-exchanger and oil drops of extractant were kneaded with sodium alginate (NaALG) solution and the kneaded sol readily gelled in a salt solution of CaCl2, BaCl2 or HCl to form spherical gel particles. The uptake properties of various nuclides, 137Cs, 85Sr, 60Co, 88Y, 152Eu and 241Am, for thirty-four specimens of microcapsules in the presence of 10-1-10-4 M HNO3 were evaluated by the batch method. The distribution coefficient (Kd) of Cs+ above 103 cm3/g was obtained for the microcapsules enclosing CuFC or AMP. The Kd of Sr2+ around 102 cm3/g was obtained for the microcapsules containing clinoptilolite, antimonic acid, zeolite A, zeolite X or titanic acid. The microcapsules enclosing DEHPA exhibited relatively large Kd values of trivalent metal ions above 103 cm3/g; for example, the Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ for a favorable microcapsule (CuFC/clinoptilolite/DEHPA/CaALG) were 1.1x104, 7.5x10, 1.1x10, 1.0x104, 1.4x104, 3.4x103 cm3/g, respectively. The uptake rates of Cs+, Y3+, Eu3+ and Am3+ for this microcapsule were rather fast; the uptake percentage above 90% was obtained after 19 h-shaking and the uptake equilibrium was attained within 1 d. The AMP/CaALG exhibited high uptake ability for Cs+ even after irradiation of 188 kGy, and DEHPA/CaALG microcapsule had similar Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ ions before and after irradiation. The microcapsules with various shapes such as spherical, columnar, fibrous and filmy forms were easily prepared by changing the way of dipping kneaded sol into gelling salt solution. The microcapsules enclosing inorganic ion-exchangers and extractants have a potential possibility for the simultaneous removal of various radioactive nuclides from waste solutions.

  3. 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) synthesized inclusions are large and uniform, and they are able to tolerate high internal P; (4) it is suitable for the study of organic material; and (5) redox control is possible due to high permeability of the fused silica to hydrogen.

  4. Reconstruction strategies for structure solution using precession electron diffraction data from hybrid inorganic-organic framework materials

    NASA Astrophysics Data System (ADS)

    Bithell, E. G.; Merrill, C. A.; Midgley, P. A.

    2010-07-01

    Precession electron diffraction has received significant recent attention, and has the potential to complement x-ray structure solution methods in situations where the latter are difficult to apply. Certain materials systems may nevertheless present challenges for solution by electron diffraction, and this is particularly true when the unit cell includes light element components. Drawing specifically on our work with hybrid inorganic-organic framework materials, we describe recent approaches to reconstructing their crystal potentials, which have led to significant improvements in the accuracy and quality of the derived potential maps for this type of structure.

  5. SNL-1, a highly selective inorganic crystalline ion exchange material for Sr{sup 2+} in acidic solutions

    SciTech Connect

    Nenoff, T.M.; Thoma, S.G.; Miller, J.E.; Trudell, D.E.

    1995-11-01

    A new inorganic ion exchange material, called SNL-1, has been prepared at Sandia National Laboratories. Developmental samples of SNL-1 have been determined to have high selectivity for the adsorption of Strontium from highly acidic solutions (1 M HNO{sub 3}). This paper presents results obtained for the material in batch ion exchange tests conducted at various solution pH values and in the presence of a number of competing cations. Results from a continuous flow column ion exchange experiment are also presented.

  6. Photoactive hybrids with the functionalized Schiff-base derivatives covalently bonded inorganic silica network: Sol–gel synthesis, characterization and photoluminescence

    Microsoft Academic Search

    Jin-Liang Liu; Shuai Xu; Bing Yan

    2011-01-01

    Three novel silica-based organic–inorganic hybrid materials containing the different Schiff-base organic compounds have been prepared through a covalent bonding self-assembly process via a sol–gel technology. The organic parts N,N?-bis(salicylidene)-1,3-propanediamine, N,N?-bis(salicylidene)-thiocarbohydrazide, and N,N?N??-tris(salicylidene)-(2-aminoethyl) amine are firstly synthesized and then functionalized by trialkoxysilyl groups through the hydrogen transfer reaction. The as-obtained silylated precursors are afterward submitted to hybridization with tetraethoxysilane (TEOS) through

  7. Blood Pressure, Left Ventricular Geometry, and Systolic Function in Children Exposed to Inorganic Arsenic

    PubMed Central

    Osorio-Yáñez, Citlalli; Ayllon-Vergara, Julio C.; Arreola-Mendoza, Laura; Aguilar-Madrid, Guadalupe; Hernández-Castellanos, Erika; Sánchez-Peña, Luz C.

    2015-01-01

    Background: Inorganic arsenic (iAs) is a ubiquitous element present in the groundwater worldwide. Cardiovascular effects related to iAs exposure have been studied extensively in adult populations. Few epidemiological studies have been focused on iAs exposure–related cardiovascular disease in children. Objective: In this study we investigated the association between iAs exposure, blood pressure (BP), and functional and anatomical echocardiographic parameters in children. Methods: A cross-sectional study of 161 children between 3 and 8 years was conducted in Central Mexico. The total concentration of arsenic (As) species in urine (U-tAs) was determined by hydride generation–cryotrapping–atomic absorption spectrometry and lifetime iAs exposure was estimated by multiplying As concentrations measured in drinking water by the duration of water consumption in years (LAsE). BP was measured by standard protocols, and M-mode echocardiographic parameters were determined by ultrasonography. Results: U-tAs concentration and LAsE were significantly associated with diastolic (DBP) and systolic blood pressure (SBP) in multivariable linear regression models: DBP and SBP were 0.013 (95% CI: 0.002, 0.024) and 0.021 (95% CI: 0.004, 0.037) mmHg higher in association with each 1-ng/mL increase in U-tAs (p < 0.025), respectively. Left ventricular mass (LVM) was significantly associated with LAsE [5.5 g higher (95% CI: 0.65, 10.26) in children with LAsE > 620 compared with < 382 ?g/L-year; p = 0.03] in an adjusted multivariable model. The systolic function parameters left ventricular ejection fraction (EF) and shortening fraction were 3.67% (95% CI: –7.14, –0.20) and 3.41% (95% CI: –6.44, –0.37) lower, respectively, in children with U-tAs > 70 ng/mL compared with < 35 ng/mL. Conclusion: Early-life exposure to iAs was significantly associated with higher BP and LVM and with lower EF in our study population of Mexican children. Citation: Osorio-Yáñez C, Ayllon-Vergara JC, Arreola-Mendoza L, Aguilar-Madrid G, Hernández-Castellanos E, Sánchez-Peña LC, Del Razo LM. 2015. Blood pressure, left ventricular geometry, and systolic function in children exposed to inorganic arsenic. Environ Health Perspect 123:629–635;?http://dx.doi.org/10.1289/ehp.1307327 PMID:25738397

  8. Expression activation and functional analysis of HLA3, a putative inorganic carbon transporter in Chlamydomonas reinhardtii.

    PubMed

    Gao, Han; Wang, Yingjun; Fei, Xiaowen; Wright, David A; Spalding, Martin H

    2015-04-01

    The CO2 concentrating mechanism (CCM) is a key component of the carbon assimilation strategy of aquatic microalgae. Induced by limiting CO2 and tightly regulated, the CCM enables these microalgae to respond rapidly to varying environmental CO2 supplies and to perform photosynthetic CO2 assimilation in a cost-effective way. A functional CCM in eukaryotic algae requires Rubisco sequestration, rapid interconversion between CO2 and HCO3(-) catalyzed by carbonic anhydrases (CAs), and active inorganic carbon (Ci) uptake. In the model microalga Chlamydomonas reinhardtii, a membrane protein HLA3 is proposed to be involved in active Ci uptake across the plasma membrane. In this study, we use an artificially designed transcription activator-like effector (dTALE) to activate the expression of HLA3. The successful activation of HLA3 expression demonstrates dTALE as a promising tool for gene-specific activation and investigation of gene function in Chlamydomonas. Activation of HLA3 expression in high CO2 acclimated cells, where HLA3 is not expressed, resulted in increased Ci accumulation and Ci-dependent photosynthetic O2 evolution specifically in very low CO2 concentrations, which confirms that HLA3 is indeed involved in Ci uptake, and suggests it is mainly associated with HCO3(-) transport in very low CO2 concentrations, conditions in which active CO2 uptake is highly limited. PMID:25660294

  9. The characteristics of inorganic electroluminescent devices with an amorphous diamond film as cathode material

    Microsoft Academic Search

    Sea-Fue Wang; Jui-Chen Pu; James C. Sung

    2009-01-01

    Diamond like carbon (DLC) thin films were used as the cathode layers of inorganic alternating current driven thick dielectric electroluminescent devices. The results indicated that electroluminescent (EL) devices with DLC cathode has superior brightness over the EL with Al or Cr-doped DLC cathodes. Cr-doping in DLC thin film can increase the electrical conductivity, but degrades the EL properties. Also, the

  10. Mn-Substituted Inorganic-Organic Hybrid Materials Based on ZnSe

    E-print Network

    Li, Jing

    ". These hybrid nanostructures possess magnetically active periodic crystalline structures, which exhibit large, magnetic, and optical properties, rigidity, and thermal stability of inorganic frame- works lattices.5,6 The insulating organic layers impose a strong quantum confine- ment on the semiconductor

  11. 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), ?-quartz (?-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.

  12. UTILIZATION OF ALUMINA RED MUD FOR SYNTHESIS OF INORGANIC POLYMERIC MATERIALS

    Microsoft Academic Search

    Dimitrios D. Dimas; Ioanna P. Giannopoulou; Dimitrios Panias

    2009-01-01

    Red mud is a residue coming from the metallurgical treatment of bauxite with the Bayer process. Million of tons of red mud are produced annually worldwide and disposed of on land, degrading vast areas. Therefore, red mud utilization is a first-priority issue for any alumina plant. In the present work, the potential use of red mud for synthesis of inorganic

  13. Organic-inorganic electronics

    Microsoft Academic Search

    David B. Mitzi; Konstantinos Chondroudis; Cherie R. Kagan

    2001-01-01

    Organic-inorganic hybrid materials enable the integration of useful organic and inorganic characteristics within a single molecular-scale composite. Unique electronic and optical properties have been observed, and many others can be envisioned for this promising class of materials. In this paper, we review the crystal structures and physical properties of one family of crystalline, self-assembling, organic-inorganic hybrids based on the layered

  14. Reflectance Function Approximation for Material Classification

    E-print Network

    Dyer, Charles R.

    Reflectance Function Approximation for Material Classification Edward Wild CS 766 Final Project Report Abstract Reflectance functions are approximated from data using kernel re- gression and used results show that some reflectance functions can be approximated quite accurately with kernel regression

  15. Synchrotron X-ray diffraction studies of inorganic materials and heterogeneous catalysts

    Microsoft Academic Search

    J. M. Newsam; K. S. Liang

    1989-01-01

    The special features of synchrotron X-radiation and the types of instrumentation required for a range of synchrotron X-ray diffraction experiments are outlined. A diverse range of applications to inorganic and heterogeneous catalyst systems are discussed. Grazing incidence X-ray diffraction experiments have revealed a number of surface structures and followed surface phase transformations; similar studies of boundary and interfacial structures are

  16. Synthesis and properties of soft nanocomposite materials with novel organic\\/inorganic network structures

    Microsoft Academic Search

    Kazutoshi Haraguchi

    2011-01-01

    We have fabricated new types of polymer hydrogels and polymer nanocomposites, that is, nanocomposite gels (NC gels) and soft polymer nanocomposites (M-NCs), with novel organic\\/inorganic network structures. Both NC gels and M-NCs were synthesized by in situ free-radical polymerization in the presence of exfoliated clay platelets in aqueous systems and were obtained in various forms and sizes with a wide

  17. Protonic conducting properties of sol-gel derived organic\\/inorganic nanocomposite membranes doped with acidic functional molecules

    Microsoft Academic Search

    I. Honma; Y. Takeda; J. M. Bae

    1999-01-01

    High temperature protonic conducting polymer membranes provide new technological applications in electrochemical devices including electrochromic displays, chemical sensors, fuel cells and others. Organic\\/inorganic nanocomposite membranes consisting of SiO2\\/PEO (polyethylene oxides) hybrids are a remarkable family of isotropic, flexible, amorphous polymer materials, which have been synthesized through sol-gel processes. The hybrid membrane doped with acidic moieties such as monododecylphosphate or phosphotungstic

  18. 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 [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry, Northwest University, Xi'an 710069 (China); Xue Ganglin, E-mail: xglin707@163.co [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry, Northwest University, Xi'an 710069 (China); Fu Feng; Wang Jiwu [Department of Chemistry, Yanan University, Yan'an 716000 (China)

    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

  19. Fractal Geometric Characterization of Functionally Graded Materials

    E-print Network

    Ostoja-Starzewski, Martin

    Fractal Geometric Characterization of Functionally Graded Materials A. Saharan1 ; M. Ostoja graded materials (FGM) is studied from the standpoint of fractal geometry. First, upon introducing fractals, and an interfacial fractal dimension is estimated for varying degrees of fineness. Avariation

  20. Distribution of inorganic mercury in Sacramento River water and suspended colloidal sediment material.

    PubMed

    Roth, D A; Taylor, H E; Domagalski, J; Dileanis, P; Peart, D B; Antweiler, R C; Alpers, C N

    2001-02-01

    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 microm 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 river between Bend Bridge and Colusa. Analysis of temporal variations showed that Hg loading was positively correlated to discharge. PMID:11243317

  1. 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.

  2. 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.

  3. MATERIALS AEROMETRIC DATABASE FOR USE IN DEVELOPING MATERIALS DAMAGE FUNCTION

    EPA Science Inventory

    Meteorological and air quality data acquired at field exposure sites have been accumulated into the Materials Aerometric Database (MAD). Task Group VII of the National Acid Precipitation Assessment Program (NAPAP) will use the MAD to develop damage functions for materials exposed...

  4. Development of hybrid organic-inorganic surface imprinted Mn-doped ZnS QDs and their application as a sensing material for target proteins.

    PubMed

    Tan, Lei; Huang, Cong; Peng, Rongfei; Tang, Youwen; Li, Weiming

    2014-11-15

    Applying molecular imprinting techniques to the surface of functionalized quantum dots (QDs) allows the preparation of molecularly imprinted polymers (MIPs) with accessible, surface exposed binding sites and excellent optical properties. This paper demonstrates a new strategy for producing such hybrid organic-inorganic imprinted Mn-doped ZnS QDs for specific recognition of bovine hemoglobin. The technique provides surface grafting imprinting in aqueous solutions using amino modified Mn-doped ZnS QDs as supports, acrylamide and methacrylic acid as functional monomers, ?-methacryloxypropyl trimethoxy silane as the grafting agent, and bovine hemoglobin as a template. The amino propyl functional monomer layer directs the selective occurrence of imprinting polymerization at the QDs surface through copolymerization of grafting agents with functional monomers, but also acts as an assistive monomer to drive the template into the formed polymer shells to create effective recognition sites. Using MIP-QDs composites as a fluorescence sensing material, trace amounts of bovine hemoglobin are signaled with high selectivity by emission intensity changes of Mn-doped ZnS QDs, which is embedded into the imprinted polymers. PMID:24951920

  5. Assembly of one dimensional inorganic nanostructures into functional 2D and 3D architectures. Synthesis, arrangement and functionality.

    PubMed

    Joshi, Ravi K; Schneider, Jörg J

    2012-08-01

    This review will focus on the synthesis, arrangement, structural assembly, for current and future applications, of 1D nanomaterials (tubes, wires, rods) in 2D and 3D ordered arrangements. The ability to synthesize and arrange one dimensional nanomaterials into ordered 2D or 3D micro or macro sized structures is of utmost importance in developing new devices and applications of these materials. Micro and macro sized architectures based on such 1D nanomaterials (e.g. tubes, wires, rods) provide a platform to integrate nanostructures at a larger and thus manageable scale into high performance electronic devices like field effect transistors, as chemo- and biosensors, catalysts, or in energy material applications. Carbon based, metal oxide and metal based 1D arranged materials as well as hybrid or composite 1D materials of the latter provide a broad materials platform, offering a perspective for new entries into fascinating structures and future applications of such assembled architectures. These architectures allow bridging the gap between 1D nanostructures and the micro and macro world and are the basis for an assembly of 1D materials into higher hierarchy domains. This critical review is intended to provide an interesting starting point to view the current state of the art and show perspectives for future developments in this field. The emphasis is on selected nanomaterials and the possibilities for building three dimensional arrays starting from one dimensional building blocks. Carbon nanotubes, metal oxide nanotubes and nanowires (e.g. ZnO, TiO(2), V(2)O(5), Cu(2)O, NiO, Fe(2)O(3)), silicon and germanium nanowires, and group III-V or II-VI based 1D semiconductor nanostructures like GaS and GaN, pure metals as well as 1D hybrid materials and their higher organized architectures (foremost in 3D) will be focussed. These materials have been the most intensively studied within the last 5-10 years with respect to nano-micro integration aspects and their functional and application oriented properties. The critical review should be interesting for a broader scientific community (chemists, physicists, material scientists) interested in synthetic and functional material aspects of 1D materials as well as their integration into next higher organized architectures. PMID:22722888

  6. Influence of image charge effect on exciton fine structure in an organic-inorganic quantum well material

    SciTech Connect

    Takagi, Hidetsugu; Kunugita, Hideyuki; Ema, Kazuhiro [Department of Physics, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554 (Japan); Sato, Mikio; Takeoka, Yuko [Department of Materials and Life Sciences, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554 (Japan)

    2013-12-04

    We have investigated experimentally excitonic properties in organic-inorganic hybrid multi quantum well crystals, (C{sub 4}H{sub 9}NH{sub 3}){sub 2}PbBr{sub 4} and (C{sub 6}H{sub 5}?C{sub 2}H{sub 4}NH{sub 3}){sub 2}PbBr{sub 4}, by measuring photoluminescence, reflectance, photoluminescence excitation spectra. In these materials, the excitonic binding energies are enhanced not only by quantum confinement effect (QCE) but also by image charge effect (ICE), since the dielectric constant of the barrier layers is much smaller than that of the well layers. By comparing the 1s-exciton and 2s-exciton energies, we have investigated the influence of ICE with regard to the difference of the Bohr radius.

  7. Boundary Element Methods for Functionally Graded Materials

    NSDL National Science Digital Library

    Paulino, Glaucio

    2002-05-28

    Functionally graded materials (FGMs) possess a smooth variation of material properties due to continuous change in microstructural details. For example, the material gradation may change gradually from a pure ceramic to a pure metal. This work focuses on potential (both steady state and transient) and elasticity problems for inhomogeneous materials. The Green\\'s function(GF) for these materials (e.g. exponentially graded) are expressed as the GF for the homogeneous material plus additional terms due to material gradation. The numerical implementations are performed using a Galerkin (rather than collocation) approximation. A number of examples have been carried out. The results of some specific test problems agree within plotting accuracy with available analytical solutions.

  8. Electron microscopy localization and characterization of functionalized composite organic-inorganic SERS nanoparticles on leukemia cells

    Microsoft Academic Search

    Ai Leen Koh; Catherine M. Shachaf; Sailaja Elchuri; Garry P. Nolan; Robert Sinclair

    2008-01-01

    We demonstrate the use of electron microscopy as a powerful characterization tool to identify and locate antibody-conjugated composite organic-inorganic nanoparticle (COINs) surface enhanced Raman scattering (SERS) nanoparticles on cells. U937 leukemia cells labeled with antibody CD54-conjugated COINs were characterized in their native, hydrated state using wet scanning electron microscopy (SEM) and in their dehydrated state using high-resolution SEM. In both

  9. The freshwater tidal wetland Liberty Island, CA was both a source and sink of inorganic and organic material to the San Francisco Estuary

    Microsoft Academic Search

    P. W. LehmanS; S. Mayr; L. Mecum; C. Enright

    2010-01-01

    It is hypothesized that perennial freshwater tidal wetland habitat exports inorganic and organic material needed to support\\u000a the estuarine food web and to create favorable habitat for aquatic organisms in San Francisco Estuary. It is also hypothesized\\u000a that most of the material flux in this river-dominated region is controlled by river flow. The production and export of material\\u000a by Liberty

  10. An Effective Way to Optimize the Functionality of Graphene-Based Nanocomposite: Use of the Colloidal Mixture of Graphene and Inorganic Nanosheets.

    PubMed

    Jin, Xiaoyan; Adpakpang, Kanyaporn; Young Kim, In; Mi Oh, Seung; Lee, Nam-Suk; Hwang, Seong-Ju

    2015-01-01

    The best electrode performance of metal oxide-graphene nanocomposite material for lithium secondary batteries can be achieved by using the colloidal mixture of layered CoO2 and graphene nanosheets as a precursor. The intervention of layered CoO2 nanosheets in-between graphene nanosheets is fairly effective in optimizing the pore and composite structures of the Co3O4-graphene nanocomposite and also in enhancing its electrochemical activity via the depression of interaction between graphene nanosheets. The resulting CoO2 nanosheet-incorporated nanocomposites show much greater discharge capacity of ~1750 mAhg(-1) with better cyclability and rate characteristics than does CoO2-free Co3O4-graphene nanocomposite (~1100?mAhg(-1)). The huge discharge capacity of the present nanocomposite is the largest one among the reported data of cobalt oxide-graphene nanocomposite. Such a remarkable enhancement of electrode performance upon the addition of inorganic nanosheet is also observed for Mn3O4-graphene nanocomposite. The improvement of electrode performance upon the incorporation of inorganic nanosheet is attributable to an improved Li(+) ion diffusion, an enhanced mixing between metal oxide and graphene, and the prevention of electrode agglomeration. The present experimental findings underscore an efficient and universal role of the colloidal mixture of graphene and redoxable metal oxide nanosheets as a precursor for improving the electrode functionality of graphene-based nanocomposites. PMID:26053331

  11. 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. ore material collected from a shallow sand and gravel aquifer was used as the immobile column matrix material. ariables in the study included flow rate, pH, ioni...

  12. Terahertz and infrared transmission of an organic/inorganic hybrid thermoelectric material

    SciTech Connect

    Heyman, J. N., E-mail: heyman@macalester.edu; Alebachew, B. A.; Kaminski, Z. S.; Nguyen, M. D. [Physics Department, Macalester College, St. Paul, Minnesota 55105 (United States); Coates, N. E.; Urban, J. J. [The Molecular Foundry, Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    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. Organic-inorganic composite materials: optical properties of laser-patterned and protective-coated waveguides

    NASA Astrophysics Data System (ADS)

    Krug, Herbert; Tiefensee, Frank; Oliveira, Peter W.; Schmidt, Helmut K.

    1992-12-01

    A composite materials based on organically modified Si alkoxides and modified alkoxides from Zr were prepared. The index of refraction of the system was tailored by the variation of the modified Zr component. Channel waveguides were prepared by a laserwriting technique based on the ability to photopolymerize this material. To decrease optical loss caused by effects of the waveguide surface and to be independent of the used substrate, a buffer layer and a protective layer of the same material of lower index of refraction was combined with a waveguiding film and optical losses were determined.

  14. Environmental degradation using functionally graded material approach

    E-print Network

    Sevostianov, Igor

    Environmental degradation using functionally graded material approach I. Sevostianov a,*, N to manufacture aircraft components. Dexter found that the damage or degradation depended on the type of material, Durban 4041, South Africa Abstract Attempts to model the degradation of polymer composites have been

  15. Inorganic salts of biguanide Searching for new materials for second harmonic generation

    NASA Astrophysics Data System (ADS)

    Matulková, Irena; N?mec, Ivan; Císa?ová, Ivana; N?mec, Petr; Mi?ka, Zden?k

    2008-08-01

    Five inorganic salts of biguanide with carbonic, nitric, phosphoric and phosphorous acids were prepared and X-ray structural analysis has been performed for three novel compounds. Biguanidium(1+) phosphite trihydrate crystallizes in the triclinic space group P1¯, a = 7.1470(1) Å, b = 9.6530(2) Å, c = 11.3140(2) Å, ? = 70.094(1)°, ? = 75.688(1)°, ? = 86.099(1)°, V = 713.71(2) Å 3, Z = 2, R = 0.0350 for 3031 observed reflections. The crystal structure is based on a network of phosphite anions and water molecules. Biguanidium(1+) cations form pairs through two intermolecular hydrogen bonds of the N-H…N type and fill the network with anions and water molecules. Biguanidium(2+) phosphite monohydrate crystallizes in the triclinic space group P1¯, a = 6.9690(2) Å, b = 7.3500(3) Å, c = 8.1730(3) Å, ? = 82.518(2)°, ? = 83.015(2)°, ? = 82.811(2)°, V = 409.44(3) Å 3, Z = 2, R = 0.0308 for 1779 observed reflections. The structure is formed of a network of alternating biguanidium(2+) cations, phosphite anions and pairs of water molecules interconnected by a system of intermolecular hydrogen bonds. Biguanidium(2+) hydrogen phosphate monohydrate crystallizes in the triclinic space group P1¯, a = 7.0630(2) Å, b = 7.8740(3) Å, c = 8.1120(3) Å, ? = 102.706(2)°, ? = 104.976(2)°, ? = 92.632(3)°, V = 422.61(3) Å 3, Z = 2, R = 0.0337 for 1827 observed reflections. The crystal structure is formed by pairs of anions that are mutually connected in chains through two water molecules. These chains are interconnected by biguanidium(2+) cations to form a three-dimensional network. The FTIR and FT Raman spectra of all five compounds were recorded, calculated (HF, B3LYP and MP2 methods) and discussed. Quantitative measurements of second harmonic generation of powdered biguanidium(2+) nitrate and novel biguanidium(2+) carbonate monohydrate at 800 nm were performed and a relative efficiency (compared to KDP) of 87% and 20% was observed, respectively.

  16. Hybrid inorganic-organic materials with an optoelectronically active aromatic cation: (C7H7)2SnI6 and C7H7PbI3.

    PubMed

    Maughan, Annalise E; Kurzman, Joshua A; Neilson, James R

    2015-01-01

    Inorganic materials with organic constituents-hybrid materials-have shown incredible promise as chemically tunable functional materials with interesting optical and electronic properties. Here, the preparation and structure are reported of two hybrid materials containing the optoelectronically active tropylium ion within tin- and lead-iodide inorganic frameworks with distinct topologies. The crystal structures of tropylium tin iodide, (C7H7)2SnI6, and tropylium lead iodide, C7H7PbI3, were solved using high-resolution synchrotron powder X-ray diffraction informed by X-ray pair distribution function data and high-resolution time-of-flight neutron diffraction. Tropylium tin iodide contains isolated tin(IV)-iodide octahedra and crystallizes as a deep black solid, while tropylium lead iodide presents one-dimensional chains of face-sharing lead(II)-iodide octahedra and crystallizes as a bright red-orange powder. Experimental diffuse reflectance spectra are in good agreement with density functional calculations of the electronic structure. Calculations of the band decomposed charge densities suggest that the deep black color of tropylium tin iodide is attributed to iodide ligand to tin metal charge transfer, while the bright red-orange color of tropylium lead iodide arises from charge transfer between iodine and tropylium states. Understanding the origins of the observed optoelectronic properties of these two compounds, with respect to their distinct topologies and organic-inorganic interactions, provides insight into the design of tropylium-containing compounds for potential optical and electronic applications. PMID:25522913

  17. Continuous spray forming of functionally gradient materials

    SciTech Connect

    McKechnie, T.N.; Richardson, E.H.

    1995-12-01

    Researchers at Plasma Processes Inc. have produced a Functional Gradient Material (FGM) through advanced vacuum plasma spray processing for high heat flux applications. Outlined in this paper are the manufacturing methods used to develop a four component functional gradient material of copper, tungsten, boron, and boron nitride. The FGM was formed with continuous gradients and integral cooling channels eliminating bondlines and providing direct heat transfer from the high temperature exposed surface to a cooling medium. Metallurgical and x-ray diffraction analyses of the materials formed through innovative VPS (vacuum plasma spray) processing are also presented. Applications for this functional gradient structural material range from fusion reactor plasma facing components to missile nose cones to boilers.

  18. 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

  19. 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

    2015-01-01

    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

  20. Porous materials. Function-led design of new porous materials.

    PubMed

    Slater, Anna G; Cooper, Andrew I

    2015-05-29

    Porous solids are important as membranes, adsorbents, catalysts, and in other chemical applications. But for these materials to find greater use at an industrial scale, it is necessary to optimize multiple functions in addition to pore structure and surface area, such as stability, sorption kinetics, processability, mechanical properties, and thermal properties. Several different classes of porous solids exist, and there is no one-size-fits-all solution; it can therefore be challenging to choose the right type of porous material for a given job. Computational prediction of structure and properties has growing potential to complement experiment to identify the best porous materials for specific applications. PMID:26023142

  1. Improved electronic coupling in hybrid organic-inorganic nanocomposites employing thiol-functionalized P3HT and bismuth sulfide nanocrystals

    NASA Astrophysics Data System (ADS)

    Martinez, L.; Higuchi, S.; MacLachlan, A. J.; Stavrinadis, A.; Miller, N. C.; Diedenhofen, S. L.; Bernechea, M.; Sweetnam, S.; Nelson, J.; Haque, S. A.; Tajima, K.; Konstantatos, G.

    2014-08-01

    In this study, we employ a thiol-functionalized polymer (P3HT-SH) as a leverage to tailor the nanomorphology and electronic coupling in polymer-nanocrystal composites for hybrid solar cells. The presence of the thiol functional group allows for a highly crystalline semiconducting polymer film at low thiol content and allows for improved nanomorphologies in hybrid organic-inorganic systems when employing non-toxic bismuth sulfide nanocrystals. The exciton dissociation efficiency and carrier dynamics at this hybrid heterojunction are investigated through photoluminescence quenching and transient absorption spectroscopy measurements, revealing a larger degree of polaron formation when P3HT-SH is employed, suggesting an increased electronic interaction between the metal chalcogenide nanocrystals and the thiol-functionalized P3HT. The fabricated photovoltaic devices show 15% higher power conversion efficiencies as a result of the improved nanomorphology and better charge transfer mechanism together with the higher open circuit voltages arising from the deeper energy levels of P3HT-SH.In this study, we employ a thiol-functionalized polymer (P3HT-SH) as a leverage to tailor the nanomorphology and electronic coupling in polymer-nanocrystal composites for hybrid solar cells. The presence of the thiol functional group allows for a highly crystalline semiconducting polymer film at low thiol content and allows for improved nanomorphologies in hybrid organic-inorganic systems when employing non-toxic bismuth sulfide nanocrystals. The exciton dissociation efficiency and carrier dynamics at this hybrid heterojunction are investigated through photoluminescence quenching and transient absorption spectroscopy measurements, revealing a larger degree of polaron formation when P3HT-SH is employed, suggesting an increased electronic interaction between the metal chalcogenide nanocrystals and the thiol-functionalized P3HT. The fabricated photovoltaic devices show 15% higher power conversion efficiencies as a result of the improved nanomorphology and better charge transfer mechanism together with the higher open circuit voltages arising from the deeper energy levels of P3HT-SH. Electronic supplementary information (ESI) available: 1H NMR images of P3HT-SH, transient absorption spectra measurements of P3HT and P3HT-SH, photoelectron spectroscopy and hole mobility studies of P3HT and P3HT-SH and optimization of the hybrid organic-inorganic solar cells. See DOI: 10.1039/c4nr01679c

  2. Inorganic adsorber material for off-gas cleaning in fuel reprocessing plants

    Microsoft Academic Search

    J. G. Wilhelm; H. Schuettelkopf; M. W. First

    1973-01-01

    USA (28 Aug 1972). impregnated, amorphous silicic acid was developed for ; use in off-gas cleaning systems of fuel reprocessing plants. Extensive ; experimental work was performed to evaluate the removal efficiency of this ; material from off-gas containing NOâ for elemental iodine and methyl iodide. ; Experimental data are given on the influence exerted by relative humidity ; temperature,

  3. 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.

  4. Structural characterization of the organic\\/inorganic networks in the hybrid material (TMOS–TMSM–MMA)

    Microsoft Academic Search

    Z. Sassi; J. C. Bureau; A. Bakkali

    2002-01-01

    Using a sol–gel process, we had previously investigated the reaction mechanisms (hydrolysis and condensation of alkoxysilan monomers, polymerization of methacrylate groups) allowing to give a specific hybrid material (tetramethylorthosilicate (TMOS)–3(trimethoxysilyl)propyl methacrylate (TMSM)–methylmethacrylate (MMA)). The superimposition and the competition of the chemical reactions lead to a system where reactions are generally not fully completed. The formed networks in each of the

  5. 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.

  6. Fracture Analysis of Functionally Graded Materials

    NASA Astrophysics Data System (ADS)

    Zhang, Ch.; Gao, X. W.; Sladek, J.; Sladek, V.

    2010-05-01

    This paper reports our recent research works on crack analysis in continuously non-homogeneous and linear elastic functionally graded materials. A meshless boundary element method is developed for this purpose. Numerical examples are presented and discussed to demonstrate the efficiency and the accuracy of the present numerical method, and to show the effects of the material gradation on the crack-opening-displacements and the stress intensity factors.

  7. Structure meets function at materials gathering.

    PubMed

    Service, R F

    1994-04-22

    SAN FRANCISCO-Engineers, physicists, and other scientists interested in material behavior came together at the 1994 spring meeting of the Materials Research Society from 4 to 8 April. Among the 2200 papers given, researchers heard presentations on a variety of functional substances: a semiconductor suitable for a laser that gives off blue light, an improved magnetic refrigerator, and a method of keeping pollutants from forming in engine exhaust. PMID:17732726

  8. Solid-Solid Phase Transformations in Inorganic Materials 2005 Edited by TMS (The Minerals, Metals & Materials Society), 2005

    E-print Network

    Laughlin, David E.

    such as conductive springs and interconnections, potentially displacing the conventional copper- beryllium alloys & Materials Society), 2005 ON THE PRODUCT PHASES OF THE CELLULAR TRANSFORMATION IN Cu-Ti AGE HARDENING ALLOYS-Ti alloys, cellular precipitation, discontinuous precipitation Abstract Cu-Ti alloys have significant high

  9. Organic-inorganic hybrid materials towards passive and active architectures for the next generation of optical networks

    NASA Astrophysics Data System (ADS)

    Ferreira, R. A. S.; André, P. S.; Carlos, L. D.

    2010-09-01

    The advances in optoelectronics over the last three decades have been quite dramatic, namely the mass manufacturing of low cost integrated circuits, revolutionizing the speed and the capability of computing and communication. However, today's ever-increasing demand for high-bandwidth data is outgrowing the performance of electronics in many applications, such as in telecommunications where the traffic demand has been increasing steadily and, therefore, the transmission technology requires bandwidth that exceeds the one provided by actual copper based networks. In this context, the fabrication of low-cost integrated optics (IO) devices using sol-gel derived organic-inorganic hybrid (OIH) materials has received increasing attention in the last years. This review will focus on examples of OIHs that can be used in IO devices for the next generation of optical networks. Emphasis will be given to passive (planar and channel waveguides, couplers and multimode interference splitters) and active (lasers and optical amplifiers) optical architectures for long haul/metro and access/indoor networks.

  10. 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. PMID:25781702

  11. Inorganic metallodielectric materials fabricated using two single-step methods based on the Tollen's process.

    PubMed

    Peterson, Molly S M; Bouwman, Jason; Chen, Aiqing; Deutsch, Miriam

    2007-02-01

    Two methods for preparing polycrystalline silver shells on colloidal silica spheres are reported. These do not include the use of organic ligands or metal seeding steps and are based on the Tollen's process for silvering glass. Reaction parameters such as temperature and reactant concentrations are adjusted to slow the reaction kinetics, which we find leads to preferential silver growth on the spheres. The resulting shells are polycrystalline and granular, showing highly uniform sphere coverage. Surface morphologies range from sparsely interconnected grains for shells approximately 20 nm thick, to complete (yet porous) shells of interconnected silver clusters which are up to approximately 140 nm in thickness. The extinction spectra of the core-shell materials are markedly different from those of smooth continuous shells, showing clear evidence that the granular shell geometry influences the plasmon resonance of the composite system. Spheres coated with shells 20-40 nm thick are also suitable for colloidal crystallization. Monolayers of self-assembled spheres with long-range ordering are demonstrated. PMID:17084855

  12. 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.

  13. Scanning tunneling microscopy studies of organic and inorganic materials for photovoltaics and photoelectrochemistry

    NASA Astrophysics Data System (ADS)

    Hiesgen, Renate; Meissner, Dieter

    1992-12-01

    Thin film solar cells require a structural control in nanometer dimensions. The only techniques currently available to investigate and control thin film preparation techniques in real space are based on scanning probe techniques as developed by Rohrer and Binning in 1981. However, the investigation of surface roughness on the ten to hundred nanometer range has proven to be especially complicated due to the convolution of tip and surface structures depending on the relative size dimensions of both the tip and the surface features. Special care is necessary to avoid multiple tip imaging as the major source of errors. Examples given in this paper include investigations of nanometer clusters of metals as used for semiconductor surface modifications in photoelectrochemical solar cells and of amorphous hydrocarbon films investigated as possible new materials for photovoltaics or as selective absorbers for solar thermal applications. More detailed investigations of molecular thin films for organic solar cells are presented. Here, besides information about the film structure, crystal growth mechanisms of organic crystalilites prepared by evaporation techniques also were investigated using scanning tunneling microscopy (STM) and scanning electron microscopy (SEM) techniques.

  14. 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.

  15. Chemo-mechanical microscale characterization of materials heterogeneity in oil/gas shales: linking organics and inorganics

    NASA Astrophysics Data System (ADS)

    Ferralis, N.; Abedi, S.; Grossman, J. C.; Ulm, F.

    2013-12-01

    From a materials perspective, the unconventional peculiarity of oil/gas shales resides in the intrinsic multi-scale heterogeneity in their chemical composition, organic maturity, mineralogy and microtexture. In contrast to common assumptions of maturity being driven only by the reservoir conditions (temperature and pressure), the presence of organic matter with different maturity within a few microns apart calls into question the role played by the organic and mineral heterogeneity into the chemo-mechanical properties of the material. Understanding how the upscaling of chemical diversity affects the fracturability and in general the mechanical strength of oil/gas shales is crucial. Compared to conventional oil and gas reservoirs, as well as coal, such heterogeneity requires novel and additional characterization tools from nano- to macro-scales to allow for a complete understanding of the role played by such heterogeneity in the chemo- mechanical properties of gas shales. Here we present a novel suite of chemical and mineralogical characterization tools that allow the in situ, non-destructive imaging of organic maturity and mineralogy from the microscale to the millimeter scale. This method is based on a combination of Raman, fluorescence and UV-Visible absorption spectroscopy. The upscaling is designed to provide a maturity population distribution from the nanoscale to the conventionally used macro-scale averaged parameters (such as vitrinite reflectance). Furthermore, in combination with registered micro/nano-mechanical indentation data a direct correlation of fracture mechanics and chemistry is made, allowing for the determination of high yield strain regions, relations between organic and inorganic anisotropy and interface mechanics. The underlying scientific insight at the nano and micro-scale of the potential origin of fractures in oil/gas shales, will potentially provide a connection bottom-up link to continuum fracture mechanics.

  16. 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.

  17. Modeling Bamboo as a Functionally Graded Material

    SciTech Connect

    Silva, Emilio Carlos Nelli [Department of Mechatronics and Mechanical Systems, Escola Politecnica da Universidade de Sao Paulo, Av. Professor Mello Moraes, 2231, Sao Paulo, SP, 05508-900 (Brazil); Walters, Matthew C.; Paulino, Glaucio H. [Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, IL 61801 (United States)

    2008-02-15

    Natural fibers are promising for engineering applications due to their low cost. They are abundantly available in tropical and subtropical regions of the world, and they can be employed as construction materials. Among natural fibers, bamboo has been widely used for housing construction around the world. Bamboo is an optimized composite material which exploits the concept of Functionally Graded Material (FGM). Biological structures, such as bamboo, are composite materials that have complicated shapes and material distribution inside their domain, and thus the use of numerical methods such as the finite element method and multiscale methods such as homogenization, can help to further understanding of the mechanical behavior of these materials. The objective of this work is to explore techniques such as the finite element method and homogenization to investigate the structural behavior of bamboo. The finite element formulation uses graded finite elements to capture the varying material distribution through the bamboo wall. To observe bamboo behavior under applied loads, simulations are conducted considering a spatially-varying Young's modulus, an averaged Young's modulus, and orthotropic constitutive properties obtained from homogenization theory. The homogenization procedure uses effective, axisymmetric properties estimated from the spatially-varying bamboo composite. Three-dimensional models of bamboo cells were built and simulated under tension, torsion, and bending load cases.

  18. Improved electronic coupling in hybrid organic-inorganic nanocomposites employing thiol-functionalized P3HT and bismuth sulfide nanocrystals.

    PubMed

    Martinez, L; Higuchi, S; MacLachlan, A J; Stavrinadis, A; Miller, N C; Diedenhofen, S L; Bernechea, M; Sweetnam, S; Nelson, J; Haque, S A; Tajima, K; Konstantatos, G

    2014-09-01

    In this study, we employ a thiol-functionalized polymer (P3HT-SH) as a leverage to tailor the nanomorphology and electronic coupling in polymer-nanocrystal composites for hybrid solar cells. The presence of the thiol functional group allows for a highly crystalline semiconducting polymer film at low thiol content and allows for improved nanomorphologies in hybrid organic-inorganic systems when employing non-toxic bismuth sulfide nanocrystals. The exciton dissociation efficiency and carrier dynamics at this hybrid heterojunction are investigated through photoluminescence quenching and transient absorption spectroscopy measurements, revealing a larger degree of polaron formation when P3HT-SH is employed, suggesting an increased electronic interaction between the metal chalcogenide nanocrystals and the thiol-functionalized P3HT. The fabricated photovoltaic devices show 15% higher power conversion efficiencies as a result of the improved nanomorphology and better charge transfer mechanism together with the higher open circuit voltages arising from the deeper energy levels of P3HT-SH. PMID:25029606

  19. Surface functionalization of inorganic nano-crystals with fibronectin and E-cadherin chimera synergistically accelerates transgene delivery into embryonic stem cells

    Microsoft Academic Search

    K. Kutsuzawa; E. H. Chowdhury; M. Nagaoka; K. Maruyama; Y. Akiyama; T.. Akaike

    2006-01-01

    Stem cells holding great promises in regenerative medicine have the potential to be differentiated to a specific cell type through genetic manipulation. However, conventional ways of gene transfer to such progenitor cells suffer from a number of disadvantages particularly involving safety and efficacy issues. Here, we report on the development of a bio-functionalized inorganic nano-carrier of DNA by embedding fibronectin

  20. Novel electromagnetic materials from functionalized structures

    NASA Astrophysics Data System (ADS)

    Xiao, Xiao

    Materials, exhibiting the novel electromagnetic responses those may not be found in nature, have the potential to manipulate the electromagnetic field passing through them. Consequently, these materials promise a number of applications, such as highly sensitive sensor, superlenses, high-gain antennas and electromagnetic wave cloaking. In the literature we would investigate various electromagnetic materials composed from functionalized structures (components). The novel electromagnetic materials can be photonic crystals, which are composed of the periodic dielectric or metallic structures. The propagation of the electromagnetic wave in photonic crystals is affected in the same way as the electrons propagating in the periodic potential in solid. We demonstrated that the photonic crystals can be used as a tool to tune the birefringence of the electromagnetic field. Metamaterials, which are composed of the artificial structures exhibiting strong local resonances, are also a kind of novel electromagnetic materials. The strong local resonance can squeeze the wavelength of the incoming electromagnetic field to the subwavelength region (i.e. superlenses) and revise the effective electromagnetic response of the materials (i.e. the negative indexes). For metamaterials we focus on the Plasmonic metamaterials in the thesis: we would show that these materials could be used to guide electromagnetic wave or introduce various kinds of extraordinary transmissions, both of which, of course, are achieved at subwavelength region. Moreover, the novel electromagnetic materials can be even the topological insulators, whose non-trivial electronic surface states can have extraordinary responses under the electromagnetic field. These non-trivial quantum hall surface states can introduce the mode conversion between different electromagnetic modes on the surfaces of the topological insulators and thus modify the propagation properties of the electromagnetic field through them. We would demonstrate that the non-trivial surface states of the topological insulators could modify the coherence of the thermal radiation from them.

  1. Love wave propagation in functionally graded piezoelectric material layer

    E-print Network

    Wang, Ji

    Love wave propagation in functionally graded piezoelectric material layer Jianke Du *, Xiaoying Jin is used to investigate Love waves in functionally graded piezoelectric material (FGPM) layer bonded. Numerical examples indicate that appropriate gradient distributing of the material properties make Love

  2. Formation of gel of preformed size-selected titanium-oxo-alkoxy nanoparticles: towards organic-inorganic hybrid material with efficient interfacial electron transfer

    NASA Astrophysics Data System (ADS)

    Gorbovyi, Pavlo; Uklein, Andrii; Traore, Mamadou; Museur, Luc; Kanaev, Andrei

    2014-12-01

    We report on preparation of a new organic–inorganic hybrid material with high photonic sensitivity, of which the inorganic component is gel of preformed size-selected titanium-oxo-alkoxy (TOA) nanoparticles. The inorganic nanoparticles of 5 nm size are generated in perfect micromixing conditions and assembled into the gel network in monomer HEMA (2-hydroxyethyl methacrylate) solutions at sufficiently slow input of water molecules in neutral pH conditions. The gelation is found to compete with precipitation and is promoted by an increase of the nanoparticle concentration. As a result, homogeneous optical-grade gels are obtained at titanium molar concentrations of 1.5 M and higher. After the organic polymerization, the organicinorganic pHEMA-TOA hybrids (pHEMA = poly(2-hydroxyethyl methacrylate)) show a high quantum yield of photoinduced charges separation (Ti3+/absorbed photons) and storage capacity (Ti3+/Ti4+), respectively 75% and 25%, which confirm the importance of the material nanoscale morphology control.

  3. Research unit INTERNANO: Mobility, aging and functioning of engineered inorganic nanoparticles at the aquatic-terrestrial interface

    NASA Astrophysics Data System (ADS)

    Schaumann, Gabriele Ellen; Metreveli, George; Baumann, Thomas; Klitzke, Sondra; Lang, Friederike; Manz, Werner; Nießner, Reinhard; Schulz, Ralf; Vogel, Hans-Jörg

    2013-04-01

    Engineered inorganic nanoparticles (EINP) are expected to pass the wastewater-river-topsoil-groundwater pathway. Despite their increasing release, the processes governing the EINP aging and the changes in functionality in the environment are up to now largely unknown. The objective of the interdisciplinary research unit INTERNANO funded by the DFG is to identify the processes relevant for the fate of EINP and EINP-associated pollutants in the interfacial zone between aquatic and terrestrial ecosystems. The research unit consists of six subprojects and combines knowledge from aquatic and terrestrial sciences as well as from microbiology, ecotoxicology, physicochemistry, soil chemistry and soil physics. For the identification of key processes we will consider compartment specific flow conditions, physicochemistry and biological activity. Situations representative for a floodplain system are simulated using micromodels (?m scale) as well as incubation, soil column and joint laboratory stream microcosm experiments. These results will be transferred to a joint aquatic-terrestrial model system on EINP aging, transport and functioning across the aquatic-terrestrial transition zone. EINP isolation and characterization will be carried out via a combination of chromatographic, light scattering and microscopic methods including dynamic light scattering, elemental analysis, hydrodynamic radius chromatography, field flow fractionation as well as atomic force microscopy, Raman microscopy and electron microscopy. INTERNANO generates fundamental aquatic-terrestrial process knowledge, which will help to evaluate the environmental significance of the EINP at aquatic-terrestrial interfaces. Thus, INTERNANO provides a scientific basis to assess and predict the environmental impact of EINP release into the environment.

  4. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): A Strip-Loading Optical Waveguide Using Well Poled Stability Organic/Inorganic Hybrid Materials

    NASA Astrophysics Data System (ADS)

    Gao, Wei-Nan; Tian, Mei-Qiang; Sun, Xiao-Qiang; Wang, Wei; Deng, Ling; Gao, Lei; Zhang, Da-Ming

    2009-03-01

    An optical waveguide for a polymer modulator based on organic/inorganic hybrid electro-optic (EO) materials is designed and fabricated by utilizing a strip-loading structure. This hybrid material has a controllable refractive index, high EO coefficient and good poled stability, which are suitable for the EO modulators and switches. The embedded waveguide made of the above EO material can reduce the coupling loss. The light is coupled into the guided-core layer and then undergoes a transition from the buried waveguide into the EO material. Obvious modulation is observed by application of ac voltage to the EO material. The measured V? of co-planar waveguide (CPW) is 5 V for the Mach-Zehnder (MZ) modulator in length of 3.5 cm.

  5. Gen IV Materials Handbook Functionalities and Operation

    SciTech Connect

    Ren, Weiju [ORNL

    2009-12-01

    This document is prepared for navigation and operation of the Gen IV Materials Handbook, with architecture description and new user access initiation instructions. Development rationale and history of the Handbook is summarized. The major development aspects, architecture, and design principles of the Handbook are briefly introduced to provide an overview of its past evolution and future prospects. Detailed instructions are given with examples for navigating the constructed Handbook components and using the main functionalities. Procedures are provided in a step-by-step fashion for Data Upload Managers to upload reports and data files, as well as for new users to initiate Handbook access.

  6. Inorganic photovoltaic cells

    Microsoft Academic Search

    Robert W. Miles; Guillaume Zoppi; Ian Forbes

    2007-01-01

    The inorganic semiconductor materials used to make photovoltaic cells include crystalline, multicrystalline, amorphous, and microcrystalline Si, the III-V compounds and alloys, CdTe, and the chalcopyrite compound, copper indium gallium diselenide (CIGS). We show the structure of the different devices that have been developed, discuss the main methods of manufacture, and review the achievements of the different technologies.

  7. Fabrication of functional materials in microfluidics

    NASA Astrophysics Data System (ADS)

    Shum, Ho Cheung

    In this thesis, we present a study on how droplets prepared in microfluidics can be used for fabrication of functional materials. We utilize the high degree of fluidic control enabled by miniaturizing the channels to achieve monodisperse single and multiple emulsion with high encapsulation efficiency. By engineering the interfaces of such emulsions and/or applying appropriate reactions, novel functional materials have been fabricated for encapsulation and release applications and for carrying out reactions in confined environments. Glass capillary microfluidics is used in the majority of the thesis. Glass offers excellent solvent resistance to most organic solvents needed for fabricating the desired materials. In Chapter 1, we describe a double-emulsion-templated approach to form polymer vesicles, also known as polymersomes. By dissolving amphiphilic block copolymers in a volatile solvent, which forms the shell layer of double emulsions, polymersomes are formed after evaporation of the volatile solvent. In Chapter 2, we apply the same approach to fabricate phospholipid vesicles. In Chapter 3, we investigate the physics of membrane formation at interfaces laden with amphiphilic diblock copolymers. In Chapter 4, we fabricate polymersomes with multiple compaitalents by using controlled double emulsion drops with multiple inner droplets as templates. In Chapter 5, we describe a non-microfluidic approach for fabricating similar polymersomes with large number of compartments. In Chapter 6, we show that the double-emulsion templated approach for forming polymersomes can be applied to two-dimensional stamped devices, which can be easily scaled up for production of large amount of polymersomes. Apart from polymersomes, controlled emulsions can also be used for generating other functional materials. In Chapter 7, we use double emulsion drops as microreactors for fabricating particles of hydroxyapatite. In Chapter 8, we generate solid capsules by emulsifying a molten phase as the shell phase of double emulsions and subsequently cooling the emulsions. In Chapter 9, we describe several strategies that have been applied to form non-spherical particles using microfluidic emulsions as templates. In Chapter 10, we demonstrate that controlled double emulsions cannot be formed at low interfacial tension between the shell and the continuous phases. Instead, compound jets with highly corrugated interfaces are observed.

  8. The Synthesis of Functional Mesoporous Materials

    SciTech Connect

    Fryxell, Glen E.

    2006-11-01

    The ability to decorate a silica surface with specific ligand fields and/or metal complexes creates powerful new capabilities for catalysis, chemical separations and sensor development. Integrating this with the ability to control the spacing of these complexes across the surface, as well as the symmetry and size of the pore structure, allows the synthetic chemist to hierarchically tailor these structured nanomaterials to specific needs. The next step up the “scale ladder” is provided by the ability to coat these mesoporous materials onto complex shapes, allowing for the intimate integration of these tailored materials into device interfaces. The ability to tailor the pore structure of these mesoporous supports is derived from the surfactant templated synthesis of mesoporous materials, an area which has seen an explosion of activity over the last decade.[1,2] The ability to decorate the surface with the desired functionality requires chemical modification of the oxide interface, most commonly achieved using organosilane self-assembly.[3-6] This manuscript describes recent results from the confluence of these two research areas, with a focus on synthetic manipulation of the morphology and chemistry of the interface, with the ultimate goal of binding metal centers in a chemically useful manner.

  9. Graphene-templated directional growth of an inorganic nanowire.

    PubMed

    Lee, Won Chul; Kim, Kwanpyo; Park, Jungwon; Koo, Jahyun; Jeong, Hu Young; Lee, Hoonkyung; Weitz, David A; Zettl, Alex; Takeuchi, Shoji

    2015-05-01

    Assembling inorganic nanomaterials on graphene is of interest in the development of nanodevices and nanocomposite materials, and the ability to align such inorganic nanomaterials on the graphene surface is expected to lead to improved functionalities, as has previously been demonstrated with organic nanomaterials epitaxially aligned on graphitic surfaces. However, because graphene is chemically inert, it is difficult to precisely assemble inorganic nanomaterials on pristine graphene. Previous techniques based on dangling bonds of damaged graphene, intermediate seed materials and vapour-phase deposition at high temperature(,) have only formed randomly oriented or poorly aligned inorganic nanostructures. Here, we show that inorganic nanowires of gold(I) cyanide can grow directly on pristine graphene, aligning themselves with the zigzag lattice directions of the graphene. The nanowires are synthesized through a self-organized growth process in aqueous solution at room temperature, which indicates that the inorganic material spontaneously binds to the pristine graphene surface. First-principles calculations suggest that this assembly originates from lattice matching and ? interaction to gold atoms. Using the synthesized nanowires as templates, we also fabricate nanostructures with controlled crystal orientations such as graphene nanoribbons with zigzag-edged directions. PMID:25799519

  10. Functionalized graphene and other two-dimensional materials for photovoltaic devices: device design and processing.

    PubMed

    Liu, Zhike; Lau, Shu Ping; Yan, Feng

    2015-08-01

    Graphene is the thinnest two-dimensional (2D) carbon material and has many advantages including high carrier mobilities and conductivity, high optical transparency, excellent mechanical flexibility and chemical stability, which make graphene an ideal material for various optoelectronic devices. The major applications of graphene in photovoltaic devices are for transparent electrodes and charge transport layers. Several other 2D materials have also shown advantages in charge transport and light absorption over traditional semiconductor materials used in photovoltaic devices. Great achievements in the applications of 2D materials in photovoltaic devices have been reported, yet numerous challenges still remain. For practical applications, the device performance should be further improved by optimizing the 2D material synthesis, film transfer, surface functionalization and chemical/physical doping processes. In this review, we will focus on the recent advances in the applications of graphene and other 2D materials in various photovoltaic devices, including organic solar cells, Schottky junction solar cells, dye-sensitized solar cells, quantum dot-sensitized solar cells, other inorganic solar cells, and perovskite solar cells, in terms of the functionalization techniques of the materials, the device design and the device performance. Finally, conclusions and an outlook for the future development of this field will be addressed. PMID:26024242

  11. Research unit INTERNANO: Mobility, aging and functioning of engineered inorganic nanoparticles at the aquatic-terrestrial interface

    NASA Astrophysics Data System (ADS)

    Schaumann, G. E.; Baumann, T.; Duester, L.; Klitzke, S.; Lang, F.; Manz, W.; Nießner, R.; Schulz, R.; Vogel, H.-J.

    2012-04-01

    Engineered inorganic nanoparticles (EINP) are expected to pass the wastewater-river-topsoil-groundwater pathway. Despite their increasing release, the processes governing the EINP aging and the changes in functionality in the environment are up to now largely unknown. The objective of the interdisciplinary research unit INTERNANO funded by the German Research Foundation (DFG) is to identify the processes relevant for the fate of EINP and EINP-associated pollutants in the interfacial zone between aquatic and terrestrial ecosystems. The research unit consists of six subprojects and combines knowledge from aquatic and terrestrial sciences as well as from microbiology, ecotoxicology, physicochemistry, soil chemistry and soil physics. For the identification of key processes we will consider compartment specific flow conditions, physicochemistry and biological activity. Situations representative for a floodplain system are simulated using micromodels (?m scale) as well as incubation, soil column and joint laboratory stream microcosm experiments. These results will be transferred to a joint aquatic-terrestrial model system on EINP aging, transport and functioning across the aquatic-terrestrial transition zone. EINP isolation and characterization will be carried out via a combination of chromatographic, light scattering and microscopic methods including dynamic light scattering, elemental analysis, hydrodynamic radius chromatography, field flow fractionation as well as atomic force microscopy, Raman microscopy, dynamic light scattering methods and electron microscopy. INTERNANO generates fundamental aquatic-terrestrial process knowledge, which will help to evaluate the environmental significance of the EINP at aquatic-terrestrial interfaces. Therefore, INTERNANO serves as a qualitative basis to predict the environmental impact of EINP contamination.

  12. Structure and reaction studies of biological organic and inorganic composite materials: Abalone shells, diatoms, and a unique birch bark

    Microsoft Academic Search

    Charlotte Marie Zaremba

    1998-01-01

    Biopolymer\\/calcium carbonate composites grown on inorganic abiotic substrates implanted between the shell and the shell-secreting epithelium of live red abalones (Haliotis rufescens) results in an unusual highly (104)-oriented aggregate of microcrystalline calcite that precedes nacre deposition. Calcite of this orientation has never before been observed in nature. Also with this method, nacre deposition is found to correct for calcite surface

  13. Inorganic-based sol–gel synthesis of nano-structured LiFePO 4 \\/C composite materials for lithium ion batteries

    Microsoft Academic Search

    Jun Ma; Baohua Li; Hongda Du; Chengjun Xu; Feiyu Kang

    An inorganic and non-toxic compounds combination of FeCl2·4H2O, Li2CO3 and H3PO4 was chosen to synthesize homogeneous nano-structured LiFePO4\\/C composite material via a simplified sol–gel route. The dependency of the physicochemical properties and the corresponding\\u000a electrochemical responses on the residual carbon content were investigated in details. Rietveld refinement of X-ray diffraction\\u000a measurement and X-ray photoelectron spectroscopy analysis confirmed the feasibility of

  14. Synthesis of an organic-inorganic hybrid material by solid state intercalation of 2-mercaptopyridine into Na, Al(III)- and Co(II)-montmorillonite

    Microsoft Academic Search

    I. Bekri-Abbes; E. Srasra

    2006-01-01

    The preparation of an organic-inorganic hybrid material by solid state intercalation of 2-mercaptopyridine (2Mpy) into Na-,\\u000a Co(II)- and Al(III)-montmorillonite has been studied using a variety of techniques. The extension ofd\\u000a 001from XRD proves that the intercalation of 2-mercaptopyridine into Na-, Co(II)- and Al(III)-mont occurs at ambient temperature\\u000a in 5 mn. When the intercalated samples were heated at different temperatures, we

  15. A method to quantify organic functional groups and inorganic compounds in ambient aerosols using attenuated total reflectance FTIR spectroscopy and multivariate chemometric techniques

    NASA Astrophysics Data System (ADS)

    Coury, Charity; Dillner, Ann M.

    An attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopic technique and a multivariate calibration method were developed to quantify ambient aerosol organic functional groups and inorganic compounds. These methods were applied to size-resolved particulate matter samples collected in winter and summer of 2004 at three sites: a downtown Phoenix, Arizona location, a rural site near Phoenix, and an urban fringe site between the urban and rural site. Ten organic compound classes, including four classes which contain a carbonyl functional group, and three inorganic species were identified in the ambient samples. A partial least squares calibration was developed and applied to the ambient spectra, and 13 functional groups related to organic compounds (aliphatic and aromatic CH, methylene, methyl, alkene, aldehydes/ketones, carboxylic acids, esters/lactones, acid anhydrides, carbohydrate hydroxyl and ethers, amino acids, and amines) as well as ammonium sulfate and ammonium nitrate were quantified. Comparison of the sum of the mass measured by the ATR-FTIR technique and gravimetric mass indicates that this method can quantify nearly all of the aerosol mass on sub-micrometer size-segregated samples. Analysis of sample results shows that differences in organic functional group and inorganic compound concentrations at the three sampling sites can be measured with these methods. Future work will analyze the quantified data from these three sites in detail.

  16. Enhancing the value of commodity polymers: Part 1. Structure-property relationships in composite materials based on maleated polypropylene/inorganic phosphate glasses. Part 2. New value-added applications for polyesters

    NASA Astrophysics Data System (ADS)

    Gupta, Mohit

    The first part of the thesis (Chapters 2 & 3) describes a new class of organic polymer/inorganic glass composite materials with property improvements that are impossible to achieve with classical polymer blends or composites. These materials exhibit good processability, superior mechanical performance, good thermal stability, and have excellent gas barrier properties. Low glass transition temperature phosphate glasses (Pglass) are used as inorganic fillers and slightly maleated polypropylene is used as the organic polymer matrix. The Pglass, which was dispersed as spherical droplets in the unoriented composites can be elongated into high aspect ratio platelets during the biaxial stretching process. Biaxially oriented films exhibited a brick wall type microstructure with highly aligned inorganic platelets in a ductile organic matrix and the oxygen barrier properties are significantly improved due to presence of Pglass platelets as impermeable inclusions. Mechanical properties of the biaxially oriented films showed significant improvements compared to neat polymer due to uniform dispersion of the Pglass platelets. Properly dispersed and aligned platelets have proven to be very effective for increasing the composite modulus. These developed materials therefore show promise to help fulfill the ever increasing demand for new advanced materials for a wide variety of advanced packaging applications because of their gas barrier properties, flexibility, transparency, mechanical strength and performance under humid conditions. The second part of the thesis (Chapters 4 & 5) describes new value-added applications for polyesters. Chapter 4 reports a novel process for the decolorization of green and blue colored PET bottle flakes using hydrogen peroxide. The decolorized flakes were characterized for color, intrinsic viscosity values. Decolorized flakes exhibited color values similar to those of colorless recycled PET and even though IV values decreased, bleached flakes still exhibit useful molecular weight. The consumption of H2O2 during the bleaching process was quantified by titrating the residual peroxide using a standard solution of potassium permanganate. Chapter 5 reports synthesis of ductile amorphous polymers which change their color as a function of mechanical deformation. Cyano--OPV moieties were covalently incorporated into the backbone of amorphous polyester PETG. The materials exhibit a significant color change upon compression consistent with efficient breakup of the dye aggregates upon deformation and therefore can be useful for technological applications that require smart coatings with integrated scratch detectors.

  17. Using the soil and water assessment tool to estimate dissolved inorganic nitrogen water pollution abatement cost functions in central portugal.

    PubMed

    Roebeling, P C; Rocha, J; Nunes, J P; Fidélis, T; Alves, H; Fonseca, S

    2014-01-01

    Coastal aquatic ecosystems are increasingly affected by diffuse source nutrient water pollution from agricultural activities in coastal catchments, even though these ecosystems are important from a social, environmental and economic perspective. To warrant sustainable economic development of coastal regions, we need to balance marginal costs from coastal catchment water pollution abatement and associated marginal benefits from coastal resource appreciation. Diffuse-source water pollution abatement costs across agricultural sectors are not easily determined given the spatial heterogeneity in biophysical and agro-ecological conditions as well as the available range of best agricultural practices (BAPs) for water quality improvement. We demonstrate how the Soil and Water Assessment Tool (SWAT) can be used to estimate diffuse-source water pollution abatement cost functions across agricultural land use categories based on a stepwise adoption of identified BAPs for water quality improvement and corresponding SWAT-based estimates for agricultural production, agricultural incomes, and water pollution deliveries. Results for the case of dissolved inorganic nitrogen (DIN) surface water pollution by the key agricultural land use categories ("annual crops," "vineyards," and "mixed annual crops & vineyards") in the Vouga catchment in central Portugal show that no win-win agricultural practices are available within the assessed BAPs for DIN water quality improvement. Estimated abatement costs increase quadratically in the rate of water pollution abatement, with largest abatement costs for the "mixed annual crops & vineyards" land use category (between 41,900 and 51,900 € tDIN yr) and fairly similar abatement costs across the "vineyards" and "annual crops" land use categories (between 7300 and 15,200 € tDIN yr). PMID:25602550

  18. Heterogeneous Charge Carrier Dynamics in Organic-Inorganic Hybrid Materials: Nanoscale Lateral and Depth-Dependent Variation of Recombination Rates in Methylammonium Lead Halide Perovskite Thin Films.

    PubMed

    Bischak, Connor G; Sanehira, Erin M; Precht, Jake T; Luther, Joseph M; Ginsberg, Naomi S

    2015-07-01

    We reveal substantial luminescence yield heterogeneity among individual subdiffraction grains of high-performing methylammonium lead halide perovskite films by using high-resolution cathodoluminescence microscopy. Using considerably lower accelerating voltages than is conventional in scanning electron microscopy, we image the electron beam-induced luminescence of the films and statistically characterize the depth-dependent role of defects that promote nonradiative recombination losses. The highest variability in the luminescence intensity is observed at the exposed grain surfaces, which we attribute to surface defects. By probing deeper into the film, it appears that bulk defects are more homogeneously distributed. By identifying the origin and variability of a surface-specific loss mechanism that deleteriously impacts device efficiency, we suggest that producing films homogeneously composed of the highest-luminescence grains found in this study could result in a dramatic improvement of overall device efficiency. We also show that although cathodoluminescence microscopy is generally used only to image inorganic materials it can be a powerful tool to investigate radiative and nonradiative charge carrier recombination on the nanoscale in organic-inorganic hybrid materials. PMID:26098220

  19. Determination of Organic and Inorganic Percentages and Mass of Suspended Material at Four Sites in the Illinois River in Northwestern Arkansas and Northeastern Oklahoma, 2005-07

    USGS Publications Warehouse

    Galloway, Joel M.

    2008-01-01

    The Illinois River located in northwestern Arkansas and northeastern Oklahoma is influenced by point and nonpoint sources of nutrient enrichment. This has led to increased algal growth within the stream, reducing water clarity. Also, sediment runoff from fields, pastures, construction sites, and other disturbed areas, in addition to frequent streambank failure, has increased sedimentation within the stream and decreased water clarity. A study was conducted by the U.S. Geological Survey in cooperation with the Arkansas Department of Environmental Quality and the U.S. Environmental Protection Agency to characterize the increased turbidity by determining the organic and inorganic composition and mass of suspended material in the Illinois River from August 2005 through July 2007. Water-quality samples were collected at four sites on the Illinois River (listed in downstream order): near Viney Grove, Arkansas; at Savoy, Arkansas; south of Siloam Springs, Arkansas; and near Tahlequah, Oklahoma. In general, turbidity, total suspended solids, suspended-sediment concentration, organic material concentration (measured as volatile suspended solids and ash-free dry mass), and chlorophyll a concentration were the greatest in samples collected from the Illinois River at Savoy and the least in samples from the most upstream Illinois River site (near Viney Grove) and the most downstream site (near Tahlequah) from August 2005 through July 2007. For example, the suspended-sediment concentration at the Illinois River at Savoy had a median of 15 milligrams per liter, and the total suspended solids had a median of 12 milligrams per liter. The Illinois River near Tahlequah had the least suspended-sediment concentration with a median of 10 milligrams per liter and the least total suspended solids with a median of 6 milligrams per liter. The turbidity, total suspended solids, suspended-sediment concentration, organic material concentration, and chlorophyll a concentration in samples collected during high-flow events were greater than in samples collected during base-flow conditions at the Illinois River at Savoy, south of Siloam Springs, and near Tahlequah. For example, the median turbidity for the Illinois River at Savoy was 3 nephelometric turbidity ratio units during base-flow conditions and 52 nephelometric turbidity ratio units during high-flow conditions. Organic material in the Illinois River generally composed between 13 and 47 percent of the total suspended material in samples collected from August 2005 through July 2007. Therefore, most of the suspended material in samples collected from the sites was inorganic material. Overall, the highest percentage of organic material was found at the Illinois River near Viney Grove and at the Illinois River near Tahlequah. The Illinois River south of Siloam Springs had the lowest percentage of organic material among the four sites. In general, the percentage of organic material was greater in samples collected during base-flow conditions compared to samples collected during high-flow conditions. The mean seasonal concentrations and percentages of organic material were the least in the fall (September through November) in samples collected from August 2005 to July 2007 from the four Illinois River sites, while the greatest concentrations and percentages of organic material occurred at various times of the year depending on the site. The greatest concentrations of organic material occurred in the summer (June through August) in samples from sites on the Illinois River near Viney Grove, at Savoy and south of Siloam Springs, but in the spring (March through May) in samples from the Illinois River near Tahlequah. The greatest percentages of organic material (least percentages of inorganic material) occurred in the summer in samples from the site near Viney Grove, the winter and summer at the site at Savoy, in the spring, fall, and winter (December through February) at the site south of Siloam Springs, an

  20. Functional organic materials for electronics industries

    NASA Technical Reports Server (NTRS)

    Shibayama, K.; Ono, H.

    1982-01-01

    Topics closely related with organic, high molecular weight material synthesis are discussed. These are related to applications such as display, recording, sensors, semiconductors, and I.C. correlation. New materials are also discussed. General principles of individual application are not included. Materials discussed include color, electrochromic, thermal recording, organic photoconductors for electrophotography, and photochromic materials.

  1. Enhancing the value of commodity polymers: Part 1. Structure-property relationships in composite materials based on maleated polypropylene\\/inorganic phosphate glasses. Part 2. New value-added applications for polyesters

    Microsoft Academic Search

    Mohit Gupta

    2010-01-01

    The first part of the thesis (Chapters 2 & 3) describes a new class of organic polymer\\/inorganic glass composite materials with property improvements that are impossible to achieve with classical polymer blends or composites. These materials exhibit good processability, superior mechanical performance, good thermal stability, and have excellent gas barrier properties. Low glass transition temperature phosphate glasses (Pglass) are used

  2. Directed deposition of inorganic oxide networks on patterned polymer templates

    NASA Astrophysics Data System (ADS)

    Ford, Thomas James Robert

    Inspired by nature, we have successfully directed the deposition of inorganic oxide materials on polymer templates via a combination of top-down and bottom-up fabrication methods. We have functionally mimicked the hierarchical silica exoskeletons of diatoms, where specialized proteins chaperone the condensation of silicic acid into nanoscale silica networks confined by microscopic vesicle walls. We replaced the proteins with functionally analogous polyamines and vesicles with lithographically defined polymer templates. We grafted the polyamines either to the surface or throughout the template by changing the template chemistry and altering our grafting strategy. Exposure to an inorganic oxide precursor solution led to electrostatic aggregation at the polyamine chains, catalyzing hydrolysis and condensation to form long-range inorganic oxide nanoparticle networks. Grafted to epoxy surfaces, swelling effects and the hyperbranched brush morphology lead to the formation of nanofruit features that generated thin, conformal inorganic coatings. When the polyamines were grafted throughout hydrogel templates, we obtained composite networks that yielded faithful inorganic replicas of the original patterns. By varying the polyamine chain length and combustion parameters, we controlled the nanoparticle size, morphology, and crystalline phase. The polyamine morphology affected the resulting inorganic network in both fabrication schemes and we could control the depostion over multiple length scales. Because our methods were compatible with a variety of lithographic methods, we were able to generate inorganic replicas of 1D, 2D, and 3D polymer structures. These may be used for a wide range of applications, including sensing, catalysis, photonic, phononic, photovoltaic, and others that require well-defined inorganic structures.

  3. Surface functionalized mesoporous material and method of making same

    Microsoft Academic Search

    Xiangdong Feng; Jun Liu; Glen E. Fryxell

    2001-01-01

    According to the present invention, an organized assembly of functional molecules with specific interfacial functionality (functional group(s)) is attached to available surfaces including within mesopores of a mesoporous material. The method of the present invention avoids the standard base soak that would digest the walls between the mesopores by boiling the mesoporous material in water for surface preparation then removing

  4. 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.

  5. Measuring oxygen yields of a thermal conversion/elemental analyzer-isotope ratio mass spectrometer for organic and inorganic materials through injection of CO.

    PubMed

    Yin, Xijie; Chen, Zhigang

    2014-12-01

    The thermal conversion/elemental analyzer-isotope ratio mass spectrometer (TC/EA-IRMS) is widely used to measure the ?(18) O value of various substances. A premise for accurate ?(18) O measurement is that the oxygen in the sample can be converted into carbon monoxide (CO) quantitatively or at least proportionally. Therefore, a precise method to determine the oxygen yield of TC/EA-IRMS measurements is needed. Most studies have used the CO peak area obtained from a known amount of a solid reference material (for example, benzoic acid) to calibrate the oxygen yield of the sample. Although it was assumed that the oxygen yield of the solid reference material is 100%, no direct evidence has been provided. As CO is the analyte gas for ?(18) O measurement by IRMS, in this study, we use a six-port valve to inject CO gas into the TC/EA. The CO is carried to the IRMS by the He carrier gas and the CO peak area is measured by the IRMS. The CO peak area thus obtained from a known amount of the injected CO is used to calibrate the oxygen yield of the sample. The oxygen yields of commonly used organic and inorganic reference materials such as benzoic acid (C6 H5 COOH), silver phosphate (Ag3 PO4 ), calcium carbonate (CaCO3 ) and silicon dioxide (SiO2 ) are investigated at different reactor temperatures and sample sizes. We obtained excellent linear correlation between the peak area for the injected CO and its oxygen atom amount. C6 H5 COOH has the highest oxygen yield, followed by Ag3 PO4 , CaCO3 and SiO2 . The oxygen yields of TC/EA-IRMS are less than 100% for both organic and inorganic substances, but the yields are relatively stable at the specified reactor temperature and for a given quantity of sample. PMID:25476948

  6. Designing conjugated polymer-based functional materials via the incorporation of supramolecular complexities

    E-print Network

    Kwan, Phoebe Hoi-Ying, 1978-

    2005-01-01

    One of the major goals in molecule engineering is the creation of molecule- or polymer- based devices that mimic the integrated functions of their macroscopic (and often inorganic) counterparts. Because of their unique ...

  7. Data-mined similarity function between material compositions

    NASA Astrophysics Data System (ADS)

    Yang, Lusann; Ceder, Gerbrand

    2013-12-01

    A new method for assessing the similarity of material compositions is described. A similarity measure is important for the classification and clustering of compositions. The similarity of the material compositions is calculated utilizing a data-mined ionic substitutional similarity based upon the probability with which two ions will substitute for each other within the same structure prototype. The method is validated via the prediction of crystal structure prototypes for oxides from the Inorganic Crystal Structure Database, selecting the correct prototype from a list of known prototypes within five guesses 75% of the time. It performs particularly well on the quaternary oxides, selecting the correct prototype from a list of known prototypes on the first guess 65% of the time.

  8. Density functional theory in materials science

    PubMed Central

    Neugebauer, Jörg; Hickel, Tilmann

    2013-01-01

    Materials science is a highly interdisciplinary field. It is devoted to the understanding of the relationship between (a) fundamental physical and chemical properties governing processes at the atomistic scale with (b) typically macroscopic properties required of materials in engineering applications. For many materials, this relationship is not only determined by chemical composition, but strongly governed by microstructure. The latter is a consequence of carefully selected process conditions (e.g., mechanical forming and annealing in metallurgy or epitaxial growth in semiconductor technology). A key task of computational materials science is to unravel the often hidden composition–structure–property relationships using computational techniques. The present paper does not aim to give a complete review of all aspects of materials science. Rather, we will present the key concepts underlying the computation of selected material properties and discuss the major classes of materials to which they are applied. Specifically, our focus will be on methods used to describe single or polycrystalline bulk materials of semiconductor, metal or ceramic form. PMID:24563665

  9. Design and Simulation of 2×2 MMI Coupler and Thermo-optic Switch Using Sol-Gel Derived Organic-Inorganic Hybrid Material

    NASA Astrophysics Data System (ADS)

    Samah, M. Firdaus A.; Nawabjan, Amirjan; Abdullah, Ahmad Sharmi; Ibrahim, Mohd Haniff; Kassim, Norazan Mohd; Mohamad, Abu Bakar

    2011-05-01

    A new design of Multimode Interference (MMI) thermo-optic switch with improved crosstalk figure is demonstrated in this paper. The device is designed and simulated using BeamProp 3D from Rsoft and 3D BPM CAD softwares. The devices are designed based on sol-gel derived organic-inorganic hybrid material, vinyltriethoxysilane (VTES), tetraethoxysilane (TEOS) and tetrabutoxytitanate (TTBu) or VTT with refractive index of 1.47 as a core and surrounded by silica with refractive index of 1.45 at 1550 nm wavelength. The switching power is 164mW and the simulation result show that the propagation loss of the MMI device is 1.8 dB and zero crosstalk.

  10. Polyoxometalates Macroanions: From Self-Recognition to Functional Materials

    NASA Astrophysics Data System (ADS)

    Yin, Panchao

    Large, hydrophilic polyoxoanions with high solubility in water and/or other polar solvents demonstrate unique solution behavior by self-assembling into single layer, hollow, spherical "blackberry"-like structures, which are obviously different from small, simple ions. These macroions cannot be treated as insoluble colloidal suspensions either because they form stable "real solutions". These inorganic macroions demonstrate some features usually Pobelieved to belong only to complex biological molecules, such as the self-recognition, chiral recognition, and chiral selection in dilute solutions. Highly negatively-charged molecular rods with almost identical structures were observed to self-assemble into their individual 'blackberry' structures, demonstrating tiny differences (e.g. charge, charge distribution, and organic ligands) could lead to self-recognition behavior. Chiral recognition behavior was understood by studying the self-assembly process in the racemic mixture solutions. Moreover, chiral organic molecules (lactic acid and tartaric acid) can be used to selectively inhibit the self-assembly process of one of the enantiomers. Meanwhile, polyoxometalate-based organic-inorganic hybrid materials demonstrate amphiphilic properties by self-assembling into vesicles and reverse vesicles in polar and non-polar solvents, respectively, and form catalytic emulsions in biphasic environments. Designed hybrid molecules can be programed to different devices with applications in fluorescence, photo-electronic conversion, molecular switch, and catalyst.

  11. PMMA: A key macromolecular component for dielectric low- ? hybrid inorganic–organic polymer films

    Microsoft Academic Search

    Silvia Gross; Daniele Camozzo; Vito Di Noto; Lidia Armelao; Eugenio Tondello

    2007-01-01

    Inorganic–organic composite and hybrid films find widespread applications for the development of functional materials. Polymer matrices with embedded inorganic fillers, nanoparticles or clusters are particularly appealing for optical, electronic, dielectric and magnetic applications. In particular, the development of hybrid layers with tailored dielectric properties represents a key issue in many technological fields.In this framework, poly(methyl methacrylate) (PMMA), due to its

  12. Inorganic Semiconductors for Flexible Electronics

    Microsoft Academic Search

    Yugang Sun; John A. Rogers

    2007-01-01

    This article reviews several classes of inorganic semiconductor materi- als that can be used to form high-performance thin-film transistors (TFTs) for large area, flexible electronics. Examples ranging from thin films of various forms of silicon to nanoparticles and nanowires of compound semiconductors are presented, with an emphasis on meth- ods of depositing and integrating thin films of these materials into

  13. The Materials genome : rapid materials screening for renewable energy using high-throughput density functional theory

    E-print Network

    Jain, Anubhav, Ph.D. Massachusetts Institute of Technology

    2011-01-01

    This thesis relates to the emerging field of high-throughput density functional theory (DFT) computation for materials design and optimization. Although highthroughput DFT is a promising new method for materials discovery, ...

  14. Developing complex structures and functions through cell-directed assembly

    Microsoft Academic Search

    Helen K. Baca

    2005-01-01

    The integration of biological building blocks into functional platforms is important to applications across the field of nanotechnology. However, hybrid materials that incorporate biological units such as whole cells require functional bio\\/inorganic interfaces, benign synthesis conditions and fluidic support systems to avoid dehydration. Cell-directed assembly integrates biological materials in a uniformly nanostructured inorganic host that maintains cell accessibility, addressability, and

  15. Material design method for the functionally graded cemented carbide tool

    Microsoft Academic Search

    Toshio Nomura; Hideki Moriguchi; Keiichi Tsuda; Kazutaka Isobe; Akihiko Ikegaya; Kiyoko Moriyama

    1999-01-01

    The aim of this study is to apply the concept of functionally graded materials (FGMs) to tool materials and to develop high-performance cutting tools. The requirement of the graded structure is that the surface is highly wear resistant cermet, and the inside is tough cemented carbide. Compressive residual stress was introduced to the material surface by grading the composition. To

  16. Functional ceria–salt-composite materials for advanced ITSOFC applications

    Microsoft Academic Search

    Bin Zhu

    2003-01-01

    This paper reports our current material research and development for advanced intermediate temperature (IT, 400–700°C) solid oxide fuel cells (SOFCs). The materials reported in this work are based on ceria–salt-composites, which have super function, e.g. displaying ionic conductivity of 0.01–1Scm?1 in the IT region. They are functional ceramic materials for advanced ITSOFC applications. When these new composites are used as

  17. New materials and functionality in spintronics devices

    Microsoft Academic Search

    Lubna R. Shah

    2010-01-01

    The next generation of electronics devices, known as spintronics, which incorporate the spin property of the carriers in combination with their charge degree of freedom is the focus of to-date research. Therefore, exciting new classes of materials have been emerging for the last few years for the development of spintronics devices. This study has been carried out to understand\\/control various

  18. High-throughput data mined prediction of inorganic compounds and computational discovery of new lithium-ion battery cathode materials

    E-print Network

    Hautier, Geoffroy (Geoffroy T. F.)

    2011-01-01

    The ability to computationally predict the properties of new materials, even prior to their synthesis, has been made possible due to the current accuracy of modern ab initio techniques. In some cases, high-throughput ...

  19. Science Update: Inorganic Chemistry.

    ERIC Educational Resources Information Center

    Rawls, Rebecca

    1981-01-01

    Describes areas of inorganic chemistry which have changed dramatically in the past year or two, including photochemistry, electrochemistry, organometallic complexes, inorganic reaction theory, and solid state chemistry. (DS)

  20. http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8846343 2012 MRS Fall Meeting; Symposium E, Photovoltaic Technologies, Devices and Systems Based on Inorganic Materials, Small

    E-print Network

    Dietz, Nikolaus

    investigated for use in photovoltaic solar cells for the past years. At present, almost all photovoltaic device Meeting; Symposium E, Photovoltaic Technologies, Devices and Systems Based on Inorganic Materials, Small Organic Molecules and Hybrids; E15.02; Published at Mater. Res. Soc. Proc. Vol. 1493, E15.02, pp.1-6 (2013

  1. Boundary conditions for envelope functions at interfaces between dissimilar materials

    Microsoft Academic Search

    G. T. Einevoll; L. J. Sham

    1994-01-01

    In the effective-mass approximation, the validity of the boundary conditions for an envelope function F acoss an interface between two different materials is predicated on the similarity of the nearest band-edge Bloch functions. Such approximations break down when the two materials are very dissimilar, e.g., a metal and a semiconductor. By studying one-dimensional model potentials we derive more accurate functional

  2. Organic-Inorganic Hybrid Materials Based on Basket-like {Ca?P6Mo18O73} Cages.

    PubMed

    Zhang, He; Yu, Kai; Lv, Jing-Hua; Gong, Li-Hong; Wang, Chun-Mei; Wang, Chun-Xiao; Sun, Di; Zhou, Bai-Bin

    2015-07-20

    Four basket-like organic-inorganic hybrids, formulated as [{Cu(II)(H2O)2}{Ca4(H2O)4(HO0.5)3(en)2}{Ca?P6Mo4(V)Mo14(VI)O73}]·7H2O (1), (H4bth)[{Fe(II)(H2O)}{Ca?P6Mo18(VI)O73}]·4H2O (2), (H2bih)3[{Cu(II)(H2O)2}{Ca?P6Mo2(V)Mo16(VI)O73}]·2H2O (3), (H2bib)3[{Fe(II)(H2O)2}{Ca?P6Mo2(V) Mo16(VI)O73}]·4H2O (4), (bth = 1,6-bis(triazole)hexane; bih = 1,6-bis(imidazol)hexane; bib = 1,4-bis(imidazole)butane) have been hydrothermally synthesized and fully characterized. Compounds 1-4 contain polyoxoanion [Ca?P6Mon(V)Mo18-n(VI)O73]((6+n)-) (n = 0, 2, or 4) (abbreviated as {P6Mo18O73}) as a basic building block, which is composed of a "basket body" {P2Mo14} unit and a "handle"-liked {P4Mo4} fragment encasing an alkaline-earth metal Ca(2+) cation in the cage. Compound 1 exhibits an infrequent 2D layer structure linked by the Cu(H2O)2 linker and an uncommon tetranuclear calcium complex, while compound 2 is 8-connected 2-D layers connected by binuclear {Fe2(H2O)3} segaments, which are observed for the first time as 2-D basket-like assemblies. Compounds 3 and 4 are similar 1D Z-typed chains bonded by M(H2O)2 units (M = Cu for 3 and Fe for 4). The optical band gaps of 1-4 reveal their semiconductive natures. They exhibit universal highly efficient degradation ability for typical dyes such as methylene blue, methyl orange, and rhodamine B under UV light. The lifetime and catalysis mechanism of the catalysts have been investigated. The compounds also show good bifunctional electrocatalytic behavior for oxidation of amino acids and reduction of NO2(-). PMID:26130499

  3. Identification of the Preisach probability functions for soft magnetic materials

    Microsoft Academic Search

    Ermanno Cardelli; Lorenzo Fiorucci; Edward Della Torre

    2001-01-01

    Presents a novel technique for the identification of the parameters of the probability function used in the Preisach-based modeling. This technique seems to pass over the problems linked with the use of a product of two single-valued functions as a probability function that in the case of soft magnetic materials may cause an unacceptable lack in accuracy of the model.

  4. Inorganic raw materials economy and provenance of chipped industry in some stone age sites of northern and central Italy.

    PubMed

    Bietti, Amilcare; Boschian, Giovanni; Crisci, Gino Mirocle; Danese, Ermanno; De Francesco, Anna Maria; Dini, Mario; Fontana, Federica; Giampietri, Alessandra; Grifoni, Renata; Guerreschi, Antonio; Liagre, Jérémie; Negrino, Fabio; Radi, Giovanna; Tozzi, Carlo; Tykot, Robert

    2004-06-01

    An opportunistic and local choice of raw materials is typically attested in the Lower and Middle Paleolithic industries throughout Italy. The quality of the raw material usually affected the flaking technology and quality of the products. In the Upper Paleolithic and the Mesolithic, raw material procurement strategies were more complex. Flint was exploited both locally, in areas where abundant outcrops of raw materials were available (such as the Lessini mountains), and in distant localities, after which it was transported or exchanged over medium/long distances. Different routes of exchange were thus followed in the various periods; good reconstruction of these routes have been provided by a study of the Garfagnana sites in Northern Tuscany, and the Mesolithic deposit of Mondeval de Sora (Dolomites). An interesting example of a Late Upper Paleolithic flint quarry and workshop were found in Abruzzo, in the San Bartolomeo shelter. The extended trade of obsidian from Lipari, Palmarola and Sardinia to the Italian Peninsula is attested in the Neolithic, with some differences concerning the age and different areas. PMID:15636064

  5. JOURNAL OF MATERIALS SCIENCE LETTERS 21, 2002, 251 255 Organic-inorganic sol-gel coating for corrosion protection

    E-print Network

    Cao, Guozhong

    for corrosion protection of stainless steel T. P. CHOU Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA E-mail: gzcao@u.washington.edu One of the most effective corrosion example. This is the main reason for the durability and corrosion resistance be- havior of this particular

  6. Sol-Gel Synthesis of a Biotemplated Inorganic Photocatalyst: A Simple Experiment for Introducing Undergraduate Students to Materials Chemistry

    ERIC Educational Resources Information Center

    Boffa, Vittorio; Yue, Yuanzheng; He, Wen

    2012-01-01

    As part of a laboratory course, undergraduate students were asked to use baker's yeast cells as biotemplate in preparing TiO[subscript 2] powders and to test the photocatalytic activity of the resulting materials. This laboratory experience, selected because of the important environmental implications of soft chemistry and photocatalysis, provides…

  7. Histologic Evaluation of Bone Healing Capacity Following Application of Inorganic Bovine Bone and a New Allograft Material in Rabbit Calvaria

    PubMed Central

    Paknejad, Mojgan; Rokn, AmirReza; Rouzmeh, Nina; Heidari, Mohadeseh; Titidej, Azadehzeinab; Kharazifard, Mohammad Javad; Mehrfard, Ali

    2015-01-01

    Objectives: Considering the importance of bone augmentation prior to implant placement in order to obtain adequate bone quality and quantity, many studies have been conducted to evaluate different techniques and materials regarding new bone formation. In this study, we investigated the bone healing capacity of two different materials deproteinized bovine bone mineral (DBBM with the trade name of Bio-Oss) and demineralized freeze-dried bone allograft (DFDBA with the trade name of DynaGraft). Materials and Methods: This randomized blinded prospective study was conducted on twelve New Zealand white rabbits. Three cranial defects with an equal diameter were created on their calvarium. Subsequently, they were distributed into three groups: 1. The control group without any treatment; 2. The Bio-Oss group; 3. The DynaGraft group. After 30 days, the animals were sacrificed for histologic and histomorphometric analysis. Results: Substantial new bone formation was observed in both groups. DynaGraft: 56/1 % ± 15/1 and Bio-Oss: 53/55 % ± 13/5 compared to the control group: 28/6 % ± 11/2. All groups showed slight inflammation and a small amount of residual biomaterial was observed. Conclusion: Considerable new bone formation was demonstrated in both DynaGraft and Bio-Oss groups in comparison with the control group. Both materials are considered biocompatible regarding the negligible foreign body reaction. PMID:26005452

  8. Comparison of inorganic ion exchange materials for removing cesium, strontium, and transuranic elements from K-basin water

    Microsoft Academic Search

    G. N. Brown; J. R. Bontha; K. J. Carson; R. J. Elovich; J. R. DesChane

    1997-01-01

    The work presented in this report was conducted by the Pacific Northwest National Laboratory (PNNL) under the Efficient Separations and Crosscutting Program (ESP), Office of Science and Technology, U.S. Department of Energy (DOE). The objective of this work was to investigate radionuclide uptake by several newly produced ion exchange materials under actual waste conditions, and to compare the performance of

  9. Studies on structure-function relationships in functional metal oxide semiconductor photoelectrodes and inorganic-polymer composite materials

    Microsoft Academic Search

    Ryan Lee Spray

    2009-01-01

    Metal oxides have interesting physical and electronic properties that have resulted great contributions to the field of catalysis, sensing, portable energy storage and photoelectrochemistry. As many of these applications rely on the interfacial area of the active metal oxide, it is important to tailor the surface composition and morphology in order to increase efficiency. This thesis will discuss techniques to

  10. A review of piezoelectric polymers as functional materials for electromechanical transducers

    NASA Astrophysics Data System (ADS)

    Ramadan, Khaled S.; Sameoto, D.; Evoy, S.

    2014-03-01

    Polymer based MEMS and microfluidic devices have the advantages of mechanical flexibility, lower fabrication cost and faster processing over silicon based ones. Also, many polymer materials are considered biocompatible and can be used in biological applications. A valuable class of polymers for microfabricated devices is piezoelectric functional polymers. In addition to the normal advantages of polymers, piezoelectric polymers can be directly used as an active material in different transduction applications. This paper gives an overview of piezoelectric polymers based on their operating principle. This includes three main categories: bulk piezoelectric polymers, piezocomposites and voided charged polymers. State-of-the-art piezopolymers of each category are presented with a focus on fabrication techniques and material properties. A comparison between the different piezoelectric polymers and common inorganic piezoelectric materials (PZT, ZnO, AlN and PMN-PT) is also provided in terms of piezoelectric properties. The use of piezopolymers in different electromechanical devices is also presented. This includes tactile sensors, energy harvesters, acoustic transducers and inertial sensors.

  11. Selenium, selected inorganic elements, and organochlorine pesticides in bottom material and biota from the Colorado River delta

    USGS Publications Warehouse

    Garcia-Hernandez, J.; King, K.A.; Velasco, A.L.; Shumilin, E.; Mora, M.A.; Glenn, E.P.

    2001-01-01

    Concentrations of selenium (Se) in bottom material ranged from 0.6 to 5.0 ??g g-1, and from 0.5 to 18.3 ??g g-1 in biota; 23% of samples exceeded the toxic threshold. Concentrations of DDE in biota exceeded the toxic threshold in 30% of the samples. Greater concentrations of selenium in biota were found at sites with strongly reducing conditions, no output, alternating periods of drying and flooding or dredging activities, and at sites that received water directly from the Colorado River. The smallest Se concentrations in biota were found at sites where an outflow and exposure or physical disturbance of the bottom material were uncommon. ?? 2001 Academic Press.

  12. Wavelength dependence of the damage threshold of inorganic materials under extreme-ultraviolet free-electron-laser irradiation

    Microsoft Academic Search

    S. P. Hau-Riege; R. A. London; R. M. Bionta; D. Ryutov; R. Soufli; S. Bajt; M. A. McKernan; S. L. Baker; J. Krzywinski; R. Sobierajski; R. Nietubyc; D. Klinger; J. B. Pelka; M. Jurek; L. Juha; J. Chalupský; J. Cihelka; V. Hájková; A. Velyhan; J. Krása; K. Tiedtke; S. Toleikis; H. Wabnitz; M. Bergh; C. Caleman; N. Timneanu

    2009-01-01

    We exposed bulk SiC and films of SiC and B4C to single 25 fs long free-electron-laser pulses with wavelengths between 13.5 and 32 nm. The materials are candidates for x-ray free-electron laser optics. We found that the threshold for surface-damage of the bulk SiC samples exceeds the fluence required for thermal melting at all wavelengths. The damage threshold of the

  13. Beneficial reuse of FGD material in the construction of low permeability liners: Impacts on inorganic water quality constituents

    SciTech Connect

    Cheng, C.M.; Tu, W.; Zand, B.; Butalia, T.; Wolfe, W.; Walker, H. [Ohio State University, Columbus, OH (United States)

    2007-05-15

    In this paper, we examine the water quality impacts associated with the reuse of fixated flue gas desulfurization (FGD) material as a low permeability liner for agricultural applications. A 0.457-m-thick layer of fixated FGD material from a coal-fired power plant was utilized to create a 708 m{sup 2} swine manure pond at the Ohio Agricultural Research and Development Center Western Branch in South Charleston, Ohio. To assess the effects of the fixated FGD material liner, water quality samples were collected over a period of 5 years from the pond surface water and a sump collection system beneath the liner. Water samples collected from the sump and pond surface water met all Ohio nontoxic criteria, and in fact, generally met all national primary and secondary drinking water standards. Furthermore it was found that hazardous constituents (i.e., As, B, Cr, Cu, and Zn) and agricultural pollutants (i.e., phosphate and ammonia) were effectively retained by the FGD liner system. The retention of As, B, Cr, Cu, Zn, and ammonia was likely due to sorption to mineral components of the FGD liner, while Ca, Fe, and P retention were a result of both sorption and precipitation of Fe- and Ca-containing phosphate solids.

  14. Functional materials for sustainable energy technologies: four case studies.

    PubMed

    Kuznetsov, V L; Edwards, P P

    2010-01-01

    The critical topic of energy and the environment has rarely had such a high profile, nor have the associated materials challenges been more exciting. The subject of functional materials for sustainable energy technologies is demanding and recognized as a top priority in providing many of the key underpinning technological solutions for a sustainable energy future. Energy generation, consumption, storage, and supply security will continue to be major drivers for this subject. There exists, in particular, an urgent need for new functional materials for next-generation energy conversion and storage systems. Many limitations on the performances and costs of these systems are mainly due to the materials' intrinsic performance. We highlight four areas of activity where functional materials are already a significant element of world-wide research efforts. These four areas are transparent conducting oxides, solar energy materials for converting solar radiation into electricity and chemical fuels, materials for thermoelectric energy conversion, and hydrogen storage materials. We outline recent advances in the development of these classes of energy materials, major factors limiting their intrinsic functional performance, and potential ways to overcome these limitations. PMID:19943280

  15. Harvesting Vibrational Energy Using Material Work Functions

    PubMed Central

    Varpula, Aapo; Laakso, Sampo J.; Havia, Tahvo; Kyynäräinen, Jukka; Prunnila, Mika

    2014-01-01

    Vibration energy harvesters scavenge energy from mechanical vibrations to energise low power electronic devices. In this work, we report on vibration energy harvesting scheme based on the charging phenomenon occurring naturally between two bodies with different work functions. Such work function energy harvester (WFEH) is similar to electrostatic energy harvester with the fundamental distinction that neither external power supplies nor electrets are needed. A theoretical model and description of different operation modes of WFEHs are presented. The WFEH concept is tested with macroscopic experiments, which agree well with the model. The feasibility of miniaturizing WFEHs is shown by simulating a realistic MEMS device. The WFEH can be operated as a charge pump that pushes charge and energy into an energy storage element. We show that such an operation mode is highly desirable for applications and that it can be realised with either a charge shuttle or with switches. The WFEH is shown to give equal or better output power in comparison to traditional electrostatic harvesters. Our findings indicate that WFEH has great potential in energy harvesting applications. PMID:25348004

  16. Harvesting vibrational energy using material work functions.

    PubMed

    Varpula, Aapo; Laakso, Sampo J; Havia, Tahvo; Kyynäräinen, Jukka; Prunnila, Mika

    2014-01-01

    Vibration energy harvesters scavenge energy from mechanical vibrations to energise low power electronic devices. In this work, we report on vibration energy harvesting scheme based on the charging phenomenon occurring naturally between two bodies with different work functions. Such work function energy harvester (WFEH) is similar to electrostatic energy harvester with the fundamental distinction that neither external power supplies nor electrets are needed. A theoretical model and description of different operation modes of WFEHs are presented. The WFEH concept is tested with macroscopic experiments, which agree well with the model. The feasibility of miniaturizing WFEHs is shown by simulating a realistic MEMS device. The WFEH can be operated as a charge pump that pushes charge and energy into an energy storage element. We show that such an operation mode is highly desirable for applications and that it can be realised with either a charge shuttle or with switches. The WFEH is shown to give equal or better output power in comparison to traditional electrostatic harvesters. Our findings indicate that WFEH has great potential in energy harvesting applications. PMID:25348004

  17. Topology optimization of compliant mechanisms with multiple materials using a peak function material interpolation scheme

    Microsoft Academic Search

    L. Yin; G. K. Ananthasuresh

    2001-01-01

    .   In the topology optimization of structures, compliant mechanisms or materials, a density-like function is often used for material\\u000a interpolation to overcome the computational difficulties encountered in the large “0-1” type integer programming problem.\\u000a In this paper, we illustrate that a gradually formed continuous peak function can be used for material interpolation. One\\u000a of the advantages of introducing the peak

  18. Functional oxide nanobelts - from materials to nanodevices

    NASA Astrophysics Data System (ADS)

    Lin, Zhong; Wang

    2003-11-01

    Nanowire and nanotube based materials have been demonstrated as building blocks for nanocircuits, nanosystems and nano-optoelectronics. Recently, ultra-long belt-like, quasi-one-dimensional nanostructures (so called nanobelts or nanoribbons) have been successfully synthesized for semiconducting oxides of zinc, tin, indium, cadmium and gallium, by simply evaporating the desired commercial metal oxide powders at high temperatures [1]. The as-synthesized oxide nanobelts are pure, structurally uniform, single crystalline and most of them free from dislocations; they have a rectangular-like cross-section with typical widths of 30 - 300 nm, width-to-thickness ratios of 5 - 10 and lengths of up to a few millimeters. The belt-like morphology appears to be a unique and common structural characteristic for the family of semiconducting oxides with cations of different valence states and materials of distinct crystallographic structures. Using the technique demonstrated for measuring the mechanical properties of carbon nanotubes based on in-situ transmission electron microscopy [2,3], the bending modulus of the oxide nanobelts has been measured and the nanobelt is shown to be a dual mode nanoresonator for NEMS technology. Field effect transistors [4] and ultra-sensitive nano-size gas sensors [5], nanoresonators and nanocantilevers [6] have also been fabricated based on individual nanobelts. Thermal transport along the nanobelt has also been measured. Nanocantilevers based on nanobelts have been fabricated. Very recently, structurally nanobelts exhibiting piezoelectric and ferroelectric properties have been synthesized, which could be a candidate for nano-scale traducers, actuators and sensors. [1] Z.W. Pan, Z.R. Dai and Z.L. Wang, Science, 209 (2001) 1947. [2] P. Poncharal, Z.L. Wang, D. Ugarte and W.A. de Heer, Science, 283 (1999) 1513; Electron Microscopy of Nanotubes, ed. Z.L. Wang and C. Hui, Kluwer Academic Publisher (2003). [3] R.P. Gao, Z.L. Wang, Z.G. Bai, W. de Heer, L. Dai and M. Gao, Phys. Rev. Letts., 85 (2000) 622; Z.L. Wang, P. Poncharal and W.A. De Heer, Pure Appl. Chem. Vol. 72 (2000) 209. [4] M. Arnold, P. Avouris, Z.L. Wang,. Phys. Chem. B, 107 (2002) 659. [5] E. Comini, G. Faglia, G. Sberveglieri, Zhengwei Pan, Z. L. Wang Applied Physics Letters, 81 (2002) 1869. [6] W. Hughes and Z.L. Wang, Appl. Phys. Letts., 82 (2003) 2886.

  19. Multifunctional composite materials for catalysis and chemical mechanical planarization

    Microsoft Academic Search

    Cecil A. Coutinho

    2009-01-01

    Composite materials formed from two or more functionally different materials offer a versatile avenue to create a tailored material with well defined traits. Within this dissertation research, multi-functional composites were synthesized based on organic and inorganic materials. The functionally of these composites was experimentally tested and a semi-empirical model describing the sedimentation behavior of these particles was developed. This first

  20. Material selection for Multi-Function Waste Tank Facility tanks

    SciTech Connect

    Larrick, A.P.; Blackburn, L.D.; Brehm, W.F.; Carlos, W.C.; Hauptmann, J.P. [Westinghouse Hanford Co., Richland, WA (United States); Danielson, M.J.; Westerman, R.E. [Pacific Northwest Lab., Richland, WA (United States); Divine, J.R. [ChemMet Ltd., West Richland, WA (United States); Foster, G.M. [ICF Kaiser Hanford Co., Richland, WA (United States)

    1995-03-01

    This paper briefly summarizes the history of the materials selection for the US Department of Energy`s high-level waste carbon steel storage tanks. It also provides an evaluation of the materials for the construction of new tanks at the evaluation of the materials for the construction of new tanks at the Multi-Function Waste Tank Facility. The evaluation included a materials matrix that summarized the critical design, fabrication, construction, and corrosion resistance requirements: assessed. each requirement: and cataloged the advantages and disadvantages of each material. This evaluation is based on the mission of the Multi-Function Waste Tank Facility. On the basis of the compositions of the wastes stored in Hanford waste tanks, it is recommended that tanks for the Multi-Function Waste Tank Facility be constructed of ASME SA 515, Grade 70, carbon steel.

  1. Weathering processes and the composition of inorganic material transported through the orinoco river system, Venezuela and Colombia

    USGS Publications Warehouse

    Stallard, R.F.; Koehnken, L.; Johnsson, M.J.

    1991-01-01

    The composition of river-borne material in the Orinoco River system is related primarily to erosion regime, which in turn is related to tectonic setting; especially notable is the contrast between material derived from tectonically active mountain belts and that from stable cratonic regions. For a particular morpho-tectonic region, the compositional suites of suspended sediment, bed material, overback deposits, and dissolved phases are fairly uniform are are typically distinct from whose of other regions. For each region, a consistent set of chemical weathering reactions can be formulated to explain the composition of dissolved and solid loads. In developing these formulations, erosion on slopes and storage of solids in soils and alluvial sediments are important considerations. Compositionally verymature sediment is derived from areas of thick soils where erosion is transport limited and from areas where sediments are stored for extended periods of time in alluvial deposits. Compositionally immature sediments are derived from tectonically active mountain belts where erosion is weathering limited. Weathering-limited erosion also is important in the elevated parts of the Guayana Shield within areas of sleep topography. Compared to the mountain belts, sediments derived from elevated parts of the Shield are more mature. A greater degree of chemical weathering seems to be needed to erode the rock types typical of the Shield. The major-element chemistry and mineral composition of sediment delivered by the Orinoco River to the ocean are controlled by rivers that have their headwaters in mountain belts and cross the Llanos, a region of alluvial plains within the foreland basin. The composition of sediments in rivers that drain the Shield seems to be established primarily at the site of soil formation, whereas for rivers that drain the mountain belts, additional weathering occurs during s episodes of storage on alluvial plains as sediments are transported across the Llanos to the main stem of the Orinoco. After mixing into the main stem, there seems to be little subsequent alteration of sediment. ?? 1991.

  2. Morphology and thermal properties of organic–inorganic hybrid material involving monofunctional-anhydride POSS and epoxy resin

    Microsoft Academic Search

    Yiting Xu; Yingying Ma; Yuanming Deng; Cangjie Yang; Jiangfeng Chen; Lizong Dai

    2011-01-01

    Monofunctional-anhydride polyhedral oligomeric silsesquioxane (i-C4H9)7Si8O12OSi(CH3)2(C8H9O3) (AH-POSS) was synthesized and characterized by FTIR, NMR, element analysis. Then AH-POSS was incorporated into epoxy system either pre-reacted or non-reacted using hexahydrophthalic anhydride (HHPA) as curing agent. Pre-reacted system hybrid materials were obtained by two-step preparation. First, AH-POSS reacted with part of diglycidyl ether of bisphenol A (DGEBA) to form AH-POSS-epoxy precursor in DGEBA,

  3. The role of physical and chemical properties of Pd nanostructured materials immobilized on inorganic carriers on ion formation in atmospheric pressure laser desorption/ionization mass spectrometry.

    PubMed

    Silina, Yuliya E; Koch, Marcus; Volmer, Dietrich A

    2014-06-01

    Fundamental parameters influencing the ion-producing efficiency of palladium nanostructures (nanoparticles [Pd-NP], nanoflowers, nanofilms) during laser irradiation were studied in this paper. The nanostructures were immobilized on the surface of different solid inorganic carrier materials (porous and mono-crystalline silicon, anodic porous aluminum oxide, glass and polished steel) by using classical galvanic deposition, electroless local deposition and sputtering. It was the goal of this study to investigate the influence of both the nanoparticular layer as well as the carrier material on ion production for selected analyte molecules. Our experiments demonstrated that the dimensions of the synthesized nanostructures, the thickness of the active layers, surface disorders, thermal conductivity and physically or chemically adsorbed water influenced signal intensities of analyte ions during surface-assisted laser desorption/ionization (SALDI) while no effects such as plasmon resonance, photoelectric effect or catalytic activity were expected to occur. Excellent LDI abilities were seen for Pd-NPs immobilized on steel, while Pd nanoflowers on porous silicon exhibited several disadvantages; viz, strong memory effects, dependency of the analytical signal on amount of physically and chemically adsorbed water inside porous carrier, reduced SALDI activity from unstable connections between Pd and semiconductor material, decrease of the melting point of pure silicon after Pd immobilization and resulting strong laser ablation of metal/semiconductor complex, as well as significantly changed surface morphology after laser irradiation. The analytical performance of Pd-NP/steel was further improved by applying a hydrophobic coating to the steel surface before galvanic deposition. This procedure increased the distance between Pd-NPs, thus reducing thermal stress upon LDI; it simultaneously decreased spot sizes of deposited sample solutions. PMID:24913399

  4. New Functional Materials for Fluid Control and Sensing in Microfluidic

    E-print Network

    Lee, Hyowon

    New Functional Materials for Fluid Control and Sensing in Microfluidic Devices Fernando Benito INCLUDED, EXPECTED THAT THE ABILITY TO MANIPULATE FLUID STREAMS, IN MICROCHANNELS, EASILY, WOULD RESULT FLUID HANDLING INTEGRATED ON CHIP, INDEFINITELY SELF-SUSTAINING CURRENT PLATFORMS #12;PROBLEM

  5. Stochastic multiscale models for fracture analysis of functionally graded materials

    E-print Network

    Rahman, Sharif

    -intensity factors or accurate probability of fracture initiation. The concurrent multiscale model is sufficientlyStochastic multiscale models for fracture analysis of functionally graded materials Arindam three multiscale models, including sequential, invasive, and concurrent models, for fracture analysis

  6. Electronic Packaging Materials and Their Functions in Thermal Managements

    Microsoft Academic Search

    Xingcun Colin Tong

    \\u000a Advanced electronic packaging materials play a key role in the proper functioning and useful life of the packaged electronic\\u000a assembly. These functions mainly include electrical conduction, electrical insulation, mechanical support and structural profiles,\\u000a environmental protection, as well as thermal conduction and dissipation. Therefore, electronic packaging materials shall possess\\u000a required electrical, mechanical, thermal, chemical, and physical properties to provide the electronic

  7. Hydrogen Separation Using ORNL's Inorganic Membranes

    Microsoft Academic Search

    Roddie R. Judkins; Brian L. Bischoff

    Oak Ridge National Laboratory has been engaged in separations science and engineering technologies for many years. These technologies include novel nanoporous inorganic membranes developed by the Oak Ridge Gaseous Diffusion Plant and its successor organizations. Funding for the development of these nanoporous inorganic membranes for hydrogen separation has been provided by the DOE Fossil Energy Advanced Research Materials Program. For

  8. Three-dimensional thermal buckling analysis of functionally graded materials

    Microsoft Academic Search

    Kyung-Su Na; Ji-Hwan Kim

    2004-01-01

    Three-dimensional thermal buckling analysis is performed for functionally graded materials. Material properties are assumed to be temperature dependent, and varied continuously in the thickness direction according to a simple power law distribution in terms of the volume fraction of a ceramic and metal. The finite element model is adopted by using an 18-node solid element to analyze more accurately the

  9. FUNCTIONAL AND SMART MATERIALS -Structural evolution and structure analysis

    E-print Network

    Wang, Zhong L.

    FUNCTIONAL AND SMART MATERIALS -Structural evolution and structure analysis by Z.L. Wang and Z.C. Kang Georgia Institute of Technology Introduction Smart systems and smart materials Smart structures and repetivity. A smart system/structure is defined to be a non-biological physical structure having

  10. Acquiring Bidirectional Texture Functions for Large-Scale Material Samples

    E-print Network

    Bonn, Universität

    of capturing large-scale material samples. We propose a method based on controlled texture synthesis to produce measurement of a small fraction of the sample, together with few images of the large-scale structure images. Keywords bidirectional texture functions - texture synthesis - material appearance. 1

  11. Production of modern functional materials based on renewable vegetable resources

    NASA Astrophysics Data System (ADS)

    Onishchenko, D. V.; Reva, V. P.

    2013-05-01

    An energy-saving technology for production of variously structured carbon modifications from a renewable vegetable raw material, i.e., the waste of agricultural crops and peat moss, has been developed. Promising functional materials — refractory compounds (tungsten and titanium carbides) and oil sorbents possessing a combination of high operating characteristics — have been formed on the basis of the synthesized carbon modifications.

  12. Extensively Reversible Thermal Transformations of a Bistable, Fluorescence-Switchable Molecular Solid: Entry into Functional Molecular Phase-Change Materials.

    PubMed

    Srujana, P; Radhakrishnan, T P

    2015-06-15

    Functional phase-change materials (PCMs) are conspicuously absent among molecular materials in which the various attributes of inorganic solids have been realized. While organic PCMs are primarily limited to thermal storage systems, the amorphous-crystalline transformation of materials like Ge-Sb-Te find use in advanced applications such as information storage. Reversible amorphous-crystalline transformations in molecular solids require a subtle balance between robust supramolecular assembly and flexible structural elements. We report novel diaminodicyanoquinodimethanes that achieve this transformation by interlinked helical assemblies coupled with conformationally flexible alkoxyalkyl chains. They exhibit highly reversible thermal transformations between bistable (crystalline/amorphous) forms, along with a prominent switching of the fluorescence emission energy and intensity. PMID:25941070

  13. Electrochemical sensor for sensitive detection of paracetamol based on novel multi-walled carbon nanotubes-derived organic-inorganic material.

    PubMed

    Hui, Junmin; Li, Wenjuan; Guo, Yanlei; Yang, Zhu; Wang, Yingxiong; Yu, Chao

    2014-03-01

    A new electrochemical sensor based on a novel organic-inorganic material (PNFCTs) was proposed for detection of paracetamol in this paper. First, PNFCTs were prepared with multi-walled carbon nanotubes (MWNTs) and a derivative of 3,4,9,10-perylenetetracarboxylic dianhydride (PTC-NH2) via cross-linking method. Then, PNFCTs were coated onto the surface of the glassy carbon electrode (GCE) to form porous organic conducting polymer films (PNFCTs/GCE), which could not only increase the loading of paracetamol efficiently but also provide an interface with exceptional electrical conductivity for paracetamol. Finally, gold nanoparticles (GNPs) were attached to the electrode surface through electrodepositing method, which obtained GNPs/PNFCTs/GCE electrode. The electrochemical behavior of paracetamol on GNPs/PNFCTs/GCE was explored by cyclic voltammetrys (CVs) and differential pulse voltammograms (DPVs). The results showed that the GNPs/PNFCTs/GCE exhibited excellent electrocatalytic activity to paracetamol, which should be attributed to remarkable properties of the new composite nanomaterials with porous nanostructure and exceptional electrical conductivity. The wide liner range and detection limit were 0.3-575 and 0.1 ?M, respectively. Finally, it was successfully used to detect paracetamol in dilution human serum and commercial tablets. The sensor shows great promise for simple, sensitive, and selective detection paracetamol and provides a promising approach in paracetamol clinical research and overdose diagnostic applications. PMID:24005761

  14. Random-graft polymer-directed synthesis of inorganic mesostructures with ultrathin frameworks.

    PubMed

    Jo, Changbum; Seo, Yongbeom; Cho, Kanghee; Kim, Jaeheon; Shin, Hye Sun; Lee, Munhee; Kim, Jeong-Chul; Kim, Sang Ouk; Lee, Jeong Yong; Ihee, Hyotcherl; Ryoo, Ryong

    2014-05-12

    A widely employed route for synthesizing mesostructured materials is the use of surfactant micelles or amphiphilic block copolymers as structure-directing agents. A versatile synthesis method is described for mesostructured materials composed of ultrathin inorganic frameworks using amorphous linear-chain polymers functionalized with a random distribution of side groups that can participate in inorganic crystallization. Tight binding of the side groups with inorganic species enforces strain in the polymer backbones, limiting the crystallization to the ultrathin micellar scale. This method is demonstrated for a variety of materials, such as hierarchically nanoporous zeolites, their aluminophosphate analogue, TiO2 nanosheets of sub-nanometer thickness, and mesoporous TiO2, SnO2, and ZrO2. This polymer-directed synthesis is expected to widen our accessibility to unexplored mesostructured materials in a simple and mass-producible manner. PMID:24692040

  15. Prediction of the functional properties of ceramic materials from composition using artificial neural networks

    Microsoft Academic Search

    D. J. Scott; P. V. Coveney; J. A. Kilner; J. C. H. Rossiny; N. Mc N. Alford

    2007-01-01

    We describe the development of artificial neural networks (ANN) for the\\u000aprediction of the properties of ceramic materials. The ceramics studied here\\u000ainclude polycrystalline, inorganic, non-metallic materials and are investigated\\u000aon the basis of their dielectric and ionic properties. Dielectric materials are\\u000aof interest in telecommunication applications where they are used in tuning and\\u000afiltering equipment. Ionic and mixed conductors

  16. Failure behaviour of functionally gradient materials under thermal cycling conditions

    Microsoft Academic Search

    C. Tekmen; I. Ozdemir; E. Celik

    2003-01-01

    Functionally gradient coatings are coating systems, which are used to increase performances of high temperature components in the hot gas turbine section of gas turbine engines, diesel engines, in aerospace and aircraft applications. These coatings consist of a transition from the metallic bond layer to cermet and from cermet to the ceramic layer. Functionally gradient materials were applied on stainless

  17. Inorganic Reaction Mechanisms. Part I

    ERIC Educational Resources Information Center

    Cooke, D. O.

    1976-01-01

    Provides a collection of data on the mechanistic aspects of inorganic chemical reactions. Wherever possible includes procedures for classroom demonstration or student project work. The material covered includes gas phase reactions, reactions in solution, mechanisms of electron transfer, the reaction between iron III and iodine, and hydrolysis. (GS)

  18. Non-formaldehyde, crease resistant agent for cotton fabrics based on an organic-inorganic hybrid material.

    PubMed

    Schramm, Christian; Rinderer, Beate; Tessadri, Richard

    2014-05-25

    1,2,3,4-Butanetetracarboxylic acid (BTCA) was reacted with (3-aminopropyl)triethoxysilane (APTES) to a poly(amic)acid (PAA). The molar ratios of BTCA and APTES were 1/1 (B/A-1/1), 1/2 (B/A-1/2), 1/3 (B/A-1/3), and 1/4 (B/A-1/4). The as-prepared precursor solution was applied to cotton substrates. After thermal treatment (180°C) the physical-mechanical properties of the cotton samples were tested by means of dry crease recovery angle and tensile strength. For B/A-1/1 treated fabrics a significant improvement of the crease resistance was observed. FT-IR spectra revealed the formation of an imide group and an ester linkage, indicating the cross-linking of the cellulosic material. SEM images showed a smooth surface. As evidenced by TGA data the thermal stability of the cotton samples was not increased. No hydrophobicity could be observed. For B/A-1/3 and (B/A-1/4) modified cotton samples no crease resistant properties were detected. However, enhanced contact angle values were measured. A reaction mechanism for the formation of the ladder-like polysilsesquioxane and the cross-linking reaction is proposed. PMID:24708956

  19. Organic thin film transistor using a photo-curable organic/inorganic hybrid material as a gate dielectric.

    PubMed

    Hwang, Do-Hoon; Yang, Yong Suk; Lee, Jeong-Ik; Kim, Seong Hyun; Park, Oun-Ho; Kim, Ho-Cheol; Lee, Victor; Dubois, Geraud; Miller, Robert D

    2008-09-01

    A polyhedral oligomeric silsesquioxane derivative (POSS-OXT) containing photo-curable 4-membered cyclic oxetane functional groups was used as a gate dielectric of organic field effect transistor. The POSS-OXT was cross-linked and completely solidified by UV irradiation in the presence of a selected photo acid generator, and pinhole free uniform thin film was obtained. We fabricated a metal/insulator/metal device of Au/POSS-OXT (300 nm)/Au with area of 0.7 mm2 and the measured leakage current and capacitance of the device to evaluate the insulating properties of the POSS-OXT thin film. The maximum current was about 0.25 nA when 40 V was applied to the device. The observed values of the capacitance per unit area and dissipation factor were 11.4 nF/cm2 and 0.025, respectively. We fabricated an organic thin film transistor with pentacene as the active semiconductor and the photo-cross-linked POSS-OXT as an insulator. A field effect carrier mobility of 0.03 cm2/VN s was obtained with the device. PMID:19049058

  20. Innovations in materials design, Part I: The design of inorganic compounds. Part II: Searching for new electro-optical, ferro-electric, superconducting, and semiconducting materials. Final report, 1 December 1995-1 September 1996

    SciTech Connect

    Kiselyova, N.N.; Gladun, V.P.; Vashenko, N.D.; Kravchenko, N.V.; Petukhov, N.V.

    1996-09-01

    The use of computer learning strategies for predicting inorganic compounds which are believed promising as new electro-optical, ferro-electric, superconducting or semiconducting materials is explained. Prediction reliability utilizing these computer learning strategies is based on: (1) expert selection of example compounds, (2) expert assessment of data for computer learning, and (3) comparison of predictions which have been obtained using various feature sets. The classes of the inorganic compounds most promising for searching for new electro-optical, ferro-electric, superconducting, and semiconducting materials are directly based on the analysis of the application domains and the known data. The results of predicting the crystal structure types at normal pressure and room temperature for the compound with composition of AB2Se4 are presented. Types considered were chalcopyrite, Th3P4, CaFe2O4, Yb3S4, Yb3Se4, PbGa2Se4, NiCr2Se4, spinel, or olivine. Analysis of predictions showed that the structures resembling olivine and NiCr2Se4 are an inherent feature of the compounds with composition A(IV)B(II)2Se4. But the structure types Th3P4 and NiCr2Se4 are characteristic of compounds with composition A(II)B(III)2Se4. Prediction of the crystal structure types at standard conditions for compounds with composition ABX2 were also carried out. Types considered included chalcopyrite, a or b-NaFeO2, a-LiFeO2, or TISe.

  1. Some functional properties of composite material based on scrap tires

    NASA Astrophysics Data System (ADS)

    Plesuma, Renate; Malers, Laimonis

    2013-09-01

    The utilization of scrap tires still obtains a remarkable importance from the aspect of unloading the environment from non-degradable waste [1]. One of the most prospective ways for scrap tires reuse is a production of composite materials [2] This research must be considered as a continuation of previous investigations [3, 4]. It is devoted to the clarification of some functional properties, which are considered important for the view of practical applications, of the composite material. Some functional properties of the material were investigated, for instance, the compressive stress at different extent of deformation of sample (till 67% of initial thickness) (LVS EN 826) [5] and the resistance to UV radiation (modified method based on LVS EN 14836) [6]. Experiments were realized on the purposefully selected samples. The results were evaluated in the correlation with potential changes of Shore C hardness (Shore scale, ISO 7619-1, ISO 868) [7, 8]. The results showed noticeable resistance of the composite material against the mechanical influence and ultraviolet (UV) radiation. The correlation with the composition of the material, activity of binder, definite technological parameters, and the conditions supported during the production, were determined. It was estimated that selected properties and characteristics of the material are strongly dependent from the composition and technological parameters used in production of the composite material, and from the size of rubber crumb. Obtained results show possibility to attain desirable changes in the composite material properties by changing both the composition and technological parameters of examined material.

  2. Functionalized Materials From Elastomers to High Performance Thermoplastics

    SciTech Connect

    Laura Ann Salazar

    2003-05-31

    Synthesis and incorporation of functionalized materials continues to generate significant research interest in academia and in industry. If chosen correctly, a functional group when incorporated into a polymer can deliver enhanced properties, such as adhesion, water solubility, thermal stability, etc. The utility of these new materials has been demonstrated in drug-delivery systems, coatings, membranes and compatibilizers. Two approaches exist to functionalize a material. The desired moiety can be added to the monomer either before or after polymerization. The polymers used range from low glass transition temperature elastomers to high glass transition temperature, high performance materials. One industrial example of the first approach is the synthesis of Teflon(reg. sign). Poly(tetrafluoroethylene) (PTFE or Teflon(reg. sign)) is synthesized from tetrafluoroethylene, a functionalized monomer. The resulting material has significant property differences from the parent, poly(ethylene). Due to the fluorine in the polymer, PTFE has excellent solvent and heat resistance, a low surface energy and a low coefficient of friction. This allows the material to be used in high temperature applications where the surface needs to be nonabrasive and nonstick. This material has a wide spread use in the cooking industry because it allows for ease of cooking and cleaning as a nonstick coating on cookware. One of the best examples of the second approach, functionalization after polymerization, is the vulcanization process used to make tires. Natural rubber (from the Hevea brasiliensis) has a very low glass transition temperature, is very tacky and would not be useful to make tires without synthetic alteration. Goodyear's invention was the vulcanization of polyisoprene by crosslinking the material with sulfur to create a rubber that was tough enough to withstand the elements of weather and road conditions. Due to the development of polymerization techniques to make cis-polyisoprene, natural rubber is no longer needed for the manufacturing of tires, but vulcanization is still utilized.

  3. Multi Functional Uptake Behaviour of Materials Prepared by Calcining Waste Paper Sludge

    Microsoft Academic Search

    VINAY KUMAR JHA; YOSHIKAZU KAMESHIMA; AKIRA NAKAJIMA; KIYOSHI OKADA; KENNETH J. D. MACKENZIE

    2006-01-01

    This study concerns with the utilization of waste paper sludge, which contains mainly cellulose fibers and inorganic fillers together with coating materials such as calcite, kaolinite and talc. Paper sludge was fired at 500–900°C for 6 h. The crystalline phases originally present decomposed at increasing temperatures (up to 800°C) in the order kaolinite < calcite < talc. Gehlenite was formed

  4. How Much Inorganic Spectroscopy and Photochemistry?

    ERIC Educational Resources Information Center

    Gray, Harry B.

    1980-01-01

    Describes three levels of courses to treat adequately the ground state electronic structures, the spectroscopy, and the photochemistry of inorganic molecules. Suggests sequences for the courses without repeating material taught in previous courses. (Author/JN)

  5. Novel Functionalized Ceramic Getter Materials for Adsorption of Radioiodine

    SciTech Connect

    Mattigod, Shas V.; Fryxell, Glen E.; Parker, Kent E.; Kaplan, Daniel I.

    2003-08-02

    A new class of getter materials has been synthesized for immobilization of long-lived radionuclides such as 129I. These novel materials consist of nanoporous ceramic substrates with tailored pore sizes ranging from 2 – 20 nm. These high surface area (~1000 m2/g) ceramic substrates have been functionalized with self-assembled monolayers consisting of soft cation-capped thiol-functionality. The resulting getter materials exhibit highly dense binding sites, and excellent selectivity for iodide. The effectiveness of these novel getter materials was evaluated using radioiodide-spiked samples of surface water and concrete leachate and adsorption performance was compared with natural sulfide mineral getter materials. The data indicated that the novel getter materials have very high affinity for radioiodide (Kd: 4 x 104 – 3 x 105 ml/g and 6 x 105 ml/g in surface and concrete leachate respectively). Comparatively, the radioiodide Kd values for natural mineral getters were typically two to three orders magnitude less than the novel getters. The results indicated that the synthetic getter materials have the potential to immobilize and therefore retard the migration of 129I in the subsurface environment. Additional studies are being conducted to evaluate the long-term stability of these materials in waste disposal environments.

  6. [Functional properties of collagenous material from chicken feet].

    PubMed

    Alves, Sandra Geres Tavares; Prudencio-Ferreira, Sandra Helena

    2002-09-01

    Collagenous material was obtained from chicken feet skins and tendons, defatted with ethylic ether and treated with 0.05 M and 0.6 M NaCl solutions. Part of the material was dried at 35 degrees C in a forced air convection oven and another was freeze-dried. The air dried material had 77.2 g/100 g of collagen and the freeze-dried material 76.7 g/100 g. Both dehydrated materials showed the same behaviour for gel formation and cold water holding capacity. The material air dried had higher emulsifying capacity than the freeze-dried one. The collagen of freeze-dried material had higher solubility in 0.5 M acetic acid and water at 70 degrees C than air dried material. Gel strength, emulsion stability and water holding capacity at 60 degrees C were higher for freeze-dried material. The results indicate the potential use of these materials as functional ingredients in meat products. PMID:12448344

  7. Anomalous dielectric behaviour in centrosymmetric organic–inorganic hybrid chlorobismuthate(III) containing functional N,N-dimethylethylammonium ligand. Crystal structure and properties

    SciTech Connect

    Piecha, A., E-mail: anna.piecha@chem.uni.wroc.pl [Faculty of Chemistry, University of Wroc?aw, Joliot–Curie 14, 50–383 Wroc?aw (Poland); G?gor, A. [Institute of Low Temperature and Structure Research, PAS, Okólna 2, 50–950 Wroc?aw (Poland)] [Institute of Low Temperature and Structure Research, PAS, Okólna 2, 50–950 Wroc?aw (Poland); W?c?awik, M.; Jakubas, R. [Faculty of Chemistry, University of Wroc?aw, Joliot–Curie 14, 50–383 Wroc?aw (Poland)] [Faculty of Chemistry, University of Wroc?aw, Joliot–Curie 14, 50–383 Wroc?aw (Poland); Medycki, W. [Institute of Molecular Physics, PAS, M. Smoluchowskiego 17, 60-179 Pozna? (Poland)] [Institute of Molecular Physics, PAS, M. Smoluchowskiego 17, 60-179 Pozna? (Poland)

    2013-01-15

    Graphical abstract: Display Omitted Highlights: ? Novel organic–inorganic hybrid chlorobismuthate(III). ? Unprecedented dielectric response in non-polar material. ? Dielectric relaxation characterized by an exceptionally large dielectric increment. ? The NMR measurements confirmed dynamic disorder of cations. -- Abstract: The structure of [C{sub 2}H{sub 5}NH(CH{sub 3}){sub 2}{sup +}]{sub 3}[BiCl{sub 6}{sup ?}] (abbreviated as DCB) was determined by a single-crystal X-ray diffraction at 115 K. The compound adopts tetragonal symmetry with the space group I4{sub 1}/acd; a = 23.35 ?, c = 17.60 ?, V = 9598 ?{sup 3} and Z = 16. The crystal structure of DCB is built up of isolated [BiCl{sub 6}]{sup 3?} units and N,N-dimethylethylammonium counterions that are accommodated in the large voids. At ambient temperature two-thirds of the counterions appear to be dynamically disordered. Dynamics of this type of cations contributes to the enhanced dielectric permittivity of DCB. A low frequency dielectric relaxation process that takes place between 200 and 300 K is characterized by an exceptionally large dielectric increment, ?? > 100, which is unprecedented in nonferroelectric materials. The molecular motions of the N,N-dimethylethylammonium cations were studied by means of {sup 1}H NMR spin-lattice relaxation time measurements.

  8. Remote Monitoring, Inorganic Monitoring

    EPA Science Inventory

    This chapter provides an overview of applicability, amenability, and operating parameter ranges for various inorganic parameters:this chapter will also provide a compilation of existing and new online technologies for determining inorganic compounds in water samples. A wide vari...

  9. THE MATERIAL BONE: Structure-Mechanical Function Relations

    NASA Astrophysics Data System (ADS)

    Weiner, S.; Wagner, H. D.

    1998-08-01

    The term bone refers to a family of materials, all of which are built up of mineralized collagen fibrils. They have highly complex structures, described in terms of up to 7 hierarchical levels of organization. These materials have evolved to fulfill a variety of mechanical functions, for which the structures are presumably fine-tuned. Matching structure to function is a challenge. Here we review the structure-mechanical relations at each of the hierarchical levels of organization, highlighting wherever possible both underlying strategies and gaps in our knowledge. The insights gained from the study of these fascinating materials are not only important biologically, but may well provide novel ideas that can be applied to the design of synthetic materials.

  10. Confined-plume chemical deposition: rapid synthesis of crystalline coatings of known hard or superhard materials on inorganic or organic supports by resonant IR decomposition of molecular precursors.

    PubMed

    Ivanov, Borislav L; Wellons, Matthew S; Lukehart, Charles M

    2009-08-26

    A one-step process for preparing microcrystalline coatings of known superhard, very hard, or ultraincompressible ceramic compositions on either inorganic or organic supports is reported. Midinfrared pulsed-laser irradiation of preceramic chemical precursors layered between IR-transmissive hard/soft supports under temporal and spatial confinement at a laser wavelength resonant with a precursor vibrational band gives one-step deposition of crystalline ceramic coatings without incurring noticeable collateral thermal damage to the support material. Reaction plume formation at the precursor/laser beam interface initiates confined-plume, chemical deposition (CPCD) of crystalline ceramic product. Continuous ceramic coatings are produced by rastering the laser beam over a sample specimen. CPCD processing of the Re-B single-source precursor, (B(3)H(8))Re(CO)(4), the dual-source mixtures, Ru(3)(CO)(12)/B(10)H(14) or W(CO)(6)/B(10)H(14), and the boron/carbon single-source precursor, o-B(10)C(2)H(12), confined between Si wafer or NaCl plates gives microcrystalline deposits of ReB(2), RuB(2), WB(4), or B(4)C, respectively. CPCD processing of Kevlar fabric wetted by (B(3)H(8))Re(CO)(4) produces an oriented, microcrystalline coating of ReB(2) on the Kevlar fabric without incurring noticeable thermal damage of the polymer support. Similarly, microcrystalline coatings of ReB(2) can be formed on IR-transmissive IR2, Teflon, or Ultralene polymer films. PMID:19642682

  11. Inorganic Nanoparticle Nucleation on Polymer Matrices

    NASA Astrophysics Data System (ADS)

    Kosteleski, Adrian John

    The introduction of inorganic nanoparticles into organic materials enhances both the mechanical and chemical properties of the material. Metallic nanoparticles, like silver and gold, have been introduced into polymers for use as antimicrobial coatings or dielectric materials, respectively. The challenge in creating these materials currently is the difficulty to homogeneously disperse the particles throughout the polymer matrix. The uneven dispersion of nanoparticles can lead to less than optimal quality and undesired properties. By creating a polymer nanocomposite material with well-controlled size inorganic materials that are evenly dispersed throughout the polymer matrix; we can improve the materials performance and properties. The objective for this research is to use polymer networks for the in situ mineralization of silver and other metallic materials to create intricate inorganic structures. The work performed here studied the ability to nucleate silver nanoparticles using poly (acrylic acid) (PAA) as the templating agent. Ionic silver was chemically reduced by sodium borohydride (NaBH4) in the presence of PAA. The effect of varying reactant concentrations of silver, NaBH 4, and PAA on particle size was studied. Reaction conditions in terms of varying temperature and pH levels of the reaction solution were monitored to observe the effect of silver nanoparticle size, shape, and concentration. By monitoring the UV spectra over time the reaction mechanism of the silver reduction process was determined to be an autocatalytic process: a period of slow, continuous nucleation followed by rapid, autocatalytic growth. The reaction kinetics for this autocatalytic process is also reported. PAA was crosslinked both chemically and physically to 3 biopolymers; ELP, an elastin like peptide, cotton fabrics, and calcium alginate hydrogels. Various compositions of PAA were physically crosslinked with calcium alginate gels to design an antimicrobial hydrogel for use in wound dressing applications. PAA's ability to nucleate nanoparticles in a solid matrix was displayed. Interestingly enough PAA retains its ability to nucleate nanoparticle even when its reactive functional groups are used in the crosslinking process. Silver nanoparticle composition and size on the solid polymer matrices was controlled by varying the composition of PAA. PAA and silver nanoparticles effect on the mechanical properties of the calcium alginate hydrogels were also studied. Physically crosslinking PAA with calcium alginate gels enables the development of intricate gel structures that are decorated with nucleated silver; yielding a composite biomaterial with improved and enhanced antimicrobial properties.

  12. Graphene and carbon nanodots in mesoporous materials: an interactive platform for functional applications.

    PubMed

    Innocenzi, Plinio; Malfatti, Luca; Carboni, Davide

    2015-07-23

    The present review is focused on a specific class of nanocomposites obtained through integration of graphene or carbon-based nanomaterials (such as carbon nanodots) with mesoporous inorganic or hybrid materials, obtained via template assisted self-assembly. The task of integrating graphene and carbon nanodots with a self-assembly process is still very challenging and this review shows some of the solutions which have been envisaged so far. These nanocomposite materials are an ideal interactive platform for developing innovative functional applications; they have a high capability of undergoing integration into advanced devices, which well exploits the advantage of tuning the wide properties and flexibility of the soft-chemistry route. A wide range of applications have been developed so far which span from sensing to electronics up to optics and biomedicine. Even though a large number of proof-of-concepts have been reported to date, an even greater expansion of applications in the field is expected to happen in the near future. PMID:26177068

  13. Analytical Model for Thermal Elastoplastic Stresses of Functionally Graded Materials

    SciTech Connect

    Zhai, P. C.; Chen, G.; Liu, L. S.; Fang, C.; Zhang, Q. J. [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

    2008-02-15

    A modification analytical model is presented for the thermal elastoplastic stresses of functionally graded materials subjected to thermal loading. The presented model follows the analytical scheme presented by Y. L. Shen and S. Suresh [6]. In the present model, the functionally graded materials are considered as multilayered materials. Each layer consists of metal and ceramic with different volume fraction. The ceramic layer and the FGM interlayers are considered as elastic brittle materials. The metal layer is considered as elastic-perfectly plastic ductile materials. Closed-form solutions for different characteristic temperature for thermal loading are presented as a function of the structure geometries and the thermomechanical properties of the materials. A main advance of the present model is that the possibility of the initial and spread of plasticity from the two sides of the ductile layers taken into account. Comparing the analytical results with the results from the finite element analysis, the thermal stresses and deformation from the present model are in good agreement with the numerical ones.

  14. Functionalized apertures for the detection of chemical and biological materials

    DOEpatents

    Letant, Sonia E. (Livermore, CA); van Buuren, Anthony W. (Livermore, CA); Terminello, Louis J. (Danville, CA); Thelen, Michael P. (Danville, CA); Hope-Weeks, Louisa J. (Brentwood, CA); Hart, Bradley R. (Brentwood, CA)

    2010-12-14

    Disclosed are nanometer to micron scale functionalized apertures constructed on a substrate made of glass, carbon, semiconductors or polymeric materials that allow for the real time detection of biological materials or chemical moieties. Many apertures can exist on one substrate allowing for the simultaneous detection of numerous chemical and biological molecules. One embodiment features a macrocyclic ring attached to cross-linkers, wherein the macrocyclic ring has a biological or chemical probe extending through the aperture. Another embodiment achieves functionalization by attaching chemical or biological anchors directly to the walls of the apertures via cross-linkers.

  15. Alkoxide routes to Inorganic Materials

    SciTech Connect

    Thomas, George H [ORNL

    2007-12-01

    An all alkoxide solution chemistry utilizing metal 2-methoxyethoxide complexes in 2-methoxyethanol was used to deposit thin-films of metal oxides on single-crystal metal oxide substrates and on biaxially textured metal substrates. This same chemistry was used to synthesize complex metal oxide nanoparticles. Nuclear Magnetic Resonance spectroscopy was used to study precursor solutions of the alkaline niobates and tantalates. Film crystallization temperatures were determined from x-ray diffraction patterns of powders derived from the metal oxide precursor solutions. Film structure was determined via x-ray diffraction. Film morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Epitaxial thin-films of strontium bismuth tantalate (SrBi{sub 2}Ta{sub 2}O{sub 9}, SBT) and strontium bismuth niobate (SrBi{sub 2}Nb{sub 2}O{sub 9}, SBN) were deposited on single crystal [1 0 0] magnesium oxide (MgO) buffered with lanthanum manganate (LaMnO{sub 3}, LMO). Epitaxial thin films of LMO were deposited on single crystal [100] MgO via Rf-magnetron sputtering and on single crysal [100] lanthanum aluminate (LaAlO{sub 3}) via the chemical solution deposition technique. Epitaxial thin-films of sodium potassium tantalate (na{sub 0.5}K{sub 0.5}TaO{sub 3}, NKT), sodium potassium niobate (Na{sub 0.5}K{sub 0.5}NbO{sub 3}, NKN) and sodium potassium tantalum niobate (Na{sub 0.5}K{sub 0.5}Ta{sub 0.5}O{sub 3}, NKTN) were deposited on single crystal [1 0 0] lanthanum aluminate and [1 0 0] MgO substrates (NKT and NKN) and biaxially textured metal substrates via the chemical solution deposition technique. Epitaxial growth of thin-films of NKT, NKN and NKTN was observed on LAO and Ni-5% W. Epitaxial growth of thin-films of NKN and the growth of c-axis aligned thin-films of NKT was observed on MgO. Nanoparticles of SBT, SBN, NKT and NKN were synthesized in reverse micelles from alkoxide precursor solutions. X-ray diffraction and transmission electron spectroscopy investigations reveal that amorphous nanoparticles ({approx} 5 nm) of SBT and SBN were synthesized. X-ray diffraction investigations reveal that nanoparticles ({approx} nm) of NKT and NKN were also synthesized by this method.

  16. Thermal residual stresses in a functionally graded material system

    Microsoft Academic Search

    K. S. Ravichandran

    1995-01-01

    A one-dimensional calculation of thermal residual stresses, arising from the fabrication of a Functionally Graded Material (FGM) system, is presented. As a first step, calculations have been limited to the linear elastic case. The FGM system consists of ceramic (Al2O3) and metal (Ni) phases varying with distance in one direction. Several functional forms of gradation of constituents were examined to

  17. Surface functionalization of inorganic nano-crystals with fibronectin and E-cadherin chimera synergistically accelerates trans-gene delivery into embryonic stem cells.

    PubMed

    Kutsuzawa, K; Chowdhury, E H; Nagaoka, M; Maruyama, K; Akiyama, Y; Akaike, T

    2006-11-24

    Stem cells holding great promises in regenerative medicine have the potential to be differentiated to a specific cell type through genetic manipulation. However, conventional ways of gene transfer to such progenitor cells suffer from a number of disadvantages particularly involving safety and efficacy issues. Here, we report on the development of a bio-functionalized inorganic nano-carrier of DNA by embedding fibronectin and E-cadherin chimera on the carrier, leading to its high affinity interactions with embryonic stem cell surface and accelerated trans-gene delivery for subsequent expression. While only apatite nano-particles were very inefficient in transfecting embryonic stem cells, fibronectin-anchored particles and to a more significant extent, fibronectin and E-cadherin-Fc-associated particles dramatically enhanced trans-gene delivery with a value notably higher than that of commercially available lipofection system. The involvement of both cell surface integrin and E-cadherin in mediating intracellular localization of the hybrid carrier was verified by blocking integrin binding site with excess free fibronectin and up-regulating both integrin and E-cadherin through PKC activation. Thus, the new establishment of a bio-functional hybrid gene-carrier would promote and facilitate development of stem cell-based therapy in regenerative medicine. PMID:17027651

  18. 3D Printing of Functional and Biological Materials

    E-print Network

    ! 3D Printing of Functional and Biological Materials Jennifer A. Lewis Wyss Professor)! Multimaterial 3D printing ! #12;3D antennas! Li ion microbatteries! Lightweight microlattices!Flexible sensors! 3D Printing of Integrated Electronic Devices ! #12;20 nm average , 5 ­ 50 nm

  19. A Selected Bibliography of Functional Literacy Materials for Adult Learners.

    ERIC Educational Resources Information Center

    Berg, Joann La Perla; Wallace, Virginia A.

    This document is a selected, annotated bibliography of materials published in the area of coping skills for adults with functional reading skills. Publications are listed alphabetically by title under the following general topics: general coping skills; newspapers; occupational information; consumer economics; pregnancy and parenting; housing;…

  20. Functional and Smart Materials Structural Evolution and Structure Analysis

    E-print Network

    Wang, Zhong L.

    i Functional and Smart Materials Structural Evolution and Structure Analysis Contents Part I STRUCTURE AND STRUCTURAL EVOLUTION 1. Structure, Bonding and Properties 1.1 Crystal structure 1.2 Structure and coordination polyhedron 1.4 Isotypism and polymorphism 1.5 Structure and chemical bonding 1.5.1 Bonding and ion

  1. DERIVATION OF DAMAGE FUNCTIONS FOR ATMOSPHERIC DEGRADATION OF MATERIALS

    EPA Science Inventory

    The information in the pape is directed to those who develop and use damage functions which relate atmospheric degradation of materials to various causal agents in the atmosphere. Such relationships must be quantified mathematically as part of the overall cost-benefit considerati...

  2. A photometric function for diffuse reflection by particulate materials

    NASA Technical Reports Server (NTRS)

    Meador, W. E.; Weaver, W. R.

    1975-01-01

    A photometric function is proposed to describe the diffuse reflection of radiation by particulate materials. Both multiple scattering and the dominant effects of particle shadowing are included and the function is verified by comparisons with the photometries of laboratory surfaces. Brightness measurements of planetary and other diffusely scattering surfaces can be used to calculate the brightness for geometries other than those used in the measurements and for which the Minnaert function does not apply. The measurements also can be directly related to such surface characteristics as particle size, single-particle albedo, and compactness.

  3. Applications of inorganic nanoparticles as therapeutic agents

    NASA Astrophysics Data System (ADS)

    Kim, Taeho; Hyeon, Taeghwan

    2014-01-01

    During the last decade, various functional nanostructured materials with interesting optical, magnetic, mechanical and chemical properties have been extensively applied to biomedical areas including imaging, diagnosis and therapy. In therapeutics, most research has focused on the application of nanoparticles as potential delivery vehicles for drugs and genes, because nanoparticles in the size range of 2-100 nm can interact with biological systems at the molecular level, and allow targeted delivery and passage through biological barriers. Recent investigations have even revealed that several kinds of nanomaterials are intrinsically therapeutic. Not only can they passively interact with cells, but they can also actively mediate molecular processes to regulate cell functions. This can be seen in the treatment of cancer via anti-angiogenic mechanisms as well as the treatment of neurodegenerative diseases by effectively controlling oxidative stress. This review will present recent applications of inorganic nanoparticles as therapeutic agents in the treatment of disease.

  4. Organic and inorganic-organic thin film structures by molecular layer deposition: A review.

    PubMed

    Sundberg, Pia; Karppinen, Maarit

    2014-01-01

    The possibility to deposit purely organic and hybrid inorganic-organic materials in a way parallel to the state-of-the-art gas-phase deposition method of inorganic thin films, i.e., atomic layer deposition (ALD), is currently experiencing a strongly growing interest. Like ALD in case of the inorganics, the emerging molecular layer deposition (MLD) technique for organic constituents can be employed to fabricate high-quality thin films and coatings with thickness and composition control on the molecular scale, even on complex three-dimensional structures. Moreover, by combining the two techniques, ALD and MLD, fundamentally new types of inorganic-organic hybrid materials can be produced. In this review article, we first describe the basic concepts regarding the MLD and ALD/MLD processes, followed by a comprehensive review of the various precursors and precursor pairs so far employed in these processes. Finally, we discuss the first proof-of-concept experiments in which the newly developed MLD and ALD/MLD processes are exploited to fabricate novel multilayer and nanostructure architectures by combining different inorganic, organic and hybrid material layers into on-demand designed mixtures, superlattices and nanolaminates, and employing new innovative nanotemplates or post-deposition treatments to, e.g., selectively decompose parts of the structure. Such layer-engineered and/or nanostructured hybrid materials with exciting combinations of functional properties hold great promise for high-end technological applications. PMID:25161845

  5. Functional materials from cellulose-derived liquid-crystal templates.

    PubMed

    Giese, Michael; Blusch, Lina K; Khan, Mostofa K; MacLachlan, Mark J

    2015-03-01

    Cellulose nanocrystals (CNCs), known for more than 50?years, have attracted attention because of their unique properties such as high specific strength and modulus, high surface area, and fascinating optical properties. Just recently, however, their potential in supramolecular templating was identified by making use of their self-assembly behavior in aqueous dispersions in the presence of compatible precursors. The combination of the mesoporosity, photonic properties, and chiral nematic order of the materials, which are available as freestanding films, has led to a significant number of interesting and promising discoveries towards new functional materials. This Review summarizes the use of cellulose derivatives, especially CNCs, as novel templates and gives an overview of the recent developments toward new functional materials. PMID:25521805

  6. Development of Pillared M(IV) Phosphate Phosphonate Inorganic Organic Hybrid Ion Exchange Materials for Applications in Separations found in the Nuclear Fuel Cycle 

    E-print Network

    Burns, Jonathan

    2012-10-02

    , circles represent Zr4+ ion and triangles represent the base of the phosphonate tetrahedra and side view (b) only one end of the pillar is bound to a metal layer. ...................................................................... 62 19 XRPD... Actinide/lanthanide solutions, estimated error < 1%. .................................... 33 8 Molecular formula determination and percent yield calculation based on the TGA, ICP-AES and elemental analysis for the Zr?hybrid materials as a function...

  7. The role of materials biocompatibility for functional electrical stimulation applications.

    PubMed

    Plenk, Hanns

    2011-03-01

    The biocompatibility of all metallic, polymeric, or ceramic materials used for functional electrical stimulation is governed by the inevitable inflammatory tissue response, but possibly also by immunological reactions to the bulk material or released constituents. Besides chemical, physical, and corrosion properties of the conductive electrode materials, increased surface area and roughness of the electrode can influence tissue contact and signal delivery, and can also affect electrode-tissue impedance due to increased connective tissue encapsulation. The polymeric materials used for electrode insulation and those for leads and stimulator packaging seem more or less compatible in an aggressive biological environment. For the long-term performance of electrodes and leads, the relative motion in the various implant bed situations also has to be considered. PMID:21401666

  8. Functionalized mesoporous silica materials for molsidomine adsorption: Thermodynamic study

    SciTech Connect

    Alyoshina, Nonna A.; Parfenyuk, Elena V., E-mail: evp@iscras.ru

    2013-09-15

    A series of unmodified and organically modified mesoporous silica materials was prepared. The unmodified mesoporous silica was synthesized via sol–gel synthesis in the presence of D-glucose as pore-forming agent. The functionalized by phenyl, aminopropyl and mercaptopropyl groups silica materials were prepared via grafting. The fabricated adsorbent materials were characterized by Fourier transform infrared spectroscopy (FTIR) analysis, N{sub 2} adsorption/desorption and elemental analysis methods. Then their adsorption properties for mesoionic dug molsidomine were investigated at 290–313 K and physiological pH value. Thermodynamic parameters of molsidomine adsorption on the synthesized materials have been calculated. The obtained results showed that the adsorption process of molsidomine on the phenyl modified silica is the most quantitatively and energetically favorable. The unmodified and mercaptopropyl modified silica materials exhibit significantly higher adsorption capacities and energies for molsidomine than the aminopropyl modified sample. The effects are discussed from the viewpoint of nature of specific interactions responsible for the adsorption. - Graphical abstract: Comparative analysis of the thermodynamic characteristics of molsidomine adsorption showed that the adsorption process on mesoporous silica materials is controlled by chemical nature of surface functional groups. Molsidomine adsorption on the phenyl modified silica is the most quantitatively and energetically favorable. Taking into account ambiguous nature of mesoionic compounds, it was found that molsidomine is rather aromatic than dipolar. Display Omitted - Highlights: • Unmodified and organically modified mesoporous silica materials were prepared. • Molsidomine adsorption on the silica materials was studied. • Phenyl modified silica shows the highest adsorption capacity and favorable energy. • Molsidomine exhibits the lowest affinity to aminopropyl modified silica.

  9. An assessment of the release of inorganic cyanide from the fragrance materials benzyl cyanide, geranyl nitrile and citronellyl nitrile applied dermally to the rat

    Microsoft Academic Search

    J Potter; R. L Smith; A. M Api

    2001-01-01

    Organonitriles are widely used as components of fragrances that are incorporated into consumer products, many of which are for human topical use. Some organontriles are readily broken down metabolically to potentially toxic inorganic cyanide. Studies were therefore undertaken to assess whether this occurs with three representative fragrance nitriles, namely, benzyl cyanide, geranyl nitrile and citronellyl nitrile when applied dermally to

  10. Polymer Electrolyte Gated Inorganic Transistors

    Microsoft Academic Search

    Anoop Singh Dhoot; Casey Israel; Xavier Moya; Stuart Wimbush; Tim Benseman; Judith MacManus-Driscoll; John Cooper; Neil Mathur; Richard Friend

    2009-01-01

    Electric field-induced charge at the interface between gate dielectric and semiconductor is the basis of current semiconductor technology. We report that it is possible to use polymer electrolyte to gate inorganic materials, and to achieve field-induced `doping' equivalent to a full surface coverage of charged ions per unit cell area. Very high field-induced carrier densities, ˜10^15 cm-2, in the transistor

  11. Metal ion adsorption using polyamine-functionalized mesoporous materials prepared from bromopropyl-functionalized mesoporous silica

    Microsoft Academic Search

    Zeid A. Alothman; Allen W. Apblett

    2010-01-01

    Mesoporous silicas carrying di-, tri-, or penta-amine functional groups were prepared by prior functionalization of a mesoporous silica with bromopropyl-functional groups followed by nucleophilic displacement of the bromine atoms by ethylenediamine, diethylenetriamine, or tetraethylenepentamine, respectively. A synthetic method was developed that gave a starting material with very high surface coverage by the 3-brompropyl groups. Batch tests were conducted to investigate

  12. Inorganic lead compounds in electroceramics and glasses

    SciTech Connect

    Nair, N.; Bhalla, A.; Roy, R. [Pennsylvania State Univ., University Park, PA (United States)

    1996-01-01

    Lead-based compounds are numerous. When the toxicological effects of lead compounds are studied, a distinction between organic and inorganic lead compounds appears because each group behaves differently in biological systems. Examination of inorganic lead compounds exposes additional differences in their stability, modes of human exposure and socioeconomic importance. Lead-based electroceramics and glasses include inorganic lead compounds that can be controlled in the future when restrictions on lead use are enacted. The compounds widely used in electronics pose minimal health risks because of their stability. The socioeconomic impact of restricting these compounds could be significant because of their widespread use and the difficulty of locating replacement materials.

  13. Multiplexed acquisition of bidirectional texture functions for materials

    NASA Astrophysics Data System (ADS)

    den Brok, Dennis; Steinhausen, Heinz C.; Hullin, Matthias B.; Klein, Reinhard

    2015-03-01

    The bidirectional texture function (BTF) has proven a valuable model for the representation of complex spatially varying material reflectance. Its image-based nature, however, makes material BTFs extremely cumbersome to acquire: in order to adequately sample high-frequency details, many thousands of images of a given material as seen and lit from different directions have to be obtained. Additionally, long exposure times are required to account for the wide dynamic range exhibited by the reflectance of many real-world materials. We propose to significantly reduce the required exposure times by using illumination patterns instead of single light sources ("multiplexed illumination"). A BTF can then be produced by solving an appropriate linear system, exploiting the linearity of the superposition of light. Where necessary, we deal with signal-dependent noise by using a simple linear model derived from an existing database of material BTFs as a prior. We demonstrate the feasibility of our method for a number of real-world materials in a camera dome scenario.

  14. Insensitive nitrogen-rich materials incorporating the nitroguanidyl functionality.

    PubMed

    Zhang, Qinghua; He, Chunlin; Yin, Ping; Shreeve, Jean'ne M

    2014-01-01

    A new class of nitroguanidyl-functionalized nitrogen-rich materials derived from 1,3,5-triazine and 1,2,4,5-tetrazine was synthesized through reactions between N-nitroso-N'-alkylguanidines and the hydrazine derivatives of 1,3,5-triazine or 1,2,4,5-tetrazine. These compounds were fully characterized using multinuclear NMR and IR spectroscopies, elemental analysis, and differential scanning calorimetry (DSC). The heats of formation for all compounds were calculated with Gaussian 03 and then combined with experimental densities to determine the detonation pressures (P) and velocities (Dv) of the energetic materials. Interestingly, some of the compounds exhibit an energetic performance (P and Dv) comparable to that of RDX, thus holding promise for application as energetic materials. PMID:24151131

  15. Functional unit for systems using natural raw materials

    Microsoft Academic Search

    Günter Fleischer; Wulf-Peter Schmidt

    1996-01-01

    The necessity of a functional unit, which considers the equality of all benefits, is underlined especially for systems using\\u000a such natural raw materials as wood.\\u000a \\u000a The example of identifying the ecological optimal extent of paper recycling is therefore examined by using the data of 11ASA\\u000a [1]. It can be shown that the calculated quantity of the ecological optima particularly depend

  16. Chromonic liquid crystals: properties and applications as functional materials.

    PubMed

    Tam-Chang, Suk-Wah; Huang, Liming

    2008-05-01

    Chromonic liquid crystals (or chromonics) are formed by the self-organization of aromatic compounds with ionic or hydrophilic groups in aqueous solutions. This review summarizes the research on chromonic liquid crystals in the last two decades. The research embraced the studies of commercially available chromonic dyes and drugs, the syntheses and investigations of molecularly designed mesogens, the invention of novel processes for aligning chromonic liquid crystals, and the development of new applications as functional materials and biosensors. PMID:18536789

  17. Ceramic/polymer functionally graded material (FGM) lightweight armor system

    SciTech Connect

    Petrovic, J.J.; McClellan, K.J.

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Functionally graded material is an enabling technology for lightweight body armor improvements. The objective was to demonstrate the ability to produce functionally graded ceramic-polymer and ceramic-metal lightweight armor materials. This objective involved two aspects. The first and key aspect was the development of graded-porosity boron-carbide ceramic microstructures. The second aspect was the development of techniques for liquid infiltration of lightweight metals and polymers into the graded-porosity ceramic. The authors were successful in synthesizing boron-carbide ceramic microstructures with graded porosity. These graded-porosity boron-carbide hot-pressed pieces were then successfully liquid-infiltrated in vacuum with molten aluminum at 1,300 C, and with liquid polymers at room temperature. Thus, they were able to demonstrate the feasibility of producing boron carbide-aluminum and boron carbide-polymer functionally graded materials.

  18. Inorganic Sol-Gel Preparation of Medium Sized Microparticles of Li 2 TiO 3 from TiCl 4 as Tritium Breeding Material for Fusion Reactors

    Microsoft Academic Search

    A. Deptu?a; T. Olczak; W. ?ada; B. Sartowska; A. G. Chmielewski; C. Alvani; P. L. Carconi; A. Di Bartolomeo; F. Pierdominici; S. Casadio

    2003-01-01

    Microspheres of Li2TiO3 were fabricated by a classical, inorganic sol-gel process from commercially available TiCl4. Elaborated process consists of the following main steps: (1) dissolving of TiCl4 in concentrated aqueous HCl and addition of LiOH; (2) formation of sol emulsion in 2-ethylhexanol-1 containing the surfactant SPAN-80 (EH); (3) gelation of emulsion drops by extraction of water with partially dehydrated EH;

  19. Probabilistic Fracture Analysis of Functionally Graded Materials -Part I: Uncertainty and

    E-print Network

    Paulino, Glaucio H.

    Initiation, First Order Reliability Method, Fracture Toughness, Functionally Graded Material, J Young's modulus and fracture toughness are considered. The limit state function for a crack initiationProbabilistic Fracture Analysis of Functionally Graded Materials - Part I: Uncertainty

  20. The ``Missing Compounds'' affair in functionality-driven material discovery

    NASA Astrophysics Data System (ADS)

    Zunger, Alex

    2014-03-01

    In the paradigm of ``data-driven discovery,'' underlying one of the leading streams of the Material Genome Initiative (MGI), one attempts to compute high-throughput style as many of the properties of as many of the N (about 10**5- 10**6) compounds listed in databases of previously known compounds. One then inspects the ensuing Big Data, searching for useful trends. The alternative and complimentary paradigm of ``functionality-directed search and optimization'' used here, searches instead for the n much smaller than N configurations and compositions that have the desired value of the target functionality. Examples include the use of genetic and other search methods that optimize the structure or identity of atoms on lattice sites, using atomistic electronic structure (such as first-principles) approaches in search of a given electronic property. This addresses a few of the bottlenecks that have faced the alternative, data-driven/high throughput/Big Data philosophy: (i) When the configuration space is theoretically of infinite size, building a complete data base as in data-driven discovery is impossible, yet searching for the optimum functionality, is still a well-posed problem. (ii) The configuration space that we explore might include artificially grown, kinetically stabilized systems (such as 2D layer stacks; superlattices; colloidal nanostructures; Fullerenes) that are not listed in compound databases (used by data-driven approaches), (iii) a large fraction of chemically plausible compounds have not been experimentally synthesized, so in the data-driven approach these are often skipped. In our approach we search explicitly for such ``Missing Compounds''. It is likely that many interesting material properties will be found in cases (i)-(iii) that elude high throughput searches based on databases encapsulating existing knowledge. I will illustrate (a) Functionality-driven discovery of topological insulators and valley-split quantum-computer semiconductors, as well as (b) Use of ``first principles thermodynamics'' to discern which of the previously ``missing compounds'' should, in fact exist and in which structure. Synthesis efforts by Poeppelmeier group at NU realized 20 never-before-made half-Heusler compounds out of the 20 predicted ones, in our predicted space groups. This type of theory-led experimental search of designed materials with target functionalities may shorten the current process of discovery of interesting functional materials. Supported by DOE ,Office of Science, Energy Frontier Research Center for Inverse Design

  1. Inorganic-organic separators for alkaline batteries

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W. (inventor)

    1978-01-01

    A flexible separator is reported for use between the electrodes of Ni-Cd and Ni-Zn batteries using alkaline electrolytes. The separator was made by coating a porous substrate with a battery separator composition. The coating material included a rubber-based resin copolymer, a plasticizer and inorganic and organic fillers which comprised 55% by volume or less of the coating as finally dried. One or more of the filler materials, whether organic or inorganic, is preferably active with the alkaline electrolyte to produce pores in the separator coating. The plasticizer was an organic material which is hydrolyzed by the alkaline electrolyte to improve conductivity of the separator coating.

  2. Interfacial Properties and Design of Functional Energy Materials

    SciTech Connect

    Sumpter, Bobby G [ORNL; Liang, Liangbo [ORNL; Nicolai, Adrien [Rensselaer Polytechnic Institute (RPI); Meunier, V. [Rensselaer Polytechnic Institute (RPI)

    2014-01-01

    The vital importance of energy to society continues to demand a relentless pursuit of energy responsive materials that can bridge fundamental chemical structures at the molecular level and achieve improved functionality, such as efficient energy conversion/storage/transmission, over multiple length scales. This demand can potentially be realized by harnessing the power of self-assembly a spontaneous process where molecules or much larger entities form ordered aggregates as a consequence of predominately non-covalent (weak) interactions. Self-assembly is the key to bottom-up design of molecular devices, because the nearly atomic-level control is very difficult to realize in a top-down, e.g., lithographic approach. However, while function (e.g., charge mobility) in simple systems such as single crystals can often be predicted, predicting the function of the great variety of self-assembled molecular architectures is complicated by the lack of understanding and control over nanoscale interactions, mesoscale architectures, and macroscale (long-range) order. To establish a foundation toward delivering practical solutions, it is critical to develop an understanding of the chemical and physical mechanisms responsible for the self-assembly of molecular and hybrid materials on various substrates. Typically molecular self-assembly involves poorly understood non-covalent intermolecular and substrate-molecule interactions compounded by local and/or collective influences from the substrate atomic lattice (symmetry and/or topological features) and electronic structure. Thus, progress towards unraveling the underlying physicochemical processes that control the structure and macroscopic physical, mechanical, electrical, and transport properties of materials increasingly requires tight integration of theory, modeling and simulation with precision synthesis, advanced experimental characterization, and device measurements. In this mode, theory and simulation can greatly accelerate the process of materials discovery by providing atomic level understanding of physicochemical phenomena and for making predictions of trends. In particular, this approach can provide understanding, prediction and exploration of new materials and conditions before they are realized in the lab, to illuminate connections between experimental observations, and help identify new materials for targeted synthesis. Toward this end, Density Functional Theory (DFT) can provide a suitable computational framework for investigating the inter- and intramolecular bonding, molecular conformation, charge and spin configurations that are intrinsic to self-assembly of molecules on substrates. This Account highlights recent advances in using an integrated approach based on DFT and scanning probe microscopy [STM(s), AFM] to study/develop electronic materials formed from the self-assembly of molecules into supramolecular or polymeric architectures on substrates. Here it is the interplay between molecular interactions and surface electrons that is used to control the final architecture and subsequent bulk properties of the two-dimensional patterns/assemblies. Indeed a rich variety of functional energy materials become possible.

  3. Apparatus for depositing a low work function material

    DOEpatents

    Balooch, Mehdi; Dinh, Long N.; Siekhaus, Wigbert J.

    2006-10-10

    Short-wavelength photons are used to ablate material from a low work function target onto a suitable substrate. The short-wavelength photons are at or below visible wavelength. The elemental composition of the deposit is controlled by the composition of the target and the gaseous environment in which the ablation process is performed. The process is carried out in a deposition chamber to which a short-wavelength laser is mounted and which includes a substrate holder which can be rotated, tilted, heated, or cooled. The target material is mounted onto a holder that spins the target during laser ablation. In addition, the deposition chamber is provided with a vacuum pump, an external gas supply with atomizer and radical generator, a gas generator for producing a flow of molecules on the substrate, and a substrate cleaning device, such as an ion gun. The substrate can be rotated and tilted, for example, whereby only the tip of an emitter can be coated with a low work function material.

  4. Envelope-function formalism for electrons in abrupt heterostructures with material-dependent basis functions

    Microsoft Academic Search

    Bradley A. Foreman

    1996-01-01

    An envelope-function model is derived for electrons in abrupt semiconductor heterostructures. It uses material-dependent basis functions that diagonalize the bulk zone-center Hamiltonian in each unit cell of the crystal. The initial formalism is exactly equivalent to the one-electron Schrödinger equation; approximations suitable for abrupt junctions are then developed. The abrupt change in microscopic potential at an ideal interface is shown

  5. Design of Functional Materials based on Liquid Crystalline Droplets

    PubMed Central

    Miller, Daniel S.; Wang, Xiaoguang; Abbott, Nicholas L.

    2014-01-01

    This brief perspective focuses on recent advances in the design of functional soft materials that are based on confinement of low molecular weight liquid crystals (LCs) within micrometer-sized droplets. While the ordering of LCs within micrometer-sized domains has been explored extensively in polymer-dispersed LC materials, recent studies performed with LC domains with precisely defined size and interfacial chemistry have unmasked observations of confinement-induced ordering of LCs that do not follow previously reported theoretical predictions. These new findings, which are enabled in part by advances in the preparation of LCs encapsulated in polymeric shells, are opening up new opportunities for the design of soft responsive materials based on surface-induced ordering transitions. These materials are also providing new insights into the self-assembly of biomolecular and colloidal species at defects formed by LCs confined to micrometer-sized domains. The studies presented in this perspective serve additionally to highlight gaps in knowledge regarding the ordering of LCs in confined systems. PMID:24882944

  6. Functionalized DNA materials for sensing and medical applications

    NASA Astrophysics Data System (ADS)

    Woolard, Dwight L.; Jensen, James O.

    2011-06-01

    The U.S. Army has strong interests in nanoscale architectures that enable enhanced extraction and controllable multiplication of the THz/IR regime spectral signatures associated with specific bio-molecular targets. Emerging DNAbased nano-assemblies (i.e., either materials or structural devices) will be discussed that realize novel sensing paradigms through the incorporation of organic and/or biological molecules such that they effect highly predictable and controllable changes into the electro-optical properties of the resulting superstructures. Results will be given to illustrate the utility of functionalized DNA materials in biological (and chemical) sensing, and to demonstrate how the basic science can be leveraged to study and develop synthetic antibodies, reporters and vaccines for future medical applications.

  7. Fluorescent Functionalized Mesoporous Silica for Radioactive Material Extraction

    SciTech Connect

    Li, Juan; Zhu, Kake; Shang, Jianying; Wang, Donghai; Nie, Zimin; Guo, Ruisong; Liu, Chongxuan; Wang, Zheming; Li, Xiaolin; Liu, Jun

    2012-08-01

    Mesoporous silica with covalently bound salicylic acid molecules incorporated in the structure was synthesized with a one-pot, co-condensation reaction at room temperature. The as-synthesized material has a large surface area, uniform particle size, and an ordered pore structure as determined by characterization with transmission electron microscopy, thermal gravimetric analysis, and infrared spectra, etc. Using the strong fluorescence and metal coordination capability of salicylic acid, functionalized mesoporous silica (FMS) was developed to track and extract radionuclide contaminants, such as uranyl [U(VI)] ions encountered in subsurface environments. Adsorption measurements showed a strong affinity of the FMS toward U(VI) with a Kd value of 105 mL/g, which is four orders of magnitude higher than the adsorption of U(VI) onto most of the sediments in natural environments. The new materials have a potential for synergistic environmental monitoring and remediation of the radionuclide U(VI) from contaminated subsurface environments.

  8. Peptide Self-Assembly for Crafting Functional Biological Materials

    PubMed Central

    Matson, John B.; Zha, R. Helen; Stupp, Samuel I.

    2011-01-01

    Self-assembling, peptide-based scaffolds are frontrunners in the search for biomaterials with widespread impact in regenerative medicine. The inherent biocompatibility and cell signaling capabilities of peptides, in combination with control of secondary structure, has led to the development of a broad range of functional materials with potential for many novel therapies. More recently, membranes formed through complexation of peptide nanostructures with natural biopolymers have led to the development of hierarchically-structured constructs with potentially far-reaching applications in biology and medicine. In this review, we highlight recent advances in peptide-based gels and membranes, including work from our group and others. Specifically, we discuss the application of peptide-based materials in the regeneration of bone and enamel, cartilage, and the central nervous system, as well as the transplantation of islets, wound-healing, cardiovascular therapies, and treatment of erectile dysfunction after prostatectomy PMID:22125413

  9. Fabrication and application of advanced functional materials from lignincellulosic biomass

    NASA Astrophysics Data System (ADS)

    Hu, Sixiao

    This dissertation explored the conversion of lignocellulosic biomass into advanced functional materials and their potential applications. Lignocellulosic biomass represents an as-of-yet underutilized renewable source for not only biofuel production but also functional materials fabrication. This renewable source is a great alternative for fossil fuel based chemicals, which could be one of the solutions to energy crisis. In this work, it was demonstrated a variety of advanced materials including functional carbons, metal and silica nanoparticles could be derived from lignocellulosic biomass. Chapter 1 provided overall reviewed of the lignin structures, productions and its utilizations as plastics, absorbents and carbons, as well as the preparation of nano-structured silver, silica and silicon carbide/nitride from biomass. Chapter 2, 3 and 4 discussed the fabrication of highly porous carbons from isolated lignin, and their applications as electric supercapacitors for energy storage. In chapter 2, ultrafine porous carbon fibers were prepared via electrospinning followed by simultaneous carbonization and activation. Chapter 3 covered the fabrication of supercapacitor based on the porous carbon fibers and the investigation of their electrochemical performances. In chapter 4, porous carbon particulates with layered carbon nano plates structures were produced by simple oven-drying followed by simultaneous carbonization and activation. The effects of heat processing parameters on the resulting carbon structures and their electrochemical properties were discussed in details. Chapter 5 and 6 addressed the preparation of silver nanoparticles using lignin. Chapter 5 reported the synthesis, underlying kinetics and mechanism of monodispersed silver nanospheres with diameter less than 25 nm in aqueous solutions using lignin as dual reducing and capping agents. Chapter 6 covered the preparation of silver nanoparticles on electrospun celluloses ultrafine fibers using lignin as both binding and reducing agents. The efficiency of this synthetic protocol and the properties of resulting particles were examined. Chapter 7 reported the streamlined extraction of lignin/hemicelluloses and silica from rice straw and their subsequent conversion to activated carbon and monodispersed silica particles.

  10. AQUEOUS AND VAPOR PHASE MERCURY SORPTION BY INORGANIC OXIDE MATERIALS FUNCTIONALIZED WITH THIOLS AND POLY-THIOLS

    EPA Science Inventory

    The objective of the study is the development of sorbents where the sorption sites are highly accessible for the capture of mercury from aqueous and vapor streams. Only a small fraction of the equilibrium capacity is utilized for a sorbent in applications involving short residenc...

  11. Antimicrobial functions on cellulose materials introduced by anthraquinone vat dyes.

    PubMed

    Zhuo, Jingyuan; Sun, Gang

    2013-11-13

    Many anthraquinone compounds have exhibited light-active properties in solutions and on materials under UVA or fluorescent light exposure. Two anthraquinone derivatives were incorporated onto cotton fabrics by a vat dyeing process. The dyed fabrics demonstrated light-induced biocidal functions, and the functions were durable against laundering and long-term light exposure. The structures and surface morphologies of the dyed fabrics were examined by using fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Mechanical properties of the fabrics were measured by using a tensile tester. The results revealed that the anthraquinone compounds have different light-activities, resulting in different surface and mechanical impacts on the cotton cellulose. PMID:24079962

  12. New transducer material concepts for biosensors and surface functionalization

    NASA Astrophysics Data System (ADS)

    Lloyd Spetz, Anita; Pearce, Ruth; Hedin, Linnea; Khranovskyy, Volodymyr; Söderlind, Fredrik; Käll, Per-Olov; Yakimova, Rositza; Uvdal, Kajsa

    2009-05-01

    Wide bandgap materials like SiC, ZnO, AlN form a strong platform as transducers for biosensors realized as e.g. ISFET (ion selective field effect transistor) devices or resonators. We have taken two main steps towards a multifunctional biosensor transducer. First we have successfully functionalized ZnO and SiC surfaces with e.g. APTES. For example ZnO is interesting since it may be functionalized with biomolecules without any oxidation of the surface and several sensing principles are possible. Second, ISFET devises with a porous metal gate as a semi-reference electrode are being developed. Nitric oxide, NO, is a gas which participates in the metabolism. Resistivity changes in Ga doped ZnO was demonstrated as promising for NO sensing also in humid atmosphere, in order to simulate breath.

  13. Analysis of the Elastic Field in Functionally Graded Materials

    NASA Astrophysics Data System (ADS)

    Mohammadi, Mohsen

    In this thesis, the elastic field in circular beams and pipes made of functionally graded materials is considered. The following aspects are presented. First, the thermoelastic stress field in a functionally graded curved beam, where the elastic stiffness varies in the radial direction, is considered. An analytical solution is obtained where the radial variation of the stiffness is represented by a fairly general form. The stress fields corresponding to two different cases for the elastic properties are examined. The flexural stress in the curved beam is then compared with that of a ring. A relatively simple approximate solution is then developed and this is shown to be in good agreement with the analytical results. Secondly, the effect of a nonconstant Poisson's ratio upon the elastic field in functionally graded axisymmetric solids is analyzed. Both of the elastic coefficients, i.e. Young's modulus and Poisson's ratio, are permitted to vary in the radial direction. These elastic coefficients are considered to be functions of composition and are related on this basis. This allows a closed form solution for the stress function to be obtained. Two cases are discussed in this investigation: a) both Young's modulus and Poisson's ratio are allowed to vary across the radius and the effect of spatial variation of Poisson's ratio upon the maximum radial displacement is investigated; b) Young's modulus is taken as constant and the change in the maximum hoop stress resulting from a variable Poisson's ratio is calculated. Thirdly, the stress concentration factor around a circular hole in an infinite plate subjected to uniform biaxial tension and pure shear is considered. The plate is made of a functionally graded material where both Young's modulus and Poisson's ratio vary in the radial direction. For plane stress conditions, the governing differential equation for the stress function is derived and solved. A general form for the stress concentration factor in case of biaxial tension is presented. Using a Frobenius series solution, the stress concentration factor is calculated for pure shear case. The stress concentration factor for uniaxial tension is then obtained by superposition of these two modes. The effect of nonhomogeneous stiffness and varying Poisson's ratio upon the stress concentration factors are analyzed. A reasonable approximation in the practical range of Young's modulus is obtained for the stress concentration factor in pure shear loading.

  14. Materiality matters: Blurred boundaries and the domestication of functional foods

    PubMed Central

    Weiner, Kate; Will, Catherine

    2015-01-01

    Previous scholarship on novel foods, including functional foods, has suggested that they are difficult to categorise for both regulators and users. It is argued that they blur the boundary between ‘food' and ‘drug' and that uncertainties about the products create ‘experimental' or ‘restless' approaches to consumption. We investigate these uncertainties drawing on data about the use of functional foods containing phytosterols, which are licensed for sale in the EU for people wishing to reduce their cholesterol. We start from an interest in the products as material objects and their incorporation into everyday practices. We consider the scripts encoded in the physical form of the products through their regulation, production and packaging and find that these scripts shape but do not determine their use. The domestication of phytosterols involves bundling the products together with other objects (pills, supplements, foodstuffs). Considering their incorporation into different systems of objects offers new understandings of the products as foods or drugs. In their accounts of their practices, consumers appear to be relatively untroubled by uncertainties about the character of the products. We conclude that attending to materials and practices offers a productive way to open up and interrogate the idea of categorical uncertainties surrounding new food products.

  15. Designing functionally graded materials with superior load-bearing properties

    PubMed Central

    Zhang, Yu; Sun, Ming-jie; Zhang, Denzil

    2011-01-01

    Ceramic prostheses often fail from fracture and wear. We hypothesize that these failures may be substantially mitigated by an appropriate grading of elastic modulus at the ceramic surface. In this study, we elucidate the effect of elastic modulus profile on the flexural damage resistance of functionally graded materials (FGMs), providing theoretical guidlines for designing FGM with superior load-bearing property. The Young's modulus of the graded structure is assumed to vary in a power-law relation with a scaling exponent n; this is in accordance with experimental observations from our laboratory and elsewhere. Based on the theory for bending of graded beams, we examine the effect of n value and bulk-to-surface modulus ratio (Eb/Es) on stress distribution through the graded layer. Theory predicts that a low exponent (0.15 < n < 0.5), coupled with a relatively small modulus ratio (3 < Eb/Es < 6), is most desirable for reducing the maximum stress and transferring it into the interior, while keeping the surface stress low. Experimentally, we demonstrate that elastically graded materials with various n values and Eb/Es ratios can be fabricated by infiltrating alumina and zirconia with a low-modulus glass. Flexural tests show that graded alumina and zirconia with suitable values of these parameters exhibit superior load-bearing capacity, 20% to 50% higher than their homogeneous counterparts. Improving load-bearing capacity of ceramic materials could have broad impacts on biomedical, civil, structural, and an array of other engineering applications. PMID:22178651

  16. Efficient inorganic solid solar cells composed of perovskite and PbS quantum dots

    NASA Astrophysics Data System (ADS)

    Li, Yi; Zhu, Jun; Huang, Yang; Wei, Junfeng; Liu, Feng; Shao, Zhipeng; Hu, Linhua; Chen, Shuanghong; Yang, Shangfeng; Tang, Junwang; Yao, Jianxi; Dai, Songyuan

    2015-05-01

    Lead halide perovskite solar cells have attracted great interest due to their high efficiency and simple fabrication process. However, the high efficiency heavily relies on expensive organic hole-transporting materials (OHTMs) such as 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-MeOTAD), it is preferable to replace these expensive OHTMs by inorganic and low cost materials. Here, we report colloidal PbS quantum dots synthesized by a facile method and used as the inorganic hole-transporting material in a hybrid perovskite solar cell. By controlling the crystalline morphology of the perovskite capping layer, the recombination process is significantly retarded. Furthermore, a pure inorganic solar cell prepared by a two-step process demonstrated a nearly 8% power conversion efficiency due to efficient charge separation by a cascade of junctions and retarding charge recombination by a void-free capping layer. The stability of the inorganic solar cell was also tested with a little decay observed within ca. 100 h.Lead halide perovskite solar cells have attracted great interest due to their high efficiency and simple fabrication process. However, the high efficiency heavily relies on expensive organic hole-transporting materials (OHTMs) such as 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-MeOTAD), it is preferable to replace these expensive OHTMs by inorganic and low cost materials. Here, we report colloidal PbS quantum dots synthesized by a facile method and used as the inorganic hole-transporting material in a hybrid perovskite solar cell. By controlling the crystalline morphology of the perovskite capping layer, the recombination process is significantly retarded. Furthermore, a pure inorganic solar cell prepared by a two-step process demonstrated a nearly 8% power conversion efficiency due to efficient charge separation by a cascade of junctions and retarding charge recombination by a void-free capping layer. The stability of the inorganic solar cell was also tested with a little decay observed within ca. 100 h. Electronic supplementary information (ESI) available: The UV-visible absorption spectrum of the perovskite based on a one-step method before and after spinning PbS QDs. Photovoltaic characteristics of perovskite solar cells as a function of spin-coating number for PbS QDs. See DOI: 10.1039/c5nr00420a

  17. Bioinspiration from fish for smart material design and function

    NASA Astrophysics Data System (ADS)

    Lauder, G. V.; Madden, P. G. A.; Tangorra, J. L.; Anderson, E.; Baker, T. V.

    2011-09-01

    Fish are a potentially rich source of inspiration for the design of smart materials. Fish exemplify the use of flexible materials to generate forces during locomotion, and a hallmark of fish functional design is the use of body and fin deformation to power propulsion and maneuvering. As a result of nearly 500 million years of evolutionary experimentation, fish design has a number of interesting features of note to materials engineers. In this paper we first provide a brief general overview of some key features of the mechanical design of fish, and then focus on two key properties of fish: the bilaminar mechanical design of bony fish fin rays that allows active muscular control of curvature, and the role of body flexibility in propulsion. After describing the anatomy of bony fish fin rays, we provide new data on their mechanical properties. Three-point bending tests and measurement of force inputs to and outputs from the fin rays show that these fin rays are effective displacement transducers. Fin rays in different regions of the fin differ considerably in their material properties, and in the curvature produced by displacement of one of the two fin ray halves. The mean modulus for the proximal (basal) region of the fin rays was 1.34 GPa, but this varied from 0.24 to 3.7 GPa for different fin rays. The distal fin region was less stiff, and moduli for the different fin rays measured varied from 0.11 to 0.67 GPa. These data are similar to those for human tendons (modulus around 0.5 GPa). Analysis of propulsion using flexible foils controlled using a robotic flapping device allows investigation of the effect of altering flexural stiffness on swimming speed. Flexible foils with the leading edge moved in a heave show a distinct peak in propulsive performance, while the addition of pitch input produces a broad plateau where the swimming speed is relatively unaffected by the flexural stiffness. Our understanding of the material design of fish and the control of tissue stiffness is still in its infancy, and the development of smart materials to assist in investigating the active control of stiffness and in the construction of robotic fish-like devices is a key challenge for the near future.

  18. Science Update: Inorganic Chemistry

    ERIC Educational Resources Information Center

    Rawls, Rebecca

    1978-01-01

    This first in a series of articles describing the state of the art of various branches of chemistry reviews inorganic chemistry, including bioinorganic, photochemistry, organometallic, and solid state chemistries. (SL)

  19. Harvesting bioenergy with rationally designed complex functional materials

    NASA Astrophysics Data System (ADS)

    Kuang, Liangju

    A key challenge in renewable energy is to capture, convert and store solar power with earth-abundant materials and environmentally benign technologies. The goal of this thesis is to develop rationally designed complex functional materials for bio-renewable energy applications. On one hand, photoconversion membrane proteins (MPs) are nature's nanoengineering feats for renewable energy management. Harnessing their functions in synthetic systems could help understand, predict, and ultimately control matter and energy at the nanoscale. This is particularly enticing in the post-genome era as recombinant or cell-free expression of many MPs with high yields becomes possible. However, the labile nature of lipid bilayers renders them unsuitable for use in a broad range of engineered systems. A knowledge gap exists about how to design robust synthetic nanomembranes as lipid-bilayer-mimics to support MP functions and how to direct hierarchical MP reconstitution into those membranes to form 2-D or 3-D ordered proteomembrane arrays. Our studies on proteorhodopsin (PR) and bacterial reaction center (BRC), the two light-harvesting MPs, reveal that a charge-interaction-directed reconstitution (CIDR) mechanism induces spontaneous reconstitution of detergent-solubilized MPs into various amphiphilic block copolymer membranes, many of which have far superior stability than lipid bilayers. Our preliminary data also suggest MPs are not enslaved by the biological membranes they derive from; rather, the chemically nonspecific material properties of MP-supporting membranes may act as allosteric regulators. Versatile chemical designs are possible to modulate the conformational energetics of MPs, hence their transport performance in synthetic systems. On the other hand, microalgae are widely regarded as a sustainable feedstock for biofuel production. Microalgae-derived biofuels have not been commercialized yet because current technologies for microalgae dewatering add a huge cost to the final product, and present a major bottleneck. We propose to solve the microalgae dewatering problem in the context of controlling colloidal stability, where inter-algal potential is tuned via surface engineering of novel coagulation agents. We report here a nanoparticle-pinched polymer brush design that combines two known colloidal destabilization agents (e.g., nanoparticle and polymer) into one system, and allows the use of an external field (e.g., magnetic force) to not only modulate inter-algae pair potentials, but also facilitate retrieval of the coagulation agents to be reused after algal oil extraction. We will discuss our extensive data on the preparation of well-defined nanoparticle-pinched polymer brushes, their structure-dependent coagulation performance on both fresh water and marine microalgae species, and their re-suability for continuous cycles of microalgae farming and harvesting.

  20. Ultrathin coatings of nanoporous materials as property enhancements for advanced functional materials.

    SciTech Connect

    Coker, Eric Nicholas

    2010-11-01

    This report summarizes the findings of a five-month LDRD project funded through Sandia's NTM Investment Area. The project was aimed at providing the foundation for the development of advanced functional materials through the application of ultrathin coatings of microporous or mesoporous materials onto the surface of substrates such as silicon wafers. Prior art teaches that layers of microporous materials such as zeolites may be applied as, e.g., sensor platforms or gas separation membranes. These layers, however, are typically several microns to several hundred microns thick. For many potential applications, vast improvements in the response of a device could be realized if the thickness of the porous layer were reduced to tens of nanometers. However, a basic understanding of how to synthesize or fabricate such ultra-thin layers is lacking. This report describes traditional and novel approaches to the growth of layers of microporous materials on silicon wafers. The novel approaches include reduction of the quantity of nutrients available to grow the zeolite layer through minimization of solution volume, and reaction of organic base (template) with thermally-oxidized silicon wafers under a steam atmosphere to generate ultra-thin layers of zeolite MFI.

  1. Synthesis of Novel Polypeptide-Silica Hybrid Materials through Surface-Initiated N-carboxyanhydride Polymerization 

    E-print Network

    Lunn, Jonathan D.

    2011-08-08

    There is an increasing demand for materials that are physically robust, easily recovered, and able to perform a wide variety of chemical functions. By combining hard and soft matter synergistically, organic-inorganic hybrid ...

  2. Metal ion adsorption using polyamine-functionalized mesoporous materials prepared from bromopropyl-functionalized mesoporous silica.

    PubMed

    Alothman, Zeid A; Apblett, Allen W

    2010-10-15

    Mesoporous silicas carrying di-, tri-, or penta-amine functional groups were prepared by prior functionalization of a mesoporous silica with bromopropyl-functional groups followed by nucleophilic displacement of the bromine atoms by ethylenediamine, diethylenetriamine, or tetraethylenepentamine, respectively. A synthetic method was developed that gave a starting material with very high surface coverage by the 3-brompropyl groups. Batch tests were conducted to investigate the capabilities of the prepared adsorbents for the removal of copper, zinc, and cadmium from aqueous solutions. The metal adsorption capacities for these metals were determined as a function of the polyamine group used and the total nitrogen content. The tendency to chemisorb divalent metal ions was found to follow the order: Cu(2+)>Zn(2+)>Cd(2+). It was found that the ethylenediamine derivative unexpectedly exhibited the highest capacities. The metal sorption by the ethylenediamine functionalized silica was found to follow first order kinetics with rate constants for Cu(2+), Zn(2+) and Cd(2+) uptake of 0.028, 0.019, and 0.014 min(-1), respectively. The substituted mesoporous silicas showed high resistance to leaching of the grafted polyamine groups. Copper ions that were adsorbed at the surface of the mesoporous silicas can be recovered by washing with an aqueous solution of 1.0 M HNO(3). The activities of the recovered mesoporous silicas were between 80 and 90% of the original materials. PMID:20663609

  3. Self-Assembly of biologically inspired complex functional materials.

    SciTech Connect

    Brinker, C. Jeffrey

    2004-08-01

    Nature combines hard and soft materials, often in hierarchical architectures, to get synergistic, optimized properties with proven, complex functionalities. Emulating such natural designs in robust engineering materials using efficient processing approaches represents a fundamental challenge to materials chemists. This presentation will review progress on understanding so-called 'evaporation-induced silica/surfactant self-assembly' (EISA) as a simple, general means to prepare porous thin-film nanostructures. Such porous materials are of interest for membranes, low-dielectric-constant (low-k) insulators, and even 'nano-valves' that open and close in response to an external stimulus. EISA can also be used to simultaneously organize hydrophilic and hydrophobic precursors into hybrid nanocomposites that are optically or chemically polymerizable, patternable, or adjustable. In constructing composite structures, a significant challenge is how to controllably organize or define multiple materials on multiple length scales. To address this challenge, we have combined sol-gel chemistry with molecular self-assembly in several evaporation-driven processing procedures collectively referred to as evaporation-induced self-assembly (EISA). EISA starts with a silica/water/surfactant system diluted with ethanol to create a homogeneous solution. We rely on ethanol and water evaporation during dip-coating (or other coating methods) to progressively concentrate surfactant and silica in the depositing film, driving micelle formation and subsequent continuous self-assembly of silica/surfactant thin film mesophases. One of the crucial aspects of this process, in terms of the sol-gel chemistry, is to work under conditions where the condensation rate of the hydrophilic silicic acid precursors (Si-OH) is minimized. The idea is to avoid gelation that would kinetically trap the system at an intermediate non-equilibrium state. We want the structure to self-assemble then solidify, with the addition of a siloxane condensation catalyst or by heating, to form the desired mesostructured product. Operating at an acidic pH (pH = 2) minimizes the condensation rate of silanols to form siloxanes Si-O-SiIn addition, hydrogen bonding and electrostatic interactions between silanols and hydrophilic surfactant head groups can further reduce the condensation rate. These combined factors maintain the depositing film in a fluid state, even beyond the point where ethanol and water are largely evaporated. This allows the deposited film to be self-healing and enables the use of virtually any evaporation-driven process (spin-coating, inkjet printing, or aerosol processing) to create ordered nanostructured films, patterns, or particles.

  4. Basis Function Sampling: A New Paradigm for Material Property Computation

    NASA Astrophysics Data System (ADS)

    Whitmer, Jonathan K.; Chiu, Chi-cheng; Joshi, Abhijeet A.; de Pablo, Juan J.

    2014-11-01

    Wang-Landau sampling, and the associated class of flat histogram simulation methods have been remarkably helpful for calculations of the free energy in a wide variety of physical systems. Practically, convergence of these calculations to a target free energy surface is hampered by reliance on parameters which are unknown a priori. Here, we derive and implement a method built upon orthogonal functions which is fast, parameter-free, and (importantly) geometrically robust. The method is shown to be highly effective in achieving convergence. An important feature of this method is its ability to attain arbitrary levels of description for the free energy. It is thus ideally suited to in silico measurement of elastic moduli and other material properties related to free energy perturbations. We demonstrate the utility of such applications by applying our method to calculate the Frank elastic constants of the Lebwohl-Lasher model of liquid crystals.

  5. ATRP in the design of functional materials for biomedical applications

    PubMed Central

    Siegwart, Daniel J.; Oh, Jung Kwon; Matyjaszewski, Krzysztof

    2013-01-01

    Atom Transfer Radical Polymerization (ATRP) is an effective technique for the design and preparation of multifunctional, nanostructured materials for a variety of applications in biology and medicine. ATRP enables precise control over macromolecular structure, order, and functionality, which are important considerations for emerging biomedical designs. This article reviews recent advances in the preparation of polymer-based nanomaterials using ATRP, including polymer bioconjugates, block copolymer-based drug delivery systems, cross-linked microgels/nanogels, diagnostic and imaging platforms, tissue engineering hydrogels, and degradable polymers. It is envisioned that precise engineering at the molecular level will translate to tailored macroscopic physical properties, thus enabling control of the key elements for realized biomedical applications. PMID:23525884

  6. An assessment of the release of inorganic cyanide from the fragrance materials benzyl cyanide, geranyl nitrile and citronellyl nitrile applied dermally to the rat.

    PubMed

    Potter, J; Smith, R L; Api, A M

    2001-02-01

    Organonitriles are widely used as components of fragrances that are incorporated into consumer products, many of which are for human topical use. Some organontriles are readily broken down metabolically to potentially toxic inorganic cyanide. Studies were therefore undertaken to assess whether this occurs with three representative fragrance nitriles, namely, benzyl cyanide, geranyl nitrile and citronellyl nitrile when applied dermally to the rat. The nitriles (benzyl cyanide, 150 mg/kg; geranyl and citronellyl nitriles, 400 mg/kg) were applied to the shaved backs of rats and maintained under occlusion for 24 h. Urine samples were collected for 0-24 h, 24-48 h and 48-72 h from the time of first application. These samples were analysed for thiocyanate, a biomarker for cyanide formation in vivo, as described previously (Potter, J., Smith, R.L., Api, A.M., 2000. Urinary thiocyanate levels as a biomarker for the generation of inorganic cyanide from benzyl cyanide in the rat. Food and Chemical Toxicology 39, 141-146). In the case of benzyl cyanide, there was a marked increase in urinary thiocyanate levels attributable to the release of cyanide in vivo. The amount of thiocyanate recovered was equivalent to 37% of the dose for males and 32% for females. For geranyl nitrile there was no significant increase in urinary thiocyanate excretion and there was only a marginal increase in the case of citronellyl nitrile that was equivalent to 0.40% of the applied dose for males and 0.29% for females. PMID:11267708

  7. Evidence and detailed study of a second-order phase transition in the (C6H11NH3)2[PbI4] organic-inorganic hybrid material

    NASA Astrophysics Data System (ADS)

    Yangui, A.; Pillet, S.; Garrot, D.; Triki, S.; Abid, Y.; Boukheddaden, K.

    2015-03-01

    The thermal properties of the organic-inorganic hybrid material (C6H11NH3)2[PbI4] are investigated using diffuse reflectivity, spectroscopic ellipsometry, differential scanning calorimetry, Raman spectroscopy, and X-ray diffraction. The diffuse reflectivity, performed in heating mode, clearly evidences the presence of a singularity at 336 K. This is confirmed by the temperature dependence of the spectroscopic ellipsometry spectra, which points out a second-order phase transition at 336 K with a critical exponent ˜0.5. Differential scanning calorimetry measurements on a polycrystalline powder of (C6H11NH3)2[PbI4] show a reversible phase transition detected at TC = 336 K without hysteresis. Raman spectroscopy data suggest that this transition arises from a change in the interactions between inorganic sheets ({[PbI4]2-}?) and organic protonated molecules ([C6H11NH3]+). The structural analysis from power X-ray diffraction reveals an incomplete order-disorder transition of the cyclohexylammonium cation, causing a subtle contraction of the inter-plane distance. The transition results from repulsive close contacts between the organic molecules in the interlayer spacing.

  8. The impact of organic and inorganic fertilizers and lime on the species-richness and plant functional characteristics of hay meadow communities

    Microsoft Academic Search

    Francis W. Kirkham; Jerry R. B. Tallowin; Roy A. Sanderson; Anne Bhogal; Brian J. Chambers; David P. Stevens

    2008-01-01

    Vegetation responses to fertilizers and lime applied in a seven-year study at paired unimproved and semi-improved mesotrophic hay meadows in Cumbria and Monmouthshire, UK, are described in terms of species-richness and several other plant community variables. Treatments were farmyard manure (FYM) applied at rates of between 6 and 24tonneha?1 annually or every third year, inorganic fertilizers giving equivalent amounts of

  9. Identifying Optimal Inorganic Nanomateirals for Hybrid Solar Cells

    SciTech Connect

    Xiang, H.; Wei, S. H.; Gong, X. G.

    2009-01-01

    As a newly developed photovoltaic technology, organic-inorganic hybrid solar cells have attracted great interest because of the combined advantages from both components. An ideal inorganic acceptor should have a band gap of about 1.5 eV and energy levels of frontier orbitals matching those of the organic polymer in hybrid solar cells. Hybrid density functional calculations are performed to search for optimal inorganic nanomaterials for hybrid solar sells based on poly(3-hexylthiophene) (P3HT). Our results demonstrate that InSb quantum dots or quantum wires can have a band gap of about 1.5 eV and highest occupied molecular orbital level about 0.4 eV lower than P3HT, indicating that they are good candidates for use in hybrid solar cells. In addition, we predict that chalcopyrite MgSnSb{sub 2} quantum wire could be a low-cost material for realizing high-efficiency hybrid solar cells.

  10. Organic/Inorganic Complex Pigments: Ancient Colors Maya Blue

    SciTech Connect

    Polette-Niewold, L.A.; Manciu, F.S.; Torres, B.; Alvarado, M.; Jr.; Chianelli, R.R.

    2009-06-04

    Maya Blue is an ancient blue pigment composed of palygorskite clay and indigo. It was used by the ancient Maya and provides a dramatic background for some of the most impressive murals throughout Mesoamerica. Despite exposure to acids, alkalis, and chemical solvents, the color of the Maya Blue pigment remains unaltered. The chemical interaction between palygorskite and indigo form an organic/inorganic complex with the carbonyl oxygen of the indigo bound to a surface Al{sup 3+} in the Si-O lattice. In addition indigo will undergo an oxidation to dehydroindigo during preparation. The dehydro-indigo molecule forms a similar but stronger complex with the Al{sup 3+}. Thus, Maya Blue varies in color due to the mixed indigo/dehydroindigo complex. The above conclusions are the result of application of multiple techniques (X-ray diffraction, differential thermal analysis/thermal gravimetric analysis, high resolution transmission electron microscopy, scanning electron microscopy, infrared and Raman spectroscopy) to the characterization of the organic/inorganic complex. A picture of the bonding of the organic molecule to the palygorskite surface forming a surface complex is developed and supported by the results of density functional theory calculations. We also report that other organic molecules such as thioindigo form similar organic/inorganic complexes thus, opening an entirely new class of complex materials for future applications.

  11. Hot-electron distribution function in high-Z materials

    SciTech Connect

    Lindman, E.L.

    1982-01-01

    An analytic expression is obtained for the distribution of hot electrons as a function of distance into a cold material slab in which ..nu../sub E/ = ..gamma../sub E/v/sup -..cap alpha../ and ..nu..perpendicular to = ..gamma..v/sup -..beta../ are the assumed velocity dependences of the energy loss collision frequency and the scattering collision frequency and ..nu../sub E/ << ..nu..perpendicular to. For a time independent source, a time independent solution exists with a characteristic penetration length equal to (lambda/sub E/lambdaperpendicular to)/sup 1/2/ where lambda/sub E/ and lambdaperpendicular to are the mean-free-paths corresponding to ..nu../sub E/ and ..nu..perpendicular to. The distribution function at large distance from the source is proprtional to v/sub ..cap alpha..-3/ for v less than a critical velocity. For v greater than the critical velocity, the velocity dependence of the Maxwellian source reappears causing an exponential cutoff.

  12. Advanced Density Functional Theory Methods for Materials Science

    NASA Astrophysics Data System (ADS)

    Demers, Steven

    In this work we chiefly deal with two broad classes of problems in computational materials science, determining the doping mechanism in a semiconductor and developing an extreme condition equation of state. While solving certain aspects of these questions is well-trodden ground, both require extending the reach of existing methods to fully answer them. Here we choose to build upon the framework of density functional theory (DFT) which provides an efficient means to investigate a system from a quantum mechanics description. Zinc Phosphide (Zn3P2) could be the basis for cheap and highly efficient solar cells. Its use in this regard is limited by the difficulty in n-type doping the material. In an effort to understand the mechanism behind this, the energetics and electronic structure of intrinsic point defects in zinc phosphide are studied using generalized Kohn-Sham theory and utilizing the Heyd, Scuseria, and Ernzerhof (HSE) hybrid functional for exchange and correlation. Novel 'perturbation extrapolation' is utilized to extend the use of the computationally expensive HSE functional to this large-scale defect system. According to calculations, the formation energy of charged phosphorus interstitial defects are very low in n-type Zn3P2 and act as 'electron sinks', nullifying the desired doping and lowering the fermi-level back towards the p-type regime. Going forward, this insight provides clues to fabricating useful zinc phosphide based devices. In addition, the methodology developed for this work can be applied to further doping studies in other systems. Accurate determination of high pressure and temperature equations of state is fundamental in a variety of fields. However, it is often very difficult to cover a wide range of temperatures and pressures in an laboratory setting. Here we develop methods to determine a multi-phase equation of state for Ta through computation. The typical means of investigating thermodynamic properties is via 'classical' molecular dynamics where the atomic motion is calculated from Newtonian mechanics with the electronic effects abstracted away into an interatomic potential function. For our purposes, a 'first principles' approach such as DFT is useful as a classical potential is typically valid for only a portion of the phase diagram (i.e. whatever part it has been fit to). Furthermore, for extremes of temperature and pressure quantum effects become critical to accurately capture an equation of state and are very hard to capture in even complex model potentials. This requires extending the inherently zero temperature DFT to predict the finite temperature response of the system. Statistical modelling and thermodynamic integration is used to extend our results over all phases, as well as phase-coexistence regions which are at the limits of typical DFT validity. We deliver the most comprehensive and accurate equation of state that has been done for Ta. This work also lends insights that can be applied to further equation of state work in many other materials.

  13. Silver-halide/organic-composite structures: Toward materials with multiple photographic functionalities

    SciTech Connect

    Bringley, Joseph F. [Research and Development Laboratories, Eastman Kodak Company, 1999 Lake Avenue, Rochester, NY 14650-2002 (United States)]. E-mail: joseph.bringley@kodak.com; Rajeswaran, Manju [Research and Development Laboratories, Eastman Kodak Company, 1999 Lake Avenue, Rochester, NY 14650-2002 (United States); Olson, Leif P. [Research and Development Laboratories, Eastman Kodak Company, 1999 Lake Avenue, Rochester, NY 14650-2002 (United States); Liebert, Nancy M. [Research and Development Laboratories, Eastman Kodak Company, 1999 Lake Avenue, Rochester, NY 14650-2002 (United States)

    2005-10-15

    We report the synthesis and structure of the novel silver-halide-based organic-inorganic hybrids Ag{sub 2}Br{sub 6}(PPD){sub 2}, Ag{sub 2}Br{sub 6}(CD-2){sub 2}.H{sub 2}O, Ag{sub 2}Br{sub 4}(TMBD), and Ag{sub 2}I{sub 6}(CD-2){sub 2}.H{sub 2}O. 1,4-phenylenediammonium hexabromodiargentate(I) [Ag{sub 2}Br{sub 6}(PPD){sub 2}] crystals are monoclinic (P2{sub 1}/n), with unit-cell dimensions, a=10.1915(3)A, b=7.7562(2)A, c=12.4340(5)A and {beta}=93.109(1){sup o}. N,N-diethyl-2-methyl-1,4-benzenediammonium hexabromodiargentate(I) monohydrate [Ag{sub 2}Br{sub 6}(CD-2){sub 2}.H{sub 2}O] crystals are monoclinic (space group P2{sub 1}/c) with a=10.8434(2)A, b=11.4293(2)A, c=14.3729(1)A, and {beta}=96.153(1){sup o}. N,N,N',N'-tetramethyl-1,4-benzenediammonium tetrabromodiargentate(I) [Ag{sub 2}Br{sub 4}(TMBD)] crystals are orthorhombic (space group Pbcn) with a=17.0030(6)A, b=6.6163(2)A, and c=15.9762(6)A. N,N-diethyl-2-methyl-1,4-benzenediammonium hexaiododiargentate(I) monohydrate, [Ag{sub 2}I{sub 6}(CD-2){sub 2}.H{sub 2}O], are monoclinic (C2/c), with unit-cell dimensions, a=21.4691(4)A, b=12.1411(2)A, c=14.3102(2)A, and {beta}=98.657(1){sup o}. The novel structures are members of a class of silver-halide-based organic-inorganic hybrids based upon the assembly of [Ag{sub a}X{sub b}]{sup n-} clusters and protonated organoamines in aqueous mineral acids. The clusters display short intracluster Ag-Ag distances, and computational methods are used to evaluate intracluster Ag-Ag bonding. The diverse stoichiometries and cluster connectivities observed suggest a rich compositional and structural chemistry based upon the general assembly method. We have extended the methodology to include a silver-halide-organoamonium chemistry in which the organic moiety is chosen to serve a specific photographic function and demonstrate the first examples of such materials. The methodology allows for the direct assembly of [Ag{sub a}X{sub b}]{sup n-} clusters with commercial photographic color developer molecules, and we show that development is repressed but can later be 'switched on' in a unique photographic scheme. The photographic properties of Ag{sub 2}Br{sub 6}(PPD){sub 2} are examined and show an extremely facile development rate owing to the fact that the developer molecules are within molecular proximity to the clusters. As a result of their molecular nature, we anticipate that such materials could enable conventional or completely new imaging technologies with very fast image access rates and very high resolution.

  14. Synthesis of nanostructured materials in inverse miniemulsions and their applications

    NASA Astrophysics Data System (ADS)

    Cao, Zhihai; Ziener, Ulrich

    2013-10-01

    Polymeric nanogels, inorganic nanoparticles, and organic-inorganic hybrid nanoparticles can be prepared via the inverse miniemulsion technique. Hydrophilic functional cargos, such as proteins, DNA, and macromolecular fluoresceins, may be conveniently encapsulated in these nanostructured materials. In this review, the progress of inverse miniemulsions since 2000 is summarized on the basis of the types of reactions carried out in inverse miniemulsions, including conventional free radical polymerization, controlled/living radical polymerization, polycondensation, polyaddition, anionic polymerization, catalytic oxidation reaction, sol-gel process, and precipitation reaction of inorganic precursors. In addition, the applications of the nanostructured materials synthesized in inverse miniemulsions are also reviewed.

  15. Synthesis of nanostructured materials in inverse miniemulsions and their applications.

    PubMed

    Cao, Zhihai; Ziener, Ulrich

    2013-11-01

    Polymeric nanogels, inorganic nanoparticles, and organic-inorganic hybrid nanoparticles can be prepared via the inverse miniemulsion technique. Hydrophilic functional cargos, such as proteins, DNA, and macromolecular fluoresceins, may be conveniently encapsulated in these nanostructured materials. In this review, the progress of inverse miniemulsions since 2000 is summarized on the basis of the types of reactions carried out in inverse miniemulsions, including conventional free radical polymerization, controlled/living radical polymerization, polycondensation, polyaddition, anionic polymerization, catalytic oxidation reaction, sol-gel process, and precipitation reaction of inorganic precursors. In addition, the applications of the nanostructured materials synthesized in inverse miniemulsions are also reviewed. PMID:24056795

  16. Fabrication, Characterization and Modeling of Functionally Graded Materials

    NASA Astrophysics Data System (ADS)

    Lee, Po-Hua

    In the past few decades, a number of theoretical and experimental studies for design, fabrication and performance analysis of solar panel systems (photovoltaic/thermal systems) have been documented. The existing literature shows that the use of solar energy provides a promising solution to alleviate the shortage of natural resources and the environmental pollution associated with electricity generation. A hybrid solar panel has been invented to integrate photovoltaic (PV) cells onto a substrate through a functionally graded material (FGM) with water tubes cast inside, through which water flow serves as both a heat sink and a solar heat collector. Due to the unique and graded material properties of FGMs, this novel design not only supplies efficient thermal harvest and electrical production, but also provides benefits such as structural integrity and material efficiency. In this work, a sedimentation method has been used to fabricate aluminum (Al) and high-density polyethylene (HDPE) FGMs. The size effect of aluminum powder on the material gradation along the depth direction is investigated. Aluminum powder or the mixture of Al and HDPE powder is thoroughly mixed and uniformly dispersed in ethanol and then subjected to sedimentation. During the sedimentation process, the concentration of Al and HDPE particles temporally and spatially changes in the depth direction due to the non-uniform motion of particles; this change further affects the effective viscosity of the suspension and thus changes the drag force of particles. A Stokes' law based model is developed to simulate the sedimentation process, demonstrate the effect of manufacturing parameters on sedimentation, and predict the graded microstructure of deposition in the depth direction. In order to improve the modeling for sedimentation behavior of particles, the Eshelby's equivalent inclusion method (EIM) is presented to determine the interaction between particles, which is not considered in a Stokes' law based model. This method is initially applied to study the case of one drop moving in a viscous fluid; the solution recovers the closed form classic solution when the drop is spherical. Moreover, this method is general and can be applied to the cases of different drop shapes and the interaction between multiple drops. The translation velocities of the drops depend on the relative position, the center-to-center distance of drops, the viscosity and size of drops. For the case of a pair of identical spherical drops, the present method using a linear approximation of the eigenstrain rate has provided a very close solution to the classic explicit solution. If a higher order of the polynomial form of the eigenstrain rate is used, one can expect a more accurate result. To meet the final goal of mass production of the aforementioned Al-HDPE FGM, a faster and more economical material manufacturing method is proposed through a vibration method. The particle segregation of larger aluminum particles embedded in the concentrated suspension of smaller high-density polyethylene is investigated under vibration with different frequencies and magnitudes. Altering experimental parameters including time and amplitude of vibration, the suspension exhibits different particle segregation patterns: uniform-like, graded and bi-layered. For material characterization, small cylinder films of Al-HDPE system FGM are obtained after the stages of dry, melt and solidification. Solar panel prototypes are fabricated and tested at different water flow rates and solar irradiation intensities. The temperature distribution in the solar panel is measured and simulated to evaluate the performance of the solar panel. Finite element simulation results are very consistent with the experimental data. The understanding of heat transfer in the hybrid solar panel prototypes gained through this study will provide a foundation for future solar panel design and optimization.

  17. Role of CNTs in inorganic electroluminescence

    Microsoft Academic Search

    Jin-Young Kim; Segi Yu

    2011-01-01

    Inorganic electroluminescence (EL) has been considered to be utilized in flat panel displays in the future. However, the progress of the display device utilizing EL phosphor is rather mild due primary to its low brightness, high voltage operation, and poor expectation lifetime. Carbon nanotubes (CNTs) has been focused in many areas since this material has a number of useful characteristics

  18. Inorganic bonding of semiconductor strain gages

    NASA Technical Reports Server (NTRS)

    Woodruff, N. L.

    1970-01-01

    Inorganic bonding materials minimize outgassing and improve electrical and mechanical properties of semiconductor strain-gage transducers in high-vacuum and high-temperature operations. The two basic methods described are ceramic-glass-bonding and metallic bond formation between the strain gage and the substrate.

  19. A Mapping of the Electron Localization Function for Earth Materials

    SciTech Connect

    Gibbs, Gerald V.; Cox, David F.; Ross, Nancy; Crawford, T Daniel; Burt, Jason; Rosso, Kevin M.

    2005-06-01

    The electron localization function, ELF, generated for a number of geometry-optimized earth materials, provides a graphical representation of the spatial localization of the probability electron density distribution as embodied in domains ascribed to localized bond and lone pair electrons. The lone pair domains, displayed by the silica polymorphs quartz, coesite and cristobalite, are typically banana-shaped and oriented perpendicular to the plane of the SiOSi angle at ~0.60 Å from the O atom on the reflex side of the angle. With decreasing angle, the domains increase in magnitude, indicating an increase in the nucleophilic character of the O atom, rendering it more susceptible to potential electrophilic attack. The Laplacian isosurface maps of the experimental and theoretical electron density distribution for coesite substantiates the increase in the size of the domain with decreasing angle. Bond pair domains are displayed along each of the SiO bond vectors as discrete concave hemispherically-shaped domains at ~0.70 Å from the O atom. For more closed-shell ionic bonded interactions, the bond and lone pair domains are often coalesced, resulting in concave hemispherical toroidal-shaped domains with local maxima centered along the bond vectors. As the shared covalent character of the bonded interactions increases, the bond and lone pair domains are better developed as discrete domains. ELF isosurface maps generated for the earth materials tremolite, diopside, talc and dickite display banana-shaped lone pair domains associated with the bridging O atoms of SiOSi angles and concave hemispherical toroidal bond pair domains associated with the nonbridging ones. The lone pair domains in dickite and talc provide a basis for understanding the bonded interactions between the adjacent neutral layers. Maps were also generated for beryl, cordierite, quartz, low albite, forsterite, wadeite, åkermanite, pectolite, periclase, hurlbutite, thortveitite and vanthoffite. Strategies are reviewed for finding potential H docking sites in the silica polymorphs and related materials. As observed in an earlier study, the ELF is capable of generating bond and lone pair domains that are similar in number and arrangement to those provided by Laplacian and deformation electron density distributions. The formation of the bond and lone pair domains in the silica polymorphs and the progressive decrease in the SiO length as the value of the electron density at the bond critical point increases indicates that the SiO bonded interaction has a substantial component of covalent character.

  20. Synthesis of organic-inorganic hybrid nanocomposite material: alizarin-3-sulfonate in the lamella of zinc-aluminium-layered double hydroxide

    NASA Astrophysics Data System (ADS)

    Hussein, Mohd Zobir b.; Long, Chan W.; Zainal, Zulkarnain; Yahaya, Asmah H.

    2005-02-01

    A series of new organic dye-interleaved nanocomposites (NCs) were prepared by intercalation of alizarin-3-sulfonate anion (Az3S) into Zn-Al-layered double hydroxide (LDH) inorganic lamella host at different concentrations via self-assembly method. The physicochemical properties of the as-synthesized LDH and NCs were studied using PXRD, FTIR, ICP-AES, CHNS, true density and SEM techniques. Basal spacing expansions from 9.0 Å in LDH to about 10.0 and 20.0 Å in the resulting NCs were observed, suggesting that Az3S was probably orientating itself in two or more different ways in the host-matrix due to two different species that co-existed in the mother liquor during the synthesis. FTIR study on NCs further confirmed the interleaving by showing combined patterns of LDH and Az3S. Changes in chemical composition in NC, particularly the increase in carbon and sulfur content compared to the LDH were in strong agreement with the PXRD and FTIR studies. In addition, the inclusion of an organic moiety as interleaving guest in NCs was found to reduce the true density and significantly alter the microscopic surface morphology of the resulting NCs.

  1. Dislocation punching from interfaces in functionally-graded materials

    SciTech Connect

    Taya, M.; Lee, J.K. [Univ. of Washington, Seattle, WA (United States). Dept. of Mechanical Engineering] [Univ. of Washington, Seattle, WA (United States). Dept. of Mechanical Engineering; Mori, T. [Ryobi Ltd., Tokyo (Japan). Research and Development Div.] [Ryobi Ltd., Tokyo (Japan). Research and Development Div.

    1997-06-01

    A new dislocation punching model for a functionally graded material (FGM) subjected to a temperature change is proposed, using Eshelby`s model. FGM, consisting of several layers, is deposited on a ceramic substrate. Two types of microstructures are examined for a layer: one consists of a metal matrix and ceramic particles and the other of a ceramic matrix and metal particles. An elastic energy is evaluated when plastic strain, in addition to thermal mismatch strain, is introduced in the metal phase. The work dissipated by the plastic deformation is also calculated. From the condition that the reduction in the elastic energy is larger than the work dissipated, a critical thermal mismatch strain to induce stress relaxation is determined. The magnitude of the plastic strain is also determined, when the relaxation occurs. The theory is applied to a model FGM consisting of mixtures of Pd and Al{sub 2}O{sub 3} on an Al{sub 2}O{sub 3} substrate.

  2. Exploration Life Support: ELS Functions and Materials Interfaces

    NASA Technical Reports Server (NTRS)

    Duffield, Bruce

    2007-01-01

    This viewgraph presentation reviews some of the processes used to develop life support systems, and how that supports the materials that are selected. Of particular concern in the selection of materials is flammability.

  3. Functional Graphenic Materials Via a Johnson?Claisen Rearrangement

    E-print Network

    Swager, Timothy M.

    Current research in materials has devoted much attention to graphene, with a considerable amount of the chemical manipulation going through the oxidized state of the material, known as graphene oxide (GO). In this report, ...

  4. Dual-functional biomimetic materials: nonfouling poly(carboxybetaine) with active functional groups for protein immobilization.

    PubMed

    Zhang, Zheng; Chen, Shengfu; Jiang, Shaoyi

    2006-12-01

    We introduce a dual-functional biocompatible material based on zwitterionic poly(carboxybetaine methacrylate) (polyCBMA), which not only highly resists protein adsorption/cell adhesion, but also has abundant functional groups convenient for the immobilization of biological ligands, such as proteins. The dual-functional properties are unique to carboxybetaine moieties and are not found in other nonfouling moieties such as ethylene glycol, phosphobetaine, and sulfobetaine. The unique properties are demonstrated in this work by grafting a polyCBMA polymer onto a surface or by preparing a polyCBMA-based hydrogel. PolyCBMA brushes with a thickness of 10-15 nm were grafted on a gold surface using the surface-initiated atom transfer radical polymerization method. Protein adsorption was analyzed using a surface plasmon resonance sensor. The surface grafted with polyCBMA very largely prevented the nonspecific adsorption of three test proteins, that is, fibrinogen, lysozyme, and human chorionic gonadotropin (hCG). The immobilization of anti-hCG on the surface resulted in the specific binding of hCG while maintaining a high resistance to nonspecific protein adsorption. Transparent polyCBMA-based hydrogel disks were decorated with immobilized fibronectin. Aortic endothelial cells did not bind to the polyCBMA controls, but appeared to adhere well and spread on the fibronectin-modified surface. With their dual functionality and biomimetic nature, polyCBMA-based materials are very promising for their applications in medical diagnostics, biomaterials/tissue engineering, and drug delivery. PMID:17154457

  5. Organic-inorganic hybrid electroluminescence device fabricated by conjugated polymer and ZnS:Mn

    Microsoft Academic Search

    Xiaohui Yang; Xurong Xu

    2000-01-01

    An organic-inorganic hybrid device was fabricated. The architecture of the hybrid device consisted of two layers sandwiched between two injecting electrodes, one of which was a conjugated polymer layer and the other was an inorganic material layer. Emission from both the organic and inorganic layers was observed, but the mechanisms of luminescence for the layers were different. Our primary results

  6. The deposition of inorganic thin films on polymer substrates by plasma-enhanced chemical vapor deposition

    Microsoft Academic Search

    Daniel Christian Guerin

    2001-01-01

    Inorganic thin films were deposited on polymer substrates by plasma-enhanced chemical vapor deposition (PECVD). The inorganic\\/polymer composites have the flexibility of polymers with the surface properties of inorganic materials and thus have several useful and interesting properties. The coated polymer sheets had drastically reduced oxygen diffusion rates compared to the untreated polymers. The use of PECVD as a deposition method

  7. Crystallinity of inorganic films grown by atomic layer deposition: Overview and general trends

    NASA Astrophysics Data System (ADS)

    Miikkulainen, Ville; Leskelä, Markku; Ritala, Mikko; Puurunen, Riikka L.

    2013-01-01

    Atomic layer deposition (ALD) is gaining attention as a thin film deposition method, uniquely suitable for depositing uniform and conformal films on complex three-dimensional topographies. The deposition of a film of a given material by ALD relies on the successive, separated, and self-terminating gas-solid reactions of typically two gaseous reactants. Hundreds of ALD chemistries have been found for depositing a variety of materials during the past decades, mostly for inorganic materials but lately also for organic and inorganic-organic hybrid compounds. One factor that often dictates the properties of ALD films in actual applications is the crystallinity of the grown film: Is the material amorphous or, if it is crystalline, which phase(s) is (are) present. In this thematic review, we first describe the basics of ALD, summarize the two-reactant ALD processes to grow inorganic materials developed to-date, updating the information of an earlier review on ALD [R. L. Puurunen, J. Appl. Phys. 97, 121301 (2005)], and give an overview of the status of processing ternary compounds by ALD. We then proceed to analyze the published experimental data for information on the crystallinity and phase of inorganic materials deposited by ALD from different reactants at different temperatures. The data are collected for films in their as-deposited state and tabulated for easy reference. Case studies are presented to illustrate the effect of different process parameters on crystallinity for representative materials: aluminium oxide, zirconium oxide, zinc oxide, titanium nitride, zinc zulfide, and ruthenium. Finally, we discuss the general trends in the development of film crystallinity as function of ALD process parameters. The authors hope that this review will help newcomers to ALD to familiarize themselves with the complex world of crystalline ALD films and, at the same time, serve for the expert as a handbook-type reference source on ALD processes and film crystallinity.

  8. Environmental Inorganic Geochemistry Group

    E-print Network

    Tobar, Michael

    mining: the mine site as a pollution source 0930 The role of water ­ an exceptional substance 1000Environmental Inorganic Geochemistry Group Environmental Geochemistry of Mine Site Pollution. Sustainability in mining requires that pollution issues are addressed from the planning stage, through operations

  9. Morphology-preserving chemical conversion of bioorganic and inorganic templates

    NASA Astrophysics Data System (ADS)

    Vernon, Jonathan Paul

    The generation of nanostructured assemblies with complex (three-dimensional, 3D) self-assembled morphologies and with complex (multicomponent) tailorable inorganic compositions is of considerable technological and scientific interest. This dissertation demonstrates self-assembled 3D organic templates of biogenic origin can be converted into replicas comprised of numerous other functional nanocrystalline inorganic materials. Nature provides a spectacular variety of biologically-assembled 3D organic structures with intricate, hierarchical (macro-to-micro-to-nanoscale) morphologies. Such processing on readily-available structurally complex templates provides a framework for chemical conversion of synthetic organic templates and, potentially, production of organic/inorganic composites. Four specific research thrusts are detailed in this document. First, chemical conversion of a nanostructured bioorganic template into a multicomponent oxide compound (tetragonal BaTiO3) via SSG coating and subsequent morphology-preserving microwave hydrothermal processing is demonstrated. Second, morphology-preserving chemical conversion of bioorganic templates into hierarchical photoluminescent microparticles is demonstrated to reveal both the dramatic change in properties such processing can provide, and the potential utility of chemically transformed templates in anti-counterfeiting / authentication applications. Third, determination of the reaction mechanism(s) for morphology-preserving microwave hydrothermal conversion of TiO2 to BaTiO3, through Au inert markers on single crystal rutile titania, is detailed. Finally, utilization of constructive coating techniques (SSG) and moderate temperature (< 500°C) heat treatments to modify and replicate structural color is coupled with deconstructive focused ion beam microsurgery to prepare samples for microscale structure interrogation. Specifically, the effects of coating thickness and composition on reflection spectra of structurally colored templates are examined. Also, the effects of the replacement of natural material with higher index of refraction inorganic materials on optical properties are discussed. The three processing research thrusts constituting chapters 1, 2 and 4 take advantage of moderate temperature processing to ensure nanocrystalline materials, either for shape preservation or to prevent scattering in optical applications. The research thrust detailed in chapter 3 examines hydrothermal conversion of TiO2 to BaTiO3, not only to identify the reaction mechanism(s) involved in hydrothermal conversion under morphology-preserving conditions, but also to introduce inert marker experiments to the field of microwave hydrothermal processing.

  10. Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting

    PubMed Central

    Battaglia, Corsin; Söderström, Karin; Escarré, Jordi; Haug, Franz-Josef; Despeisse, Matthieu; Ballif, Christophe

    2013-01-01

    We describe a nanomoulding technique which allows low-cost nanoscale patterning of functional materials, materials stacks and full devices. Nanomoulding combined with layer transfer enables the replication of arbitrary surface patterns from a master structure onto the functional material. Nanomoulding can be performed on any nanoimprinting setup and can be applied to a wide range of materials and deposition processes. In particular we demonstrate the fabrication of patterned transparent zinc oxide electrodes for light trapping applications in solar cells. PMID:23380874

  11. The influence of mineral functional materials on chloride ion penetration of concrete

    Microsoft Academic Search

    Hu Hongmei; Ma Baoguo

    2005-01-01

    The mechanism of chloride ion penetration in high performance concrete was analyzed. The experimental results indicate that\\u000a there are two important reasons that influence the anti-chloride penetration of high performance concrete. One is the function\\u000a effect of mineral functional material, so that it increases concrete’s capability to resist chloride ion penetration. The\\u000a other is combined action of mineral functional material’s

  12. Inorganic-organic thin implant coatings deposited by lasers.

    PubMed

    Sima, Felix; Davidson, Patricia M; Dentzer, Joseph; Gadiou, Roger; Pauthe, Emmanuel; Gallet, Olivier; Mihailescu, Ion N; Anselme, Karine

    2015-01-14

    The lifetime of bone implants inside the human body is directly related to their osseointegration. Ideally, future materials should be inspired by human tissues and provide the material structure-function relationship from which synthetic advanced biomimetic materials capable of replacing, repairing, or regenerating human tissues can be produced. This work describes the development of biomimetic thin coatings on titanium implants to improve implant osseointegration. The assembly of an inorganic-organic biomimetic structure by UV laser pulses is reported. The structure consists of a hydroxyapatite (HA) film grown onto a titanium substrate by pulsed-laser deposition (PLD) and activated by a top fibronectin (FN) coating deposited by matrix-assisted pulsed laser evaporation (MAPLE). A pulsed KrF* laser source (? = 248 nm, ? = 25 ns) was employed at fluences of 7 and 0.7J/cm(2) for HA and FN transfer, respectively. Films approximately 1500 and 450 nm thick were obtained for HA and FN, respectively. A new cryogenic temperature-programmed desorption mass spectrometry analysis method was employed to accurately measure the quantity of immobilized protein. We determined that less than 7 ?g FN per cm(2) HA surface is adequate to improve adhesion, spreading, and differentiation of osteoprogenitor cells. We believe that the proposed fabrication method opens the door to combining and immobilizing two or more inorganic and organic materials on a solid substrate in a well-defined manner. The flexibility of this method enables the synthesis of new hybrid materials by simply tailoring the irradiation conditions according to the thermo-physical properties of the starting materials. PMID:25485841

  13. A review of organic and inorganic biomaterials for neural interfaces.

    PubMed

    Fattahi, Pouria; Yang, Guang; Kim, Gloria; Abidian, Mohammad Reza

    2014-03-26

    Recent advances in nanotechnology have generated wide interest in applying nanomaterials for neural prostheses. An ideal neural interface should create seamless integration into the nervous system and performs reliably for long periods of time. As a result, many nanoscale materials not originally developed for neural interfaces become attractive candidates to detect neural signals and stimulate neurons. In this comprehensive review, an overview of state-of-the-art microelectrode technologies provided fi rst, with focus on the material properties of these microdevices. The advancements in electro active nanomaterials are then reviewed, including conducting polymers, carbon nanotubes, graphene, silicon nanowires, and hybrid organic-inorganic nanomaterials, for neural recording, stimulation, and growth. Finally, technical and scientific challenges are discussed regarding biocompatibility, mechanical mismatch, and electrical properties faced by these nanomaterials for the development of long-lasting functional neural interfaces. PMID:24677434

  14. A Review of Organic and Inorganic Biomaterials for Neural Interfaces

    PubMed Central

    Fattahi, Pouria; Yang, Guang; Kim, Gloria

    2015-01-01

    Recent advances in nanotechnology have generated wide interest in applying nanomaterials for neural prostheses. An ideal neural interface should create seamless integration into the nervous system and performs reliably for long periods of time. As a result, many nanoscale materials not originally developed for neural interfaces become attractive candidates to detect neural signals and stimulate neurons. In this comprehensive review, an overview of state-of-the-art microelectrode technologies provided first, with focus on the material properties of these microdevices. The advancements in electro active nanomaterials are then reviewed, including conducting polymers, carbon nanotubes, graphene, silicon nanowires, and hybrid organic-inorganic nanomaterials, for neural recording, stimulation, and growth. Finally, technical and scientific challenges are discussed regarding biocompatibility, mechanical mismatch, and electrical properties faced by these nanomaterials for the development of long-lasting functional neural interfaces. PMID:24677434

  15. [Analysis of biological material originating from the body of general W?adys?aw Sikorski for inorganic poisons and diatoms presence].

    PubMed

    Sadlik, Józefa Krystyna; Brozek-Mucha, Zuzanna

    2009-01-01

    Results of the analysis of biological materials originating from the body of general Sikorski are presented in the paper. Samples of the liver, kidney, intestine and lung were analysed for metals and As content, and samples of the lung, liver, kidney, stomach, intestine and bone marrow--for diatoms presence. The analysis for metals and As was performed by atomic absorption spectrometry (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Before the analysis, the samples were wet digested by the classic and microwave assisted method. The analysis did not result in detecting the presence of As, Co, Ni, and Tl in any of the studied materials, while Hg was not revealed in the liver, intestines and lung and Pb in the intestines and lung. The content of Ba, Cd, Cr, Cu, Fe, Mn, Sr and Zn in all the studied materials, Hg in the kidney, and Pb in the liver and kidney did not indicate poisoning by the above-mentioned metals or arsenic. No diatoms were found in the studied materials. PMID:19711817

  16. Synthesis of porous inorganic hollow fibers without harmful solvents.

    PubMed

    Shukla, Sushumna; de Wit, Patrick; Luiten-Olieman, Mieke W J; Kappert, Emiel J; Nijmeijer, Arian; Benes, Nieck E

    2015-01-01

    A route for the fabrication of porous inorganic hollow fibers with high surface-area-to-volume ratio that avoids harmful solvents is presented. The approach is based on bio-ionic gelation of an aqueous mixture of inorganic particles and sodium alginate during wet spinning. In a subsequent thermal treatment, the bio-organic material is removed and the inorganic particles are sintered. The method is applicable to the fabrication of various inorganic fibers, including metals and ceramics. The route completely avoids the use of organic solvents, such as N-methyl-2-pyrrolidone, and additives associated with the currently used fiber fabrication methods. In addition, it inherently avoids the manifestation of so-called macro voids and allows the facile incorporation of additional metal oxides in the inorganic hollow fibers. PMID:25256812

  17. Design of Inorganic Electrides

    NASA Astrophysics Data System (ADS)

    Zhang, Yunwei; Wang, Hui; Wang, Yanchao; Ma, Yanming

    2015-03-01

    Electrides, in which all of or part of the valence electrons occupy interstitial regions in the crystal and behave as anions, have been synthesized at ambient or high-pressure conditions. Their loosely bound anionic electrons make electrides good candidates for electro-active materials. Here, we report a developed methodology to systematically design electrides for given chemical systems. The new approach is based on the swarm-intelligence CALYPSO algorithm on structure prediction and requires only the chemical compositions to predict the electride phases. In contrast to the traditional ground state structure prediction method where the total energy was solely used as the fitness function, we adopted a new fitness function in combination with the first-principles calculation to select the optimal solutions for a description of given chemical systems. The experimentally know electrides have been successfully reproduced. The results suggested that our approach is reliable and can be widely applied into design of new electrides.

  18. Towards the dynamics of the temperature field gradient in a layer of an inorganic material under radiation heating according to the data of experiments and numerical modeling

    NASA Astrophysics Data System (ADS)

    Sobol, V. R.; Goman, P. N.; Mazurenko, O. N.

    2012-05-01

    We have investigated the process of temperature field formation in a layer of a weakly conducting medium with the example of wood and green moss under irradiation of one side with an energy flux and contact heat removal through the opposite back surface of the material onto an asbestos-cement support. The experimental results were compared with the data calculated on the basis of the relations of nonstationary heat transfer in the approximations of closeness and openness of the system. The conditions for heat removal suppression have been concretized and the role of the energy exchange under the prolonged action of radiant energy for estimating the thermal stability parameters of related materials has been elucidated. The obtained data can be used to control radiant fluxes in treating wood, for effective heating of living and industrial premises, improving the methods for opposing high energy fluxes, and preventing the propagation of fire in inhabited localities and in park and forest zones.

  19. Functionalization of textile materials by alkoxysilane-grafted titanium dioxide

    Microsoft Academic Search

    Jadwiga Sójka-Ledakowicz; Joanna Lewartowska; Marcin Kudzin; Marcin Leonowicz; Teofil Jesionowski; Katarzyna Siwinska-Stefanska; Andrzej Krysztafkiewicz

    2009-01-01

    Modern materials, including textiles for specific applications, have to satisfy growing requirements. Regulations concerning\\u000a man and natural environment protection against harmful substances emission, UV radiation, and electromagnetic field radiation\\u000a become more and more stringent. Intensive development of nanotechnology offers great possibilities to create novel—conforming\\u000a to the requirements—multifunctional materials based on textile substrates. Nanoparticles of metal oxides, e.g., titania (TiO2), belong

  20. Path Planning and Control of Functionally graded Materials for Rapid Tooling

    Microsoft Academic Search

    Ren C. Luo; Yen Lin Pan; Chen Jun Wang; Zhong Hong Huang

    2006-01-01

    Rapid tooling (RT) has recently become more important due to the requirement of rapid manufacturing. RT can manufacture stronger mold and functional component than rapid prototyping (RP) does. Besides, functional component and production are valued gradually. Functionally graded materials (FGM) technology is proposed to apply to functional component. This study aims to propose a new path planning, contour path method,

  1. Potential-functional embedding theory for molecules and materials

    NASA Astrophysics Data System (ADS)

    Huang, Chen; Carter, Emily A.

    2011-11-01

    We introduce a potential-functional embedding theory by reformulating a recently proposed density-based embedding theory in terms of functionals of the embedding potential. This potential-functional based theory completes the dual problem in the context of embedding theory for which density-functional embedding theory has existed for two decades. With this potential-functional formalism, it is straightforward to solve for the unique embedding potential shared by all subsystems. We consider charge transfer between subsystems and discuss how to treat fractional numbers of electrons in subsystems. We show that one is able to employ different energy functionals for different subsystems in order to treat different regions with theories of different levels of accuracy, if desired. The embedding potential is solved for by directly minimizing the total energy functional, and we discuss how to efficiently calculate the gradient of the total energy functional with respect to the embedding potential. Forces are also derived, thereby making it possible to optimize structures and account for nuclear dynamics. We also extend the theory to spin-polarized cases. Numerical examples of the theory are given for some homo- and hetero-nuclear diatomic molecules and a more complicated test of a six-hydrogen-atom chain. We also test our theory in a periodic bulk environment with calculations of basic properties of bulk NaCl, by treating each atom as a subsystem. Finally, we demonstrate the theory for water adsorption on the MgO(001)surface.

  2. Inorganic particle analysis of dental impression elastomers.

    PubMed

    Carlo, Hugo Lemes; Fonseca, Rodrigo Borges; Soares, Carlos José; Correr, Américo Bortolazzo; Correr-Sobrinho, Lourenço; Sinhoreti, Mário Alexandre Coelho

    2010-01-01

    The aim of this study was to determine quantitatively and qualitatively the inorganic particle fraction of commercially available dental elastomers. The inorganic volumetric fraction of two addition silicones (Reprosil Putty/Fluid and Flexitime Easy Putty/Fluid), three condensation silicones (Clonage Putty/Fluid, Optosil Confort/Xantopren VL and Silon APS Putty/Fluid), one polyether (Impregum Soft Light Body) and one polysulfide (Permlastic Light Body) was accessed by weighing a previously determined mass of each material in water before and after burning samples at 600 ºC, during 3 h. Unsettled material samples were soaked in acetone and chloroform for removal of the organic portion. The remaining filler particles were sputter-coated with gold evaluation of their morphology and size, under scanning electron microscopy (SEM). Flexitime Easy Putty was the material with the highest results for volumetric particle fraction, while Impregum Soft had the lowest values. Silon 2 APS Fluid presented the lowest mean filler size values, while Clonage Putty had the highest values. SEM micrographs of the inorganic particles showed several morphologies - lathe-cut, spherical, spherical-like, sticks, and sticks mixed to lathe-cut powder. The results of this study revealed differences in particle characteristics among the elastometic materials that could lead to different results when testing mechanical properties. PMID:21271042

  3. Negative thermal expansion in functional materials: controllable thermal expansion by chemical modifications.

    PubMed

    Chen, Jun; Hu, Lei; Deng, Jinxia; Xing, Xianran

    2015-05-26

    Negative thermal expansion (NTE) is an intriguing physical property of solids, which is a consequence of a complex interplay among the lattice, phonons, and electrons. Interestingly, a large number of NTE materials have been found in various types of functional materials. In the last two decades good progress has been achieved to discover new phenomena and mechanisms of NTE. In the present review article, NTE is reviewed in functional materials of ferroelectrics, magnetics, multiferroics, superconductors, temperature-induced electron configuration change and so on. Zero thermal expansion (ZTE) of functional materials is emphasized due to the importance for practical applications. The NTE functional materials present a general physical picture to reveal a strong coupling role between physical properties and NTE. There is a general nature of NTE for both ferroelectrics and magnetics, in which NTE is determined by either ferroelectric order or magnetic one. In NTE functional materials, a multi-way to control thermal expansion can be established through the coupling roles of ferroelectricity-NTE, magnetism-NTE, change of electron configuration-NTE, open-framework-NTE, and so on. Chemical modification has been proved to be an effective method to control thermal expansion. Finally, challenges and questions are discussed for the development of NTE materials. There remains a challenge to discover a "perfect" NTE material for each specific application for chemists. The future studies on NTE functional materials will definitely promote the development of NTE materials. PMID:25864730

  4. Direct digital manufacturing of three-dimensional functionally graded material objects

    Microsoft Academic Search

    W. K. Chiu; K. M. Yu

    2008-01-01

    Among the different types of direct digital manufacturing (DDM) technologies, some of them can be used for making functionally graded material (FGM) objects. Apart from specific characteristics of the DDM process being employed, one problem in FGM object fabrication is the generation of the corresponding information complete format so that the functionally graded material information can be realized. In this

  5. A parametric study of thermomechanical behavior of functionally gradient materials

    E-print Network

    Chin, Che-Doong

    1996-01-01

    (FSDT) that accounts for the transverse shear strains and the rotations, coupled with a three dimensional heat conduction equation is formulated for a functionally gradient plate. Both problems are studied by varying the volume fraction of a ceramic...

  6. A parametric study of thermomechanical behavior of functionally gradient materials 

    E-print Network

    Chin, Che-Doong

    1996-01-01

    (FSDT) that accounts for the transverse shear strains and the rotations, coupled with a three dimensional heat conduction equation is formulated for a functionally gradient plate. Both problems are studied by varying the volume fraction of a ceramic...

  7. Advances in tribology: the materials point of view

    Microsoft Academic Search

    H. Czichos; D. Klaffke; E. Santner; M. Woydt

    1995-01-01

    The application of advanced materials in various areas of contemporary technology can lead to improvements in the function, quality and performance of engineering components and systems. In this paper, an overview of the developments in high performance materials, both organic and inorganic based, is given. This includes thin hard coatings because of their increasing importance in tribological improvements. For these

  8. Functional materials analysis using in situ and in operando X-ray and neutron scattering.

    PubMed

    Peterson, Vanessa K; Papadakis, Christine M

    2015-03-01

    In situ and in operando studies are commonplace and necessary in functional materials research. This review highlights recent developments in the analysis of functional materials using state-of-the-art in situ and in operando X-ray and neutron scattering and analysis. Examples are given covering a number of important materials areas, alongside a description of the types of information that can be obtained and the experimental setups used to acquire them. PMID:25866665

  9. Dissolution of Functional Materials and Rare Earth Oxides into Pseudo Alveolar Fluid

    Microsoft Academic Search

    Mitsutoshi TAKAYA; Yasushi SHINOHARA; Fumio SERITA; Mariko ONO-OGASAWARA; Noriko OTAKI; Tadao TOYA; Ayako TAKATA; Katsumi YOSHIDA; Norihiko KOHYAMA

    2006-01-01

    The dissolution rates of rare earth oxides and two types of rare earth containing functional materials into water, saline solution, and Gamble's fluid were measured in order to evaluate the biological effects of rare earth-containing functional materials. The tested materials were yttrium, lanthanum, cerium and neodymium oxides, and neodymium-boron-iron magnet alloy (NdBFe) and lanthanum-mish-metal-nickel-cobalt (LmNiCo) hydrogen-containing alloy. The dissolution rates

  10. Ecologically appropriate plant materials for functional restoration of rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecosystems of rangelands targeted for restoration have often been modified, hindering restoration efforts. WEhile local adaptation has long been used as an argument for the exclusive use of local plant materials, recent meta-analysis results indicate that general adaptation across a variety of envi...

  11. Gap Wave Propagation in Functionally Graded Piezoelectric Material Structures

    E-print Network

    Wang, Ji

    conditions on strip surface are applied to solve this problem. The phase velocity can be numerically responses in FGM cylinders [11-12]. Recently Han and Liu investigated the frequency and group velocity of the gradient variation about material on the phase velocity is discussed in detail. We find that gradient

  12. X-ray photoelectron spectroscopy for characterization of bionanocomposite functional materials for energy-harvesting technologies.

    PubMed

    Artyushkova, Kateryna; Atanassov, Plamen

    2013-07-22

    The analysis of hybrid multicomponent bioorganic and bioinorganic composite materials related to energy technologies by using X-ray photoelectron spectroscopy is discussed. The approaches and considerations of overcoming the difficulties of analyzing hybrid multicomponent materials are demonstrated for different types of materials used in bioenzyme fuel cells, that is, enzyme immobilization in a hybrid inorganic-organic matrix, analysis of peptide binding and structure in the mediation of silica nanoparticle formation, analysis of enzyme-polymeric multilayered architectures obtained through layer-by-layer assembly, and study of the mechanism of electropolymerization. Thorough optimization of experimental design through analysis of an adequate set of reference materials, relevant timescales of sample preparation and X-ray exposure, careful peak decomposition and cross-correlation between elemental speciation, results in a detailed understanding of the chemistry of nanocomposite constituents and interactions between them. The methodology presented and examples discussed are of significant importance to the scientific and engineering communities focused on the immobilization of enzymes, proteins, peptides, and other large biological molecules on solid substrates. PMID:23703935

  13. Analytical electron microscopy of biogenic and inorganic carbonates

    NASA Technical Reports Server (NTRS)

    Blake, David F.

    1989-01-01

    In the terrestrial sedimentary environment, the mineralogically predominant carbonates are calcite-type minerals (rhombohedral carbonates) and aragonite-type minerals (orthorhombic carbonates). Most common minerals precipitating either inorganically or biogenically are high magnesium calcite and aragonite. High magnesium calcite (with magnesium carbonate substituting for more than 7 mole percent of the calcium carbonate) is stable only at temperatures greater than 700 C or thereabouts, and aragonite is stable only at pressures exceeding several kilobars of confining pressure. Therefore, these carbonates are expected to undergo chemical stabilization in the diagenetic environment to ultimately form stable calcite and dolomite. Because of the strong organic control of carbonate deposition in organisms during biomineralization, the microchemistry and microstructure of invertebrate skeletal material is much different than that present in inorganic carbonate cements. The style of preservation of microstructural features in skeletal material is therefore often quite distinctive when compared to that of inorganic carbonate even though wholesale recrystallization of the sediment has taken place. Microstructural and microchemical comparisons are made between high magnesium calcite echinoderm skeletal material and modern inorganic high magnesium calcite inorganic cements, using analytical electron microscopy and related techniques. Similar comparisons are made between analogous materials which have undergone stabilization in the diagenetic environment. Similar analysis schemes may prove useful in distinguishing between biogenic and inorganic carbonates in returned Martian carbonate samples.

  14. Fast determination of Ziziphora tenuior L. essential oil by inorganic-organic hybrid material based on ZnO nanoparticles anchored to a composite made from polythiophene and hexagonally ordered silica.

    PubMed

    Piryaei, Marzieh; Abolghasemi, Mir Mahdi; Nazemiyeh, Hossein

    2015-01-01

    In this paper, for the first time, an inorganic-organic hybrid material based on ZnO nanoparticles was anchored to a composite made from polythiophene and hexagonally ordered silica (ZnO/PT/SBA-15) for use in solid-phase fibre microextraction (SPME) of medicinal plants. A homemade SPME apparatus was used for the extraction of volatile components of Ziziphora tenuior L. A simplex method was used for optimisation of five different parameters affecting the efficiency of the extraction. The main constituents extracted by ZnO/PT/SBA-15 and PDMS fibres and hydrodistillation (HD) methods, respectively, included pulegone (51.25%, 53.64% and 56.68%), limonene (6.73%, 6.58% and 8.3%), caryophyllene oxide (5.33%, 4.31% and 4.53%) and 1,8-cineole (4.21%, 3.31% and 3.18%). In comparison with the HD method, the proposed technique could equally monitor almost all the components of the sample, in an easier way, in a shorter time and requiring a much lower amount of the sample. PMID:25496469

  15. Structure-based design of functional amyloid materials.

    PubMed

    Li, Dan; Jones, Eric M; Sawaya, Michael R; Furukawa, Hiroyasu; Luo, Fang; Ivanova, Magdalena; Sievers, Stuart A; Wang, Wenyuan; Yaghi, Omar M; Liu, Cong; Eisenberg, David S

    2014-12-31

    Amyloid fibers, once exclusively associated with disease, are acquiring utility as a class of biological nanomaterials. Here we introduce a method that utilizes the atomic structures of amyloid peptides, to design materials with versatile applications. As a model application, we designed amyloid fibers capable of capturing carbon dioxide from flue gas, to address the global problem of excess anthropogenic carbon dioxide. By measuring dynamic separation of carbon dioxide from nitrogen, we show that fibers with designed amino acid sequences double the carbon dioxide binding capacity of the previously reported fiber formed by VQIVYK from Tau protein. In a second application, we designed fibers that facilitate retroviral gene transfer. By measuring lentiviral transduction, we show that designed fibers exceed the efficiency of polybrene, a commonly used enhancer of transduction. The same procedures can be adapted to the design of countless other amyloid materials with a variety of properties and uses. PMID:25474758

  16. Functional phosphate alkoxysilanes for facilitated transport membrane materials

    SciTech Connect

    Hovnanian, N.; Smaihi, M.; Guizard, C. [CNRS, Montpellier (France); Cardenas, A. [CNRS, Montpellier (France); [Univ. de Los Andes, Merida (Venezuela)

    1996-12-31

    Sol-gel processing of heteropolysiloxanes containing phosphate groups has been investigated for potential applications in the synthesis of facilitated transport solid membrane. The co-hydrolysis-condensation of SiP (diethylphosphatoethyltriethoxysilane) with each of the three following alkoxysilanes: tetraethoxysilane (TEOS), methyltrimethoxysilane (MTMOS) and C{sub 6}H{sub 4}[C(O)NH(CH{sub 2}){sub 3}Si(CH{sub 3})(OEt){sub 2}]{sub 2}-1,4 (abbreviated P1) have been studied. The gels produced have been characterized by {sup 29}Si and {sup 31}P MAS NMR spectroscopy to determine the chemical structure of these new materials. The connectivity and the hydrophilic properties of the materials are controlled by the chemical nature of the alkoxysilanes and the SiP concentration. Dense flexible membranes have been obtained by tape casting an have been used for the facilitated transport of Ni{sup ++} ions.

  17. Synthesis of molecularly imprinted organic-inorganic hybrid azobenzene materials by sol-gel for radiation induced selective recognition of 2,4-dichlorophenoxyacetic acid

    NASA Astrophysics Data System (ADS)

    Shuai Jiang, Guang; An Zhong, Shi; Chen, Lan; Blakey, Idriss; Whitaker, Andrew

    2011-02-01

    A novel photoresponsive functional monomer bearing a siloxane polymerisable group and azobenzene moieties was synthesized. This monomer was then used to prepare photoresponsive molecularly imprinted polymers (MIP), which have specific binding sites for 2,4-dichlorophenoxyacetic acid (2,4-D) through hydrogen bonding moieties. The binding affinity of the imprinted recognition sites was switchable by alternate irradiations with ultraviolet and visible light, suggesting that azobenzene groups located inside the binding sites could be used as chemical sensors and the trans-cis isomerization could regulate the affinity for the 2,4-D. In addition, the concentration of the 2,4-D was able to be quantified by monitoring the trans-to-cis photoisomerization rate constant.

  18. Removal of Phosphate from Aqueous Solution by Functionalized Mesoporous Materials

    Microsoft Academic Search

    Jae-Woo Choi; Seung-Yeon Lee; Seung-Gun Chung; Seok-Won Hong; Dong-Ju Kim; Sang-Hyup Lee

    In the present study, the applications of mesoporous materials based on silica, namely post-synthesized, one-pot synthesized,\\u000a and pure MCM-41, were investigated for the removal of phosphate from aqueous solution. The mesostructures were confirmed by\\u000a X-ray diffraction, Brunauer–Emmett–Teller, Fourier transform spectroscopy, and transmission electron microscopy. The absorptions\\u000a of phosphate by the mesoporous adsorbents were examined, with different adsorption models used to

  19. Materials for Hydrogen Storage: From Complex Hydrides to Functionalized Nanostructures

    NASA Astrophysics Data System (ADS)

    Das, G. P.

    2011-07-01

    The world wide effort for a transition to renewable and clean (i.e. carbon-free) form of energy has resulted in an upsurge of interest in harnessing and utilizing Hydrogen. Apart from being the most abundant element in the universe, hydrogen offers many advantages over other fuels: it is non-toxic, clean to use, and packs more energy per mass than any other fuel. Hydrogen energy production, storage and distribution constitute a multi-disciplinary area of research. Coming to the material issues for solid state storage of hydrogen, the most desirable criteria are high storage capacity, satisfactory kinetics, and optimal thermodynamics. Complex hydrides involving light metals, such as Alanates, Imides, Borates, Amidoboranes etc. show impressive gravimetric efficiencies, although the hydrogen desorption temperatures turn out to be rather high. Apart from complex hydrides, there are other kinds of novel materials that have been investigated, e.g. carbon based materials activated with nano-catalysts, clathrate hydrates, metal-organic complexes, and more recently nanostructured cages viz. fullerenes and nanotubes decorated with simple or transition metals that serve to attract hydrogen in molecular form. In this talk, after giving a broad overview on hydrogen economy, I shall focus on first-principles design of materials for hydrogen storage, from complex hydrides to various kinds of functinalized nanostructures, and discuss the recent results obtained in our laboratory [1-6]. Some outstanding issues and challenges, like how to circumvent the problem of metal clustering on surface, or how to bring down the hydrogen desorption temperature etc. will be discussed.

  20. Successful transfer of plasmid DNA into in vitro cells transfected with an inorganic plasmid-Mg/Al-LDH nanobiocomposite material as a vector for gene expression

    NASA Astrophysics Data System (ADS)

    Jaffri Masarudin, Mas; Yusoff, Khatijah; Rahim, Raha Abdul; Zobir Hussein, Mohd

    2009-01-01

    The delivery of a full plasmid, encoding the green fluorescent protein gene into African monkey kidney (Vero3) cells, was successfully achieved using nanobiocomposites based on layered double hydroxides. This demonstrated the potential of using the system as an alternative DNA delivery vector. Intercalation of the circular plasmid DNA, pEGFP-N2, into Mg/Al-NO3- layered double hydroxides (LDH) was accomplished through anion exchange routes to form the nanobiocomposite material. The host was previously synthesized at the Mg2+ to Al3+ molar ratio Ri = 2 and subsequently intercalated with plasmid DNA. Size expansion of the interlamellae host from 8.8 Å in LDH to 42 Å was observed in the resulting nanobiocomposite, indicating stable hybridization of the plasmid DNA. The powder x-ray diffraction (PXRD) results, supplemented with Fourier-transform infrared (FTIR) spectroscopy, compositional and electrophoresis studies confirmed the encapsulation episode of the biomaterial. In order to elucidate the use of this resulting nanobiocomposite as a delivery vector, an MTT assay was performed to determine any cytotoxic effects of the host towards cells. The intercalated pEGFP-N2 anion was later successfully recovered through acidification with HNO3 after treatment with DNA-degrading enzymes, thus also showing the ability of the LDH host to protect the intercalated biomaterial from degradation. Cell transfection studies on Vero3 cells were then performed, where cells transfected with the nanobiocomposite exhibited fluorescence as early as 12 h post-treatment compared to naked delivery of the plasmid itself.

  1. Alkali deposits found in biomass boilers: The behavior of inorganic material in biomass-fired power boilers -- Field and laboratory experiences. Volume 2

    SciTech Connect

    Baxter, L.L. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility; Miles, T.R.; Miles, T.R. Jr. [Miles (Thomas R.), Portland, OR (United States); Jenkins, B.M. [California Univ., Davis, CA (United States); Dayton, D.C.; Milne, T.A. [National Renewable Energy Lab., Golden, CO (United States); Bryers, R.W. [Foster Wheeler Development Corp., Livingston, NJ (United States); Oden, L.L. [Bureau of Mines, Albany, OR (United States). Albany Research Center

    1996-03-01

    This report documents the major findings of the Alkali Deposits Investigation, a collaborative effort to understand the causes of unmanageable ash deposits in biomass-fired electric power boilers. Volume 1 of this report provide an overview of the project, with selected highlights. This volume provides more detail and discussion of the data and implications. This document includes six sections. The first, the introduction, provides the motivation, context, and focus for the investigation. The remaining sections discuss fuel properties, bench-scale combustion tests, a framework for considering ash deposition processes, pilot-scale tests of biomass fuels, and field tests in commercially operating biomass power generation stations. Detailed chemical analyses of eleven biomass fuels representing a broad cross-section of commercially available fuels reveal their properties that relate to ash deposition tendencies. The fuels fall into three broad categories: (1) straws and grasses (herbaceous materials); (2) pits, shells, hulls and other agricultural byproducts of a generally ligneous nature; and (3) woods and waste fuels of commercial interest. This report presents a systematic and reasonably detailed analysis of fuel property, operating condition, and boiler design issues that dictate ash deposit formation and property development. The span of investigations from bench-top experiments to commercial operation and observations including both practical illustrations and theoretical background provide a self-consistent and reasonably robust basis to understand the qualitative nature of ash deposit formation in biomass boilers. While there remain many quantitative details to be pursued, this project encapsulates essentially all of the conceptual aspects of the issue. It provides a basis for understanding and potentially resolving the technical and environmental issues associated with ash deposition during biomass combustion. 81 refs., 124 figs., 76 tabs.

  2. Application of Patterson-function direct methods to materials characterization

    PubMed Central

    Rius, Jordi

    2014-01-01

    The aim of this article is a general description of the so-called Patterson-function direct methods (PFDM), from their origin to their present state. It covers a 20-year period of methodological contributions to crystal structure solution, most of them published in Acta Crystallographica Section A. The common feature of these variants of direct methods is the introduction of the experimental intensities in the form of the Fourier coefficients of origin-free Patterson-type functions, which allows the active use of both strong and weak reflections. The different optimization algorithms are discussed and their performances compared. This review focuses not only on those PFDM applications related to powder diffraction data but also on some recent results obtained with electron diffraction tomography data. PMID:25295171

  3. Application of Patterson-function direct methods to materials characterization.

    PubMed

    Rius, Jordi

    2014-09-01

    The aim of this article is a general description of the so-called Patterson-function direct methods (PFDM), from their origin to their present state. It covers a 20-year period of methodological contributions to crystal structure solution, most of them published in Acta Crystallographica Section A. The common feature of these variants of direct methods is the introduction of the experimental intensities in the form of the Fourier coefficients of origin-free Patterson-type functions, which allows the active use of both strong and weak reflections. The different optimization algorithms are discussed and their performances compared. This review focuses not only on those PFDM applications related to powder diffraction data but also on some recent results obtained with electron diffraction tomography data. PMID:25295171

  4. New functional materials AC3B4O12 (Review)

    NASA Astrophysics Data System (ADS)

    Vasil'ev, A. N.; Volkova, O. S.

    2007-11-01

    The physical properties of perovskites of the type AC3B4O12, whose structure derives from simple perovskites ABO3, are reviewed. The A position is subject to strong structural distortions and splits into two new positions A and C. In the structure of AC3B4O12 vacancies and any cations with a large radius, irrespective of their charge state, can be present in the icosahedral environment of A: Na +, Cd2+, Ca2+, Sr2+, Y3+, Ln3+, and Nd4+. The C position in the square environment of oxygen can be occupied only by the Jahn-Teller cations Cu2+ and Mn3+. Transition and nontransition metal ions—Mn3+, Fe3+, Al3+, Cr3+, Ti4+, Mn4+, Ge4+, Ru4+, Ir4+, Ta5+, Nb5+, Ta5+, Sb5+—can occupy the B position in an octahedral environment. Some members of the family of complex perovskites possess properties which are characteristic for systems with heavy fermions; collinear and noncollinear magnetic structures with high ordering temperatures occur in these materials; tunneling magnetoresistance and high permittivity are observed. The diversity and unique properties make these materials attractive for practical applications.

  5. Tailor-made functional surfaces based on cellulose-derived materials.

    PubMed

    Wang, Chao; Venditti, Richard A; Zhang, Kai

    2015-07-01

    As one of the most abundant natural materials in nature, cellulose has revealed enormous potential for the construction of functional materials thanks to its sustainability, non-toxicity, biocompatibility, and biodegradability. Among many fascinating applications, functional surfaces based on cellulose-derived materials have attracted increasing interest recently, as platforms for diagnostics, sensoring, robust catalysis, water treatment, ultrafiltration, and anti-microbial surfaces. This mini-review attempts to cover the general methodology for the fabrication of functional cellulose surface and a few popular applications including bioactive and non-adhesive (i.e., anti-fouling and anti-microbial) surfaces. PMID:26084889

  6. Integration of Materials and Functions in Microfluidic Devices

    NASA Astrophysics Data System (ADS)

    Chiari, Marcella

    2012-02-01

    The physical and chemical properties of a surface determine how that surface interacts with its surrounding environment. Despite the large number of potential schemes feasible for surface modification, the covalent attachment of polymers remains the most promising approach to tailor important properties of lab-on-chip (LOC) devices such as adhesion, wettability and biocompatibility. This presentation deals with ``surface related'' issues that must be addressed in the development of LOC systems. An innovative approach that allows the attachment of polymer molecules to surfaces of different composition such as glass, silicon and polymer materials will be presented. Examples of interfaces modified by ``smart coatings'' able to give an appropriate and predictable response to outside conditions and decorated with biologically relevant biomolecules will be discussed.

  7. Work function determination of promising electrode materials for thermionic converters

    NASA Technical Reports Server (NTRS)

    Jacobson, D.

    1977-01-01

    Work performed on this contract was primarily for the evaluation of selected electrode materials for thermionic energy converters. The original objective was to characterize selected nickel based superalloys up to temperatures of 1400 K. It was found that an early selection, Inconel 800 produced a high vapor pressure which interfered with the vacuum emission measurements. The program then shifted to two other areas. The first area was to obtain emission from the superalloys in a cesiated atmosphere. The cesium plasma helps to suppress the vaporization interference. The second area involved characterization of the Lanthanum-Boron series as thermionic emitters. These final two areas resulted in three journal publications which are attached to this report.

  8. Natural material adsorbed onto a polymer to enhance immune function

    PubMed Central

    Reinaque, Ana Paula Barcelos; França, Eduardo Luzía; Scherer, Edson Fredulin; Côrtes, Mayra Aparecida; Souto, Francisco José Dutra; Honorio-França, Adenilda Cristina

    2012-01-01

    Background In this study, we produced poly(ethylene glycol) (PEG) microspheres of different sizes and adsorbing a medicinal plant mixture, and verified their effect in vitro on the viability, superoxide production, and bactericidal activity of phagocytes in the blood. Methods The medicinal plant mixture was adsorbed onto PEG microspheres and its effects were evaluated by flow cytometry and fluorescence microscopy. Results Adsorption of the herbal mixture onto the PEG microspheres was achieved and the particles were internalized by phagocytes. PEG microspheres bearing the adsorbed herbal mixture stimulated superoxide release, and activated scavenging and microbicidal activity in phagocytes. No differences in functional activity were observed when the phagocytes were not incubated with PEG microspheres bearing the adsorbed herbal mixture. Conclusion This system may be useful for the delivery of a variety of medicinal plants and can confer additional protection against infection. The data reported here suggest that a polymer adsorbed with a natural product is a treatment alternative for enhancing immune function. PMID:22956861

  9. Casting inorganic structures with DNA molds

    PubMed Central

    Sun, Wei; Boulais, Etienne; Hakobyan, Yera; Wang, Wei Li; Guan, Amy; Bathe, Mark; Yin, Peng

    2014-01-01

    We report a general strategy for designing and synthesizing inorganic nanostructures with arbitrarily prescribed three-dimensional shapes. Computationally designed DNA strands self-assemble into a stiff “nano-mold” that contains a user-specified three-dimensional cavity and encloses a nucleating gold “seed”. Under mild conditions, this seed grows into a larger cast structure that fills and thus replicates the cavity. We synthesized a variety of nanoparticles with three nanometer resolution: three distinct silver cuboids with three independently tunable dimensions, silver and gold nanoparticles with diverse cross sections, and composite structures with homo-/heterogeneous components. The designer equilateral silver triangular and spherical nanoparticles exhibited plasmonic properties consistent with electromagnetism-based simulations. Our framework is generalizable to more complex geometries and diverse inorganic materials, offering a range of applications in biosensing, photonics, and nanoelectronics. PMID:25301973

  10. [Removal of chrysoidine from water by functionalized mesoporous material SBA-16].

    PubMed

    Wei, Shi-Hui; He, Yan; Li, Feng-Ting; Xu, Ran

    2010-06-01

    A series of functionalized SBA-16 were synthesized and subsequently oxidized into sulfonic functionalized mesoporous silica mixing tetraethyl orthosilicate (TEOS) and 3-mercaptopropyltriethoxysilane (TMMPS), with triblock copolymers pluronic (F127) and cetyltrimethyl ammonium bromide (CTMABr) served as the mixing template by combination of hydrothermal and co-condensation method. The materials were characterized by X-ray diffraction, nitrogen gas sorption and SEM. The results show that the resulting functional materials belong to mesoporous materials when n(TEOS): n(TMMPS) is 3-8. The removal of Chrysoidine from water reaches the highest by functionalized mesoporous material when n(TEOS): n(TMMPS) is 7. Compared with different pH values, when the pH value ranges from 4-5 the adsorption reaches the highest. PMID:20698269

  11. Analysis of smart functionally graded materials using an improved third order shear deformation theory 

    E-print Network

    Aliaga Salazar, James Wilson

    2009-06-02

    Smart materials are very important because of their potential applications in the biomedical, petroleum and aerospace industries. They can be used to build systems and structures that self-monitor to function and adapt to ...

  12. Experimental investigation on the surface potential decays of dielectric materials with q-exponential function

    Microsoft Academic Search

    Junsei Horikawa; Tatsuaki Wada

    2010-01-01

    We have studied the surface potential decays (SPD) of a variety of dielectric materials, and found that the SPD data of the samples with high charge retensions are well fitted by Tsallis q-exponential functions.

  13. New inorganic proton conductors

    SciTech Connect

    Chowdhry, U.; Barkley, J.R.; English, A.D.; Sleight, A.W.

    1982-07-01

    High values of proton conductivity have been observed in a class of hydrated metal oxide pyrochlores, HMO/sub 3/.xH/sub 2/O (M = Sb, Nb, Ta). Two new polymorphs of HSbO/sub 3/.xH/sub 2/O have been synthesized and are also found to be good proton conductors. One polymorph has a layer structure and is derived from KSbO/sub 3/ with the ilmenite structure. The other new HSbO/sub 3/.xH/sub 2/O polymorph has the cubic KSbO/sub 3/ structure. A correlation of TGA, IR, NMR, and proton conductivity data suggests that the best inorganic proton conductors (10-2-1 at 80/sup 0/C) are hydrates; this supports a Grotthus-type conduction mechanism analogous to that observed in aqueous media.

  14. Compositions, Functions, and Testing of Friction Brake Materials and Their Additives

    SciTech Connect

    Blau, PJ

    2001-10-22

    The purpose of this report is to present a survey of commercial brake materials and additives, and to indicate their typical properties and functions, especially as regards their use in heavy trucks. Most truck pad and shoe materials described here were designed to wear against cast iron. Brake material test methods are also briefly described. This report does not address issues associated with the fabrication and manufacturing of brake materials. Since there are literally thousands of brake material additives, and their combinations are nearly limitless, it is impractical to list them all here. Rather, an attempt has been made to capture the primary constituents and their functions. An Appendix contains thermo-physical properties of some current and potential brake materials.

  15. Platelet storage. Effects of leachable materials on morphology and function.

    PubMed

    Labow, R S; Tocchi, M; Rock, G

    1986-01-01

    A polyolefin plastic (PL 732) bag formulated without liquid plasticizer allows storage of platelets for 5 and, now, up to 7 days. In order to assess the leaching of compounds from this new plastic, extracts of the supernatant from platelet concentrates stored in these bags were analyzed by high-performance liquid chromatography, mass spectrometry, and gas-liquid chromatography. A leachable material was detected and identified as di(2-ethylhexyl) phthalate (DEHP). During the sterilization process, migration of the DEHP occurs from the polyvinylchloride (PVC) bags into the PL 732 plastic bag. The level of DEHP was 12-fold less in the extracts of PC supernatant stored in the PL 732 bag than those in the polyvinyl chloride (PL 146) plastic bags which were used previously for platelet storage. Platelets stored in low DEHP concentrations in the PL 732 bags were composed of 10 to 35 percent of unclassifiable shapes. These shape changes were not observed in higher concentrations of plasticizer, although the morphology scores decreased during storage in PL 146 as well. This effect on morphology was not related directly to the dose of DEHP. When platelet membranes were isolated from platelets stored in the presence of radiolabeled DEHP, the amount of bound 14C-DEHP was found to be directly proportional to the concentration of DEHP in the plasma supernatant. However, while there was a linear relationship between the protein concentration in the membrane fraction and the amount of bound DEHP, no specific DEHP binding site could be identified by electrophoresis of the solubilized platelet membranes. PMID:3727010

  16. Multi functional uptake behaviour of materials prepared by calcining waste paper sludge.

    PubMed

    Jha, Vinay Kumar; Kameshima, Yoshikazu; Nakajima, Akira; Okada, Kiyoshi; MacKenzie, Kenneth J D

    2006-01-01

    This study concerns with the utilization of waste paper sludge, which contains mainly cellulose fibers and inorganic fillers together with coating materials such as calcite, kaolinite and talc. Paper sludge was fired at 500-900 degrees C for 6 h. The crystalline phases originally present decomposed at increasing temperatures (up to 800 degrees C) in the order kaolinite < calcite < talc. Gehlenite was formed at 800 degrees C in increasing amounts above this temperature together with small amounts of magnesium aluminum silicate and anorthite. The uptake of these fired samples of Ni2+, PO3 and NH+ was investigated at room temperature. Paper sludge fired at 700 degrees C showed the highest uptake of Ni2+, PO4(3-) and NH4+ (3.93, 1.28 and 0.49 mmol/g, respectively). The main process responsible for the sorption of these ions is the ion change along with precipitation with higher solution pH. From an economic point of view, paper sludge is the cheapest raw material for preparing adsorbents with high uptake ability for heavy metal, phosphate and ammonium ions. PMID:16779942

  17. Transient multiscale thermoelastic analysis of functionally graded materials Andrew J. Goupee, Senthil S. Vel *

    E-print Network

    Vel, Senthil

    titanium/zirconia turbine blade geometry with random microstructure. For each of the model problems microstructures, which are created using a morphology description function, have material morphologies that depend a smooth spa- tial variation of microstructure and homogenized material properties. The multiscale problem

  18. The speed of sound in silk: linking material performance to biological function.

    PubMed

    Mortimer, Beth; Gordon, Shira D; Holland, Chris; Siviour, Clive R; Vollrath, Fritz; Windmill, James F C

    2014-08-13

    Sonic properties of spider silks are measured independent of the web using laser vibrometry and ballistic impact providing insights into Nature's design of functionalized high-performance materials. Through comparison to cocoon silk and other industrial fibers, we find that major ampullate silk has the largest wavespeed range of any known material. PMID:24902950

  19. A perspective on four new porphyrin-based functional materials and devices

    E-print Network

    Suslick, Kenneth S.

    CONTENTS 243 A perspective on four new porphyrin-based functional materials and devices Charles on the formation and use of porphyrins as materials and as components of devices is given. Self-assembled, self-organized, and covalent porphyrin arrays for applications as sensors, sieves, catalyts and photonic devices are discussed

  20. Evaluation of Multi-Functional Materials for Deep Space Radiation Shielding

    NASA Technical Reports Server (NTRS)

    Rojdev, Kristina; Atwell, William; Wilkins, Richard; Gersey, Brad; Badavi, Francis F.

    2009-01-01

    Small scale trade study of materials for radiation shielding: a) High-hydrogen polymers; b) Z-graded materials; c) Fiber-reinforced polymer composites. Discussed multi-functionality of fiber-reinforced polymer composites. Preliminary results of ground testing data.

  1. Microwave chemistry for inorganic nanomaterials synthesis

    NASA Astrophysics Data System (ADS)

    Bilecka, Idalia; Niederberger, Markus

    2010-08-01

    This Feature Article gives an overview of microwave-assisted liquid phase routes to inorganic nanomaterials. Whereas microwave chemistry is a well-established technique in organic synthesis, its use in inorganic nanomaterials' synthesis is still at the beginning and far away from having reached its full potential. However, the rapidly growing number of publications in this field suggests that microwave chemistry will play an outstanding role in the broad field of Nanoscience and Nanotechnology. This article is not meant to give an exhaustive overview of all nanomaterials synthesized by the microwave technique, but to discuss the new opportunities that arise as a result of the unique features of microwave chemistry. Principles, advantages and limitations of microwave chemistry are introduced, its application in the synthesis of different classes of functional nanomaterials is discussed, and finally expected benefits for nanomaterials' synthesis are elaborated.

  2. Platinum decorated functionalized defective acetylene black; a promising cathode material for the oxygen reduction reaction.

    PubMed

    Badam, Rajashekar; Vedarajan, Raman; Matsumi, Noriyoshi

    2015-06-01

    A novel single-pot method to exfoliate and functionalize acetylene black is proposed. The deliberate functionalization was found to enhance the intrinsic oxygen reduction efficiency along with the nucleation and growth of platinum nano-particles on the surface. The resulting material showed enormously high oxygen reduction reactivity compared to its commercial counterparts. PMID:25989967

  3. Deep eutectic solvents: sustainable media for nanoscale and functional materials.

    PubMed

    Wagle, Durgesh V; Zhao, Hua; Baker, Gary A

    2014-08-19

    Deep eutectic solvents (DESs) represent an alternative class of ionic fluids closely resembling room-temperature ionic liquids (RTILs), although, strictly speaking, they are distinguished by the fact that they also contain an organic molecular component (typically, a hydrogen bond donor like a urea, amide, acid, or polyol), frequently as the predominant constituent. Practically speaking, DESs are attractive alternatives to RTILs, sharing most of their remarkable qualities (e.g., tolerance to humidity, negligible vapor pressure, thermostability, wide electrochemical potential windows, tunability) while overcoming several limitations associated with their RTIL cousins. Particularly, DESs are typically, less expensive, more synthetically accessible (typically, from bulk commodity chemicals using solvent/waste-free processes), nontoxic, and biodegradable. In this Account, we provide an overview of DESs as designer solvents to create well-defined nanomaterials including shape-controlled nanoparticles, electrodeposited films, metal-organic frameworks, colloidal assemblies, hierarchically porous carbons, and DNA/RNA architectures. These breakthroughs illustrate how DESs can fulfill multiple roles in directing chemistry at the nanoscale: acting as supramolecular template, metal/carbon source, sacrificial agent (e.g., ammonia release from urea), and/or redox agent, all in the absence of formal stabilizing ligand (here, solvent and stabilizer are one and the same). The ability to tailor the physicochemical properties of DESs is central to controlling their interfacial behavior. The preorganized "supramolecular" nature of DESs provides a soft template to guide the formation of bimodal porous carbon networks or the evolution of electrodeposits. A number of essential parameters (viscosity, polarity, surface tension, hydrogen bonding), plus coordination with solutes/surfaces, all play significant roles in modulating species reactivity and mass transport properties governing the genesis of nanostructure. Furthermore, DES components may modulate nucleation and growth mechanisms by charge neutralization, modification of reduction potentials (or chemical activities), and passivation of particular crystal faces, dictating growth along preferred crystallographic directions. Broad operational windows for electrochemical reactions coupled with their inherent ionic nature facilitate the electrodeposition of alloys and semiconductors inaccessible to classical means and the use of cosolvents or applied potential control provide under-explored strategies for mediating interfacial interactions leading to control over film characteristics. The biocompatibility of DESs suggests intriguing potential for the construction of biomolecular architectures in these novel media. It has been demonstrated that nucleic acid structures can be manipulated in the ionic, crowded, dehydrating (low water activity) DES environment-including the adoption of duplex helical structures divergent from the canonical B form and parallel G-quadruplex DNA persisting near water's boiling point-challenging the misconception that water is a necessity for maintenance of nucleic acid structure/functionality and suggesting an enticing trajectory toward DNA/RNA-based nanocatalysis within a strictly anhydrous medium. DESs offer tremendous opportunities and open intriguing perspectives for generating sophisticated nanostructures within an anhydrous or low-water medium. We conclude this Account by offering our thoughts on the evolution of the field, pointing to areas of clear and compelling utility which will surely see fruition in the coming years. Finally, we highlight a few hurdles (e.g., need for a universal nomenclature, absence of water-immiscible, oriented-phase, and low-viscosity DESs) which, once navigated, will hasten progress in this area. PMID:24892971

  4. Functional carbonaceous materials from hydrothermal carbonization of biomass: an effective chemical process.

    PubMed

    Hu, Bo; Yu, Shu-Hong; Wang, Kan; Liu, Lei; Xu, Xue-Wei

    2008-10-28

    Recently, much attention has been attracted to the use of biomass to produce functional carbonaceous materials from the viewpoint of economic, environmental and societal issues. Among different techniques, the hydrothermal carbonization (HTC) process, a traditional but recently revived method, presents superior characteristics that make it a promising route of wide potential application. This perspective gives an overview of the latest advances in the HTC process of functional carbonaceous materials from biomass. First, we discuss the preparation of carbonaceous materials synthesized by the use of either highly directed or catalyst/template-assisted methods, from crude plant materials and carbohydrates respectively. These carbonaceous materials not only have special morphologies, such as nanospheres, nanocables, nanofibers, submicrocables, submicrotubes and porous structures, but also contain rich functional groups which can greatly improve hydrophilicity and chemical reactivity. Further, a general look is cast on the applications of this kind of carbonaceous materials in environmental, catalytic and electrical areas. Recent advances have demonstrated that the HTC process from biomass can provide promising methods for the rational design of a rich family of carbonaceous and hybrid functional carbon materials with important applications. PMID:19082021

  5. A new functional perturbation method for linear non-homogeneous materials

    Microsoft Academic Search

    Eli Altus; Aleksey Proskura; Sefi Givli

    2005-01-01

    A functional perturbation method (FPM), for solving boundary value problems of linear materials with non-homogeneous properties is introduced. The FPM is based on considering the unknown field such as displacements or temperatures, as a functional of the non-uniform property, i.e., elastic modulus or thermal conductivity. The governing differential equations are expanded functionally by Fréchet series, leading to a set of

  6. First steps in harnessing the potential of biomineralization as a route to new high-performance composite materialsPaper presented at Sympos. Synergistic Synthesis of Inorganic Materials, March 1996, Schloß Ringberg, Germany

    Microsoft Academic Search

    A. M Belcher; P. K Hansma; G. D Stucky; D. E Morse

    1998-01-01

    The underlying molecular mechanisms that control biomineralization have long been thought to offer the potential for new routes to synthesis of high-performance nanocomposite materials, yet these mechanisms have until recently remained elusive. The biological mineralization of composites such as the molluscan shell generally has been thought to be directed by preformed organic arrays of proteins or other biopolymers [1]. A

  7. [Analysis and separation of organic and inorganic speciations of soluble zinc in edible flowers].

    PubMed

    Peng, Shan-shan; Huang, Guo-qing

    2005-02-01

    Considering the medicinal effects of the edible flowers, the authors studied the separation of trace element zinc's soluble organic and inorganic speciations in water decoction of three edible flowers: Chrysanthemum, Cottonrose hibiscus and Honeysucker by using the 0.45 microm membrane filter and amberlite XAD-2 macroreticular resins. And trace element zinc contents were determined by atomic absorption spectrometry. The optimal conditions for separation had been established. This study verifies the economic value of developing edible flowers, and provides theoretical basis for developing edible flowers as the third functional food materials. PMID:15852882

  8. Catalysis using multifunctional organosiliceous hybrid materials.

    PubMed

    Díaz, Urbano; Brunel, Daniel; Corma, Avelino

    2013-05-01

    Organic-inorganic hybrid materials with different levels of structuration and porous hierarchy and one or several types of active sites in the framework can catalyze multistep chemical processes in a one-pot reactor system following a cascade of reaction events. It will show how the different active sites can act in a synergistic or in a consecutive way following a similar functionality model to biological multisite catalysts. Research on this subject for heterogeneous catalysts is still in the beginning stage and very interesting results can be expected if we are able to successfully combine the properties of organic and inorganic catalysts. PMID:23288312

  9. Tailoring vibration mode shapes using topology optimization and functionally graded material concepts

    NASA Astrophysics Data System (ADS)

    Montealegre Rubio, Wilfredo; Paulino, Glaucio H.; Nelli Silva, Emilio Carlos

    2011-02-01

    Tailoring specified vibration modes is a requirement for designing piezoelectric devices aimed at dynamic-type applications. A technique for designing the shape of specified vibration modes is the topology optimization method (TOM) which finds an optimum material distribution inside a design domain to obtain a structure that vibrates according to specified eigenfrequencies and eigenmodes. Nevertheless, when the TOM is applied to dynamic problems, the well-known grayscale or intermediate material problem arises which can invalidate the post-processing of the optimal result. Thus, a more natural way for solving dynamic problems using TOM is to allow intermediate material values. This idea leads to the functionally graded material (FGM) concept. In fact, FGMs are materials whose properties and microstructure continuously change along a specific direction. Therefore, in this paper, an approach is presented for tailoring user-defined vibration modes, by applying the TOM and FGM concepts to design functionally graded piezoelectric transducers (FGPT) and non-piezoelectric structures (functionally graded structures—FGS) in order to achieve maximum and/or minimum vibration amplitudes at certain points of the structure, by simultaneously finding the topology and material gradation function. The optimization problem is solved by using sequential linear programming. Two-dimensional results are presented to illustrate the method.

  10. Synthesis and characterization of a photochromic sol gel material functionalized with azo dye

    NASA Astrophysics Data System (ADS)

    Ke, Xianjun; Yan, Xingzhong; Song, Sangyup; Li, Daqun; Yang, Jame J.; Wang, Michael R.

    2007-07-01

    An azo dye functionalized sol-gel material has been designed and synthesized to possess photochromism under a green laser beam illumination control. 10-mW laser illumination with a spot size of 1 mm2 at 532 nm wavelength on the film material was found to result in 6 × 10-4 change in material refractive index. The response time of the material photochromism is around 50 ms (3-dB modulation bandwidth of 20 Hz). Further optical transmission measurements reveal low optical absorption by the film material at 1.55 ?m wavelength window. The investigation of a tunable waveguide Bragg grating device with the sol-gel material suggests a new promising platform candidate for the fabrication of all-optical controlled photonic devices.

  11. Effects of functionally graded materials on dynamics of molecular bond clusters

    NASA Astrophysics Data System (ADS)

    Zhang, WenLiang; Qian, Jin; Yao, HaiMin; Chen, WeiQiu; Gao, HuaJian

    2012-06-01

    Unlike nonspecific adhesion of conventional hard materials in engineering commonly described by JKR and DMT type models, the molecular adhesion via specific receptor-ligand bonds is stochastic by nature and has the feature that its strength strongly depends on the medium stiffness surrounding the adhesion. In this paper, we demonstrate in a stochastic-elasticity framework that a type of materials with linearly graded elastic modulus can be designed to achieve "equal load sharing" and enhanced cooperative rebinding among interfacial molecular bonds. Upon modulus gradation, multiple molecular bonds can be elastically decoupled but statistically cooperative. In general, uniform molecular adhesion can be accomplished by two strategies: homogeneous materials with sufficient stiffness higher than a threshold or heterogeneous materials satisfying the criterion on modulus gradation. These results not only provide a theoretical principle for possible applications of functionally graded materials in quantitatively controlling cell-matrix adhesion, but also have general implications on adhesion between soft materials mediated by specific molecular binding.

  12. An optimum approximation of n-point correlation functions of random heterogeneous material systems

    SciTech Connect

    Baniassadi, M., E-mail: m.baniassadi@ut.ac.ir [School of Mechanical Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); University of Strasbourg, ICube/CNRS, 2 Rue Boussingault, 67000 Strasbourg (France); Safdari, M.; Geubelle, P. H. [Aerospace Engineering Department, University of Illinois, 104 S Wright St., Urbana, Illinois 61801 (United States)] [Aerospace Engineering Department, University of Illinois, 104 S Wright St., Urbana, Illinois 61801 (United States); Garmestani, H. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive N.W., Atlanta, Georgia 30332-0245 (United States)] [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive N.W., Atlanta, Georgia 30332-0245 (United States); Ahzi, S. [University of Strasbourg, ICube/CNRS, 2 Rue Boussingault, 67000 Strasbourg (France) [University of Strasbourg, ICube/CNRS, 2 Rue Boussingault, 67000 Strasbourg (France); School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive N.W., Atlanta, Georgia 30332-0245 (United States); Remond, Y. [University of Strasbourg, ICube/CNRS, 2 Rue Boussingault, 67000 Strasbourg (France)] [University of Strasbourg, ICube/CNRS, 2 Rue Boussingault, 67000 Strasbourg (France)

    2014-02-21

    An approximate solution for n-point correlation functions is developed in this study. In the approximate solution, weight functions are used to connect subsets of (n-1)-point correlation functions to estimate the full set of n-point correlation functions. In previous related studies, simple weight functions were introduced for the approximation of three and four-point correlation functions. In this work, the general framework of the weight functions is extended and derived to achieve optimum accuracy for approximate n-point correlation functions. Such approximation can be utilized to construct global n-point correlation functions for a system when there exist limited information about these functions in a subset of space. To verify its accuracy, the new formulation is used to approximate numerically three-point correlation functions from the set of two-point functions directly evaluated from a virtually generated isotropic heterogeneous microstructure representing a particulate composite system. Similarly, three-point functions are approximated for an anisotropic glass fiber/epoxy composite system and compared to their corresponding reference values calculated from an experimental dataset acquired by computational tomography. Results from both virtual and experimental studies confirm the accuracy of the new approximation. The new formulation can be utilized to attain a more accurate approximation to global n-point correlation functions for heterogeneous material systems with a hierarchy of length scales.

  13. Chemistry 411/611 Inorganic Chemistry (2010)

    E-print Network

    Mather, Patrick T.

    2010-01-01

    1 Chemistry 411/611 Inorganic Chemistry (2010) Instructor: Assistant Professor Mathew M. Maye: M-W 4:00-5:00, and by appointment Credits: 3 Text: (Required) Shriver & Atkins, "Inorganic Chemistry. (Suggested for CHE611 Students pursuing Inorganic) Huheey, "Inorganic Chemistry: Principles of Structure

  14. Immobilization of lipase and keratinase on functionalized SBA-15 nanostructured materials

    NASA Astrophysics Data System (ADS)

    Le, Hy G.; Vu, Tuan A.; Tran, Hoa T. K.; Dang, Phuong T.

    2013-12-01

    SBA-15 nanostructured materials were synthesized via hydrothermal treatment and were functionalized with 3- aminopropyltriethoxysilane (APTES). The obtained samples were characterized by different techniques such as XRD, BET, TEM, IR and DTA. After functionalization, it showed that these nanostrucrured materials still maintained the hexagonal pore structure of the parent SBA-15. The model enzyms chosen in this study were lipase and keratinase. Lipase was a biocatalyst for hydrolyzation of long chain triglycerides or methyl esters of long chain alcohols and fatty acids; keratinase is a proteolytic enzyme that catalyzes the cleavage of keratin. The functionalized SBA-15 materials were used to immobilize lipase and keratinase, exhibiting higher activity than that of the unfunctionalized pure silica SBA-15 ones. This might be due to the enhancing of surface hydrophobicity upon functionalization. The surface functionalization of the nanostructured silicas with organic groups can favor the interaction between enzyme and the supports and consequently increasing the operational stability of the immobilized enzymes. The loading of lipase on functionalized SBA-15 materials was higher than that of keratinase. This might be rationalized by the difference in size of enzyms.

  15. Design of inorganic compounds with tetrahedral anions

    NASA Astrophysics Data System (ADS)

    Lazoryak, B. I.

    1996-04-01

    The review deals with aspects of the modelling of the compositions and properties of inorganic compounds with tetrahedral anions on the basis of crystal-chemical information. One of the possible algorithms employing crystal-chemical data for the modelling of the compositions, structures, and properties of new compounds is proposed on the basis of the structures of six structural types (glaserite, ?-K2SO4, bredigite, palmierite, NASICON, and whitlockite). The likely usefulness of such data for the solution of various problems in materials science is demonstrated. The bibliography includes 208 references.

  16. Prediction of the adhesive behavior of bio-inspired functionally graded materials against rough surfaces

    NASA Astrophysics Data System (ADS)

    Peijian, Chen; Juan, Peng; Yucheng, Zhao; Feng, Gao

    2014-06-01

    Roughness effect and adhesion properties are important characteristics to be accessed in the development of functionally graded materials for biological and biomimetic applications, particularly for the hierarchical composition in biomimetic gecko robot. A multi-asperities adhesion model to predict the adhesive forces is presented in this work. The effect of surface roughness and graded material properties, which significantly alter the adhesive strength between contact bodies, can be simultaneously considered in the generalized model. It is found that proper interfacial strength can be controlled by adjusting surface roughness ? / R, graded exponent k and material parameter E*R / ??. The results should be helpful in the design of new biomimetic materials and useful in application of micro functional instruments.

  17. [Investigation of mechanical properties of materials used for functional stabilization in pilon fractures].

    PubMed

    Sto?ko, I V; Béts, G V; Béts, I G; Karpinski?, M Iu

    2014-02-01

    Existing methods of surgical treatment of the pilon fractures do not provide early functional rehabilitation of patients. The lack of confidence in secure fixation of fragments in significant quantity of patients causes necessity to apply a plaster immobilization during long time. While seeking possibilities of early functional treatment of the pilon fractures there was proposed a theory of "functional stabilization" (instead of "artificial", but necessary plaster immobilization), materials and technologies for its realization. For substantiating, from the biomechanical point of view, of expediency of a new materials (Softcost, Scotchcost) application the data about their physic-chemical properties were adduced, and in particular, there were studied the bowing values, depending on loading, and modules of elasticity of these materials. PMID:24923122

  18. Supramolecular chirality in self-assembled soft materials: regulation of chiral nanostructures and chiral functions.

    PubMed

    Zhang, Li; Qin, Long; Wang, Xiufeng; Cao, Hai; Liu, Minghua

    2014-10-29

    Supramolecular chirality, which arises from the nonsymmetric spatial arrangement of components in the self-assembly systems, has gained great attention owing to its relation to the natural biological structures and the possible new functions in advanced materials. During the self-assembling process, both chiral and achiral components are possible to form chiral nanostructures. Therefore, it becomes an important issue how to fabricate these molecular components into chiral nanostructures. Furthermore, once the chiral nanostructure is obtained, will it show new functions that simple component molecule could not? In this research news, we report our recent development in the regulation of chiral nanostructures in soft gels or vesicle materials. We have further developed several new functions pertaining to the soft gel materials, which single chiral molecules could not perform, such as the chiroptical switch, chiral recognition and the asymmetry catalysis. PMID:24687217

  19. Controlled release of vitamin B2 using mesoporous materials functionalized with amine-bearing gate-like scaffoldings.

    PubMed

    Bernardos, Andrea; Aznar, Elena; Coll, Carmen; Martínez-Mañez, Ramón; Barat, Jose Manuel; Marcos, Ma Dolores; Sancenón, Félix; Benito, Angel; Soto, Juan

    2008-11-12

    A study on the controlled release of vitamin B(2) in pure water from mesoporous silica-based materials containing a pH- and anion-controlled nano-supramolecular gate-like ensembles built up by anchoring suitable polyamines on the external surface is reported (solid S1). This solid contains the vitamin (the delivered molecule) onto the pores, whereas the amine-based gate-like ensemble is anchored on the pore outlets. To obtain solid S1 the mesoporous MCM-41 support was first synthesized using tetraethyl orthosilicate (TEOS) as hydrolytic inorganic precursor and the surfactant hexadecyltrimethylammonium bromide (CTAB) as porogen species. Calcination of the mesostructured phase resulted in the starting solid. Then, first the vitamin and the latter an excess of 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane were added to the suspension containing the MCM-41 scaffolding and stirred. Solid S1 was characterized using standard solid state procedures. It was found that the functionalization process and the inclusion of the vitamin on the pores do not modify the mesoporous structure of the starting material. Delivery studies in water were carried out at pH 2 and 7. At pH 2 all the anions studied (sulfate, phosphate, GMP and ATP) strongly hinder vitamin release (C(anion)=1 x 10(-2) mol dm(-3)), whereas at pH 7 the delivery was observed for sulfate and GMP whereas the gate remained closed in the presence of ATP and phosphate. Selective delivery at neutral pH and no-liberation in acidic conditions can also be controlled with ATP and GMP using a suitable concentration of anion. The remarkable anion-controllable response of the gate-like ensemble at a certain pH can be explained in terms of anion complex formation with the tethered polyamines. Finally, selectivity patterns have been discussed in terms of kinetic rates of vitamin B(2) release. The pH-controlled gate-like scaffoldings on S1 might be a suitable prototype for the development of orally applicable delivery systems designed to have the particular ability to protect the cargo from the acidic conditions of the stomach (acid pH, gate closed) but will release the load at the intestine (basic pH, gate open). PMID:18727946

  20. Thermo-acoustic random response of temperature-dependent functionally graded material panels

    Microsoft Academic Search

    Hesham Hamed Ibrahim; Hong Hee Yoo; Mohammad Tawfik; Kwan-Soo Lee

    2010-01-01

    A nonlinear finite element model is provided for the nonlinear random response of functionally graded material panels subject\\u000a to combined thermal and random acoustic loads. Material properties are assumed to be temperature-dependent, and graded in\\u000a the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents.\\u000a The governing equations are derived using

  1. International Conference on Functional Materials and Nanotechnologies (FM&NT2012)

    Microsoft Academic Search

    Andris Sternberg; Inta Muzikante; Anatolijs Sarakovskis; Liga Grinberga

    2012-01-01

    The International Conference Functional Materials and Nanotechnologies (FM&NT – 2012) was held in Riga, 17–20 April 2012 at the Institute of Solid State Physics, University of Latvia (ISSP UL). The conference was organised by ISSP UL in co-operation with National Research programme in Materials Science and Information Technologies of Latvia. The purpose of this series of conferences is to bring

  2. Stochastic Finite element analysis of the free vibration of functionally graded material plates

    Microsoft Academic Search

    Afeefa Shaker; Wael Abdelrahman; Mohammad Tawfik; Edward Sadek

    2008-01-01

    The superior properties of functionally graded materials (FGM) are usually accompanied by randomness in their properties due\\u000a to difficulties in tailoring the gradients during manufacturing processes. Using the stochastic finite element method (SFEM)\\u000a proved to be a powerful tool in studying the sensitivity of the static response of FGM plates to uncertainties in their material\\u000a properties. This tool is yet

  3. Crack propagation due to brittle and ductile failures in microporous thermoelastoviscoplastic functionally graded materials

    Microsoft Academic Search

    R. C. Batra; B. M. Love

    2005-01-01

    Plane strain transient finite thermomechanical deformations of heat-conducting functionally gradient materials comprised of tungsten and nickel–iron matrix are analyzed to delineate brittle\\/ductile failures by the nodal release technique. Each material is modeled as strain-hardening, strain-rate-hardening and thermally-softening. Effective properties are derived by the rule of mixtures. At nominal strain-rate of 2000s?1 brittle crack speed approaches Rayleigh’s wave speed in the

  4. The Halogen Bond in the Design of Functional Supramolecular Materials: Recent Advances

    PubMed Central

    2013-01-01

    Halogen bonding is an emerging noncovalent interaction for constructing supramolecular assemblies. Though similar to the more familiar hydrogen bonding, four primary differences between these two interactions make halogen bonding a unique tool for molecular recognition and the design of functional materials. First, halogen bonds tend to be much more directional than (single) hydrogen bonds. Second, the interaction strength scales with the polarizability of the bond-donor atom, a feature that researchers can tune through single-atom mutation. In addition, halogen bonds are hydrophobic whereas hydrogen bonds are hydrophilic. Lastly, the size of the bond-donor atom (halogen) is significantly larger than hydrogen. As a result, halogen bonding provides supramolecular chemists with design tools that cannot be easily met with other types of noncovalent interactions and opens up unprecedented possibilities in the design of smart functional materials. This Account highlights the recent advances in the design of halogen-bond-based functional materials. Each of the unique features of halogen bonding, directionality, tunable interaction strength, hydrophobicity, and large donor atom size, makes a difference. Taking advantage of the hydrophobicity, researchers have designed small-size ion transporters. The large halogen atom size provided a platform for constructing all-organic light-emitting crystals that efficiently generate triplet electrons and have a high phosphorescence quantum yield. The tunable interaction strengths provide tools for understanding light-induced macroscopic motions in photoresponsive azobenzene-containing polymers, and the directionality renders halogen bonding useful in the design on functional supramolecular liquid crystals and gel-phase materials. Although halogen bond based functional materials design is still in its infancy, we foresee a bright future for this field. We expect that materials designed based on halogen bonding could lead to applications in biomimetics, optics/photonics, functional surfaces, and photoswitchable supramolecules. PMID:23805801

  5. Charting the complete elastic properties of inorganic crystalline compounds

    PubMed Central

    de Jong, Maarten; Chen, Wei; Angsten, Thomas; Jain, Anubhav; Notestine, Randy; Gamst, Anthony; Sluiter, Marcel; Krishna Ande, Chaitanya; van der Zwaag, Sybrand; Plata, Jose J; Toher, Cormac; Curtarolo, Stefano; Ceder, Gerbrand; Persson, Kristin A.; Asta, Mark

    2015-01-01

    The elastic constant tensor of an inorganic compound provides a complete description of the response of the material to external stresses in the elastic limit. It thus provides fundamental insight into the nature of the bonding in the material, and it is known to correlate with many mechanical properties. Despite the importance of the elastic constant tensor, it has been measured for a very small fraction of all known inorganic compounds, a situation that limits the ability of materials scientists to develop new materials with targeted mechanical responses. To address this deficiency, we present here the largest database of calculated elastic properties for inorganic compounds to date. The database currently contains full elastic information for 1,181 inorganic compounds, and this number is growing steadily. The methods used to develop the database are described, as are results of tests that establish the accuracy of the data. In addition, we document the database format and describe the different ways it can be accessed and analyzed in efforts related to materials discovery and design. PMID:25984348

  6. Porous Hybrid Organic?Inorganic Particles in Reversed?Phase Liquid Chromatography

    Microsoft Academic Search

    John E. OGara; Kevin D. Wyndham

    2006-01-01

    Reversed?phase chromatographic media have recently become available that are based on porous hybrid organic?inorganic particles. The present paper reviews hybrid particles that are made from organosilanes (organic moiety) and tetraalkoxysilanes (inorganic moiety). The hybrid particles are defined and classified within the context of a broader definition of hybrid materials. First syntheses and chromatographic evaluations are discussed for this class of

  7. Microstructure and properties of multiphase and functionally graded materials prepared by chemical vapor deposition

    SciTech Connect

    Lee, W.Y.

    1996-05-01

    The synthesis of multiphase and functionally graded materials by chemical vapor deposition is discussed from a perspective of controlling their composition and microstructure at a nano-scale level, and ultimately, tailoring their material properties. Prior research is briefly reviewed to address the current state of this novel material concept. Recent experimental results relating to controlling the selected properties of two multiphase systems, TiN + MoS{sub 2} and NiAl + Al{sub 2}O{sub 3}, are described to illustrate this concept`s potential merits and challenges for use in realistic applications.

  8. Fracture and fatigue analysis of functionally graded and homogeneous materials using singular integral equation approach

    NASA Astrophysics Data System (ADS)

    Zhao, Huaqing

    There are two major objectives of this thesis work. One is to study theoretically the fracture and fatigue behavior of both homogeneous and functionally graded materials, with or without crack bridging. The other is to further develop the singular integral equation approach in solving mixed boundary value problems. The newly developed functionally graded materials (FGMs) have attracted considerable research interests as candidate materials for structural applications ranging from aerospace to automobile to manufacturing. From the mechanics viewpoint, the unique feature of FGMs is that their resistance to deformation, fracture and damage varies spatially. In order to guide the microstructure selection and the design and performance assessment of components made of functionally graded materials, in this thesis work, a series of theoretical studies has been carried out on the mode I stress intensity factors and crack opening displacements for FGMs with different combinations of geometry and material under various loading conditions, including: (1) a functionally graded layer under uniform strain, far field pure bending and far field axial loading, (2) a functionally graded coating on an infinite substrate under uniform strain, and (3) a functionally graded coating on a finite substrate under uniform strain, far field pure bending and far field axial loading. In solving crack problems in homogeneous and non-homogeneous materials, a very powerful singular integral equation (SEE) method has been developed since 1960s by Erdogan and associates to solve mixed boundary value problems. However, some of the kernel functions developed earlier are incomplete and possibly erroneous. In this thesis work, mode I fracture problems in a homogeneous strip are reformulated and accurate singular Cauchy type kernels are derived. Very good convergence rates and consistency with standard data are achieved. Other kernel functions are subsequently developed for mode I fracture in functionally graded materials. This work provides a solid foundation for further applications of the singular integral equation approach to fracture and fatigue problems in advanced composites. The concept of crack bridging is a unifying theory for fracture at various length scales, from atomic cleavage to rupture of concrete structures. However, most of the previous studies are limited to small scale bridging analyses although large scale bridging conditions prevail in engineering materials. In this work, a large scale bridging analysis is included within the framework of singular integral equation approach. This allows us to study fracture, fatigue and toughening mechanisms in advanced materials with crack bridging. As an example, the fatigue crack growth of grain bridging ceramics is studied. With the advent of composite materials technology, more complex material microstructures are being introduced, and more mechanics issues such as inhomogeneity and nonlinearity come into play. Improved mathematical and numerical tools need to be developed to allow theoretical modeling of these materials. This thesis work is an attempt to meet these challenges by making contributions to both micromechanics modeling and applied mathematics. It sets the stage for further investigations of a wide range of problems in the deformation and fracture of advanced engineering materials.

  9. Exploration of new superconductors and functional materials, and fabrication of superconducting tapes and wires of iron pnictides

    NASA Astrophysics Data System (ADS)

    Hosono, Hideo; Tanabe, Keiichi; Takayama-Muromachi, Eiji; Kageyama, Hiroshi; Yamanaka, Shoji; Kumakura, Hiroaki; Nohara, Minoru; Hiramatsu, Hidenori; Fujitsu, Satoru

    2015-06-01

    This review shows the highlights of a 4-year-long research project supported by the Japanese Government to explore new superconducting materials and relevant functional materials. The project found several tens of new superconductors by examining ?1000 materials, each of which was chosen by Japanese experts with a background in solid state chemistry. This review summarizes the major achievements of the project in newly found superconducting materials, and the fabrication wires and tapes of iron-based superconductors; it incorporates a list of ?700 unsuccessful materials examined for superconductivity in the project. In addition, described are new functional materials and functionalities discovered during the project.

  10. The environmental impact of a hazardous material spill is a complex function of the material's physical and chemical characteristics and the

    E-print Network

    Barkan, Christopher P.L.

    12 The environmental impact of a hazardous material spill is a complex function of the material's physical and chemical characteristics and the local environmental conditions in which it is spilled of various soil types and groundwater depth regions to hazardous material spills from railroad tank car

  11. Recent Progress in Inorganic Solar Cells Using Quantum Structures

    Microsoft Academic Search

    Seung Y. Myong

    2007-01-01

    Thermalization of photogenerated carriers in bulk materials is the main bottleneck for the conversion efficiency of conventional inorganic solar cells. Furthermore, despite extensive research, the achieved conversion efficiency is nearly saturated during the last decade. Therefore, new device concepts to break through the efficiency barrier are highly requested. Nanotechnologies are the building blocks for next-generation solar cells, because low-dimensional quantum

  12. Crystal orientations in nacreous layers of organic–inorganic biocomposites

    Microsoft Academic Search

    Seung Woo Lee

    2009-01-01

    Abalone shell comprises a bio-composite material, combining the properties of inorganic calcite intergrown with organic nacre. This paper reports about the microstructure of this composite. By examining the Kikuchi patterns obtained for nacre (Haliotis discus hannai) using transmission electron microscopy, we have shown that the tiles within nacre have specific orientations. The stereographic projection spheres for the tiles of nacre

  13. Inorganic composition of the envelopes of Trachelomonas Ehr. (Euglenophyta)

    Microsoft Academic Search

    Mário J. Pereira; Ulisses M. M. Azeiteiro; Fernando Gonçalves; Amadeu M. V. M. Soares

    2003-01-01

    The Trachelomonas genus comprehends unicellular organisms and contains a highly metabolic euglenoid cell surrounded by a particular structure, the lorica, with shape, morphology and dimensions characteristic of each taxon (species, variety). This organic matrix may present a significant mineralization. The elementary lorica composition was microanalysed by energy dispersive spectrometry in scanning electron microscopy. The inorganic component found in materials obtained

  14. Electronic properties of hybrid organic-inorganic semiconductors

    Microsoft Academic Search

    B. Fluegel; Y. Zhang; A. Mascarenhas; X. Huang; J. Li

    2004-01-01

    Hybrid semiconductors comprising networks of inorganic II-VI semiconductor segments bonded to organic solvent chains show promise as a versatile material system that offers the capability of synthesizing many new electronic structures that are desirable for photonic applications. Polarized optical absorption and reflection are measured in single crystal semiconductor nanostructures composed of arrays of monolayers or linear chains. This shows very

  15. Micro-patterning and applications of organic and inorganic fluorescent

    E-print Network

    Strathclyde, University of

    in a washing step ·Relatively high resolution (~1µm) ·Flexible and fast ·Potential 3D capability µ-LED imagingMicro-patterning and applications of organic and inorganic fluorescent nano-particles D. Elfstrom) #12;Ink-Jet Printing ·A very versatile technique that allow one to print many different materials

  16. EFFECTS OF SELECTED INORGANIC LEACHATES ON CLAY PERMEABILITY

    EPA Science Inventory

    Hydraulic conductivity test results for three field clays exposed to two inorganic chemicals are documented. The hydraulic conductivities of clays exposed to waste chemicals is an important consideration in the selection of a liner material for a hazardous waste containment facil...

  17. Design and functionality of colloidal-crystal-templated materials--chemical applications of inverse opals.

    PubMed

    Stein, Andreas; Wilson, Benjamin E; Rudisill, Stephen G

    2013-04-01

    Templating with colloidal crystals composed of monodisperse spheres is a convenient chemical method to obtain porous materials with well-ordered periodicity and interconnected pore systems. The three-dimensionally ordered macroporous (3DOM) products or inverse opals are of interest for numerous applications, both for the optical properties related to structural color of these photonic crystal materials and because of their bicontinuous nanostructure, i.e., a continuous nanostructured skeleton with large interfacial area and a three-dimensionally interconnected pore system with low tortuosity. This review outlines various synthetic methods used to control the morphology of 3DOM materials with different compositions. It highlights aspects of the choice of colloidal particles, assembly of the colloidal crystal template, infiltration and processing, template removal, and other necessary modifications to enhance the functionality of the materials. It also considers syntheses within the confinement of 3DOM materials and summarizes characterization methods that are particularly useful in the analysis of 3DOM materials. The review then discusses chemical applications of 3DOM materials, namely sorption and controlled release, optical and electrochemical sensors, solar cells, lithium ion batteries, supercapacitors, fuel cells, and environmental and chemical fuel catalysis. A focus is on structural features and materials properties that enable these applications. PMID:23079696

  18. Green nesting material has a function in mate attraction in the European starling

    Microsoft Academic Search

    Lyanne Brouwer; Jan Komdeur

    2004-01-01

    The function of fresh green nest material has long been debated. It has been suggested that it reduces the number of ectoparasites in nests and on nestlings (nest protection hypothesis), or is used by males to signal condition and paternal quality (male quality hypothesis) or is used as a sexually selected ornament to attract females (courtship hypothesis). We simultaneously tested

  19. Functionally Graded Structures of AIII-BV(N) Materials for Detectors

    Microsoft Academic Search

    Mateusz Wosko; B. Paszkiewicz; T. Piasecki; J. Prazmowska; R. Paszkiewicz; A. Szyszka; W. Macherzynski; M. Tlaczala

    2006-01-01

    Functionally graded materials are widely applied for mechanical applications. Nowadays they become more and more attractive for electronic and optoelectronic devices fabrication. This is caused by their unique properties. FGM are potential candidates for high sensitive photonic devices which could operate in a wide spectral range (also for voltage tunable photodetectors). In this paper the analysis of several photodetectors constructions

  20. Buckling analysis of circular plates of functionally graded materials under uniform radial compression

    Microsoft Academic Search

    M. M. Najafizadeh; M. R. Eslami

    2002-01-01

    This study presents the buckling analysis of radially loaded solid circular plate made of functionally graded material. The edge of the plate is either simply supported or clamped and the plate is assumed to be geometrically perfect. The equilibrium and stability equations, derived through variational formulation, are used to determine the prebuckling forces and critical buckling loads. The equations are

  1. Preparation of Problem Oriented Learning Materials: Experimental Project: Farmers Functional Literacy Programme.

    ERIC Educational Resources Information Center

    Deleon, Asher, Ed.

    Using practical problems faced by farmers developing new agricultural methods, a problem-oriented approach to adult functional literacy was developed and tested in the Jaipur district. The booklet explains the first two of the project's five phases: exploration, syllabus and curriculum construction, materials preparation, action, and evaluation.…

  2. Surface Science Letters Tuning the chemical functionality of a gas sensitive material

    E-print Network

    Diebold, Ulrike

    . The different chemical surface responses of these two bulk terminations of SnO2 also change the water induced+ charge state. These two surfaces can be expected to exhibit fundamentally different chemical propertiesSurface Science Letters Tuning the chemical functionality of a gas sensitive material: Water

  3. A metalorganic framework material that functions as an enantioselective catalyst for olefin epoxidation{

    E-print Network

    The notion is that MOF-based catalysts may be able to replicate some of the key features of zeolitic with purely zeolitic catalysts is enantioselectivity. Herein, we report that a microporous MOF containingA metal­organic framework material that functions as an enantioselective catalyst for olefin

  4. Ultraprecision machining of micro-structured functional surfaces on brittle materials

    Microsoft Academic Search

    D. P. Yu; Y. S. Wong; G. S. Hong

    2011-01-01

    Ultraprecision micro-structured functional surfaces on hard and brittle materials, e.g. ceramic and glass, are gaining increasing application in a range of areas such as engineering optics and semiconductor and biomedical products. However, due to their tendency of being damaged in brittle fracture in machining, it is challenging to achieve both a high surface finish and complex surface shapes. In this

  5. A higher-order spectral element for wave propagation analysis in functionally graded materials

    Microsoft Academic Search

    A. Chakraborty; S. Gopalakrishnan

    2004-01-01

    Summary. A new higher-order spectral element (SE) is developed for wave propagation analysis of a functionally graded material (FGM) beam in the presence of thermal and mechanical loading. The element is based on first order shear deformation theory (FSDT) and takes into account the depthwise contraction due to Poisson’s ratio. A new method of element formulation is employed, which is

  6. A Potential Function Derivation of a Constitutive Equation for Inelastic Material Response

    NASA Technical Reports Server (NTRS)

    Stouffer, D. C.; Elfoutouh, N. A.

    1983-01-01

    Physical and thermodynamic concepts are used to develop a potential function for application to high temperature polycrystalline material response. Inherent in the formulation is a differential relationship between the potential function and constitutive equation in terms of the state variables. Integration of the differential relationship produces a state variable evolution equation that requires specification of the initial value of the state variable and its time derivative. It is shown that the initial loading rate, which is directly related to the initial hardening rate, can significantly influence subsequent material response. This effect is consistent with observed material behavior on the macroscopic and microscopic levels, and may explain the wide scatter in response often found in creep testing.

  7. A transient FGM interlayer based approach to joining ceramics. [Functionally gradient materials

    SciTech Connect

    Glaeser, A.M.; Shalz, M.L.; Dalgleish, B.J.; Tomsia, A.P.

    1993-01-01

    In most cases, functionally gradient materials have been designed to produce a desirable property gradient in a material or in a joint region. In this paper, the concept of a transient gradient structure is introduced. The function of the intentional property discontinuities in these multilayer interlayers is to facilitate processing of assemblies and materials combinations that would be difficult to process using conventional bonding approaches. Specifically, the methods make use of a thin or partial layer of a low melting point transient liquid phase to facilitate bonding via brazing, yet produce refractory joints. Several mechanisms for consuming the transient liquid former are outlined, and examples of interlayer designs that exploit these mechanisms are presented. Specific results from experiments joining alumina to alumina via Cu/Pt/Cu, Cu/Ni/Cu, Cu/Nb/Cu and Sn/Nb/Sn interlayers are presented.

  8. Evaluation of functional substances in the selected food materials for space agriculture

    NASA Astrophysics Data System (ADS)

    Tomita-Yokotani, Kaori; Kimura, Yasuko; Yamashita, Masamichi; Kimura, Shunta; Sato, Seigo; Katoh, Hiroshi; Abe, Yusuke; Ajioka, Reiko

    We have been studying the useful life-support system in closed bio-ecosystem for space agriculture. We have already proposed the several species as food material, such as Nostoc sp. HK-01 and Prunnus sp., cyanobacterium and Japanese cherry tree, respectively. The cyanobacterium, Nostoc sp Hk-01, has high tolerances to several space environment. Furthermore, the woody plant materials have useful utilization elements in our habitation environment. The studies of woody plants under a space-environment in the vegetable kingdom have a high contribution to the study of various and exotic environmental responses, too. We have already found that they can produce the important functional substances for human. Here, we will show the evaluation of functional substances in the selected food materials under the possible conditions for space agriculture after cooking.

  9. Multi-paradigm simulation at nanoscale: Methodology and application to functional carbon material

    NASA Astrophysics Data System (ADS)

    Su, Haibin

    2012-12-01

    Multiparadigm methods to span the scales from quantum mechanics to practical issues of functional nanoassembly and nanofabrication are enabling first principles predictions to guide and complement the experimental developments by designing and optimizing computationally the materials compositions and structures to assemble nanoscale systems with the requisite properties. In this talk, we employ multi-paradigm approaches to investigate functional carbon materials with versatile character, including fullerene, carbon nanotube (CNT), graphene, and related hybrid structures, which have already created an enormous impact on next generation nano devices. The topics will cover the reaction dynamics of C60 dimerization and the more challenging complex tubular fullerene formation process in the peapod structures; the computational design of a new generation of peapod nano-oscillators, the predicted magnetic state in Nano Buds; opto-electronic properties of graphene nanoribbons; and disorder / vibronic effects on transport in carbonrich materials.

  10. Interfacial Coatings for Inorganic Composite Insulation Systems

    NASA Astrophysics Data System (ADS)

    Hooker, M. W.; Fabian, P. E.; Stewart, M. W.; Grandlienard, S. D.; Kano, K. S.

    2006-03-01

    Inorganic (ceramic) insulation materials are known to have good radiation resistance and desirable electrical and mechanical properties at cryogenic and elevated temperatures. In addition, ceramic materials can withstand the high-temperature reaction cycle used with Nb3Sn superconductor materials, allowing the insulation to be co-processed with the superconductor in a wind-and-react fabrication process. A critical aspect in the manufacture of ceramic-based insulation systems is the deposition of suitable fiber-coating materials that prevent chemical reaction of the fiber and matrix materials, and thus provide a compliant interface between the fiber and matrix, which minimizes the impact of brittle failure of the ceramic matrix. Ceramic insulation produced with CTD-FI-202 fiber interfaces have been found to exhibit very high shear and compressive strengths. However, this material is costly to produce. Thus, the goal of the present work is to evaluate alternative, lower-cost materials and processes. A variety of oxide and polyimide coatings were evaluated, and one commercially available polyimide coating has been shown to provide some improvement as compared to uncoated and de-sized S2 glass.

  11. Interfacial Coatings for Inorganic Composite Insulation Systems

    SciTech Connect

    Hooker, M. W.; Fabian, P. E.; Stewart, M. W.; Grandlienard, S. D.; Kano, K. S. [Composite Technology Development, Inc., Lafayette, CO, 80026 (United States)

    2006-03-31

    Inorganic (ceramic) insulation materials are known to have good radiation resistance and desirable electrical and mechanical properties at cryogenic and elevated temperatures. In addition, ceramic materials can withstand the high-temperature reaction cycle used with Nb3Sn superconductor materials, allowing the insulation to be co-processed with the superconductor in a wind-and-react fabrication process. A critical aspect in the manufacture of ceramic-based insulation systems is the deposition of suitable fiber-coating materials that prevent chemical reaction of the fiber and matrix materials, and thus provide a compliant interface between the fiber and matrix, which minimizes the impact of brittle failure of the ceramic matrix. Ceramic insulation produced with CTD-FI-202 fiber interfaces have been found to exhibit very high shear and compressive strengths. However, this material is costly to produce. Thus, the goal of the present work is to evaluate alternative, lower-cost materials and processes. A variety of oxide and polyimide coatings were evaluated, and one commercially available polyimide coating has been shown to provide some improvement as compared to uncoated and de-sized S2 glass.

  12. Synthesis and modification of functional poly(lactide) copolymers: toward biofunctional materials.

    PubMed

    Noga, David E; Petrie, Timothy A; Kumar, Anjli; Weck, Marcus; García, Andrés J; Collard, David M

    2008-07-01

    A polylactide copolymer with pendant benzyloxy groups has been synthesized by the copolymerization of a benzyl-ether substituted monomer with lactide. Debenzylation of the polymer to provide pendant hydroxyl groups followed by modification with succinic anhydride affords the corresponding carboxylic acid functionalized copolymer that is amenable to standard carbodiimide coupling conditions to attach amine-containing biological molecules. An amino-substituted biotin derivative was coupled to the carboxyl functional groups of copolymer films as proof-of-concept. In a demonstration of the function of these new materials, an RGD-containing peptide sequence was tethered to copolymer films at various densities and was shown to enhance the adhesion of epithelial cells. This strategy provides the opportunity for the attachment of a variety of ligands, allowing for the fabrication of a versatile class of biodegradable, biocompatible materials. PMID:18576683

  13. Nonlinear optical polymers derived from organic/inorganic composites

    SciTech Connect

    Tripathy, S.K.; Kumar, J.; Chen, J.I.; Marturunkakul, S.; Jeng, R.J.; Li, L.; Jiang, X.L. [Univ. of Massachusetts Lowell, MA (United States)

    1994-12-31

    A general approach to the development of multicomponent multifunctional stable nonlinear optical materials based on sol-gel reactions has been discussed. The authors have shown that these second order NLO organic/inorganic composites exhibit excellent room temperature stability of the second order optical nonlinearity. The final structure is an orientationally ordered organic/inorganic network. After an initial decay, excellent long term stability at elevated temperatures, ranged from 100 to 120 C is observed for a number of different systems. The second order optical nonlinearities are reasonably large for practical device considerations.

  14. Photomobile polymer materials with crosslinked liquid-crystalline structures: molecular design, fabrication, and functions.

    PubMed

    Ube, Toru; Ikeda, Tomiki

    2014-09-22

    Crosslinked liquid-crystalline polymer materials that macroscopically deform when irradiated with light have been extensively studied in the past decade because of their potential in various applications, such as microactuators and microfluidic devices. The basic motions of these materials are contraction-expansion and bending-unbending, which are observed mainly in polysiloxanes and polyacrylates that contain photochromic moieties. Other sophisticated motions such as twisting, oscillation, rotation, and translational motion have also been achieved. In recent years, efforts have been made to improve the photoresponsive and mechanical properties of this novel class of materials through the modification of molecular structures, development of new fabrication methods, and construction of composite structures. Herein, we review structures, functions, and working mechanisms of photomobile materials and recent advances in this field. PMID:25196371

  15. Raman spectra of inorganic ions

    NASA Astrophysics Data System (ADS)

    Degen, I. A.; Newman, G. A.

    1993-06-01

    This paper contains the Raman spectra of 79 inorganic salts and sulphur which may be used as an aid in qualitative inorganic analyses. These were obtained some years ago by conventional Raman spectroscopy. No such collection exists and the order of the reference spectra is identical to those in a collection of IR spectra. A table of characteristic frequencies for 17 polyatomic ions is given. These data have increased relevance following the emergence of FT-Raman as a rapid and efficient modern technique.

  16. Facile Fabrication of Organic–Inorganic Hybrid Beads by Aminated Alginate Enabled Gelation and Biomimetic Mineralization

    Microsoft Academic Search

    Jian Li; Hong Wu; Yanpeng Liang; Zhongyi Jiang; Yanjun Jiang; Lei Zhang

    2012-01-01

    Inspired by biomineralization, design and preparation of biomimetic organic–inorganic composites have become a hot issue and a research frontier in many areas, including enzyme engineering. In this research, a unique and facile method for fabricating organic–inorganic hybrid beads is proposed. Modified alginate with a dual function of gelation and mineralization was synthesized for fabrication of hybrid carriers for enzyme immobilization.

  17. Heterostructures based on inorganic and organic van der Waals systems

    SciTech Connect

    Lee, Gwan-Hyoung [Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Chul-Ho [KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 136-701 (Korea, Republic of); Zande, Arend M. van der [Energy Frontier Research Center (EFRC), Columbia University, New York, New York 10027 (United States); Han, Minyong [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Cui, Xu; Arefe, Ghidewon; Hone, James [Department of Mechanical Engineering, Columbia University, New York, New York 10027 (United States); Nuckolls, Colin [Department of Chemistry, Columbia University, New York, New York 10027 (United States); Heinz, Tony F. [Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States); Department of Physics, Columbia University, New York, New York 10027 (United States); Kim, Philip, E-mail: pk2015@columbia.edu [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Department of Physics, Columbia University, New York, New York 10027 (United States)

    2014-09-01

    The two-dimensional limit of layered materials has recently been realized through the use of van der Waals (vdW) heterostructures composed of weakly interacting layers. In this paper, we describe two different classes of vdW heterostructures: inorganic vdW heterostructures prepared by co-lamination and restacking; and organic-inorganic hetero-epitaxy created by physical vapor deposition of organic molecule crystals on an inorganic vdW substrate. Both types of heterostructures exhibit atomically clean vdW interfaces. Employing such vdW heterostructures, we have demonstrated various novel devices, including graphene/hexagonal boron nitride (hBN) and MoS{sub 2} heterostructures for memory devices; graphene/MoS{sub 2}/WSe{sub 2}/graphene vertical p-n junctions for photovoltaic devices, and organic crystals on hBN with graphene electrodes for high-performance transistors.

  18. Concepts of inorganic solid-state nanostructured solar cells

    Microsoft Academic Search

    Thomas Dittrich; Abdelhak Belaidi; Ahmed Ennaoui

    2011-01-01

    The development of inorganic solid-state nanostructured solar cells over the last years has been reviewed with respect to concepts and materials. Major attention has been paid to solar cells with extremely thin absorber, solar cells with ultra-thin nano-composite absorber and solar cells with quantum dot absorber layers. The focus has been set to structured transparent electron conductors and absorber materials

  19. Integration of functional materials and surface modification for polymeric microfluidic systems

    NASA Astrophysics Data System (ADS)

    Kitsara, Maria; Ducrée, Jens

    2013-03-01

    The opportunity for the commercialization of microfluidic systems has surged over the recent decade, primarily for medical and the life science applications. This positive development has been spurred by an increasing number of integrated, highly functional lab-on-a-chip technologies from the research community. Toward commercialization, there is a dire need for economic manufacture which involves optimized cost for materials and structuring on the front-end as well as for a range of back-end processing steps such as surface modification, integration of functional elements, assembly and packaging. Front-end processing can readily resort to very well established polymer mass fabrication schemes, e.g. injection molding. Also assembly and packaging can often be adopted from commercially available processes. In this review, we survey the back-end processes of hybrid material integration and surface modification which often need to be tailored to the specifics of miniaturized polymeric microfluidic systems. On the one hand, the accurate control of these back-end processes proves to be the key to the technical function of the system and thus the value creation. On the other hand, the integration of functional materials constitutes a major cost factor.

  20. Functionally gradient material for membrane reactors to convert methane gas into value-added products

    DOEpatents

    Balachandran, U.; Dusek, J.T.; Kleefisch, M.S.; Kobylinski, T.P.

    1996-11-12

    A functionally gradient material for a membrane reactor for converting methane gas into value-added-products includes an outer tube of perovskite, which contacts air; an inner tube which contacts methane gas, of zirconium oxide, and a bonding layer between the perovskite and zirconium oxide layers. The bonding layer has one or more layers of a mixture of perovskite and zirconium oxide, with the layers transitioning from an excess of perovskite to an excess of zirconium oxide. The transition layers match thermal expansion coefficients and other physical properties between the two different materials. 7 figs.

  1. Carbon-Based Nanomaterials: Multi-Functional Materials for Biomedical Engineering

    PubMed Central

    Cha, Chaenyung; Shin, Su Ryon; Annabi, Nasim; Dokmeci, Mehmet R.; Khademhosseini, Ali

    2013-01-01

    Functional carbon-based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e., thermal and electrical conductivity, high mechanical strength, and optical properties), extensive research efforts are being made to utilize these materials for various industrial applications, such as high-strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineering. This Perspective highlights different types of carbon-based nanomaterials currently used in biomedical applications. PMID:23560817

  2. Inorganic Molecules; A Visual Database

    NSDL National Science Digital Library

    Inorganic Molecules: A Visual Data Base contains text and graphics describing 66 molecules and ions commonly used as examples in general chemistry courses. For each molecule, fifteen molecular properties are presented visually by eight or nine different molecular models created by the CAChe Scientific Molecular Modeling program.

  3. Infrared Spectrometry of Inorganic Salts

    ERIC Educational Resources Information Center

    Ackermann, Martin N.

    1970-01-01

    Describes a general chemistry experiment which uses infrared spectroscopy to analyze inorganic ions and thereby serves to introduce an important instrumental method of analysis. Presents a table of eight anions and the ammonium ion with the frequencies of their normal modes, as well as the spectra of three sulfate salts. (RR)

  4. Photocatalytic Activity of Inorganic Sunscreens

    Microsoft Academic Search

    Tatiana Picatonotto; Davide Vione; M. Eugenia Carlotti; Marina Gallarate

    2001-01-01

    Some inorganic pigments are used as ingredients for sunscreens as they can absorb, reflect or scatter UV radiation. Titanium dioxide and zinc oxide, which are used for this purpose, are semiconductor oxides and show photocatalytic activity. As a consequence, they can promote transformation of organic molecules upon absorption of radiation. This work studies the activity of some of these pigments,

  5. 29 CFR 1926.1118 - Inorganic arsenic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Labor 8 2012-07-01 2012-07-01 false Inorganic arsenic. 1926.1118 Section 1926.1118 Labor Regulations... Toxic and Hazardous Substances § 1926.1118 Inorganic arsenic. Note: The requirements applicable to...

  6. 29 CFR 1926.1118 - Inorganic arsenic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Labor 8 2010-07-01 2010-07-01 false Inorganic arsenic. 1926.1118 Section 1926.1118 Labor Regulations... Toxic and Hazardous Substances § 1926.1118 Inorganic arsenic. Note: The requirements applicable to...

  7. 29 CFR 1926.1118 - Inorganic arsenic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Labor 8 2011-07-01 2011-07-01 false Inorganic arsenic. 1926.1118 Section 1926.1118 Labor Regulations... Toxic and Hazardous Substances § 1926.1118 Inorganic arsenic. Note: The requirements applicable to...

  8. 29 CFR 1926.1118 - Inorganic arsenic.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Labor 8 2013-07-01 2013-07-01 false Inorganic arsenic. 1926.1118 Section 1926.1118 Labor Regulations... Toxic and Hazardous Substances § 1926.1118 Inorganic arsenic. Note: The requirements applicable to...

  9. 29 CFR 1926.1118 - Inorganic arsenic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Labor 8 2014-07-01 2014-07-01 false Inorganic arsenic. 1926.1118 Section 1926.1118 Labor Regulations... Toxic and Hazardous Substances § 1926.1118 Inorganic arsenic. Note: The requirements applicable to...

  10. Using The Interfaces In Self-Assembled Protein Cage Architectures For Materials Synthesis

    NASA Astrophysics Data System (ADS)

    Douglas, Trevor

    2007-03-01

    The self-assembled architectures of viral capsids have been used as models for understanding processes of encapsulation of both hard and soft materials. We have explored modifications to the exterior and interior interfaces of viral (and other protein cage architectures) while maintaining the assembly of stable icosahedral capsid particles. This has allowed us to utilize the high symmetry of the viral capsid to engineer unique functionality for highly ordered multivalent presentation for controlled nucleation of hard inorganic materials and packaging of soft organic materials. Of particular interest is the nature of the hard-soft interface in these systems. Through the incorporation of peptides derived from phage display we can direct the nucleation and growth of specific inorganic phases, constrained within the protein cage architecture. The coupled synthesis of cage-constrained ferrimagnetic and antiferromagnetic nanoparticles results in formation of stable composites that exhibit unique exchange bias magnetic coupling. To understand the role of the protein in directing inorganic materials synthesis, we have probed the protein-mineral interface using genetic and chemical modifications, spatially controlled inorganic synthesis, high-resolution transmission electron microscopy, and cryo-electron microscopy and image reconstruction. The role of protein interfaces in these assembled protein cage architectures has been explored to understand and exploit packaging of a wide range of materials as diverse as nucleic acids, drugs, and inorganic nano-materials.

  11. Functional mesoporous materials for energy applications: solar cells, fuel cells, and batteries

    NASA Astrophysics Data System (ADS)

    Ye, Youngjin; Jo, Changshin; Jeong, Inyoung; Lee, Jinwoo

    2013-05-01

    This feature article presents recent progress made in the synthesis of functional ordered mesoporous materials and their application as high performance electrodes in dye-sensitized solar cells (DSCs) and quantum dot-sensitized solar cells (QDSCs), fuel cells, and Li-ion batteries. Ordered mesoporous materials have been mainly synthesized using two representative synthetic methods: the soft template and hard template methods. To overcome the limitations of these two methods, a new method called CASH was suggested. The CASH method combines the advantages of the soft and hard template methods by employing a diblock copolymer, PI-b-PEO, which contains a hydrophilic block and an sp2-hybridized-carbon-containing hydrophobic block as a structure-directing agent. After discussing general techniques used in the synthesis of mesoporous materials, this article presents recent applications of mesoporous materials as electrodes in DSCs and QDSCs, fuel cells, and Li-ion batteries. The role of material properties and mesostructures in device performance is discussed in each case. The developed soft and hard template methods, along with the CASH method, allow control of the pore size, wall composition, and pore structure, providing insight into material design and optimization for better electrode performances in these types of energy conversion devices. This paper concludes with an outlook on future research directions to enable breakthroughs and overcome current limitations in this field.

  12. Functional mesoporous materials for energy applications: solar cells, fuel cells, and batteries.

    PubMed

    Ye, Youngjin; Jo, Changshin; Jeong, Inyoung; Lee, Jinwoo

    2013-06-01

    This feature article presents recent progress made in the synthesis of functional ordered mesoporous materials and their application as high performance electrodes in dye-sensitized solar cells (DSCs) and quantum dot-sensitized solar cells (QDSCs), fuel cells, and Li-ion batteries. Ordered mesoporous materials have been mainly synthesized using two representative synthetic methods: the soft template and hard template methods. To overcome the limitations of these two methods, a new method called CASH was suggested. The CASH method combines the advantages of the soft and hard template methods by employing a diblock copolymer, PI-b-PEO, which contains a hydrophilic block and an sp(2)-hybridized-carbon-containing hydrophobic block as a structure-directing agent. After discussing general techniques used in the synthesis of mesoporous materials, this article presents recent applications of mesoporous materials as electrodes in DSCs and QDSCs, fuel cells, and Li-ion batteries. The role of material properties and mesostructures in device performance is discussed in each case. The developed soft and hard template methods, along with the CASH method, allow control of the pore size, wall composition, and pore structure, providing insight into material design and optimization for better electrode performances in these types of energy conversion devices. This paper concludes with an outlook on future research directions to enable breakthroughs and overcome current limitations in this field. PMID:23546219

  13. Impact of energy alignment and morphology on the efficiency in inorganic–organic hybrid solar cells

    Microsoft Academic Search

    M. Gruber; B. A. Stickler; G. Trimmel; F. Schürrer; K. Zojer

    2010-01-01

    Carrier transport in hybrid inorganic–organic solar cells has been studied by means of a two-dimensional drift-diffusion-based model including the generation and motion of excitons. The devices consist of a polymer serving as donor material and a semiconducting small-band gap inorganic component as acceptor material. For the first time it is taken into account that, in strong contrast to purely organic

  14. Oxide materials for electronics Inorganic Materials and Ceramics Research Group

    E-print Network

    ­ spray pyrolysis Ceramic processing and coating technology Pressing, tape casting, extrusion Spray (ferroelectricity) NTNU NanoLab NORTEM #12;In situ X-ray diffraction In situ T, atmosphere, up to 20 bar pressure the anisotropic nature of piezoelectricity: Ba0.92Ca0.08TiO3 textured by tape casting with templates. Haugen et al

  15. Organic-inorganic hybrid resists for EUVL

    NASA Astrophysics Data System (ADS)

    Singh, Vikram; Kalyani, Vishwanath; Satyanarayana, V. S. V.; Pradeep, Chullikkattil P.; Ghosh, Subrata; Sharma, Satinder; Gonsalves, Kenneth E.

    2014-03-01

    Herein, we describe preliminary results on organic-inorganic hybrid photoresists, capable of showing line patterns up to 16 nm under e-beam exposure studies, prepared by incorporating polyoxometalates (POMs) clusters into organic photoresist materials. Various Mo and W based clusters such as (TBA)2[Mo6O19], (TBA)5(H)[P2V3W15O62] and (TBA)4[P2Mo18O61] (where TBA = tetrabutyl ammonium counter ion) have been incorporated into PMMA matrix by mixing POM solutions and standard PMMA polymer in anisole (MW ~ 95000, MicroChem) in 1:33 w/v ratio. E-beam exposure followed by development with MIBK solutions showed that these new organic-inorganic hybrid photoresists show good line patterns upto 16 nm, which were not observed in the case of control experiments done on pure PMMA polymer resist. The observed enhancement of resist properties in the case of hybrid resists could possibly be due to a combination of features imparted to the resist by the POM clusters such as increased sensitivity, etch resistance and thermal stability.

  16. Porous inorganic—organic shape memory polymers

    PubMed Central

    Zhang, Dawei; Burkes, William L.; Schoener, Cody A.; Grunlan, Melissa A.

    2012-01-01

    Thermoresponsive shape memory polymers (SMPs) are a type of stimuli-sensitive materials that switch from a temporary shape back to their permanent shape upon exposure to heat. While the majority of SMPs have been fabricated in the solid form, porous SMP foams exhibit distinct properties and are better suited for certain applications, including some in the biomedical field. Like solid SMPs, SMP foams have been restricted to a limited group of organic polymer systems. In this study, we prepared inorganic–organic SMP foams based on the photochemical cure of a macromer comprised of inorganic polydimethylsiloxane (PDMS) segments and organic poly(?-caprolactone) (PCL) segments, diacrylated PCL40-block-PDMS37-block-PCL40. To achieve tunable pore size with high interconnectivity, the SMP foams were prepared via a refined solvent-casting/particulate-leaching (SCPL) method. By varying design parameters such as degree of salt fusion, macromer concentration in the solvent and salt particle size, the SMP foams with excellent shape memory behavior and tunable pore size, pore morphology, and modulus were obtained. PMID:22956854

  17. Preparation of functional composite materials based on chemically derived graphene using solution process

    NASA Astrophysics Data System (ADS)

    Kim, M.; Hyun, W. J.; Mun, S. C.; Park, O. O.

    2015-04-01

    Chemically derived graphenes were assembled into functional composite materials using solution process from stable solvent dispersion. We have developed foldable electronic circuits on paper substrates using vacuum filtration of graphene nanoplates dispersion and a selective transfer process without need for special equipment. The electronic circuits on paper substrates revealed only a small change in conductance under various folding angles and maintained an electronic path after repetitive folding and unfolding. We also prepared flexible. binder-free graphene paper-like materials by addition of graphene oxide as a film stabilizer. This graphene papers showed outstanding electrical conductivity up to 26,000 S/m and high charge capacity as an anode in lithium-ion battery without any post-treatments. For last case, multi-functional thin film structures of graphene nanoplates were fabricated by using layer-by-layer assembly technique, showing optical transparency, electrical conductivity and enhanced gas barrier property.

  18. Free vibration of functionally graded material beams with surface-bonded piezoelectric layers in thermal environment

    Microsoft Academic Search

    Shi-rong Li; Hou-de Su; Chang-jun Cheng

    2009-01-01

    Free vibration of statically thermal postbuckled functionally graded material (FGM) beams with surface-bonded piezoelectric\\u000a layers subject to both temperature rise and voltage is studied. By accurately considering the axial extension and based on\\u000a the Euler-Bernoulli beam theory, geometrically nonlinear dynamic governing equations for FGM beams with surface-bonded piezoelectric\\u000a layers subject to thermo-electromechanical loadings are formulated. It is assumed that the

  19. Method and apparatus for determination of mechanical properties of functionally-graded materials

    SciTech Connect

    Giannakopoulos, A.E.; Suresh, S.

    1999-12-07

    Techniques for the determination of mechanical properties of homogeneous or functionally-graded materials from indentation testing are presented. The technique is applicable to indentation on the nano-scale through the macro-scale including the geological scale. The technique involves creating a predictive load/depth relationship for a sample, providing an experimental load/depth relationship, comparing the experimental data to the predictive data, and determining a physical characteristic from the comparison.

  20. Method and apparatus for determination of mechanical properties of functionally-graded materials

    DOEpatents

    Giannakopoulos, Antonios E. (Somerville, MA); Suresh, Subra (Wellesley, MA)

    1999-01-01

    Techniques for the determination of mechanical properties of homogenous or functionally-graded materials from indentation testing are presented. The technique is applicable to indentation on the nano-scale through the macro-scale including the geological scale. The technique involves creating a predictive load/depth relationship for a sample, providing an experimental load/depth relationship, comparing the experimental data to the predictive data, and determining a physical characteristic from the comparison.

  1. Segregation effects in sol-gel zirconia-silica materials analyzed through their radial distribution functions

    Microsoft Academic Search

    P. Salas; J. Montoya; V. M. Castaño; R. Rodríguez

    2000-01-01

    A novel method to characterize segregation effects in silica-zirconia materials prepared by the sol-gel method through the\\u000a alkoxide route is reported. These segregation effects were studied by using the Radial Distribution Function obtained from\\u000a the X-ray diffractograms. The information obtained by this technique allows one to predict the spatial distribution of one\\u000a of the oxides into the other as a

  2. The optical applications of 3D sub-wavelength block-copolymer nanostructured functional materials

    E-print Network

    Poole, Zsolt; Ohodnicki, Paul; Chen, Kevin

    2015-01-01

    A method to engineer the refractive indices of functional materials (TiO2, ZnO, SnO2, SiO2), by nanostructuring in the deep sub-wavelength regime (light reflections from 38% down to ~3% with a wide angular span, are demonstrated with the developed wet processing route. A high temperature oxygen free fiber optic hydrogen sensor realized by accessing nano-engine...

  3. Silacrown modified xerogels as functional hybrid materials for carbon composite electrodes

    Microsoft Academic Search

    M. Colilla; P. Aranda; M. Darder; E. Ruiz-Hitzky

    2010-01-01

    The entrapment of the ionophore 1,1-dimethylsila-17-crown-6 (DMS17C6) in a polysiloxane matrix derived from the 3-(trimethoxysilyl) propyl methacrylate (MAPTS) and tetramethoxysilane (TMOS) alkoxysilanes, yields a functional hybrid material suitable for the development of bulk-modified electrodes. The resulting sensors exhibit a long-time stability, robustness and a suitable electroanalytical performance in the potentiometric detection of alkali metal ions (i.e. Li+, Na+ and K+)

  4. Ion conducting organic/inorganic hybrid polymers

    NASA Technical Reports Server (NTRS)

    Meador, Maryann B. (Inventor); Kinder, James D. (Inventor)

    2010-01-01

    This invention relates to a series of organic/inorganic hybrid polymers that are easy to fabricate into dimensionally stable films with good ion-conductivity over a wide range of temperatures for use in a variety of applications. The polymers are prepared by the reaction of amines, preferably diamines and mixtures thereof with monoamines with epoxy-functionalized alkoxysilanes. The products of the reaction are polymerized by hydrolysis of the alkoxysilane groups to produce an organic-containing silica network. Suitable functionality introduced into the amine and alkoxysilane groups produce solid polymeric membranes which conduct ions for use in fuel cells, high-performance solid state batteries, chemical sensors, electrochemical capacitors, electro-chromic windows or displays, analog memory devices and the like.

  5. Fabrication and electrocatalytic application of functionalized nanoporous carbon material with different transition metal oxides

    NASA Astrophysics Data System (ADS)

    Samiee, L.; Shoghi, F.; Vinu, A.

    2013-01-01

    In the work presented here, an attempt is made to study the effect of functionalization with different transition metal oxides on the mesostructural properties as well as electrochemical behavior of Pt/nanoporous carbon supports. In this respect, the functionalized samples have been synthesized by using CMK-3 and metallocene as transition metal sources. The platinum catalysts (5 wt% Pt) obtained through a conventional wet impregnation method. All the materials have been characterized by XRD (low and high), N2 adsorption-desorption isotherms, high-resolution transmission electron microscopy, high-resolution field emission scanning electron, EDX mapping images and cyclic voltammetry (CV) and rotating disk electrode (RDE) techniques. The results showed that the mesostructural order has been destroyed by functionalization of CMK-3 with CoO, whereas it is not that much affected in NiO and CuO functionalized samples. EDX image mapping exhibited the good and uniform dispersion of functionalizing elements (Ni, Cu, Fe and Co), Pt in the carbon supports. Moreover, XRD studies revealed the formation of smaller platinum crystallite sizes in NiO and CuO functionalized samples in relative to other functionalized supports. Electrochemical measurements were performed using CV and RDE method. Kinetic analysis revealed an activity increases in the following order: CMK-3-NiO-Pt > CMK-3-CuO-Pt > CMK-3-CoO-Pt > CMK-3-Fe2O3-Pt which is showing of simultaneous effect of surface area and surface reactivity parameters.

  6. Synthesis of Pt/PEI-MWCNT composite materials on polyethyleneimine-functionalized MWNTs as supports

    SciTech Connect

    Yi, Sung-Chul; Jung, Chi Young [Department of Chemical Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)] [Department of Chemical Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Wha Jung, E-mail: whajungk@konkuk.ac.kr [Department of Materials Chemistry and Engineering, Konkuk University, 1-Hwayang-dong, Kwangjin-gu, Seoul 143-701 (Korea, Republic of)

    2011-12-15

    Graphical abstract: Schematic diagram for (a) the preparation of Pt/MWCNT functionalized with PEI and (b) TEM of Pt/PEI-MWCNT. Highlights: Black-Right-Pointing-Pointer We prepared Pt/PEI/MWCNT where MWCNT was first functionalized by PEI (polyethyleneimine) followed by Pt deposit onto it. Black-Right-Pointing-Pointer PEI functionalization provided high density homogeneous functional groups on MWCNT's sidewall. Black-Right-Pointing-Pointer Cationic PEI leads to homogeneous dispersion in solutions such as water and organic solvents. Black-Right-Pointing-Pointer Pt/PEI/MWCNT catalyst exhibits excellent electrocatalytic activity compared to that of Pt/MWCNT catalyst obtained with polyvinylpyrrolidine (PVP). -- Abstract: Composite materials with highly dispersed platinum (Pt) nanoparticles on multiwalled carbon nanotubes (MWCNTs), functionalized with polyethyleneimine (PEI) by a noncovalent method were prepared. The PEI-functionalization provided high density homogeneous functional groups on the MWCNTs' sidewalls for binding Pt nanoparticles. Cationic PEI leads to homogeneous dispersion in solutions such as water and organic solvents. The effects of a reducing agent on the Pt nanoparticles that form on the surfaces of the MWCNT were studied by varying the molar ratio of NaOH to H{sub 2}PtCl{sub 6}. These composite materials were characterized with transmission electron micrograph (TEM), X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS). The Pt/PEI-MWCNT catalyst exhibits excellent electrocatalytic activity and compared with Pt/PVP-MWCNT catalysts obtained with polyvinylpyrrolidone (PVP). Finally, the cyclic voltammogram of methanol electrooxidation for Pt/PEI-MWCNT shows better tolerance to CO and methanol oxidation to CO{sub 2} than of Pt/PVP-MWCNT.

  7. Dendritic Encapsulation of Function: Applying Nature's Site Isolation Principle from Biomimetics to Materials Science.

    PubMed

    Hecht, Stefan; Fréchet, Jean M. J.

    2001-01-01

    The convergence of our understanding of structure-property relationships for selected biological macromolecules and our increased ability to prepare large synthetic macromolecules with a structural precision that approaches that of proteins have spawned a new area of research where chemistry and materials science join with biology. While evolution has enabled nature to perfect processes involving energy transfer or catalysis by incorporating functions such as self-replication and repair, synthetic macromolecules still depend on our synthetic skills and abilities to mesh structure and function in our designs. Clearly, we can take advantage of our understanding of natural systems to mimic the structural features that lead to optimized function. For example, numerous biological systems make use of the concept of site isolation whereby an active center or catalytic site is encapsulated, frequently within a protein, to afford properties that would not be encountered in the bulk state. The ability of the dendritic shell to encapsulate functional core moieties and to create specific site-isolated nanoenvironments, and thereby affect molecular properties, has been explored. By utilizing the distinct properties of the dendrimer architecture active sites that have either photophysical, photochemical, electrochemical, or catalytic functions have been placed at the core. Applying the general concept of site isolation to problems in materials research is likely to prove extremely fruitful in the long term, with short-term applications in areas such as the construction of improved optoelectronic devices. This review focuses on the evolution of a natural design principle that contributes to bridging the gap between biology and materials science. The recent progress in the synthesis of dendrimer-encapsulated molecules and their study by a variety of techniques is discussed. These investigations have implications that range from the preliminary design of artificial enzymes, catalysts, or light-harvesting systems to the construction of insulated molecular wires, light-emitting diodes, and fiber optics. PMID:11169692

  8. Comparative study on functionalized SBA15 and SBA16 nanostructured materials used for immobilization of D-amino acid oxidase

    Microsoft Academic Search

    Le Gia Hy; Dang Tuyet Phuong; Hoang Yen; Nguyen Thi Vuong Hoan; Bui Thi Hai Linh; Hoang Vinh Thang; Tran Thi Kim Hoa; Dinh Cao Thang; Vu Thi Hanh Nguyen; Phan Thi Hong Thao; Chu Van Giap; Vu Anh Tuan

    2008-01-01

    SBA-15 and SBA-16 nanostucrured materials were synthesized via hydrothermal treatment and were functionalized with 3-aminopropyltriethoxysilane (APTES), and vinyltriethoxysilane (VTES). The obtained samples were characterized by different techniques such as XRD, BET, IR and TEM. After functionalization, it showed that these nanostrucrured materials were still maintained the hexagonal pore structure of the parent SBA-15 and cubic cage structure of the parent

  9. Prediction and Relation of Thermal Conductivity with Average Relative Atomic Mass and Density for Semiconducting Compound Functional Crystal Materials

    Microsoft Academic Search

    Qingren Wu; Yibin Xu; Tonggeng Xi

    2007-01-01

    Thermal conductivity plays an important role in dominating a functional material's behavior in heat conduction processes and its applicability. Thus it is important to develop a prediction method for thermal conductivity to improve the thermal design and manufacturing processes of functional materials. According to the microscopy theories of heat conduction and the Koop-Neumann Law, a new method of predicting the

  10. Inorganic metal oxide/organic polymer nanocomposites and method thereof

    DOEpatents

    Gash, Alexander E.; Satcher, Joe H.; Simpson, Randy

    2004-03-30

    A synthetic method for preparation of hybrid inorganic/organic energetic nanocomposites is disclosed herein. The method employs the use of stable metal inorganic salts and organic solvents as well as an organic polymer with good solubility in the solvent system to produce novel nanocomposite energetic materials. In addition, fuel metal powders (particularly those that are oxophillic) can be incorporated into composition. This material has been characterized by thermal methods, energy-filtered transmission electron microscopy (EFTEM), N.sub.2 adsoprtion/desorption methods, and Fourier-Transform (FT-IR) spectroscopy. According to these characterization methods the organic polymer phase fills the nanopores of the composite material, providing superb mixing of the component phases in the energetic nanocomposite.

  11. Evaluation of a low temperature hardening Inorganic Phosphate Cement for high-temperature applications

    SciTech Connect

    Alshaaer, M., E-mail: mazen72@yahoo.co [Materials Research Laboratory, Deanship of Academic Research, University of Jordan, Amman 11942 (Jordan); Cuypers, H. [Department of Mechanics of Materials and Constructions (MEMC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels (Belgium); Mosselmans, G. [Belgian Research Center of Cement Industry (CRIC-OCCN), Bld du Souverain 68, 1170 Brussels (Belgium); Rahier, H. [Research Group of Physical Chemistry and Polymer Science (FYSC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels (Belgium); Wastiels, J. [Department of Mechanics of Materials and Constructions (MEMC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels (Belgium)

    2011-01-15

    Phase and mechanical changes of Inorganic Phosphate Cement (IPC) are identified along with changes in macro properties as functions of temperature and time. In addition to amorphous phases, the presence of significant amounts of brushite and wollastonite in the reference IPC is confirmed using X-ray diffraction. The thermal behavior of IPC up to 1000 {sup o}C shows that contraction of the solid phase in IPC due to chemical transformations causes reduction in the volume of the material. Also the ongoing meta-stable calcium phosphate transformations and reactions over a long time contribute significantly to the phase instability of the material at ambient conditions. It is found that the strength of IPC increases with ageing at ambient conditions but the formation microcracks below 105 {sup o}C causes a sharp reduction in the mechanical performance of IPC. According to the results obtained by Mercury intrusion porosimetry, the pore system of the reference IPC is dominated by mesopores.

  12. Luminescence of sensitive materials: towards new optical sensing

    NASA Astrophysics Data System (ADS)

    Cornu, Lucile; Gaudon, Manuel; Ilin, Evgeniy; Aymonier, Cyril; Veber, Philippe; Garcia, Alain; Kahn, Myrtil; Champouret, Yohan; Jubera, Veronique

    2014-03-01

    In the last decades, considerable efforts have been carried out to develop new tools and knowledge in the domain of functionalized materials, for application ranging information, lighting, communication, energy, optical sources or detection. To couple an optical answer with another property is possible through the follow-up of the luminescence. The control of the structural symmetry, oxidation state or surface chemistry enables the chemists to precisely tune the emission. Illustrations will be provided on inorganic powder and crystal materials.

  13. Development and qualification of functional materials for the EU Test Blanket Modules: Strategy and R&D activities

    NASA Astrophysics Data System (ADS)

    Zmitko, M.; Poitevin, Y.; Boccaccini, L.; Salavy, J.-F.; Knitter, R.; Möslang, A.; Magielsen, A. J.; Hegeman, J. B. J.; Lässer, R.

    2011-10-01

    Europe has developed two reference tritium breeder blankets concepts for a DEMO fusion reactor: the Helium-Cooled Lithium-Lead and the Helium-Cooled Pebble-Bed. Both will be tested in ITER under the form of Test Blanket Modules (TBMs). The paper reviews the current status of development and qualification of the EU TBMs functional materials; i.e. ceramic solid breeder materials, beryllium/beryllides multiplier materials and Lithium-Lead liquid metal breeder material Pb-15.7Li. For each functional material the main functional/performance requirements with key qualification issues, current status of the R&D activities and the EU development strategy are presented. In the development strategy major steps considered are listed pointing out importance of the 'Development/qualification/procurement plan', currently under elaboration, for definition of a roadmap of further activities aiming at delivery of qualified functional materials to be used in the European TBMs in ITER.

  14. Tuning physical properties by assembling subnanometer inorganic and organic units

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Parilla, P. A.; Ahrenkiel, S. P.; Mascarenhas, A.; Islam, Z.; Ren, Y.; Lee, P. L.; McNevin, M. J.; Naumov, I.; Fu, H. X.; Huang, X. Y.; Li, J.

    2008-03-01

    Designing inorganic-organic hybrid materials in a nanoscopic scale allows taking the full advantage of the two worlds, which has recently been demonstrated in a new family of hybrid crystalline materials that are the fully ordered assemblies of sub-nanometer scale inorganic units (e.g., few monolayer-thick slab, single atomic chain) and organic molecules[1].They have been shown to exhibit a number of unique properties that are not readily available in either of the components or their nanostructures: for instance, strongly enhanced exciton-polariton absorption and exciton binding energy[2], a massive bandgap blue shift (˜ 2 eV) from that of the bulk inorganic semiconductor[3], and fine-tuning of thermal expansion and achieving zero-thermal expansio[4]. They have great potential for applications in areas including transparent conducting materials, thermoelectric materials, UV optoelectronic devices, because of their unusual electronic, vibrational and optical properties and the flexibility in tailoring the material properties adapting to the specific application requirements. .[1] X. H. Huang et al., JACS 125, 7049 (03). [2] Y. Zhang et al., PRL 96, 26405 (06). [3] B. Fluegel et al., PRB 70, 205308 (04). [4] Y. Zhang et al., PRL 99, 215901 (07).

  15. Ion energy-angle distribution functions at the plasma-material interface in oblique magnetic fields

    NASA Astrophysics Data System (ADS)

    Khaziev, Rinat; Curreli, Davide

    2015-04-01

    The ion energy-angle distribution (IEAD) at the wall of a magnetized plasma is of fundamental importance for the determination of the material processes occurring at the plasma-material interface, comprising secondary emissions and material sputtering. Here, we present a numerical characterization of the IEAD at the wall of a weakly collisional magnetized plasma with the magnetic field inclined at an arbitrary angle with respect to the wall. The analysis has been done using two different techniques: (1) a fluid-Monte Carlo method, and (2) particle-in-cell simulations, the former offering a fast but approximate method for the determination of the IEADs, the latter giving a computationally intensive but self-consistent treatment of the plasma behavior from the quasi-neutral region to the material boundary. The two models predict similar IEADs, whose similarities and differences are discussed. Data are presented for magnetic fields inclined at angles from normal to grazing incidence (0°-85°). We show the scaling factors of the average and peak ion energy and trends of the pitch angle at the wall as a function of the magnetic angle, for use in the correlation of fluid plasma models to material models.

  16. RGD Surface Functionalization of the Hydrophilic Acrylic Intraocular Lens Material to Control Posterior Capsular Opacification

    PubMed Central

    Huang, Yi-Shiang; Bertrand, Virginie; Bozukova, Dimitriya; Pagnoulle, Christophe; Labrugère, Christine; De Pauw, Edwin; De Pauw-Gillet, Marie-Claire; Durrieu, Marie-Christine

    2014-01-01

    Posterior Capsular Opacification (PCO) is the capsule fibrosis developed on implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LECs) undergoing Epithelial Mesenchymal Transition (EMT). Literature has shown that the incidence of PCO is multifactorial including the patient's age or disease, surgical technique, and IOL design and material. Reports comparing hydrophilic and hydrophobic acrylic IOLs have shown that the former has more severe PCO. On the other hand, we have previously demonstrated that the adhesion of LECs is favored on hydrophobic compared to hydrophilic materials. By combining these two facts and contemporary knowledge in PCO development via the EMT pathway, we propose a biomimetically inspired strategy to promote LEC adhesion without de-differentiation to reduce the risk of PCO development. By surface grafting of a cell adhesion molecule (RGD peptide) onto the conventional hydrophilic acrylic IOL material, the surface-functionalized IOL can be used to reconstitute a capsule-LEC-IOL sandwich structure, which has been considered to prevent PCO formation in literature. Our results show that the innovative biomaterial improves LEC adhesion, while also exhibiting similar optical (light transmittance, optical bench) and mechanical (haptic compression force, IOL injection force) properties compared to the starting material. In addition, compared to the hydrophobic IOL material, our bioactive biomaterial exhibits similar abilities in LEC adhesion, morphology maintenance, and EMT biomarker expression, which is the crucial pathway to induce PCO. The in vitro assays suggest that this biomaterial has the potential to reduce the risk factor of PCO development. PMID:25501012

  17. Applications of Click Chemistry Reactions to the Synthesis of Functional Materials

    NASA Astrophysics Data System (ADS)

    Accurso, Adrian A.

    This body of work focuses on the production of functional materials using the most reliable carbon-hetoratom bond-forming processes available, which are widely termed "click chemistry" reactions in the literature. This focus on function is enabled by a basis in synthetic chemistry, and where appropriate, brings in techniques from the related fields of materials science and biology to address current needs in those areas. Chapter 1 concerns the in situ production of azide and alkyne-based click chemistry adhesive polymers. Screening of a library of multivalent azides and alkynes was accomplished on a custom-built highthroughput instrument and followed up on a lap-shear testing apparatus. The conductivity of composites made of the adhesive was also explored according to standard methods. The second and third chapters explore the synthesis and function of a family of related [3.3.1]-bicyclononane dichlorides, which we have termed "WCL" electrophiles, and their potential applications for surface functionalization, the synthesis of polycations, and candidate membrane disruptive compounds. The rates of consumption of dichlorides and hydrolysis of model compounds were also explored using NMR, GC-MS, and HPLC-based methods.

  18. BioPen: direct writing of functional materials at the point of care

    NASA Astrophysics Data System (ADS)

    Han, Yu Long; Hu, Jie; Genin, Guy M.; Lu, Tian Jian; Xu, Feng

    2014-05-01

    Rapid and precise patterning of functional biomaterials is desirable for point-of-care (POC) tissue engineering and diagnostics. However, existing technologies such as dip-pen nanolithography and inkjet printing are currently unsuitable for POC applications due to issues of cost and portability. Here, we report the development of `BioPen', a portable tool for continuous, defined and scalable deposition of functional materials with micrometer spatial resolution and nanolitre volumetric resolution. BioPen is based upon the ballpoint pen but with multiple ``ink sources'' (functional material solutions) and with an apparatus that can be optimized for writing living cells, proteins, nucleic acids, etc. We demonstrate POC detection of human immunodeficiency virus type 1 (HIV-1) nucleic acid by writing on paper with BioPen using ``ink'' consisting of nucleic acid probes and nucleic acid-modified gold nanoparticles. We also demonstrate POC tissue engineering by writing a continuous pattern of living, functional, interconnected cells with a defined extracellular environment. Because it is simple, accurate, inexpensive and portable, BioPen has broad potential for POC detection of diagnostic biomarkers, and for POC engineering of tissues for a range of healing applications.

  19. BioPen: direct writing of functional materials at the point of care.

    PubMed

    Han, Yu Long; Hu, Jie; Genin, Guy M; Lu, Tian Jian; Xu, Feng

    2014-01-01

    Rapid and precise patterning of functional biomaterials is desirable for point-of-care (POC) tissue engineering and diagnostics. However, existing technologies such as dip-pen nanolithography and inkjet printing are currently unsuitable for POC applications due to issues of cost and portability. Here, we report the development of 'BioPen', a portable tool for continuous, defined and scalable deposition of functional materials with micrometer spatial resolution and nanolitre volumetric resolution. BioPen is based upon the ballpoint pen but with multiple "ink sources" (functional material solutions) and with an apparatus that can be optimized for writing living cells, proteins, nucleic acids, etc. We demonstrate POC detection of human immunodeficiency virus type 1 (HIV-1) nucleic acid by writing on paper with BioPen using "ink" consisting of nucleic acid probes and nucleic acid-modified gold nanoparticles. We also demonstrate POC tissue engineering by writing a continuous pattern of living, functional, interconnected cells with a defined extracellular environment. Because it is simple, accurate, inexpensive and portable, BioPen has broad potential for POC detection of diagnostic biomarkers, and for POC engineering of tissues for a range of healing applications. PMID:24799039

  20. Metal- and Polymer-Matrix Composites: Functional Lightweight Materials for High-Performance Structures

    NASA Astrophysics Data System (ADS)

    Gupta, Nikhil; Paramsothy, Muralidharan

    2014-06-01

    The special topic "Metal- and Polymer-Matrix Composites" is intended to capture the state of the art in the research and practice of functional composites. The current set of articles related to metal-matrix composites includes reviews on functionalities such as self-healing, self-lubricating, and self-cleaning capabilities; research results on a variety of aluminum-matrix composites; and investigations on advanced composites manufacturing methods. In addition, the processing and properties of carbon nanotube-reinforced polymer-matrix composites and adhesive bonding of laminated composites are discussed. The literature on functional metal-matrix composites is relatively scarce compared to functional polymer-matrix composites. The demand for lightweight composites in the transportation sector is fueling the rapid development in this field, which is captured in the current set of articles. The possibility of simultaneously tailoring several desired properties is attractive but very challenging, and it requires significant advancements in the science and technology of composite materials. The progress captured in the current set of articles shows promise for developing materials that seem capable of moving this field from laboratory-scale prototypes to actual industrial applications.

  1. PREFACE: International Conference on Advanced Structural and Functional Materials Design 2008

    NASA Astrophysics Data System (ADS)

    Kakeshita, Tomoyuki

    2009-07-01

    The Ministry of Education, Culture, Sports, Science and Technology of Japan started the Priority Assistance for the Formation of Worldwide Renowned Centers of Research - Global COE Program. This program is based on the competitive principle where a third party evaluation decides which program to support and to give priority support to the formation of world-class centers of research. Our program Center of Excellence for Advanced Structural and Functional Materials Design was selected as one of 13 programs in the field of Chemistry and Materials Science. This center is composed of two materials-related Departments in the Graduate School of Engineering: Materials and Manufacturing Science and Adaptive Machine Systems, and 4 Research Institutes: Center for Atomic and Molecular Technologies, Welding and Joining Research Institute, Institute of Scientific and Industrial Research and Research Center for Ultra-High Voltage Electron Microscopy. Recently, materials research, particularly that of metallic materials, has specialized only in individual elemental characteristics and narrow specialty fields, and there is a feeling that the original role of materials research has been forgotten. The 6 educational and research organizations which make up the COE program cooperatively try to develop new advanced structural and functional materials and achieve technological breakthrough for their fabrication processes from electronic, atomic, microstructural and morphological standpoints, focusing on their design and application: development of high performance structural materials such as space plane and turbine blades operating under a severe environment, new fabrication and assembling methods for electronic devices, development of evaluation technique for materials reliability, and development of new biomaterials for regeneration of biological hard tissues. The aim of this international conference was to report the scientific progress in our Global COE program and also to discuss related research topics. The organizing committee gratefully thanks participants for presenting their recent results and for discussions with our COE members and international attendees. November 2008 Professor Tomoyuki Kakeshita Chairman of the Conference Vice Dean, Graduate School of Engineering, Osaka University, Division of Materials and Manufacturing Science, Graduate School of Engineering Leader of Global COE Program, Osaka University, ''Center of Excellence for Advanced Structural and Functional Materials Design'' Organization Chairman: T Kakeshita (Osaka University) Advisory Board:H Mehrer (University Münster, Germany), E K H Salje (University of Cambridge, United Kingdom), H-E Schaefer (University of Stuttgart, Germany), P Veyssiere (CNRS-ONERA, France) Organizing Committee: T Kakeshita, H Araki, H Fujii, S Fujimoto, Y Fujiwara, A Hirose, S Kirihara, M Mochizuki, H Mori, T Nagase, H Nakajima, T Nakano, R Nakatani, K Nogi, Y Setsuhara, Y Shiratsuchi, T Tanaka, T Terai, H Tsuchiya, N Tsuji, H Utsunomiya, H Yasuda, H Yasuda (Osaka University) Executive Committee: T Kakeshita, S Fujimoto, Y Fujiwara, A Hirose, T Tanaka, H Yasuda (Osaka University) Conference Secretariat: Y Fujiwara (Osaka University) Proceedings Editors: T Kakeshita and Y Fujiwara (Osaka University) Conference photograph

  2. Evaluation of functional stability of quercetin as a raw material and in different topical formulations by its antilipoperoxidative activity

    Microsoft Academic Search

    Rúbia Casagrande; Sandra R. Georgetti; Waldiceu A. Verri Jr; José R. Jabor; Antonio C. Santos; Maria J. V. Fonseca

    2006-01-01

    The present study evaluates the antioxidant activity of the flavonol quercetin, and its functional stability as a raw material\\u000a and when added in formulations. The iron-chelating activity was determined using the bathophenanthroline assay, and the functional\\u000a stability was evaluated with the antilipoperoxidative assay. Raw material presented concentration-dependent antilipoperoxidative\\u000a and iron-chelating activities. The initial antilipoperoxidative activity of the raw material, cream

  3. Synthesis and characterization of silicon-based polymers for use as organic\\/inorganic hybrids and silicon carbide precursors

    Microsoft Academic Search

    Alan Sellinger

    1997-01-01

    Organic\\/inorganic hybrids from silsesquioxanes. This Dissertation describes the synthesis and characterization of methacrylate, epoxy and liquid crystalline (LC)-containing organic\\/inorganic hybrid materials based on silsesquioxanes. While the methacrylate and epoxy groups provide polymerizable moieties to the hybrids, the LC component is anticipated to provide toughness, and oxidative stability as well as minimize shrinkage during curing. The inorganic silsesquioxane portion, ((RSiOsb{1.5})sb8, cubes),

  4. Fully Ordered and Nano-Structured Inorganic-Organic Hybrid Semiconductors

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Huang, X.-Y.

    2005-03-01

    A family of novel inorganic-organic hybrid nanostructures based on II-VI semiconductors has been synthesized, including the first monolayer inorganic/organic superlattices with all covelent bonds (3D structures) and the smallest quantum wires (1D), the chains being formed of single II-VI atomic bonds [1]. These materials are atomistically reassembled crystals without the structural fluctuation typically found in other nanostrutures, and exhibit a number of remarkable properties (e.g., a giant bandgap tunability of 1-2 eV [1,2]). As a prototype system, a 3D structure ?-ZnTe(en)0.5 shows a strongly enhanced free exciton absorption (a few times of that in the II-VI binary), Raman lines as sharp as any binary semiconductor, band edge free exciton emission, and more than 10 times enhancement in the exciton binding energy. First-principles density function band structure calculations have been performed to obtain the band gap shift, dispersion relations (effective masses), and dielectric constants of the hybrid material, and the relevant band offsets. [1] X.-Y. Huang, J. Li, Y. Zhang, and A. Mascarenahs, JACS 125, 7049 (2003). [2] B. Fluegel, Y. Zhang, A. Mascarenahs, X.-Y. Huang, and J. Li, PRB 70, 205308 (2004).

  5. Incidental and Intentional Learning of Verbal Episodic Material Differentially Modifies Functional Brain Networks

    PubMed Central

    Kuhnert, Marie-Therese; Bialonski, Stephan; Noennig, Nina; Mai, Heinke; Hinrichs, Hermann; Helmstaedter, Christoph; Lehnertz, Klaus

    2013-01-01

    Learning- and memory-related processes are thought to result from dynamic interactions in large-scale brain networks that include lateral and mesial structures of the temporal lobes. We investigate the impact of incidental and intentional learning of verbal episodic material on functional brain networks that we derive from scalp-EEG recorded continuously from 33 subjects during a neuropsychological test schedule. Analyzing the networks' global statistical properties we observe that intentional but not incidental learning leads to a significantly increased clustering coefficient, and the average shortest path length remains unaffected. Moreover, network modifications correlate with subsequent recall performance: the more pronounced the modifications of the clustering coefficient, the higher the recall performance. Our findings provide novel insights into the relationship between topological aspects of functional brain networks and higher cognitive functions. PMID:24260362

  6. Thiol-Ene functionalized siloxanes for use as elastomeric dental impression materials

    PubMed Central

    Cole, Megan A.; Jankousky, Katherine C.; Bowman, Christopher N.

    2014-01-01

    Objectives Thiol- and allyl-functionalized siloxane oligomers are synthesized and evaluated for use as a radical-mediated, rapid set elastomeric dental impression material. Thiol-ene siloxane formulations are crosslinked using a redox-initiated polymerization scheme, and the mechanical properties of the thiol-ene network are manipulated through the incorporation of varying degrees of plasticizer and kaolin filler. Formulations with medium and light body consistencies are further evaluated for their ability to accurately replicate features on both the gross and microscopic levels. We hypothesize that thiol-ene functionalized siloxane systems will exhibit faster setting times and greater detail reproduction than commercially available polyvinylsiloxane (PVS) materials of comparable consistencies. Methods Thiol-ene functionalized siloxane mixtures formulated with varying levels of redox initiators, plasticizer, and kaolin filler are made and evaluated for their polymerization speed (FTIR), consistency (ISO4823.9.2), and surface energy (goniometer). Feature replication is evaluated quantitatively by SEM. The Tg, storage modulus, and creep behavior are determined by DMA. Results Increasing redox initiation rate increases the polymerization rate but at high levels also limits working time. Combining 0.86 wt% oxidizing agent with up to 5 wt% plasticizer gave a working time of 3 min and a setting time of 2 min. The selected medium and light body thiol-ene formulations also achieved greater qualitative detail reproduction than the commercial material and reproduced micrometer patterns with 98% accuracy. Significance Improving detail reproduction and setting speed is a primary focus of dental impression material design and synthesis. Radical-mediated polymerizations, particularly thiol-ene reactions, are recognized for their speed, reduced shrinkage, and ‘click’ nature. PMID:24553250

  7. Nanoscale chemical tomography of buried organic-inorganic interfaces in the chiton tooth.

    PubMed

    Gordon, Lyle M; Joester, Derk

    2011-01-13

    Biological organisms possess an unparalleled ability to control the structure and properties of mineralized tissues. They are able, for example, to guide the formation of smoothly curving single crystals or tough, lightweight, self-repairing skeletal elements. In many biominerals, an organic matrix interacts with the mineral as it forms, controls its morphology and polymorph, and is occluded during mineralization. The remarkable functional properties of the resulting composites-such as outstanding fracture toughness and wear resistance-can be attributed to buried organic-inorganic interfaces at multiple hierarchical levels. Analysing and controlling such interfaces at the nanometre length scale is critical also in emerging organic electronic and photovoltaic hybrid materials. However, elucidating the structural and chemical complexity of buried organic-inorganic interfaces presents a challenge to state-of-the-art imaging techniques. Here we show that pulsed-laser atom-probe tomography reveals three-dimensional chemical maps of organic fibres with a diameter of 5-10?nm in the surrounding nano-crystalline magnetite (Fe(3)O(4)) mineral in the tooth of a marine mollusc, the chiton Chaetopleura apiculata. Remarkably, most fibres co-localize with either sodium or magnesium. Furthermore, clustering of these cations in the fibre indicates a structural level of hierarchy previously undetected. Our results demonstrate that in the chiton tooth, individual organic fibres have different chemical compositions, and therefore probably different functional roles in controlling fibre formation and matrix-mineral interactions. Atom-probe tomography is able to detect this chemical/structural heterogeneity by virtue of its high three-dimensional spatial resolution and sensitivity across the periodic table. We anticipate that the quantitative analysis and visualization of nanometre-scale interfaces by laser-pulsed atom-probe tomography will contribute greatly to our understanding not only of biominerals (such as bone, dentine and enamel), but also of synthetic organic-inorganic composites. PMID:21228873

  8. Beyond molecules: mesoporous supramolecular frameworks self-assembled from coordination cages and inorganic anions.

    PubMed

    Luo, Dong; Zhou, Xiao-Ping; Li, Dan

    2015-05-18

    Biological function arises by the assembly of individual biomolecular modules into large aggregations or highly complex architectures. A similar strategy is adopted in supramolecular chemistry to assemble complex and highly ordered structures with advanced functions from simple components. Here we report a series of diamond-like supramolecular frameworks featuring mesoporous cavities, which are assembled from metal-imidazolate coordination cages and various anions. Small components (metal ions, amines, aldehydes, and anions) are assembled into the hierarchical complex structures through multiple interactions including covalent bonds, dative bonds, and weak C?H???X (X=O, F, and ?) hydrogen bonds. The mesoporous cavities are large enough to trap organic dye molecules, coordination cages, and vitamin?B12 . The study is expected to inspire new types of crystalline supramolecular framework materials based on coordination motifs and inorganic ions. PMID:25850862

  9. Hard X-ray spectroscopic nano-imaging of hierarchical functional materials at work.

    PubMed

    Andrews, Joy C; Weckhuysen, Bert M

    2013-11-11

    Heterogeneous catalysts often consist of an active metal (oxide) in close contact with a support material and various promoter elements. Although macroscopic properties, such as activity, selectivity and stability, can be assessed with catalyst performance testing, the development of relevant, preferably quantitative structure-performance relationships require the use of advanced characterisation methods. Spectroscopic imaging in the hard X-ray region with nanometer-scale resolution has very recently emerged as a powerful approach to elucidate the hierarchical structure and related chemistry of catalytic solids in action under realistic reaction conditions. This X-ray-based chemical imaging method benefits from the combination of high resolution (?30 nm) with large X-ray penetration and depth of focus, and the possibility for probing large areas with mosaic imaging. These capabilities make it possible to obtain spatial and temporal information on chemical changes in catalytic solids as well as a wide variety of other functional materials, such as fuel cells and batteries, in their full complexity and integrity. In this concept article we provide details on the method and setup of full-field hard X-ray spectroscopic imaging, illustrate its potential for spatiotemporal chemical imaging by making use of recent showcases, outline the pros and cons of this experimental approach and discuss some future directions for hierarchical functional materials research. PMID:24038941

  10. Reconstruction of nonstationary disordered materials and media: Watershed transform and cross-correlation function.

    PubMed

    Tahmasebi, Pejman; Sahimi, Muhammad

    2015-03-01

    Nonstationary disordered materials and media, those for which the probability distribution function of any property varies spatially when shifted in space, are abundant and encountered in astrophysics, oceanography, air pollution patterns, large-scale porous media, biological tissues and organs, and composite materials. Their reconstruction and modeling is a notoriously difficult and largely unsolved problem. We propose a method for reconstructing a broad class of such media based on partitioning them into locally stationary zones. Two methods are used for the partitioning. One is based on the Shannon entropy, while the second method utilizes a watershed transform. The locally stationary zones are then reconstructed based on a cross-correlation function and one-dimensional raster path that we recently introduced [P. Tahmasebi and M. Sahimi, Phys. Rev. Lett. 110, 078002 (2013)], with overlaps between the zones to ensure seamless transition from one zone to another. A large number of examples, including porous media, ecological systems, disordered materials, and biological tissues and organs, are reconstructed and analyzed to demonstrate the accuracy of the method. PMID:25871117

  11. Dissolution of functional materials and rare earth oxides into pseudo alveolar fluid.

    PubMed

    Takaya, Mitsutoshi; Shinohara, Yasushi; Serita, Fumio; Ono-Ogasawara, Mariko; Otaki, Noriko; Toya, Tadao; Takata, Ayako; Yoshida, Katsumi; Kohyama, Norihiko

    2006-10-01

    The dissolution rates of rare earth oxides and two types of rare earth containing functional materials into water, saline solution, and Gamble's fluid were measured in order to evaluate the biological effects of rare earth-containing functional materials. The tested materials were yttrium, lanthanum, cerium and neodymium oxides, and neodymium-boron-iron magnet alloy (NdBFe) and lanthanum-mish-metal-nickel-cobalt (LmNiCo) hydrogen-containing alloy. The dissolution rates of the rare earth oxides were very low, resulting in concentrations of rare earth elements in the test solutions of the order of ppb. In the most extreme case, Gamble's fluid dissolved 1,400 times more of the rare earth oxides than pure water. Fairly high concentration of neodymium were found in the dissolving fluids, which means that trace neodymium present as an impurity in each rare earth oxide dissolved preferentially. For yttrium oxide, the ratio of neodymium to yttrium that dissolved in the saline solution was greater than 78,000 to 1, taking into account the amount of each that was originally present in the yttrium oxide. PMID:17085926

  12. Comparative materials differences revealed in engineered bone as a function of cell-specific differentiation

    NASA Astrophysics Data System (ADS)

    Gentleman, Eileen; Swain, Robin J.; Evans, Nicholas D.; Boonrungsiman, Suwimon; Jell, Gavin; Ball, Michael D.; Shean, Tamaryn A. V.; Oyen, Michelle L.; Porter, Alexandra; Stevens, Molly M.

    2009-09-01

    An important aim of regenerative medicine is to restore tissue function with implantable, laboratory-grown constructs that contain tissue-specific cells that replicate the function of their counterparts in the healthy native tissue. It remains unclear, however, whether cells used in bone regeneration applications produce a material that mimics the structural and compositional complexity of native bone. By applying multivariate analysis techniques to micro-Raman spectra of mineralized nodules formed in vitro, we reveal cell-source-dependent differences in interactions between multiple bone-like mineral environments. Although osteoblasts and adult stem cells exhibited bone-specific biological activities and created a material with many of the hallmarks of native bone, the `bone nodules' formed from embryonic stem cells were an order of magnitude less stiff, and lacked the distinctive nanolevel architecture and complex biomolecular and mineral composition noted in the native tissue. Understanding the biological mechanisms of bone formation in vitro that contribute to cell-source-specific materials differences may facilitate the development of clinically successful engineered bone.

  13. Inorganic semiconductor nanomaterials for flexible and stretchable bio-integrated electronics

    E-print Network

    Rogers, John A.

    REVIEW Inorganic semiconductor nanomaterials for flexible and stretchable bio nanomaterials, techniques for their assembly, and strategies for incorporation into functional systems now in the synthesis of one- and two-dimensional semiconductor nanomaterials (that is, NWs and nanomembranes

  14. Inorganic nanotube nanofluidics

    NASA Astrophysics Data System (ADS)

    Fan, Rong

    The ability to manipulate charge carriers (electrons and holes) in metal-oxide semiconductor field effect transistors (MOSFETs) has revolutionized how information is processed and stored, and created the modern digital age. Introducing direct field effect modulation in fluidic systems would enable the manipulation of ionic and molecular species at a similar level and even logic operation. Due to strong Debye screening in aqueous solutions, field effect manipulation of ion transport arises only in systems whose dimensions are comparable to the critical Debye Length, i.e. in nanofluidic systems. Nanofluidics has already been explored in various cases, e.g. biological channel proteins and artificial solid-state nanopores. All these two terminal systems usually transport the ions the same way as passive electron conduction in a resistor. My work is aimed at developing nanotube nanofluidic units with a third terminal that can electrically turn on/off and control ion and biomolecule transport. Moreover, the systematic study on "doping" and transient phenomena can provide rich information to assess the electrokinetics theory and fluidic physics in nanoscale. Silica nanotubes were synthesized by oxidation/etching approach using vertical silicon nanowires as templates. A single nanotube was integrated into a metal-oxide-solution field effect transistor (MOSolFET) by interfacing with two microfluidic channels and a metallic gate electrode. Concentration dependence of ionic conductance through single nanotubes revealed the emergence of unipolar environment at low ionic strength regime. In this case, ionic conductance is only associated with majority ions and governed by surface potentials and charge densities. By applying a gate voltage, the ionic conductance can be quickly modulated. The gate voltages alter the surface potential of the silica nanotubes via capacitive coupling through the nanotube wall and the electrical double layer. In a negatively charged silica nanotube, a positive gate voltage depletes cations (majority) while a negative gate further enhances cation concentration. The resulting device is essentially a p-type ionic transistor. The inherent carrier concentration within nanotubes is determined by surface potentials and charge densities. Therefore, surface modification, which alters surface charges, can change the inherent carrier density and even switch channel polarity. We functionalize the hydroxyl group terminated silica surfaces with aminosilane chemistry, thus modifying the surface charge density and creating ambipolar and n-type nanofluidic transistors. We further employed the Poisson-Boltzmann model to systematically analyze these results. Transient responses upon switching on gate voltages lead us to propose a first kinetic model to explain the field effect modulation in nanofluidic systems. This single nanotube-based nanofluidic device, which has dimensions comparable to the size of biomolecules, represents a new-platform for single molecule detection. lambda-DNA translocations through single nanotubes were stochastically sensed by ionic current changes. The results turned out that both charge effect and geometrical effect play key roles in, single molecule sensing. These high aspect ratio nanotubes provide a novel approach to investigate the conformational evolution from the fine structure of ionic current curves, which is mechanistically different from that for narrow nanopores. The development of microtrench-based fabrication process enables the custom-designed and multiplexed nanotube nanofluidic systems. The anionic dye diffusion was regulated by ionic strength, in agreement with unipolar transport mechanism. A well-aligned mesoporous nanochannel thin film was exploited for sub-10nm nanofluidics. Nanofluidics is attracting increasing attention in bioanalytical technology and biophysics field. MOSolFETs represent the key units for building up large-scale nanofluidic processors and logic circuits. This nanotube nanofluidic platform has been utilized for single molecule detection and holds gr

  15. 2D-network of inorganic-organic hybrid material built on Keggin type polyoxometallate and amino acid: [L-C{sub 2}H{sub 6}NO{sub 2}]{sub 3}[(PO{sub 4})Mo{sub 12}O{sub 36}].5H{sub 2}O

    SciTech Connect

    Alizadeh, M.H. [Department of Chemistry, School of Sciences, Ferdowsi University, Mashhad 91779-1436 (Iran, Islamic Republic of)], E-mail: mhalizadehg@yahoo.com; Mirzaei, M. [Department of Chemistry, School of Sciences, Ferdowsi University, Mashhad 91779-1436 (Iran, Islamic Republic of); Razavi, H. [Department of Chemistry, Georgetown University, Washington, DC 20057 (United States)

    2008-03-04

    A new inorganic-organic hybrid material based on polyoxometallate, [L-C{sub 2}H{sub 6}NO{sub 2}]{sub 3}[(PO{sub 4})Mo{sub 12}O{sub 36}].5H{sub 2}O, has been successfully synthesized and characterized by single-crystal X-ray analysis, elemental analysis, infrared and ultraviolet spectroscopy, proton nuclear magnetic resonance and differential thermal analysis techniques. The title compound crystallizes in the monoclinic space group, P2{sub 1}/c{sub ,} with a = 12.4938 (8) A, b = 19.9326 (12) A, c = 17.9270 (11) A, {beta} = 102.129 (1){sup o}, V = 4364.8 (5) A{sup 3}, Z = 4 and R{sub 1}(wR{sub 2}) = 0.0513, 0.0877. The most remarkable structural feature of this hybrid can be described as two-dimensional inorganic infinite plane-like (2D/{infinity} [(PO{sub 4})Mo{sub 12}O{sub 36}]{sup 3-}) which forming via weak Van der Waals interactions along the z axis. The characteristic band of the Keggin anion [(PO{sub 4})Mo{sub 12}O{sub 36}]{sup 3-} appears at 210 nm in the UV spectrum. Thermal analysis indicates that the Keggin anion skeleton begins to decompose at 520 deg. C.

  16. Dynamical mean-field theory using Wannier functions: A flexible route to electronic structure calculations of strongly correlated materials

    Microsoft Academic Search

    F. Lechermann; A. Georges; A. Poteryaev; S. Biermann; M. Posternak; A. Yamasaki; O. K. Andersen

    2006-01-01

    A versatile method for combining density functional theory in the local density approximation with dynamical mean-field theory (DMFT) is presented. Starting from a general basis-independent formulation, we use Wannier functions as an interface between the two theories. These functions are used for the physical purpose of identifying the correlated orbitals in a specific material, and also for the more technical

  17. PREFACE: 12th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials (FGM 2012)

    NASA Astrophysics Data System (ADS)

    Zhou, Zhangjian; Li, Jingfeng; Zhang, Lianmeng; Ge, Changchun

    2013-03-01

    The 12th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials (FGM-2012) was held in Beijing, China, from 22-36 October 2012. This was part of a series of conferences organized every two years endorsed by International Advisory Committee for FGM's, which serves as a forum for scientists, educators, engineers and young students interested in the development of functionally graded materials (FGM). The series continues from the previous international symposium on FGM held in Sendai, Japan (1990), San Francisco, USA (1992), Lausanne, Switzerland (1994), Tsukuba, Japan (1996), Dresden, Germany (1998), Estes Park, USA (2000), Beijing, China (2002), Leuven, Belgium (2004), Hawaii, USA (2006), Sendai, Japan (2008) and Guimaraes, Portugal (2010). Functionally graded materials are non-uniform materials which are designed with embodied continuous spatial variations in composition and microstructure for the specific purpose of adjusting their thermal, structural, mechanical, biological or functional response to specific application conditions. Such multi-phase materials cover a range of space and time scales, and are best understood by means of a comprehensive multiscale, multiphysics approach. These kinds of materials are presently in the forefront of materials research, receiving worldwide attention. They have a broad range of applications including for example, biomedical, biomechanical, automotive, aerospace, mechanical, civil, nuclear, and naval engineering. New applications are continuously being discovered and developed. The objective of the FGM-2012 intends to provide opportunities for exchanging ideas and discussing state-of-the-art theories, techniques and applications in the fields of multiscale, multifunctional and FGM, through invited lectures, oral and poster presentations. FGM-2012 was organized and hosted by University of Science and Technology Beijing, China, together with Tsing-hua University and Wuhan University of Technology, and was supported by National Natural Science Foundation of China. On behalf of the organizing committee of FGM-2012, I express my great appreciation to their support of the symposium. Nearly 100 scholars and students from Japan, Brazil, Germany, Russia, United States of America, Portugal, France, Switzerland, Turkey, Singapore, China, and so on, attended FGM-2012, and 57 of the presented papers were collected and selected for publication. The subjects of these papers cover simulation and characterization, advanced fabrication technology, novel application of FGM and layer materials. I cordially thank all of the authors and attendees for their support, and my appreciation is also given to the advisory committee, organizing committee, and the conference volunteers for their hard work. Professor Zhangjian Zhou Proceedings Editor Beijing, December 2012 Committees International Advisory Committee Professor Glaucio H Paulino, USA Professor Marek-Jerzy Pindera, USA Professor Jeong-Ho Kim, USA Professor Emer Fazil Erdogan, USA Professor Dr Monika Willert-Porada, Germany Professor Emer Wolfgang G J Bunk, Germany Professor Omer Van Der Biest, Belgium Professor Michael M Gasik, Finland Professor Evgeny Levashov, Russia Professor Lianmeng Zhang, China Professor Qingjie Zhang, China Professor Wei Pan, China Professor Chang-Chun Ge, China Professor Jing-Feng Li, China Professor Zhangjian Zhou, China Associate Professor Serkan Dag, Turkey Professor Fernando A Rochinha, Brazil Professor Emilio C N Silva, Brazil Professor Luis August Rocha, Portugal Dr Sasa Novak, Slovenia Dr Masayuki Niino, Japan Professor Akira Kawasaki, Japan Professor Ichiro Shiota, Japan Dr Akinaga Kumakawa, Japan Dr Yoshikazu Shinohara, Japan Professor Kiyotaka Matsuura, Japan Professor Yoshinari Miyamoto, Japan Professor Takashi Goto, Japan Professor Yoshimi Watanabe, Japan Professor Kazuhiro Hasezaki, Japan Professor Soshu Kirihara, Japan Professor Emer Toshio Hirai, Japan Mr Choji Endou, Japan Dr Seiichi Uemura, Japan Local Organizing Committee Professor Changchun Ge (Chairman) Professor Xuanhui

  18. Efficient positioning of absorbing material in complex systems by using the Patch Transfer Function method

    NASA Astrophysics Data System (ADS)

    Totaro, N.; Guyader, J. L.

    2012-06-01

    Given the need to decrease energy consumption in the automobile industry, vehicle weight has become an important issue. Regarding acoustic comfort, the weight of noise reduction devices must be minimized inside vehicle compartments. Consequently, these devices, for example those using poro-elastic materials, must be designed carefully to maximize their influence on noise reduction. The present paper describes a method developed to obtain an efficient positioning of a given surface (or mass) of absorbing material characterized by its surface impedance. This technique is based on the Patch Transfer Function method used to couple complex vibro-acoustic sub-domains and which has been successfully applied in the European ViSPeR and Silence projects. First, a numerical analysis of the possibilities of this method is performed on a non-rectangular cavity with rigid walls after which an experimental validation of this numerical analysis is performed to evaluate the accuracy of the method under real conditions.

  19. Optimum gradient material for a functionally graded dental implant using metaheuristic algorithms.

    PubMed

    Sadollah, Ali; Bahreininejad, Ardeshir

    2011-10-01

    Despite dental implantation being a great success, one of the key issues facing it is a mismatch of mechanical properties between engineered and native biomaterials, which makes osseointegration and bone remodeling problematical. Functionally graded material (FGM) has been proposed as a potential upgrade to some conventional implant materials such as titanium for selection in prosthetic dentistry. The idea of an FGM dental implant is that the property would vary in a certain pattern to match the biomechanical characteristics required at different regions in the hosting bone. However, matching the properties does not necessarily guarantee the best osseointegration and bone remodeling. Little existing research has been reported on developing an optimal design of an FGM dental implant for promoting long-term success. Based upon remodeling results, metaheuristic algorithms such as the genetic algorithms (GAs) and simulated annealing (SA) have been adopted to develop a multi-objective optimal design for FGM implantation design. The results are compared with those in literature. PMID:21783149

  20. Fabrication of TiC/Ni functionally gradient materials and their mechanical and thermal properties

    NASA Astrophysics Data System (ADS)

    Ma, Xiangfeng; Tanihata, Kimiaki; Miyamoto, Yoshinari; Kumakawa, Akinaga; Nagata, Satoshi; Yamada, Tomohiko; Hirano, Tohru

    1992-08-01

    A TiC/Ni functionally gradient material (FGM) fabricated via gas-pressure combustion sintering is presently investigated to establish its mechanical and thermal properties. Attention is given to the FGM's specific thermal conductivities with different thermal cycling conditions; these are found to decrease with thermal cycling in all samples tested, implying that the lateral cracks are generated in the FGM and then propagated by the thermal cycle. High compressive stresses are induced at the TiC surface when this is constrained by a Cu block.