These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Aerosol route to functional nanostructured inorganic and hybrid porous materials.  

PubMed

The major advances in the field of the designed construction of hierarchically structured porous inorganic or hybrid materials wherein multiscale texturation is obtained via the combination of aerosol or spray processing with sol-gel chemistry, self-assembly and multiple templating are the topic of this review. The available materials span a very large set of structures and chemical compositions (silicates, aluminates, transition metal oxides, nanocomposites including metallic or chalcogenides nanoparticles, hybrid organic-inorganic, biohybrids). The resulting materials are manifested as powders or smart coatings via aerosol-directed writing combine the intrinsic physical and chemical properties of the inorganic or hybrid matrices with defined multiscale porous networks having a tunable pore size and connectivity, high surface area and accessibility. Indeed the combination of soft chemical routes and spray processing provides "a wind of change" in the field of "advanced materials". These strategies give birth to a promising family of innovative materials with many actual and future potential applications in various domains such as catalysis, sensing, photonic and microelectronic devices, nano-ionics and energy, functional coatings, biomaterials, multifunctional therapeutic carriers, and microfluidics, among others. PMID:20963791

Boissiere, Cedric; Grosso, David; Chaumonnot, Alexandra; Nicole, Lionel; Sanchez, Clement

2011-02-01

2

Inorganic Materials  

NASA Astrophysics Data System (ADS)

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.

?erný, Radovan

3

New inorganic materials  

SciTech Connect

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.

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

1983-05-01

4

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

PubMed

Organisms produce various organic/inorganic hybrid materials, which are called biominerals. They form through the self-organization of organic molecules and inorganic elements under ambient conditions. Biominerals often have highly organized and hierarchical structures from nanometer to macroscopic length scales, resulting in their remarkable physical and chemical properties that cannot be obtained by simple accumulation of their organic and inorganic constituents. These observations motivate us to create novel functional materials exhibiting properties superior to conventional materials-both synthetic and natural. Herein, we introduce recent progress in understanding biomineralization processes at the molecular level and the development of organic/inorganic hybrid materials by these processes. We specifically outline fundamental molecular studies on silica, iron oxide, and calcium carbonate biomineralization and describe material synthesis based on these mechanisms. These approaches allow us to design a variety of advanced hybrid materials with desired morphologies, sizes, compositions, and structures through environmentally friendly synthetic routes using functions of organic molecules. PMID:25375353

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

2015-01-28

5

Inorganic polymer engineering materials  

SciTech Connect

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.

Stone, M.L.

1993-06-01

6

Principles of Inorganic Materials Design  

NASA Astrophysics Data System (ADS)

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

Lalena, John N.; Cleary, David

2005-04-01

7

Hydrothermal solidification of inorganic waste materials  

Microsoft Academic Search

To create an environmently friendly community, the authors have investigated the recycling technology of inorganic, wastes to make high performance building materials and the stabilization technology of toxic heavy metals by using hydrothermal treatment. The inorganic waste materials used were bottom ash and fly ash from incinerated municipal waste, incinerated ash from sewage sludge, concrete waste, and construction sludge. These

Mikihiro Oida; H. Maenami; H. Shin; H. Kuno; Hideki Ishida

2001-01-01

8

Ampholine-functionalized hybrid organic-inorganic silica material as sorbent for solid-phase extraction of acidic and basic compounds.  

PubMed

A novel sorbent for solid-phase extraction (SPE) was synthesized by chemical immobilization of ampholine on hybrid organic-inorganic silica material. The ampholine-functionalized hybrid organic-inorganic silica sorbent is consisted of aliphatic amine groups, carboxyl groups and long carbon chains, allowing for extraction of both acidic and basic compounds. The retention properties of the developed sorbent were evaluated for 1-hydroxy-2-naphthoic acid (HNA), 1-naphthoic acid (NA), 3-hydroxybenzoic acid (HBA), benzoic acid (BA), sorbic acid (SA), vanillic aldehyde (VA), butyl 4-hydroxybenzoate (BHB), propyl 4-hydroxybenzoate (PHB), ethyl 4-hydroxybenzoate (EHB), and methyl 4-hydroxybenzoate (MHB). The results show that such a sorbent has three types of interaction, i.e., electrostatic interaction, hydrophobic interaction, and hydrogen bonding, exhibiting high extraction efficiency towards the compounds tested. The adsorption capacities of the analytes ranged from 0.61 to 6.54?gmg(-1). The reproducibility of the sorbent preparation was evaluated at three spiking concentration levels, with relative standard deviations (RSDs) of 1.0-10.5%. The recoveries of ten acidic and basic compounds spiked in beverage Coca-Cola(®) sample ranged from 82.5% to 98.2% with RSDs less than 5.8%. Under optimum conditions, the ampholine-functionalized hybrid organic-inorganic silica sorbent rendered higher extraction efficiency for acidic compounds than that of the commercially available ampholine-functionalized silica particles, and was comparable to that of the commercial Oasis WAX and Oasis WCX. PMID:23953713

Wang, Tingting; Chen, Yihui; Ma, Junfeng; Chen, Mingliang; Nie, Chenggang; Hu, Minjie; Li, Ying; Jia, Zhijian; Fang, Jianghua; Gao, Haoqi

2013-09-20

9

Inorganic-organic materials incorporating alumoxane nanoparticles  

NASA Astrophysics Data System (ADS)

Chemically functionalized alumina nanoparticles (carboxylate-alumoxanes) are used as the inorganic component of a new class of inorganic-organic material. Lysine- or para-hydroxybenzoic acid-derivatized alumoxanes are prepared from the reaction of boehmite, [Al(O)(OH)]n, with the appropriate carboxylic acid. The peripheral hydroxides and amines of these alumoxanes react directly with DER 332 epoxide to form a hybrid material, or in the presence of a resin and hardener system, to form a composite material. Solid state NMR spectroscopy demonstrates that the alumoxanes are chemically bound to the resin matrix. The properties and cure times of the alumoxane materials are distinct from both the pure resins and from a physical blend of the resins with traditional fillers. A significant increase in thermal stability and tensile strength is observed for the resin systems. In order to produce molecular coupling layers, epoxides cross-linked with self-assembled monolayers (SAMs) grown on the native oxide of aluminum thin films on silicon substrates have been investigated. Specifically, SAMs have been formed by the attachment of different carboxylic acids. In order to investigate the cross-linking reaction between carboxylate monolayers and an epoxide, grown monolayers were reacted with a mono-epoxy resin. In addition to these surface materials, aluminum oxide surfaces supporting carboxylate monolayers were reacted in pairs with DER 332 to form a structural adhesive. These materials have been characterized variously by SEM, AFM, XPS, EDX, and contact angle measurements. The particle size dependence on pH of a series of alumoxanes was investigated. For each of the alumoxanes, PCS particle size measurements were obtained as a function of pH. In all cases, particle size control was afforded by variations in pH. Finally, crystal structures of several model compounds were determined by X-ray crystallography, and shown to form either sheets of dimers or tetrameric units. Through a review of structures found in the Cambridge Crystallographic Database, compounds of the type X-CH(OH)CH 2NH-Y were investigated. The results of this study lead to a generalized approach for predicting the packing motifs of racemic mixtures in polar space groups.

Vogelson, Cullen Taylor

10

Preparation and screening of crystalline inorganic materials  

DOEpatents

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

Schultz, Peter G. (La Jolla, CA); Xiang, Xiaodong (Danville, CA); Goldwasser, Isy (Palo Alto, CA); Brice{hacek over (n)}o, Gabriel (Baldwin Park, CA); Sun, Xiao-Dong (Fremont, CA); Wang, Kai-An (Cupertino, CA)

2008-10-28

11

Combinatorial screening of inorganic and organometallic materials  

DOEpatents

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

Schultz, Peter G. (Oakland, CA); Xiang, Xiaodong (Alameda, CA); Goldwasser, Isy (Alameda, CA)

2002-01-01

12

Inorganic polymers and materials. Final report  

SciTech Connect

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

Sneddon, Larry G.

2001-01-01

13

Engineering living functional materials.  

PubMed

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

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

2015-01-16

14

Utilization of specific and non-specific peptide interactions with inorganic nanomaterials on the surface of bacteriophage M13: Methodologies towards phage supported bi-functional materials  

NASA Astrophysics Data System (ADS)

Many types of organisms create a variety of nano and micro scale materials from precursors available in their surrounding environments by a process called biomineralization. As scientists begin to understand how these organisms utilize specific and non-specific interactions with a variety of biopolymers such as chitin, peptides, proteins and nucleic acids with these precursors to create inorganic/organic composite materials, they have begun to wonder about the synthesis of other types of non-biologically templated synthetic techniques that might be possible. Bioengineered organisms and biopolymers have begun to be used for these types of studies. A variety of selection techniques exist for discovering biopolymers with an affinity for a target material, however, one of the most notable is a technique called peptide phage display. This is a technique that utilizes a commercially available randomized peptide library attached at the tip of the filamentous bacteriophage M13. In this dissertation capabilities of bacteriophage M13 are explored in regard to the creation of bi-functional nano materials by exploiting both specific peptide interactions as well as non-specific peptide interactions on the surface of the organism. Chapter 2 focuses on utilizing the specific peptide interactions of the randomized library at pIII in order to discover peptides with high binding affinity for a variety of nanomaterials. Selection studies called biopanning are performed on a variety of nanomaterials such as CaMoO4, allotropes of Ni, Fe2O3 and Fe3O4, and Rh and Pt with the fcc type crystal structure. Similarities and differences between peptides discovered for these materials are discussed. Chapter 3 focuses on utilizing the non-specific peptide interactions on the long axis of M13 called pVIII. The pVIII region consists of 2700 copies of the same 50 amino acid protein which as a negatively charged domain which is exposed to solution. The pVIII region therefore provides the surface of the phage with a negative charge on which nanomaterials can be supported. Metal salt precursors reduced in the presence of WT M13 are studied in this chapter. Metal salt precursors of Fe, Co, Ru, Rh and Pd seem to be the most effective at coating the surface of the phage based on the positively charged metal-aquo complexes formed in water, which are attracted to the negative pVIII region. Other types of reactions are explored with WT phage as a scaffold such as conversion chemistry in a polyol solvent to access several intermetallic phases as well as co-precipitation reactions to access ternary oxides. Chapter 4 focuses on combining research from chapter 2 and chapter 3 to create a bi-functional material that utilizes both specific and non-specific peptide interactions with inorganic materials on the surface of M13 to attach two different types of nanomaterials. The example provided here is a magnetically recoverable hydrogenation catalyst made up of a pVIII region coated with rhodium nanoparticles held in place by non-specific peptide interactions and a pIII region attached to iron oxide nanoparticles via specific peptide interactions. This is the first example in the literature of a commercially available pIII bioengineered M13 bacteriophage forming a bi-functional material. This research provides a methodology to design and build single and multi-component materials on the surface of bacteriophage M13 without the necessity for additional bioengineering and library characterization. The simplicity of use will make the technique available to a wider variety of researchers in the materials science community.

Avery, Kendra Nicole

15

Lithium-based inorganic-organic framework materials  

E-print Network

supervisors who really pushed me and helped to focus my abilities. My heartfelt thanks go to the people who have made my working environment so enjoyable and fruitful: my friends and co-workers in the Functional Inorganic and Hybrid Materials group. Many... grinding jars and balls, and b) mixer mill. . 18 Figure 4. Single crystal diffractometer: a) the entire apparatus apart from connected PC, and b) a close-up of the arrangement around a diffracting crystal. ...................... 20 Figure 5. Powder X...

Yeung, Hamish Hei-Man

2013-01-01

16

Strongly coupled inorganic/nanocarbon hybrid materials for advanced electrocatalysis.  

PubMed

Electrochemical systems, such as fuel cell and water splitting devices, represent some of the most efficient and environmentally friendly technologies for energy conversion and storage. Electrocatalysts play key roles in the chemical processes but often limit the performance of the entire systems due to insufficient activity, lifetime, or high cost. It has been a long-standing challenge to develop efficient and durable electrocatalysts at low cost. In this Perspective, we present our recent efforts in developing strongly coupled inorganic/nanocarbon hybrid materials to improve the electrocatalytic activities and stability of inorganic metal oxides, hydroxides, sulfides, and metal-nitrogen complexes. The hybrid materials are synthesized by direct nucleation, growth, and anchoring of inorganic nanomaterials on the functional groups of oxidized nanocarbon substrates including graphene and carbon nanotubes. This approach affords strong chemical attachment and electrical coupling between the electrocatalytic nanoparticles and nanocarbon, leading to nonprecious metal-based electrocatalysts with improved activity and durability for the oxygen reduction reaction for fuel cells and chlor-alkali catalysis, oxygen evolution reaction, and hydrogen evolution reaction. X-ray absorption near-edge structure and scanning transmission electron microscopy are employed to characterize the hybrids materials and reveal the coupling effects between inorganic nanomaterials and nanocarbon substrates. Z-contrast imaging and electron energy loss spectroscopy at single atom level are performed to investigate the nature of catalytic sites on ultrathin graphene sheets. Nanocarbon-based hybrid materials may present new opportunities for the development of electrocatalysts meeting the requirements of activity, durability, and cost for large-scale electrochemical applications. PMID:23339685

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

2013-02-13

17

Engineering the Interface Between Inorganic Materials and Cells  

SciTech Connect

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

Schaffer, David

2014-05-31

18

Molecular interactions in inorganic-organic composite materials  

NASA Astrophysics Data System (ADS)

Inorganic-organic interactions play a key role in determining the molecular and macroscopic properties of resulting composites. These materials have a wide variety of applications including use as catalysts, hosts for optical and electronic applications, and as adsorbents. Tailoring composites for each unique application is accomplished using local interactions between inorganic and organic species to control both local and mesoscopic ordering. For many inorganic-organic composites, no local order exists thereby inhibiting local characterization of these materials using diffraction techniques. However, using NMR methods that are not dependent upon periodicity, unique insight about inorganic-organic interactions in locally amorphous materials can be achieved. Using solid-state NMR methods, inorganic-organic interactions have been utilized to unambiguously establish the local organization of a variety of mesoporous materials as well as provide insight into the biological processes controlling biomineralization. For example, such experiments have revealed the location and coordination of aluminum species in the aluminosilicate framework of mesoporous materials. Such findings are crucial for the preparation of advanced catalytically active materials. These techniques have also provided increase understanding of the formation process of the inorganic network and have lead to the synthesis of the first mesophase material with a 2D crystalline architecture. This discovery is promising for enhancing the thermal and mechanical strength of mesoporous catalysts that had previously been locally disordered and thermally unstable. These investigations provide a wealth of knowledge for understanding the influence organic molecules exert upon silica structures and can be utilized to provide advanced, tailored composites.

Christiansen, Sean Condon

19

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

PubMed

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

Wang, Hailiang; Dai, Hongjie

2013-04-01

20

Combinatorial Measurement Methods for Inorganic Materials  

E-print Network

) devices, or the Seebeck coefficients of thermoelectric materials for vehicular waste heat recovery devices. At present, this tool produces library films for our thermoelectric materials and advanced MOS gate stack materials projects. Thermoelectric materials have a major applicationforvehicularwasteheatrecovery, which

21

Boron-10 loaded inorganic shielding material  

NASA Technical Reports Server (NTRS)

Shielding material containing Boron 10 and gadoliunium for neutron absorption has been developed to reduce interference from low energy neutrons in measurement of fission neutron spectrum using Li-6 fast neutron spectrometer.

Baker, S. I.; Ryskiewicz, R. S.

1972-01-01

22

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

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

23

Solid freeform fabrication of organic-inorganic hybrid materials  

Microsoft Academic Search

Freeform fabrication methods build materials by the repetitive addition of thin layers. In principle, these methods are very applicable to sol-gel glasses and organic-inorganic hybrids where diffusion and shrinkage during solidification are important. The chemical conversion of metal alkoxides to oxides may require the diffusion of water into the part and does require the diffusion out of the alcohol reaction

Paul Calvert; John O'Kelly; Chad Souvignier

1998-01-01

24

MEASUREMENT TECHNIQUES FOR INORGANIC TRACE MATERIALS IN CONTROL SYSTEM STREAMS  

EPA Science Inventory

The report gives results of a study showing that inorganic materials in control process streams at trace levels can be determined using modified, commercially available sampling equipment and atomic absorption analysis procedures; however, special care must be taken to attain hig...

25

Inorganic photochromic and cathodochromic recording materials.  

NASA Technical Reports Server (NTRS)

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

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

1971-01-01

26

Nanoelectromechanics of Inorganic and Biological Systems: From Structural Imaging to Local Functionalities  

SciTech Connect

Coupling between electrical and mechanical phenomena is extremely common in inorganic materials, and nearly ubiquitous in biological systems, underpinning phenomena and devices ranging from SONAR to cardiac activity and hearing. This paper briefly summarizes the Scanning Probe Microscopy (SPM) approach, referred to as Piezoresponse Force Microscopy (PFM), for probing electromechanical coupling on the nanometer scales, and delineates some existing and emerging applications to probe local structure and functionality in inorganic ferroelectrics, calcified and connective tissues, and complex biosystems based on electromechanical detection.

Rodriguez, Brian [University College, Dublin; Kalinin, Sergei V [ORNL; Jesse, Stephen [ORNL; Thompson, G. L. [Clemson University; Vertegel, Alexey [ORNL; Hohlbauch, Sophia [Asylum Research, Santa Barbara, CA; Proksch, Roger [Asylum Research, Santa Barbara, CA

2008-01-01

27

Combinatorial Screening Of Inorganic And Organometallic Materials  

DOEpatents

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.

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

2002-06-25

28

Template-free routes to porous inorganic materials.  

PubMed

New approaches to solid-state reactivity have allowed us to develop unusual routes to porous inorganic materials. This article describes our recent work on template-free routes involving the selective leaching of one phase from a two-phase composite to form porous oxides. Subsequent reactions have been developed to yield porous metals, conformal coatings, and hierarchically porous materials. Pores can also be generated through simple redox processes in transition-metal oxides; such redox cycling allows mesopores to be produced in a regenerative process in a material which is already macroporous. PMID:17028730

Toberer, Eric S; Seshadri, Ram

2006-08-14

29

Slurry Nebulization in Plasmas for Analysis of Inorganic Materials  

Microsoft Academic Search

This review summarizes and discusses the preparation of slurries for analysis of inorganic materials by inductively coupled plasma optical emission spectrometry (ICP?OES) and inductively coupled plasma mass spectrometry (ICP?MS). Details about the grinding step for slurry preparation, the stabilization of slurries, and the calibration strategies are critically discussed. Typical applications described in the literature and the state?of?the?art including advantages and

Mirian C. Santos; Joaquim A. Nóbrega

2006-01-01

30

NEW PROTON CONDUCTIVE COMPOSITE MATERIALS WITH INORGANIC AND STYRENE GRAFTED AND SULFONATED VDF/CTFE FLUOROPOLYMERS  

SciTech Connect

Creation of new membrane materials for proton exchange membrane fuel cells (PEMFCs) operating at elevated temperature and low relative humidity (RH) is one of the major challenges in the implementation of the fuel cell technology. New candidate membrane materials are required to efficiently conduct protons at 120oC and RH down to 15%. Based on these criteria, we are working on the development of new membrane materials, which are composites of inorganic proton conductors with a functionalized and cross-linkable Teflon-type polymer. The synthesis of crosslinkable P(VDF-CTFE) copolymer with controllable structure, molecular weight and terminal and side chain silane groups was described in [1]. The chemistry of the synthesis was centered on a specifically designed functional borane initiator containing silane groups. The major role of polymer matrix is to maintain the continuity of charge transfer and to ensure membrane integrity. The primary considerations include sufficient proton conductivity, thermal and chemical stability at elevated temperature, mechanical strength, compatibility with inorganic particulate phases, processibility to form uniform thin film, and cost effectiveness. Several classes of inorganic proton conductors with high water retention capability, including mesoporous materials (sulfated and/or sulfonated alumina, zirconia, titania) and zirconium phosphate of different structure have been chosen as candidate components for the new composite membranes for PEMFC operation at elevated temperatures and reduced RH. The primary requirement to the inorganic phases is the ability to provide high proton conductivity with the minimum amount of water (reduced humidity).

Lvov, Serguei [ORNL; Payne, Terry L [ORNL

2008-01-01

31

Interactions between lipid bilayers and inorganic material surfaces  

NASA Astrophysics Data System (ADS)

Because of their unique biological and material properties, lipid bilayers have been extensively studied for use in biosensor and drug delivery applications. In the past, these systems have mostly taken the form of bulk solutions. More recently, researchers have integrated bilayers with chip-based architectures to take advantage of advanced optical, scanning probe and electronic characterization. These applications typically involve the creation of hybrid devices with inorganic and bilayer components, both of which affect the final device performance. In particular, the properties of supported lipid bilayers (SLBs) are known to depend on the substrate chemistry and topography as well as the lipid used. In spite of the large body of work involving these systems, there is still much that remains unknown about the formation and ultimate structure of the interface between these very different materials. One outstanding question in the study of SLBs is the role that the bilayer deposition method plays in determining the bilayer properties. In this work, we have developed a new method for forming and patterning lipid bilayers: bubble collapse deposition (BCD). This method is similar to an in situ version of Langmuir-Blodgett deposition, and offers unique possibilities for the fabrication of lipid-based devices. Briefly, a lipid monolayer is "inked" onto the surface of an air bubble. This bubble is then brought down on a solid support and the air is withdrawn. This withdrawal of air shrinks the bubble, which causes the monolayer to fold over on itself and redeposit on the surface as a bilayer. With BCD, we have demonstrated the first SLB formation on alumina using uncharged lipids. Using this system, we have measured a previously unobserved enhanced hydrodynamic coupling at the alumina surface. We have also used BCD to produce a hybrid lipid-gated chemical delivery device with potentially sub-cellular spatial resolution. Because of the unique material properties of the lipid seals in this system, these devices can retain a chemical of interest for weeks and yet rapidly release this load (within tens of ms) when triggered by a simple optical input. Finally, we have used BCD to directly transfer lipids from a cell membrane to a substrate surface. We present studies characterizing which membrane components are transferred, including lipids, proteins and the cytoskeleton. These studies offer both increased functionality of hybrid lipid systems and fundamental insights into the interactions between lipids and common semiconductor fabrication materials.

Mager, Morgan Douglas

32

Thermal and chemical degradation of inorganic membrane materials. Topical report  

SciTech Connect

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).

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

1994-04-01

33

Phases of functionalized polymer-inorganic composites in solution studied via molecular dynamics  

NASA Astrophysics Data System (ADS)

Using self-assembling polymer systems to direct the formation of inorganic crystals, polymer-inorganic composite materials offer new opportunities in materials design. Molecular dynamics simulations allow for an exploration of the wide range of phases in these systems. Amphiphilic ABA triblocks with A hydrophilic, B hydrophobic, and functional ends with an affinity to inorganic particles are modeled to capture the minimum physics needed to describe polymer-inorganc systems currently being investigated by experiment. A number of phases are formed in solution as the attraction strength between the inorganic particles and the affinity of those particles to the functional end beads of the polymer are varied. Some of the phases found include hexagonal, square columnar, lamellar, perforated lamellar, and the gyroid. Polymer stretching plays an important role in each of the phases found, with a characteristic multi-modal behavior in the polymer end to end distance distribution. In the gyroid phase, for instance, the peaks correspond to the polymers being in two preferred conformations: v-shaped with a small end to end distance and fully extended in a line with the largest possible end to end distance. At high interaction strengths, inorganic particles are found to crystallize and form plate-like structures.

Anderson, Joshua; Sknepnek, Rastko; Travesset, Alex

2009-03-01

34

A review on helium mobility in inorganic materials  

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

35

Functionalized inorganic membranes for gas separation  

DOEpatents

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.

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

36

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

PubMed

Owing to their physical and chemical properties, inorganic functional materials have tremendous impacts on key technologies such as energy generation and storage, information, medicine, and automotive engineering. Nature, on the other hand, provides evolution-optimized processes, which lead to multifunctional inorganic-bio-organic materials with complex structures. Their formation occurs under physiological conditions, and is goverened by a combination of highly regulated biological processes and intrinsic chemical properties. Nevertheless, insights into the molecular mechanisms of biomineralization open up promising perspectives for bioinspired and biomimetic design and the development of inorganic-bio-organic multifunctional hybrids. Therefore, biomimetic approaches may disclose new synthetic routes under ambient conditions by integrating the concept of gene-regulated biomineralization principles. The skeletal structures of marine sponges provide an interesting example of biosilicification via enzymatically controlled and gene-regulated silica metabolism. Spicule formation is initiated intracellularly by a fine-tuned genetic mechanism, which involves silica deposition in vesicles (silicassomes) under the control of the enzyme silicatein, which has both catalytic and templating functions. In this review, we place an emphasis on the fabrication of biologically inspired materials with silicatein as a biocatalyst. PMID:22510103

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

2012-05-01

37

Organic-inorganic hybrid materials: perfluorinated ionomers as sol-gel polymerization templates for inorganic alkoxides  

Microsoft Academic Search

Mauritz et al. exploited the polar\\/nonpolar nanophase-separated morphologies of Nafion® perfluorinated ionomer membranes, as well as a Nafion® ionomeric precursor film, as interactive templates that are capable of directing the condensation polymerizations of inorganic alkoxides and organoalkoxysilanes as well as the ultimate geometrical distribution of the inorganic oxide, or organically modified silicon oxide phases that result upon drying. This paper

Kenneth A. Mauritz

1998-01-01

38

Dense organic-inorganic framework materials containing transition metal ions  

NASA Astrophysics Data System (ADS)

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.

Feller, Russell Kenneth

2008-10-01

39

UTILIZATION OF METALLURGICAL SOLID BY-PRODUCTS FOR THE DEVELOPMENT OF INORGANIC POLYMERIC CONSTRUCTION MATERIALS  

Microsoft Academic Search

This paper deals with the geopolymerization of the red mud generated in the primary aluminium production and the slag generated in the ferronickel production, in order to develop inorganic polymeric materials with advanced mechanical and physical properties. In particular, the effect of the main synthesis parameters of the inorganic polymeric materials on their mechanical strength and water absorption was investigated.

I. GIANNOPOULOU; D. DIMAS; I. MARAGKOS; D. PANIAS

40

Regeneration of mesoporous inorganic materials using ordered mesoporous carbon as the template  

Microsoft Academic Search

Regeneration of mesoporous inorganic materials from ordered mesoporous carbons has been successfully performed in the present work. A mesoporous silica SBA-15 are used as a template for the synthesis of the mesoporous carbon CMK-3. Subsequently, mesoporous inorganic replica materials can be obtained from the mesoporous carbon. This synthetic principle is very useful for the preparation of various kinds of the

Ji Man Kirn; Min Kang; Seung Hwan Yi; Jae Eui Yie; Sang Hoon Joo; Ryong Ryoo

2003-01-01

41

A review of nitrate reduction using inorganic materials  

Microsoft Academic Search

In a biological denitrification system for water and wastewater treatment, an external carbon source (electron donor) is usually needed to generate dedicated microbial communities if intrinsic organic substances are insufficient. Alternative sources of electron donors, especially inorganic donors, are becoming more and more attractive in order to replace or reduce carbon use. In this article, inorganic electron donors, i.e. zero-valent

Ivan Zhu

2012-01-01

42

Inorganic-organic electrolyte materials for energy applications  

NASA Astrophysics Data System (ADS)

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

Fei, Shih-To

43

Interfacial and transport properties of nanoconstrained inorganic and organic materials  

NASA Astrophysics Data System (ADS)

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.

Kocherlakota, Lakshmi Suhasini

44

Synthesis and applications of bioinspired inorganic nanostructured materials  

NASA Astrophysics Data System (ADS)

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

Bassett, David C.

2011-12-01

45

Processing and optimization of functional ceramic coatings and inorganic nanomaterials  

NASA Astrophysics Data System (ADS)

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 (500-600 °C) temperature oxidation protection. Chemical vapor deposition (CVD/MOCVD) techniques will be utilized to deposit the metal suicide and oxide coatings. The focus of this study will be to establish optimum deposition conditions and evaluate the metal oxide coating as oxidation - thermal barriers for Mo substrates under both isothermal (static) and cyclic oxidation conditions. The second part of this section will involve a systematic evaluation of a boron nitride (BN) interface coating prepared by chemical vapor deposition. Ceramic matrix composites (CMCs) are prospective candidates for high (>1000 °C) temperature applications and fiber- matrix interfaces are the dominant design parameters in ceramic matrix composites (CMCs). An important goal of the study is to determine a set of process parameters, which would define a boron nitride (BN) interface coating by a chemical vapor deposition (CVD) process with respect to coating. In the first part of the second section, we will investigate a new approach to synthesize ultrafine metal oxides that combines microwave heating and an in-situ ultrasonic mixing of two or more liquid precursors with a tubular flow reactor. Different metal oxides such as nickel ferrite and zinc aluminate spinels will be studied. The synthesis of metal oxides were investigated in order to study the effects of the nozzle and microwave (INM process) on the purity, composition, and particle size of the resulting powders. The second part of this research section involves a study of microwave frequency effects on the synthesis of nanocrystalline tetragonal barium titanate. The effects of microwave frequency (fixed and variable), microwave bandwidths sweep time, and aging time on the microstructure, particle sizes, phase purity, surface areas, and porosities of the as-prepared BaTiO3 were systematically investigated. The final part of the research involves a new rapid and facile synthetic route to prepare size-tunable, ultranarrow, high surface area OMS-2 nanomaterials via open-vessel microwave-assisted refluxing preparations without employing templates or surfactants. The particle size control is achieved by varying the concentration or type of non-aqueous co-solvent. The structural, textural, and catalytic application properties of the prepared nanomaterials are investigated.

Nyutu, Edward Kennedy G.

46

Inorganic arsenic impairs differentiation and functions of human dendritic cells  

SciTech Connect

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.

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

47

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

PubMed

In this article, three different inorganic/organic doped carbon aerogel (CA) materials (Ni-CA, Pd-CA, and Ppy-CA) were, respectively, mixed with ionic liquid (IL) to form three stable composite films, which were used as enhanced elements for an integrated sensing platform to increase the surface area and to improve the electronic transmission rate. Subsequently, the effect of the materials performances such as adsorption, specific surface area and conductivity on electrochemistry for myoglobin (Mb) was discussed using N2 adsorption-desorption isotherm measurements, scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). Moreover, they could act as sensors toward the detection of hydrogen peroxide (H2O2) with lower detection limits (1.68 ?M, 1.02 ?M, and 0.85 ?M, for Ni-CA/IL/Mb-CPE, Pd-CA/IL/Mb-CPE, and Ppy-CA/IL/Mb-CPE, respectively) and smaller apparent Michaelis-Menten constants KM. The results indicated that the electroconductibility of the doped CA materials would become dominant, thus playing an important role in facilitating the electron transfer. Meanwhile, the synergetic effect with [BMIm]BF4 IL improved the capability of the composite inorganic/organic doped CA/IL matrix for protein immobilization. This work demonstrates the feasibility and the potential of a series of CA-based hybrid materials as biosensors, and further research and development are required to prepare other functional CAs and make them valuable for more extensive application in biosensing. PMID:24279516

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

2013-12-17

48

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

PubMed Central

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

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

2014-01-01

49

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

NASA Astrophysics Data System (ADS)

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

Manavbasi, Alp

50

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

PubMed

Conspectus The ultimate goal of solid state chemistry is to gain a clear correlation between atomic, defect, and electronic structure and intrinsic properties of solid state materials. Solid materials can generally be classified as amorphous, quasicrystalline, and crystalline based on their atomic arrangement, in which crystalline materials can be further divided into single crystals, microcrystals, and nanocrystals. Conventional solid state chemistry mainly focuses on studying single crystals and microcrystals, while recently nanocrystals have become a hot research topic in the field of solid state chemistry. As more and more nanocrystalline materials have been artificially fabricated, the solid state chemistry for studying those nanosolids has become a new subdiscipline: solid state nanochemistry. However, solid state nanochemistry, usually called "nanochemistry" for short, primarily studies the microstructures and macroscopic properties of a nanomaterial's aggregation states. Due to abundant microstructures in the aggregation states, it is only possible to build a simple but imprecise correlation between the microscopic morphology and the macroscopic properties of the nanostructures. Notably, atomically thin two-dimensional inorganic materials provide an ideal platform to establish clear structure-property relationships in the field of solid state nanochemistry, thanks to their homogeneous dispersion without the assistance of a capping ligand. In addition, their atomic structures including coordination number, bond length, and disorder degree of the examined atoms can be clearly disclosed by X-ray absorption fine structure spectroscopy. Also, their more exposed interior atoms would inevitably induce the formation of various defects, which would have a non-negligible effect on their physicochemical properties. Based on the obtained atomic and defect structural characteristics, density-functional calculations are performed to study their electronic structures. Then, after the properties of the individual ultrathin two-dimensional materials or their assembled highly oriented thin film-based nanodevices are measured, the explicit relationship between atomic, defect, and electronic structure and intrinsic properties could be established. In this Account, we focus on our recent advances in the field of solid state nanochemistry, including atomic structure characterization of ultrathin two-dimensional inorganic materials by X-ray absorption fine structure spectroscopy, characterization of their different types of structural defects by positron annihilation spectra and electron spin resonance, and investigation of their electronic structure by density-functional calculations. In addition, we summarize the close correlation between atomic, defect, and electronic structure variations and the optoelectronic, electrical, magnetic, and thermal properties of ultrathin two-dimensional materials. Finally, we also propose the major challenges and opportunities that face solid state nanochemistry. We believe that all the past achievements in ultrathin two-dimensional materials could bring new opportunities for solid state nanochemistry. PMID:25489751

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

2015-01-20

51

Transition Metal Chalcogenides: Ultrathin Inorganic Materials with Tunable Electronic Properties.  

PubMed

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

Heine, Thomas

2014-12-01

52

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

NASA Technical Reports Server (NTRS)

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

Lee, S. M.

1979-01-01

53

Thermal/chemical degradation of inorganic membrane materials  

SciTech Connect

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

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

1993-09-01

54

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

SciTech Connect

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.

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

2008-10-06

55

Solution Phase Routes to Functional Nanostructured Materials for Energy Applications  

E-print Network

J. New Organic-Inorganic Perovskite Materials with Differentnanowires from hybrid-perovskite materials. The materialsPerovskite Semiconductors in Porous Templates Introduction Layered organic-inorganic hybrid perovskites represent a unique class of materials

Rauda, Iris Ester

2012-01-01

56

Development of inorganic resists for electron beam lithography: Novel materials and simulations  

NASA Astrophysics Data System (ADS)

Electron beam lithography is gaining widespread utilization as the semiconductor industry progresses towards both advanced optical and non-optical lithographic technologies for high resolution patterning. The current resist technologies are based on organic systems that are imaged most commonly through chain scission, networking, or a chemically amplified polarity change in the material. Alternative resists based on inorganic systems were developed and characterized in this research for high resolution electron beam lithography and their interactions with incident electrons were investigated using Monte Carlo simulations. A novel inorganic resist imaging scheme was developed using metal-organic precursors which decompose to form metal oxides upon electron beam irradiation that can serve as inorganic hard masks for hybrid bilayer inorganic-organic imaging systems and also as directly patternable high resolution metal oxide structures. The electron beam imaging properties of these metal-organic materials were correlated to the precursor structure by studying effects such as interactions between high atomic number species and the incident electrons. Optimal single and multicomponent precursors were designed for utilization as viable inorganic resist materials for sub-50nm patterning in electron beam lithography. The electron beam imaging characteristics of the most widely used inorganic resist material, hydrogen silsesquioxane (HSQ), was also enhanced using a dual processing imaging approach with thermal curing as well as a sensitizer catalyzed imaging approach. The interaction between incident electrons and the high atomic number species contained in these inorganic resists was also studied using Monte Carlo simulations. The resolution attainable using inorganic systems as compared to organic systems can be greater for accelerating voltages greater than 50 keV due to minimized lateral scattering in the high density inorganic systems. The effects of loading nanoparticles in an electron beam resist was also investigated using a newly developed hybrid Monte Carlo approach that accounts for multiple components in a solid film. The resolution of the nanocomposite resist process was found to degrade with increasing nanoparticle loading. Finally, the electron beam patterning of self-assembled monolayers, which were found to primarily utilize backscattered electrons from the high atomic number substrate materials to form images, was also investigated and characterized. It was found that backscattered electrons limit the resolution attainable at low incident electron energies.

Jeyakumar, Augustin

57

Hybrid materials based on organic luminophores in inorganic glass matrix  

NASA Astrophysics Data System (ADS)

Hybrid materials were synthesized based on borate glass matrix and the tris(8-hydroxyquinoline) aluminum (Alq3) organic luminophore, which is used as a green luminophore in OLED devices. The luminescent properties of hybrid materials with 0.02-0.1 wt % of Alq3 in glass were studied. The luminescence peak of the hybrid material is significantly shifted to shorter wavelengths (443 nm versus 518 nm in pure Alq3 powder).

Petrova, O. B.; Avetisov, R. I.; Avetisov, I. Kh.; Mushkalo, O. A.; Khomyakov, A. V.; Cherednichenko, A. G.

2013-06-01

58

Structural control in the synthesis of inorganic porous materials  

NASA Astrophysics Data System (ADS)

Mesoporous (2.0--50.0 nm pore diameter) and macroporous (50.0 nm on up) materials have been the basis of my studies. These materials, for many years, possessed large pore size distributions. Recently, however, it has been possible to synthesize both mesoporous and macroporous materials that possess highly ordered uniform pores throughout the material. Workers at Mobil Corporation in 1992 discovered a hexagonally arrayed mesoporous material, designated MCM-41, which exhibited uniform pores ranging from 2.0--10.0 nm in diameter. In my work MCM-41 was used as a host for the incorporation of meso-tetrakis(5-trimethylammoniumpentyl)porphyrin (TMAP-Cl) and as a model for the synthesis of mesoporous alumino- and galloaluminophosphates which were created using cluster precursors of the type MO4Al 12(OH)24(H2O)12 7+, M = Al or Ga. Macroporous materials with uniform pore sizes have been synthesized by our group with frameworks consisting of a variety of metal oxides, metals, organosilanes, aluminophosphates and bimodal pores. These materials are synthesized from the addition of metal precursors to preordered polystyrene spheres. Removal of the spheres results in the formation of macropores with highly uniform pores extending microns in length. Porous materials with uniform and adjustable pore sizes in the mesoporous and macroporous size regimes offer distinct advantages over non-ordered materials for numerous reasons. First, catalysis reactions that are based on the ability of the porous materials to impose size and shape restrictions on the substrate are of considerable interest in the petroleum and petrochemical industries. As pore diameters increase larger molecules can be incorporated into the pores, i.e., biological molecules, dyes, etc. For the macroporous materials synthesized by our group it has been envisioned that these structures may not only be used for catalysis because of increased efficiencies of flow but for more advanced applications, e.g., photonic crystals, porous electrodes, electrochemical capacitors, etc. One of the more interesting macroporous materials takes advantage of having silicalite as the framework. This bimodal pore material may find use as an acid catalyst as aluminum is doped into the framework.

Holland, Brian Thomas

59

Inorganic Materials as Ameliorants for Soil Remediation of Metal Toxicity to Wild Mustard (Sinapis arvensis L.)  

Microsoft Academic Search

The ameliorating effects of different inorganic materials were investigated on a soil originating from a zinc smelter dumping site contaminated by toxic metals. Wild mustard (Sinapis arvensis L.) was used as a test plant. The soil was amended with different doses of mining sludge, Perferric Red Latosol (LVj), steel shots, cyclonic ash, silifertil, and superphosphate. The most effective amendments improved

Mateus Rosas Ribeiro Filho; José Oswaldo Siqueira; Jaco Vangronsveld; Cláudio Roberto Fonsêca Sousa Soares; Nilton Curi

2011-01-01

60

Comparison of organic and inorganic packing materials in the removal of ammonia gas in biofilters  

Microsoft Academic Search

Two organic and two inorganic packing materials were compared with regard to the removal of ammonia gas in a biofilter inoculated with night-soil sludge. By gradually increasing the inlet load of ammonia, the complete removal capacity, which was defined as the inlet load of ammonia that was completely removed, and the maximum removal capacity of ammonia, which was the value

Nam-Jin Kim; Mitsuyo Hirai; Makoto Shoda

2000-01-01

61

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

PubMed Central

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

2010-01-01

62

Integrative self-assembly of functional hybrid nanoconstructs by inorganic wrapping of single biomolecules, biomolecule arrays and organic supramolecular assemblies  

NASA Astrophysics Data System (ADS)

Synthesis of functional hybrid nanoscale objects has been a core focus of the rapidly progressing field of nanomaterials science. In particular, there has been significant interest in the integration of evolutionally optimized biological systems such as proteins, DNA, virus particles and cells with functional inorganic building blocks to construct mesoscopic architectures and nanostructured materials. However, in many cases the fragile nature of the biomolecules seriously constrains their potential applications. As a consequence, there is an on-going quest for the development of novel strategies to modulate the thermal and chemical stabilities, and performance of biomolecules under adverse conditions. This feature article highlights new methods of ``inorganic molecular wrapping'' of single or multiple protein molecules, individual double-stranded DNA helices, lipid bilayer vesicles and self-assembled organic dye superstructures using inorganic building blocks to produce bio-inorganic nanoconstructs with core-shell type structures. We show that spatial isolation of the functional biological nanostructures as ``armour-plated'' enzyme molecules or polynucleotide strands not only maintains their intact structure and biochemical properties, but also enables the fabrication of novel hybrid nanomaterials for potential applications in diverse areas of bionanotechnology.

Patil, Avinash J.; Li, Mei; Mann, Stephen

2013-07-01

63

Mechanical properties of hybrid inorganic-organic framework materials: establishing fundamental structure-property relationships.  

PubMed

The mechanical properties of hybrid framework materials, including both nanoporous metal-organic frameworks (MOFs) and dense inorganic-organic frameworks, are discussed in this critical review. Although there are relatively few studies of this kind in the literature, major recent advances in this area are beginning to shed light on the fundamental structure-mechanical property relationships. Indeed research into the mechanical behavior of this important new class of solid-state materials is central to the design and optimal performance of a multitude of technological applications envisaged. In this review, we examine the elasticity of hybrid frameworks by considering their Young's modulus, Poisson's ratio, bulk modulus and shear modulus. This is followed by discussions of their hardness, plasticity, yield strength and fracture behavior. Our focus is on both experimental and computational approaches. Experimental work on single crystals and amorphized monoliths involved primarily the application of nanoindentation and atomic force microscopy to determine the elastic moduli and hardness properties. The compressibility and bulk moduli of single crystals and polycrystalline powders were studied by high-pressure X-ray crystallography in the diamond anvil cell, while in one instance spectroscopic ellipsometry has also been used to estimate the elastic moduli of MOF nanoparticles and deposited films. Theoretical studies, on the other hand, encompassed the application of first principles density-functional calculations and finite-temperature molecular dynamics simulations. Finally, by virtue of the diverse mechanical properties achievable in hybrid framework materials, we propose that a new domain be established in the materials selection map to define this emerging class of materials (137 references). PMID:21221446

Tan, Jin Chong; Cheetham, Anthony K

2011-02-01

64

Biomimetic materials: recent developments in organic-inorganic hybrids  

Microsoft Academic Search

There are a variety of biological materials that are composites of ceramics and organic phases, and successfully combine impressive toughness with high modulus and strength. This behavior is in contrast to the general situation with synthetic composites, where toughness is generally found to decrease with increase in modulus and tensile strength. Preserving toughness is very important in many applications, as

Z. Ahmad; J. E. Mark

1998-01-01

65

Radiation induced EPR centers in foodstuffs and inorganic materials.  

PubMed

EPR investigations of a variety of irradiated materials have provided the potential for useful dosimetry applications. Herbs and spices imported into Australia have been investigated to establish whether or not they have been irradiated. Post-irradiation studies have shown that there is more than one free radical species in most cases which decay rapidly with time. Changes to transition metal ion signals, e.g., Cu2+ or Fe3+, appear to be permanent against further irradiation. Thus if these signals change upon irradiation, the material almost certainly has not previously been irradiated. Power saturation studies of alanine, a favored dosimetry material, suggest two distinguishable types of behavior consistent with the presence of spin-flip transitions. Irradiation of vanadium doped beryl yields stable VO2+ ions which may provide a useful dosimetry material. Dosimetry applications would appear to demand low cost, user friendly, automated EPR spectrometers. A patented option based on a 2.5 GHz microstrip microwave bridge will be described briefly. PMID:8386046

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

1993-01-01

66

Replication of micro-optical elements in hybrid organic-inorganic materials  

NASA Astrophysics Data System (ADS)

In this paper, a detailed study of replication of microlenses by UV-assisted moulding in hybrid glass materials is presented. Circular aspherical, spherical and cylindrical microlenses were designed and fabricated in photoresist by using the grey-scale lithography based on high-energy beam sensitive glass. A semi-transparent replication master was then generated. Hybrid organic-inorganic resins were synthesized by sol-gel processing of functionalized alkoxysilanes. The resin viscosity and refractive index depended on synthesis conditions. Transparent, well adhering, several tens of microns-thick films were deposited on fused silica substrates by adjusting the solvent content of the formulation. The thermal expansion coefficient of our material, determined by a Michelson interferometric technique was 1.75 10-4 K-1. High replication fidelity e. g. better than 5% is demonstrated by controlling changes, at the various process steps, in the radius of curvature i.e. focal lengths of microlenses performing the measurements with a Twyman-Green interferometer. Close to diffraction limited microlenses with f-numbers ranging from f/1.4 to f/10 were fabricated.

Topart, Patrice A.; Beaulieu, Rene M.; Leclair, Sebastien; Poirier, Michel; Pelletier, Jeremy; Bernier, M.; Jerominek, Hubert

2003-01-01

67

Treeing Breakdown in Inorganic-filler\\/LDPE Nanocomposite Material  

Microsoft Academic Search

A nano-composite material of magnesium oxide (MgO) added to a low-density polyethylene (LDPE) was subjected to electrical tree breakdown investigation. The LDPE without nano-fillers was lower in breakdown voltage than the LDPE added with nano-fillers. The breakdown voltage was increased by increase of nano-filler concentrations in LDPE. This result much coincided with the result on tree inception voltage which was

Rudi Kurnianto; Yoshinobu Murakami; Masayuki Nagao; Naohiro Hozumi; Yoshinao Murata

2007-01-01

68

Inorganic chemical analysis of environmental materials—A lecture series  

USGS Publications Warehouse

At the request of the faculty of the Colorado School of Mines, Golden, Colorado, the authors prepared and presented a lecture series to the students of a graduate level advanced instrumental analysis class. The slides and text presented in this report are a compilation and condensation of this series of lectures. The purpose of this report is to present the slides and notes and to emphasize the thought processes that should be used by a scientist submitting samples for analyses in order to procure analytical data to answer a research question. First and foremost, the analytical data generated can be no better than the samples submitted. The questions to be answered must first be well defined and the appropriate samples collected from the population that will answer the question. The proper methods of analysis, including proper sample preparation and digestion techniques, must then be applied. Care must be taken to achieve the required limits of detection of the critical analytes to yield detectable analyte concentration (above "action" levels) for the majority of the study's samples and to address what portion of those analytes answer the research question-total or partial concentrations. To guarantee a robust analytical result that answers the research question(s), a well-defined quality assurance and quality control (QA/QC) plan must be employed. This QA/QC plan must include the collection and analysis of field and laboratory blanks, sample duplicates, and matrix-matched standard reference materials (SRMs). The proper SRMs may include in-house materials and/or a selection of widely available commercial materials. A discussion of the preparation and applicability of in-house reference materials is also presented. Only when all these analytical issues are sufficiently addressed can the research questions be answered with known certainty.

Crock, J.G.; Lamothe, P.J.

2011-01-01

69

Observing assembly of complex inorganic materials from polyoxometalate building blocks.  

PubMed

Understanding the aqueous state of discrete metal-oxo clusters, prenucleation clusters, and even simple ions is valuable for controlling the growth of metal-oxide materials from water. Niobium polyoxometalates (Nb-POMs) are unique in the aqueous metal-oxo cluster landscape in their unusual solubility behavior: specifically, their solubility in water increases with increasing ion-pairing contact with their counterions, and thus provides a rare opportunity to observe these and related solution phenomena. Here, we isolate in the solid state the monomeric and dimeric building blocks, capped Keggin ions, of the extended Keggin chain materials that are now well-known: not only in Nb-POM chemistry, but Mo and V POM chemistry as well. Rb13[GeNb13O41]·23H2O (Rb1), Cs10.6[H2.4GeNb13O41]·27H2O (Cs1) and Cs18H6[(NbOH)SiNb12O40]2·38H2O (Cs2) were characterized by single-crystal X-ray diffraction. Small angle X-ray scattering (SAXS) of solutions of Rb1 and Cs1 in varying conditions revealed oligomerization of the monomers into chain structures: the extent of oligomerization is controlled by pH, concentration, and the counterion. We distinctly observe chains of up to six Keggin ions in solution, with the large alkali cations for charge-balance. This combined solid state and solution study reveals in great detail the growth of a complex material from discrete monomeric building blocks. The fundamentals of the processes we are able to directly observe in this study, ion-association and hydrolysis leading to condensation, universally control the self-assembly and precipitation of materials from water. PMID:24116690

Hou, Yu; Zakharov, Lev N; Nyman, May

2013-11-01

70

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

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

71

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

SciTech Connect

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

Baxter, L.L. [Sandia National Labs., Livermore, CA (United States); Jenkins, B.M. [California Univ., Davis, CA (United States). Dept. of Biological and Argicultural Engineering

1995-08-01

72

Nanostructured inorganic materials: Synthesis and associated electrochemical properties  

NASA Astrophysics Data System (ADS)

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.

Yau, Shali Zhu

73

Electrodeposition of inorganic materials with tailored shapes and chiral morphologies  

NASA Astrophysics Data System (ADS)

This dissertation investigates the electrodeposition of metal oxide films and biomaterial deposits on polycrystalline and single crystal substrates. Paper I describes the mechanisms and the characterization of an electrodeposited polycrystalline insulator, ceria (CeO2), on Hastelloy substrates produced by the electrochemical oxidation of Ce(III) acetate complexes. In Paper II, epitaxial films of magnetite (Fe3O4) and fenihydrite (Fe10O14(OH)2) are deposited on gold single crystals. Paper III reports the electrodeposition of epitaxial e3O 4 and zinc ferrite (ZnFe2O4) periodic nanostructures known as superlattices by pulsing between two potentials. Papers IV and V describe chiral electrodeposition. In Paper IV, epitaxial, chiral orientations of cupric oxide (CuO) are electrodeposited on Au(00l) single crystals. In Paper V, chiral morphologies of the biomaterial calcite (CaCO3) are electrochemically deposited on stainless steel substrates. In both chiral electrodeposition studies, the chirality of these materials is controlled by the enantiomer in solution. The first two appendices of this dissertation cover morphology and x-ray diffraction characterization. The third appendix has supplementary information from the calcite paper (Paper V) followed by unpublished biomineralization results.

Kulp, Elizabeth Ann

74

The functionalization of metallic and semiconductor surfaces with organic and inorganic species  

NASA Astrophysics Data System (ADS)

The discipline of surface chemistry has rapidly expanded within recent years, attaining richness and diversity not unlike the more traditional divisions of organic, inorganic, physical, and biological chemistries. The boundless human drive to better understand the natural order as well as to better improve the existence of mankind has not ignored the physical, material, and chemical activities of interfaces, but rather the opposite. As computers shrink to ever-smaller sizes while growing in complexity---as devices and machines diminish to near-inconceivable dimensions---as the agents of technology miniaturize to comply with the endless demands of more-for-less---the chemistry of surfaces will continue to fulfill a crucial part in the advancement of new industries. This thesis details work into three realms of surface chemistry. Chapter One introduces porous silicon and presents a background of this unique, nanocrystalline substance. Described particularly is a new surface reaction to functionalize this material with organic groups; named carbocation-mediated hydrosilylation, this chemical treatment yields substrates derivatized with silicon-carbon bonds, the optimal surface group for imparting stability and functionality to the easily corroded, chemically limited material. Chapter Two discusses the electroless deposition of noble metal particles upon a number of metal and semiconductor surfaces. These reactions require neither external reducing agents nor electrical current to accomplish the formation of metal films, exciting and essential not merely from the fundamental perspectives of surface researches, but also from the aspects of fabricating micro- and nanoscale devices via controlled and patterned metallization reactions. Chapter Three returns to porous silicon and discusses attempts to covalently functionalize the material surface with thiolate-encapsulated gold nanoparticles; such surface-bound species may be useful for sensing, composite materials, and a myriad of other utilities.

Schmeltzer, Jason M.

75

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

PubMed

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

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

2014-03-01

76

Structure and function of an inorganic-organic separator for electrochemical cells: Preliminary study  

NASA Technical Reports Server (NTRS)

The structure of a new separator material for electrochemical cells has been investigated. Investigation into details of the separator structure showed it to be multilayered and to consist mainly of a quasi-impervious organic skin, a porous region of mixed organic and inorganic material, and an area of nonuniformly treated substrate. The essential feature of the coating (slurry) is believed to be interconnected pores which allow ionic conductivity. The interconnected pores are believed to be formed by the interaction of the plasticizer and inorganic fibers. The major failure mode of silver zinc cells using such a separator (zinc nodules shorting adjacent plates) was investigated.

Bozek, J. M.

1974-01-01

77

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

NASA Astrophysics Data System (ADS)

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.

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

2013-01-01

78

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

PubMed

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

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

2001-01-01

79

Investigation of electrical phenomena of inorganic-filler\\/LDPE nanocomposite material  

Microsoft Academic Search

A nanocomposite material, composed of nano-size inorganic-filler added to a low-density polyethylene (LDPE), was subjected to electrical property investigations. The volume resistibility of LDPE, under 80 kV\\/mm DC field at 90 C, increases by the power of 10 due to the addition of only a few percent of nano-filler. On the other hand, lightning impulse breakdown strength was estimated by

Y. Murata; Y. Sekiguchi; Y. Inoue; M. Kanaoka

2005-01-01

80

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

Microsoft Academic Search

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

Jian Luo

2007-01-01

81

Applications of Solid-State NMR to the Study of Organic\\/Inorganic Multicomponent Materials  

Microsoft Academic Search

The characterization of a variety of organic\\/inorganic multicomponent materials (OIMM) through solid-state NMR (SSNMR) spectroscopy will be reviewed. Many examples of applications to OIMM will be described, based on the observation of different nuclei and the use of various SSNMR methods, such as 1D and 2D techniques, measurements on relaxation and spin diffusion processes. OIMM are a very general category

Marco Geppi; Silvia Borsacchi; Giulia Mollica; Carlo Alberto Veracini

2009-01-01

82

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

NASA Astrophysics Data System (ADS)

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

Varotto, Alessandro

83

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

NASA Technical Reports Server (NTRS)

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

1987-01-01

84

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

PubMed

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

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

2001-01-01

85

Design of Bioactive Organic-inorganic Hybrid Materials with Self-setting Ability  

NASA Astrophysics Data System (ADS)

Paste-like materials with ability of self-setting are attractive for bone substitutes, since they can be injected from the small hole with minimized invasion to the patient. Although bone cements which set as apatite are clinically used, there is limitation on clinical applications due to their mechanical properties such as high brittleness and low fracture toughness. To overcome this problem, organic-inorganic hybrids based on a flexible polymer are attractive. We have obtained an idea for design of self-setting hybrids using polyion complex fabricated by ionic interaction of anionic and cationic polymers. We aimed at preparation of organic-inorganic hybrids exhibiting self-setting ability and bioactivity. The liquid component was prepared from cationic chitosan aqueous solution. The powder component was prepared by mixing various carrageenans with ?-tricalcium phosphate (?-TCP). The obtained cements set within 1 day. Compressive strength showed tendency to increase with increase in ?-TCP content in the powder component. The prepared cements formed the apatite in simulated body fluid within 3 days. Novel self-setting materials based on organic-inorganic hybrid can be designed utilizing ionic interaction of polysaccharide.

Miyazaki, T.; Machida, S.; Morita, Y.; Ishida, E.

2011-10-01

86

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

PubMed

As heavy metal ions severely harm human health, it is important to develop simple, sensitive and accurate methods for their detection in environment and food. Electrochemical detection featured with short analytical time, low power cost, high sensitivity and easy adaptability for in-situ measurement is one of the most developed methods. This review introduces briefly the recent achievements in electrochemical sensing of heavy metal ions with inorganic, organic and bio-materials modified electrodes. In particular, the unique properties of inorganic nanomaterials, organic small molecules or their polymers, enzymes and nucleic acids for detection of heavy metal ions are highlighted. By employing some representative examples, the design and sensing mechanisms of these electrodes are discussed. PMID:25108108

Cui, Lin; Wu, Jie; Ju, Huangxian

2015-01-15

87

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

E-print Network

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, ...

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

2012-01-01

88

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

NASA Astrophysics Data System (ADS)

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.

Euliss, Larken E.

89

Nano-Ablation of Inorganic Materials Using Laser Plasma Soft X-rays at around 10 nm  

Microsoft Academic Search

We have investigated the direct nanomachining of inorganic materials using laser plasma soft X-rays (LPSXs). LPSXs were generated by the irradiation of Ta targets with Q-switched 532 nm Nd:YAG laser light at an energy density of ˜104 J\\/cm2. Under this condition, Ta plasma emits soft X-rays at around 10 nm. The LPSXs were focused on the surfaces of inorganic materials,

Tetsuya Makimura; Hisao Miyamoto; Satoshi Uchida; Takashige Fujimori; Hiroyuki Niino; Kouichi Murakami

2006-01-01

90

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

PubMed

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

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

2013-01-01

91

An hybrid organic inorganic approach to erbium-functionalized nanodots for emission in the telecom window  

NASA Astrophysics Data System (ADS)

A new class of hybrid materials for efficient laser emission and amplification in the 1.55 ?m eye-safe telecommunication window has been designed, elaborated and characterized, based on lanthanide-doped yttrium oxide nanoparticle guests embedded in a polymer host matrix. The average size of these nanocrystals can be finely tuned by controlling the relative quantities of an organic fuel (glycine) with respect to the yttrium- and lanthanide-containing reactants involved in the combustion reaction leading to nanoparticle synthesis. Two complementary sensitizers have been added to Er/Y 2O 3 nanocrystals in order to improve the Erbium luminescence efficiency: cerium to increase population inversion between the emitting and the ground state by accelerating the de-excitation process from the 4I 11/2 initially uppermost excited state at 980 nm down to 4I 13/2 state emitting around 1.55 ?m, and ytterbium to improve the pumping efficiency of the material owing to its strong absorption cross section at 980 nm and subsequent efficient energy transfer towards the 4I 11/2 state of erbium ion. Y 2O 3 nanoparticles with an optimized erbium-ytterbium composition have been incorporated in a PMMA polymer matrix, resulting in a hybrid amorphous material displaying high gain coefficient values (up to 30 cm -1 as from Amplified Spontaneous Emission experiments) upon moderate 980 nm pumping intensities. These materials open attractive perspectives in the domain of polymer-based telecom amplifiers, with the additional asset of multifunctional properties whereby gain originating from the inorganic Y 2O 3 nanocrystals can be associated to nonlinear responses attached to an adequately functionalized polymer host matrix.

Le Quang, A. Q.; Zyss, J.; Ledoux, I.; Truong, V. G.; Jurdyc, A.-M.; Jacquier, B.; Le, D. H.; Gibaud, A.

2005-11-01

92

Surface Functionalization of Graphene-based Materials  

NASA Astrophysics Data System (ADS)

Graphene-based materials have generated tremendous interest in the past decade. Manipulating their characteristics using wet-chemistry methods holds distinctive value, as it provides a means towards scaling up, while not being limited by yield. The majority of this thesis focuses on the surface functionalization of graphene oxide (GO), which has drawn tremendous attention as a tunable precursor due to its readily chemically manipulable surface and richly functionalized basal plane. Firstly, a room-temperature based method is presented to reduce GO stepwise, with each organic moiety being removed sequentially. Characterization confirms the carbonyl group to be reduced first, while the tertiary alcohol is reduced last, as the optical gap decrease from 3.5 eV down to 1 eV. This provides greater control over GO, which is an inhomogeneous system, and is the first study to elucidate the order of removal of each functional group. In addition to organically manipulating GO, this thesis also reports a chemical methodology to inorganically functionalize GO and tune its wetting characteristics. A chemical method to covalently attach fluorine atoms in the form of tertiary alkyl fluorides is reported, and confirmed by MAS 13C NMR, as two forms of fluorinated graphene oxide (FGO) with varying C/F and C/O ratios are synthesized. Introducing C-F bonds decreases the overall surface free energy, which drastically reduces GO's wetting behavior, especially in its highly fluorinated form. Ease of solution processing leads to development of sprayable inks that are deposited on a range of porous and nonporous surfaces to impart amphiphobicity. This is the first report that tunes the wetting characteristics of GO. Lastly as a part of a collaboration with ConocoPhillips, another class of carbon nanomaterials - carbon nanotubes (CNTs), have been inorganically functionalized to repel 30 wt% MEA, a critical solvent in CO 2 recovery. In addition to improving the solution processability of CNTs, composite, homogeneous solutions are created with polysulfones and polyimides to fabricate CNT-polymer nanocomposites that display contact angles greater than 150o with 30 wt% MEA. This yields materials that are inherently supersolvophobic, instead of simply surface treating polymeric films, while the low density of fluorinated CNTs makes them a better alternative to superhydrophobic polymer materials.

Mathkar, Akshay

93

Inorganically functionalized PbS-CdS colloidal nanocrystals: integration into amorphous chalcogenide glass and luminescent properties.  

PubMed

Inorganic semiconductor nanocrystals (NCs) with bright, stable, and wavelength-tunable luminescence are very promising emitters for various photonic and optoelectronic applications. Recently developed strategies for inorganic surface capping of colloidal NCs using metal chalcogenide complexes have opened new perspectives for their applications. Here we report an all-inorganic surface functionalization of highly luminescent IR-emitting PbS-CdS NCs and studies of their luminescence properties. We show that inorganic capping allows simple low-temperature encapsulation of inorganic NCs into a solution-cast IR-transparent amorphous As(2)S(3) matrix. The resulting all-inorganic thin films feature stable IR luminescence in the telecommunication wavelength region. The high optical dielectric constant of As(2)S(3) also helps reduce the dielectric screening of the radiating field inside the quantum dot, enabling fast radiative recombination in PbS-CdS NCs. PMID:22239647

Kovalenko, Maksym V; Schaller, Richard D; Jarzab, Dorota; Loi, Maria A; Talapin, Dmitri V

2012-02-01

94

Hydrophilic solid-phase extraction of melamine with ampholine-modified hybrid organic-inorganic silica material.  

PubMed

In this work, an ampholine-functionalized hybrid organic-inorganic silica sorbent was successfully used to extract melamine from a milk formula sample by a hydrophilic interaction solid-phase extraction protocol. Primary factors affecting the extraction efficiency of the material such as extraction solvent, elution solvent, sample loading volume, and elution volume have been thoroughly optimized. Under the optimized hydrophilic solid-phase extraction conditions, the recoveries of melamine spiked in milk formula samples ranged from 86.2 to 101.8% with relative standard deviations of 4.1-9.4% (n = 3). The limit of detection (S/N = 3) was 0.32 ?g/g. The adsorption capacity toward melamine was 30 ?g of melamine per grams of sorbent. Due to its simplicity, rapidity and cost effectiveness, the newly developed hydrophilic solid-phase extraction method should provide a promising tool for daily monitoring of doped melamine in milk formula. PMID:25330461

Wang, Tingting; Zhu, Yiming; Ma, Junfeng; Xuan, Rongrong; Gao, Haoqi; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

2015-01-01

95

Nanocrystal-Based Polymer Composites as Novel Functional Materials  

Microsoft Academic Search

\\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

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

96

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

PubMed Central

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

2012-01-01

97

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

NASA Astrophysics Data System (ADS)

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

Bu?ko, Aleksandra; Zieli?ska, Sonia; Ortyl, Ewelina; Larkowska, Maria; Barille, Regis

2014-12-01

98

Nanocomposites of phosphonic-Acid-functionalized polyethylenes with inorganic quantum dots.  

PubMed

Insertion of diethyl vinyl phosphonates and free vinyl phosphonic acid, respectively, into [(P^O)Pd(Me)(dmso)] ((P^O) =?(2) -P,O-Ar2 PC6 H4 SO2 O with Ar = 2-MeOC6 H4 ) (1-dmso) occurs in a 2,1- as well as 1,2-fashion, to form a four-and a five-membered chelate [(P^O)Pd{?(2) -C,O-CH(P(O)(OR)2 )CH2 CH3 }] and [(P^O)Pd{?(2) -C,O-CH2 CH(P(O)(OR)2 )CH3 }] (R = H, Et). No decomposition or other reactions of 1 by free phosphonic acid moieties occur. Copolymerization in a pressure reactor by 1-dmso yields linear random poly(ethylene-co-diethyl vinyl phosphonate) and poly(ethylene-co-vinyl phosphonic acid). In these copolymerizations, reversible coordination of the phosphonate moieties of free monomer as well as chelate formation by incorporated monomer retards chain growth as also evidenced by relative binding studies of diethyl phosphonate towards 1. Post-polymerization emulsification of poly(ethylene-co-vinyl phosphonic acid) together with CdSe/CdS quantum dots (QDs) yields submicron (ca. 50 nm from dynamic light scattering (DLS) and transmission electron microscopy (TEM)) polymer particles with the QDs embedded in the functionalized polyethylene in a nonaggregated fashion. This embedding benefits the fluorescence behavior in terms of continuous emission and life-time as revealed by wide-field fluorescence measurements. These composite particle dispersions are employed as a ?masterbatch" together with an aqueous high density polyethylene (HDPE) dispersion to generate thin films (by spin-coating) and bulk materials (from the melt), respectively, in which the inorganic nanoparticles remain highly disperse. PMID:25367370

Rünzi, Thomas; Baier, Moritz C; Negele, Carla; Krumova, Marina; Mecking, Stefan

2015-01-01

99

Conceptual study of in-tank cesium removal using an inorganic ion exchange material  

SciTech Connect

Presently, the Hanford Site contains approximately 230,000 m{sup 3} of mixed waste stored in 177 underground tanks. Approximately 55,000 m{sup 3} of this waste is sludge, 90,000 m{sup 3} is salt cake, and 80,000 m{sup 3} is supernate. Although the pretreatment and final disposal requirements for the waste have not been entirely defined, it is likely that some supernatant pretreatment will be required to remove {sup 137}Cs and possibly {sup 90}Sr and the transuranic components. The objective of this study was to estimate the number of HLW glass canisters resulting from the use of inorganic ion exchanger materials as in-tank pretreatment technology. The variables in the study were: number of contacts between waste and ion exchange material; ion exchange material; and decontamination requirement. This conceptual study investigates a generic in-tank Cs removal flowsheet using crystalline silico-titanates and IE-96 zeolites, and the impact of each ion exchanger on the number of glass canisters produced. In determining glass formulation, data based on current reference technology was used. Sample calculations from the worksheets and summaries of final calculated results are included at the end of this report.

Goheen, R.S.; Kurath, D.E.

1996-04-01

100

Muorganic/inorganic nanostructured materials: Towards synergistic mechanical and optical properties  

NASA Astrophysics Data System (ADS)

This study utilizes the "bricks" and "mortar" approach to assemble representative organic and inorganic nanostructures into functional hybrid nanomaterials. Zero-dimensional spherical nanoparticles, one-dimensional silver nanowires, and two-dimensional silver nanoplates represent the inorganic functional nanostructured "bricks". Functional-group bearing polystyrene2-polyethyleneoxide1 (PS2-PEO 1) star polymer, poly(allylamine hydrochloride), and poly(styrene sulfonate) were employed as the "mortar". Mechanical, optical, and electrical properties of the resulting organic/inorganic microstructures were investigated to establish structure-property relationships. Beyond the design, fabrication, and characterization of these novel hybrid nanomaterials two potential applications have been explored: (1) ultra-thin composite film-based pressure sensor and (2) single nanoparticle SERS-based chemical sensors. One-dimensional silver nanowires (diameter = 80 +/- 5 nm, length = 6 +/- 2 microm) were sandwiched into layer-by-layer (LbL) polyelectrolyte film to yield a series of robust freestanding ultrathin structures (< 100 nm thick). The sandwich architecture allows facile control over volume fraction of silver nanowires (2.5 ? ? ? 22.5%), and hence their composite Young's moduli. Furthermore, the composite film was found to be conductive (110--660 S/cm) within the range of volume fraction in par with percolation threshold predicted for a two-dimensional film. Subsequently, an array of silver nanowires was unidirectionally aligned by means of Langmuir-Blodgett (LB) technique. The unidirectionally oriented silver nanowires were sandwiched into LbL film to give an anisotropic nanocomposite film with much stiffer (fivefold) mechanical response in the direction of nanowire orientation. In addition to their tailored mechanical and electrical properties, these films are robust and can be easily transferred onto various microfabricated substrates. To fabricate these nanostructures, two experimental techniques were developed to characterize the micromechanical properties of the nanocomposite film and array of one-dimensional metallic nanostructures: interferometry of bulged film and buckling of array of highly-oriented nanowires, respectively. Next, using the same silver nanowire building block a different design of organic/inorganic hybrid nanostructures was explored. With the aid of a three-arm (X-PEO)1-(PS1-Y)2 star polymer linker, spherical gold nanoparticles were assembled onto a silver nanowire surface. We demonstrated that such hybrid, silver-gold nanowires resembling nanocobs, possess significant SERS ability and can serve as bright anisotropic SERS-markers for Raman-based chemical sensor. The influence of core nanostructure geometries (1-D silver nanowire versus 2-D silver nanoplates) were subsequently investigated for their single-nanoparticle hybrid SERS-enhancing ability and control over optical plasmon absorption within the visible and near infrared range. In the latter design, an improved design of SERS-nanostructure was explored by replacing the three-arm star polymer with polyelectrolyte "mortar" which can absorb chemical analytes into the intra-particle "hot-spots".

Gunawidjaja, Ray

101

New developments in the Inorganic Crystal Structure Database (ICSD): accessibility in support of materials research and design.  

PubMed

The materials community in both science and industry use crystallographic data models on a daily basis to visualize, explain and predict the behavior of chemicals and materials. Access to reliable information on the structure of crystalline materials helps researchers concentrate experimental work in directions that optimize the discovery process. The Inorganic Crystal Structure Database (ICSD) is a comprehensive collection of more than 60,000 crystal structure entries for inorganic materials and is produced cooperatively by Fachinformationszentrum Karlsruhe (FIZ), Germany, and the US National Institute of Standards and Technology (NIST). The ICSD is disseminated in computerized formats with scientific software tools to exploit the content of the database. Features of a new Windows-based graphical user interface for the ICSD are outlined, together with directions for future development in support of materials research and design. PMID:12037357

Belsky, Alec; Hellenbrandt, Mariette; Karen, Vicky Lynn; Luksch, Peter

2002-06-01

102

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

SciTech Connect

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.

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

1993-09-01

103

Periodic mesoporous organic–inorganic hybrid materials: Applications in membrane separations and adsorption  

Microsoft Academic Search

This review discusses the state of the art on the synthesis, functionalization and emerging applications of mesoporous silica materials. Mesoporous silica materials can be synthesized as membranes or powders with controlled pore size and geometry depending on the synthesis conditions. Mesoporous membranes are generally grown on porous supports by solvent evaporation or hydrothermal synthesis techniques. Synthesis of powdered mesoporous silica

Parveen Kumar; Vadim V. Guliants

2010-01-01

104

Mineral classification revisited: use of quasiternary diagrams in the visualization of compositional distribution of inorganic material in coal  

SciTech Connect

A comparative study to determine the elemental composition of individual inorganic particles in the Pittsburgh No. 8 coal sample has been carried out with two different magnifications by SEM-EDS. The classification of particles into mineral classes left 30-40% of the particles unclassified. It was deduced that the sample contained the following minerals: calcite, kaolinite, pyrite, quartz, apatite, muscovite, and montmorillonite. The information of the compositional distribution of inorganic material in the coal sample is enhanced by use of the quasiternary diagrams. Minerals, such as apatite, calcite, pyrite, and quartz, can clearly be identified from the quasiternary diagram. A suitable elemental definition of the three corners in the quasiternary diagram enables the discussion of the compositional distribution and identity of the inorganic material that remains unclassified in the mineral classification. By combining the information from mineral classification and quasiternary diagrams, the composition of the inorganic material of the coal sample can be understood. This information can be used in the prediction of ash-related problems regardless of the fuel type. 50 refs., 6 figs., 2 tabs.

Heikki J. Ollila; Jouni H.A. Daavitsainen; Laura H. Nuutinen; Minna S. Tiainen; Mika E. Virtanen; Risto S. Laitinen [University of Oulu, Oulu (Finland). Department of Chemistry

2006-03-15

105

Lanthanide organic-inorganic hybrids based on functionalized metal-organic frameworks (MOFs) for a near-UV white LED.  

PubMed

A novel near-UV white LED based on lanthanide organic-inorganic hybrid material is realized through postsynthetically modified MOFs and MOF-based polymers. The hybrids materials have high quantum yield and satisfactory luminescence stability; the assembled white LED has tuneable correlated color temperature and high color rendering index. PMID:25352310

Lu, Ye; Yan, Bing

2014-12-18

106

ROMP-Derived cyclooctene-based monolithic polymeric materials reinforced with inorganic nanoparticles for applications in tissue engineering  

PubMed Central

Summary Porous monolithic inorganic/polymeric hybrid materials have been prepared via ring-opening metathesis copolymerization starting from a highly polar monomer, i.e., cis-5-cyclooctene-trans-1,2-diol and a 7-oxanorborn-2-ene-derived cross-linker in the presence of porogenic solvents and two types of inorganic nanoparticles (i.e., CaCO3 and calcium hydroxyapatite, respectively) using the third-generation Grubbs initiator RuCl2(Py)2(IMesH2)(CHPh). The physico-chemical properties of the monolithic materials, such as pore size distribution and microhardness were studied with regard to the nanoparticle type and content. Moreover, the reinforced monoliths were tested for the possible use as scaffold materials in tissue engineering, by carrying out cell cultivation experiments with human adipose tissue-derived stromal cells. PMID:21283558

Weichelt, Franziska; Lenz, Solvig; Tiede, Stefanie; Reinhardt, Ingrid

2010-01-01

107

Design of hybrid conjugated polymer materials: 1) Novel inorganic/organic hybrid semiconductors and 2) Surface modification via grafting approaches  

NASA Astrophysics Data System (ADS)

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

Peterson, Joseph J.

108

Inorganic materials as ameliorants for soil remediation of metal toxicity to wild mustard (Sinapis arvensis L.).  

PubMed

The ameliorating effects of different inorganic materials were investigated on a soil originating from a zinc smelter dumping site contaminated by toxic metals. Wild mustard (Sinapis arvensis L.) was used as a test plant. The soil was amended with different doses of mining sludge, Perferric Red Latosol (LVj), steel shots, cyclonic ash, silifertil, and superphosphate. The most effective amendments improved plant growth with 45% and reduced metal uptake by over 70% in comparison to untreated soil. Reductions in availability as estimated by BaCl2-extractable metals reached up to 90% for Zn and 65% for Cd as compared to unamended soil. These reductions were associated with lower shoot and root metal contents. Shoot Zn content was reduced from 1,369 microg g(-1) in plants grown on untreated soil to 377 microg g(-1) when grown on cyclonic ash amended soil while Cd decreased from 267 to 44 microg g(-1) in steel shots amended soil. Superphosphate addition had no ameliorating effect. On the contrary, it increased BaCl2-extractable amounts of Zn. Considering all parameters we determined, steel shots, cyclonic ash and silifertil are the most promising for remediating metal contaminated soil in the tropics. Further studies evaluating impacts, cost-effectiveness and durability of effects will be conducted. PMID:21598779

Ribeiro Filho, Mateus Rosas; Siqueira, José Oswaldo; Vangronsveld, Jaco; Soares, Cláudio Roberto Fonsêca Sousa; Curi, Nilton

2011-01-01

109

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

NASA Astrophysics Data System (ADS)

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.

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

2014-12-01

110

A combined remote Raman and fluorescence spectrometer system for detecting inorganic and biological materials  

NASA Astrophysics Data System (ADS)

We have developed a combined remote telescopic Raman and laser-induced native fluorescence (LINF) spectrograph with 532 nm pulsed laser excitation and a gated CCD detector. With this system, we have measured time-resolved Raman and LINF spectral measurements at 9 m with 10-ns time resolution. A comparison of Raman spectra of calcite crystal and that of chicken eggshell show that the CaCO 3 in the chicken eggshell is arranged in a calcite structure. The strong LINF band in the spectrum of the calcite crystal has lifetime longer than 1 ?s, whereas the lifetime of LINF bands of the eggshell are in 10's of nano-sec (ns). The time-resolved Raman spectra of tomato and poinsettia (Euphorbia pulcherrimum) green leaves show resonance Raman features of carotenes. The time-resolved remote LINF spectrum of ruby crystals, and LINF spectra of tomato and poinsettia green leaves yield information that the LINF lifetime of ruby lines is much longer (in milliseconds (ms)) as compared with the fluorescence lifetime of the tomato and the poinsettia leaves (in 10s of ns). These results show that it will be possible to discriminate between inorganic and biogenic materials on the basis of LINF lifetimes even with 8 nano-sec laser pulses and gated detection.

Sharma, Shiv K.; Misra, Anupam K.; Lucey, Paul G.

2006-12-01

111

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

PubMed Central

There is currently no paradigm in immunology that enables an accurate prediction of how the immune system will respond to any given agent. Here we show that the immunological responses induced by members of a broad class of inorganic crystalline materials are controlled purely by their physicochemical properties in a highly predictable manner. We show that structurally and chemically homogeneous layered double hydroxides (LDHs) can elicit diverse human dendritic cell responses in vitro. Using a systems vaccinology approach, we find that every measured response can be modeled using a subset of just three physical and chemical properties for all compounds tested. This correlation can be reduced to a simple linear equation that enables the immunological responses stimulated by newly synthesized LDHs to be predicted in advance from these three parameters alone. We also show that mouse antigen–specific antibody responses in vivo and human macrophage responses in vitro are controlled by the same properties, suggesting they may control diverse responses at both individual component and global levels of immunity. This study demonstrates that immunity can be determined purely by chemistry and opens the possibility of rational manipulation of immunity for therapeutic purposes. PMID:24799501

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

2014-01-01

112

Activation and splitting of carbon dioxide on the surface of an inorganic electride material  

PubMed Central

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

Toda, Yoshitake; Hirayama, Hiroyuki; Kuganathan, Navaratnarajah; Torrisi, Antonio; Sushko, Peter V.; Hosono, Hideo

2013-01-01

113

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...

114

Cloning, expression, and functional analysis of rat liver cytosolic inorganic pyrophosphatase gene and characterization of its functional promoter.  

PubMed

Inorganic pyrophosphate (PPi) is formed in several metabolic processes and its hydrolysis by the ubiquitously expressed enzyme inorganic pyrophosphatase (iPPase) is essential for the reactions to proceed in the direction of biosynthesis. Recently, we have reported differential expression and activity of cytosolic iPPase in rat liver with aging. In this article we report the cloning of the coding region of rat liver cytosolic iPPase gene in a bacterial expression vector, its expression, purification, and functional analysis by in-gel enzyme assay. SDS-PAGE and Western blot analysis of this expressed protein revealed that its molecular weight (MW) is approximately 33 kDa, while in-gel assay showed that it is functionally active just as the liver cytosolic iPPase. We have determined the genomic organization of this gene by genome blast approach. We have also cloned and characterized its proximal approximate 1 kb functional promoter (-1009 to +82) by transient transfection and luciferase assay of different 5'-deleted iPPase promoter-luciferase constructs and also established its transcription start site by primer extension analysis, along with protein-DNA interaction studies for a few putative transcription factor binding sites. PMID:17933215

Panda, Harekrushna; Pandey, Ravi S; Debata, Priya R; Supakar, Prakash C

2007-01-01

115

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

NASA Technical Reports Server (NTRS)

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.

Talham, Daniel R.; Adair, James H.

1999-01-01

116

Micromachining of inorganic transparent materials using pulsed laser plasma soft x-rays at 10 nm (Invited Paper)  

Microsoft Academic Search

We have investigated micromachining of inorganic transparent materials by direct soft X-ray ablation. The pulsed soft X-rays were generated by irradiation of a Ta target in a vacuum chamber with Nd:YAG laser light at 532 nm, with a pulse duration of 7 ns, at a fluence of 104 J\\/cm2. The laser plasma soft X-rays (LPSX's) were focused on the surfaces

Tetsuya Makimura; Youichi Kenmotsu; Hisao Miyamoto; Satoshi Uchida; Hiroyuki Niino; Kouichi Murakami

2005-01-01

117

Nano-ablation of inorganic materials using laser plasma soft X-rays at around 10 nm  

Microsoft Academic Search

We have investigated direct nanomachining of inorganic materials using laser plasma soft X-rays. Soft X-rays (X) were generated by irradiation of Ta targets (Ta) with 532 nm Nd:YAG laser light(Y) with a pulse duration of 7 ns, at an energy density of about 104 J\\/cm2. Under the condition, Ta plasma emit soft X-rays at around 10 nm. The soft X-rays

T. Makimura; H. Miyamoto; S. Uchida; H. Niinot; K. Murakami

2005-01-01

118

Mechanism of Fibrillation Inhibition of Amyloid Peptides by Inorganic Nanoparticles Reveal Functional Similarities with Proteins  

PubMed Central

Aggregation of amyloid-? peptides (A?) into fibrils is the key pathological feature of many neurodegenerative disorders. Typical drugs inhibit A? fibrillation by binding to monomers in 1:1 ratio and display low efficacy. Here, we report that model CdTe nanoparticles (NPs) can efficiently prevent fibrillation of A? associating with 100–330 monomers at once. The inhibition is based on the binding multiple A? oligomers rather than individual monomers. The oligomer route of inhibition is associated with strong van der Waals interactions characteristic for NPs and presents substantial advantages in the mitigation of toxicity of the misfolded peptides. Molar efficiency and the inhibition mechanism revealed by NPs are analogous to those found for proteins responsible for prevention of amyloid fibrillation in human body. Besides providing a stimulus for finding biocompatible NPs with similar capabilities, these data suggest that inorganic NPs can mimic some sophisticated biological functionalities of proteins. PMID:21495130

Yoo, Seong Il; Yang, Ming; Subramanian, Vivekanandan; Brender, Jeffrey R.; Sun, Kai; Joo, Nam Eok; Jeong, Soo-Hwan; Ramamoorthy, Ayyalusamy; Kotov, Nicholas A.

2012-01-01

119

Templated aqueous synthesis of inorganics within carboxyl-containing block copolymer domains  

E-print Network

Template-directed, aqueous-based syntheses of nanoscale inorganic materials in carboxyl-functionalized block copolymer domains (nanoreactors) were demonstrated. First, the successful application of electroless metal ...

Boontongkong, Yot

2002-01-01

120

Functional materials for rechargeable batteries.  

PubMed

There is an ever-growing demand for rechargeable batteries with reversible and efficient electrochemical energy storage and conversion. Rechargeable batteries cover applications in many fields, which include portable electronic consumer devices, electric vehicles, and large-scale electricity storage in smart or intelligent grids. The performance of rechargeable batteries depends essentially on the thermodynamics and kinetics of the electrochemical reactions involved in the components (i.e., the anode, cathode, electrolyte, and separator) of the cells. During the past decade, extensive efforts have been dedicated to developing advanced batteries with large capacity, high energy and power density, high safety, long cycle life, fast response, and low cost. Here, recent progress in functional materials applied in the currently prevailing rechargeable lithium-ion, nickel-metal hydride, lead acid, vanadium redox flow, and sodium-sulfur batteries is reviewed. The focus is on research activities toward the ionic, atomic, or molecular diffusion and transport; electron transfer; surface/interface structure optimization; the regulation of the electrochemical reactions; and the key materials and devices for rechargeable batteries. PMID:21394791

Cheng, Fangyi; Liang, Jing; Tao, Zhanliang; Chen, Jun

2011-04-19

121

Functional composite materials based on chemically converted graphene.  

PubMed

Graphene, a one-atom layer of graphite, possesses a unique two-dimensional structure and excellent mechanical, thermal, and electrical properties. Thus, it has been regarded as an important component for making various functional composite materials. Graphene can be prepared through physical, chemical and electrochemical approaches. Among them, chemical methods were tested to be effective for producing chemically converted graphene (CCG) from various precursors (such as graphite, carbon nanotubes, and polymers) in large scale and at low costs. Therefore, CCG is more suitable for synthesizing high-performance graphene based composites. In this progress report, we review the recent advancements in the studies of the composites of CCG and small molecules, polymers, inorganic nanoparticles or other carbon nanomaterials. The methodology for preparing CCG and its composites has been summarized. The applications of CCG-based functional composite materials are also discussed. PMID:21360763

Bai, Hua; Li, Chun; Shi, Gaoquan

2011-03-01

122

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

USGS Publications Warehouse

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.

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

2008-01-01

123

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

NASA Astrophysics Data System (ADS)

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

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

2008-11-01

124

An Assessment of Inorganic Ion-Exchange Materials for the Removal of Strontium from Simulated Hanford Tank Wastes  

Microsoft Academic Search

Several inorganic ion-exchange materials were evaluated for the removal of strontium from two simulated Hanford tank wastes (NCAW and 101SY-Cs5) using static batch experiments. Sodium titanium silicate, Na2Ti2O3SiO4·2H2O(NaTS), was the best material in NCAW with a Kd of 2.7 × 10 mL\\/g at a volume-to-mass ratio of 200:1. In the 101SY-Cs5 simulant, strontium extraction was more difficult due to the

PAUL SYLVESTER; ELIZABETH A. BEHRENS; GINA M. GRAZIANO; ABRAHAM CLEARFIELD

1999-01-01

125

Novel layered crystalline organic polymer-inorganic hybrid material comprising calcium phosphate with unique architectures for superior performance catalyst support.  

PubMed

An organic copolymer-inorganic hybrid material, calcium phosphonate-phosphate (CaPS-PVPA), is fabricated under mild conditions. In particular, CaPS-PVPA is not prepared with traditional methods such as a hydrothermal one, but with amorphous reactions for a simple, fast, cost-effective and environmentally benign approach. Characterization shows that CaPS-PVPA is a layered crystalline mesoporous material, and could be readily used as a catalytic support. A catalyst with immobilization of chiral salen Mn(iii) onto CaPS-PVPA demonstrate a superior catalytic disposition (conv. > 99% and ee > 99%), which offers great potential for industry scale applications. PMID:25340324

Huang, Jing; Tang, Mei; Li, Xin; Zhong, Guo Zhen; Li, Chang Ming

2014-12-14

126

Design of Chiral Hybrid Organic-Inorganic Mesoporous Materials as Enantioselective Epoxidation and Alkylation Catalysts  

Microsoft Academic Search

The nineties have seen important advances in the synthesis of hybrid organicinorganic mesoporous materials based on the functionalization\\u000a of the surface of new micelle-templated mineral oxides such as MCM-41 type silicates.1 The major advantages of these new supports are their large surface area, their regular system of monodisperse mesopores and\\u000a homogeneity of chemical surface properties, which allow the preparation of

Daniel Brunei; Monique Laspéras

127

Inorganic biomimetic nanostructures.  

PubMed

Supramolecular structures modeled after biological systems (DNA and enzymes) are being developed to simultaneously mimic natural biological functions including catalysis, information storage, and self-assembly and to engineer novel electronic and magnetic properties. Structural mimics of nucleic acids containing multiple metal-coordinating ligands, and comprising natural and artificial bases or completely synthetic systems, create stable double-stranded structures with new electronic, spectroscopic, and magnetic properties. Supramolecular inorganic mimics of enzymatic function, including metallonucleases and metalloproteases, have begun to be constructed. Alternatively, metal-organic-frameworks have potential as artificial catalysts with substrate-specificity and size-selectivity analogous to biological processes. This review describes some of the recent themes in inorganic supramolecular systems that aim to mimic and exploit nature's ability to self-assemble polyfunctional architectures for new materials and biological applications. PMID:19818676

Levine, Lauren A; Williams, Mary Elizabeth

2009-12-01

128

Zeolites and mesoporous materials as advanced functional material  

Microsoft Academic Search

With their unique regular channel system, porous materials offer a wide range of applications as host-guest system ranging from membranes with a molecular sieve function to devices with laser or sensor function. The state of the art of the development of zeolites and zeolite-like materials as advanced materials with (i) separation, (ii) electric\\/electronic, and (iii) optical functions is evaluated.

2004-01-01

129

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

NASA Astrophysics Data System (ADS)

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

?azarek, ?ukasz; Anto?czak, Arkadiusz J.; Wójcik, Micha? R.; Kozio?, Pawe? E.; Stepak, Bogusz; Abramski, Krzysztof M.

2014-08-01

130

Hybrid inorganic-organic adsorbents Part 1: Synthesis and characterization of mesoporous zirconium titanate frameworks containing coordinating organic functionalities.  

PubMed

A series of functional hybrid inorganic-organic adsorbent materials have been prepared through postsynthetic grafting of mesoporous zirconium titanate xerogel powders using a range of synthesized and commercial mono-, bis-, and tris-phosphonic acids, many of which have never before been investigated for the preparation of hybrid phases. The hybrid materials have been characterized using thermogravimetric analysis, diffuse reflectance infrared (DRIFT) and 31P MAS NMR spectroscopic techniques and their adsorption properties studied using a 153Gd radiotracer. The highest level of surface functionalization (molecules/nm2) was observed for methylphosphonic acid (?3 molecules/nm2). The level of functionalization decreased with an increase in the number of potential surface coordinating groups of the phosphonic acids. Spectral decomposition of the DRIFT and 31P MAS NMR spectra showed that each of the phosphonic acid molecules coordinated strongly to the metal oxide surface but that for the 1,1-bis-phosphonic acids and tris-phosphonic acids the coordination was highly variable resulting in a proportion of free or loosely coordinated phosphonic acid groups. Functionalization of a porous mixed metal oxide framework with the tris-methylenephosphonic acid (ATMP-ZrTi-0.33) resulted in a hybrid with the highest affinity for 153Gd3+ in nitric acid solutions across a wide range of acid concentrations. The ATMP-ZrTi-0.33 hybrid material extracted 153Gd3+ with a Kd value of 1×10(4) in 0.01 M HNO3 far exceeding that of the other hybrid phases. The unfunctionalized mesoporous mixed metal oxide had negligible affinity for Gd3+ (Kd<100) under identical experimental conditions. It has been shown that the presence of free or loosely coordinated phosphonic acid groups does not necessarily translate to affinity for 153Gd3+. The theoretical cation exchange capacity of the ATMP-ZrTi-0.33 hybrid phase for Gd3+ has been determined to be about 0.005 mmol/g in 0.01 M HNO3. This behavior and that of the other hybrid phases suggests that the surface-bound ATMP ligand functions as a chelating ligand toward 153Gd3+ under these acidic conditions. PMID:21073158

Griffith, Christopher S; De Los Reyes, Massey; Scales, Nicholas; Hanna, John V; Luca, Vittorio

2010-12-01

131

Hybrid organic-inorganic POSS dendritic materials: photoluminescence chromophore control via confinement and steric hindrance  

NASA Astrophysics Data System (ADS)

An inorganic silsesquioxane and organic 4-vinyl biphenyl chromophore based dendrimer was synthesized and the steric hindrance of the dendrons was used as a trigger to control the photophysical properties in the near-UV and blue spectral ranges. Consistent photoluminescence quantum yields and time resolved fluorescence were measured in solution, confirming that molecular engineering of the dendrons together with confinement around the inorganic core allows the design of more efficient photoluminescent dendrimers. Low temperature photoluminescent studies were completed to demonstrate the stability of the dendrimer photophysical properties. A very general strategy is then presented which uses stable chemistry to control the emission spectral range by changing the chromophore, and gives control of photoluminescence efficiency by grafting side-groups onto the chromophores.

André, P.; Cheng, G.; Ruseckas, A.; Cole-Hamilton, D. J.; Samuel, I. D. W.

2009-08-01

132

Alkylene-bridged polysilsesquioxane aerogels: highly porous hybrid organic-inorganic materials  

Microsoft Academic Search

Alkylene-bridged polysilsesquioxane gels were prepared by sol-gel polymerizations of ?, ?-bis(triethoxysilyl)alkanes 1–5. The gels were extracted with supercritical carbon dioxide to afford a novel class of hybrid organic-inorganic aerogels. The effect of the length of the alkylene bridging group and catalyst (HCl and NaOH) on the structure was examined. The molecular structure was characterized by solid-state 13C and 29Si cross

Douglas A. Loy; Gregory M. Jamison; Brigitta M. Baugher; Edward M. Russick; Roger A. Assink; S. Prabakar; Kenneth J. Shea

1995-01-01

133

Fractal Geometric Characterization of Functionally Graded Materials  

E-print Network

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

Ostoja-Starzewski, Martin

134

A new sensitive organic/inorganic hybrid material based on titanium oxide for the potentiometric detection of iron(III).  

PubMed

The formation of a new hybrid material based on titanium dioxide as inorganic support and containing an iron organochelator (ICL670) is described. An organophosphorous coupling agent was used to graft the organic molecule on the oxide surface. The attachment of the organic substrate was well-confirmed by FTIR (DRIFT), solid-state (31)P and (13)C CPMAS NMR, thermal analysis and the integrity of the structural and morphological parameters were verified using XRD and TEM analyses. The interaction between the material and dissolved iron(III) was also investigated through potentiometric measurements and demonstrated the interest of this new non-siliceous based hybrid material. The obtained linear evolution of the open circuit potential from 10(-2) to 10(-6) mol L(-1) can be used for the analytical detection of iron(III). PMID:23000208

Becuwe, M; Rouge, P; Gervais, C; Courty, M; Dassonville-Klimpt, A; Sonnet, P; Baudrin, E

2012-12-15

135

Designing and nanoscale engineering of organic/inorganic electronic materials for organic light-emitting diodes  

NASA Astrophysics Data System (ADS)

Organic light-emitting diodes (OLEDs) have been intensively studied due to their emerging applications in flat panel display technologies. The motivation of the present research has been the desire to (a) explore new routes to OLED functional layers with rigorous control of layer properties; (b) probe the effects of OLED anode-hole transport layer interfacial energetics on charge injection, luminous efficiency; (c) acquire micron-scale multicolor OLED pixels for potential high resolution OLED display application; (d) better understand and further improve charge injection into molecular and macromolecular solids by designing and implementing novel OLED anode materials. In the first part, a spin-coating/siloxane cross-linking approach has been applied to OLED charge transport layers which provides a high throughput route to robust, pinhole-free, adherent thin films with covalently interlinked, glassy structures (Chapter 2). In anode-hole transport layer contact study (Chapter 3), it is shown that integrity of electrode/organic interfacial contact is crucial to the performance and stability of organic light emitting diodes (OLEDs). It is demonstrated that self-assembled or spincoated nm-scale thick silane derived hole transport layer on ITO can effectively prevent de-wetting of the vapor deposited TPD hole transport layers (Chapter 3), leading to significantly enhanced light output (15,000 cd/m2), luminous efficiency (1.2%), and thermal stability (up to 110°C). In applying soft lithography techniques to OLED micro-patterning, we designed and implemented high temperature micro-contact printing, which readily affords pixel features down to 1.0 micron dimensions, and which, by virtue of the length scale-dependent carrier tunneling through SAM structures, affords tenability in luminescence patterns (Chapter 4). To facilitate hole injection at anode side of OLED, MOCVD derived, highly transparent, high work function thin film TCO materials is synthesized and employed as OLED anodes (Chapter 5). Besides exhibiting high electrical conductivities (1000--3300 S/cm) and outstanding optical transparencies (>90%), these TCO films possess unusually high work functions (5.2--6.1 eV vs. 4.7 eV for ITO). OLED devices fabricated with these materials as anodes exhibit electroluminescence performance comparable to or better than ITO-based devices.

Cui, Ji

2001-07-01

136

Nano-Ablation of Inorganic Materials Using Laser Plasma Soft X-rays at around 10 nm  

NASA Astrophysics Data System (ADS)

We have investigated the direct nanomachining of inorganic materials using laser plasma soft X-rays (LPSXs). LPSXs were generated by the irradiation of Ta targets with Q-switched 532 nm Nd:YAG laser light at an energy density of ˜104 J/cm2. Under this condition, Ta plasma emits soft X-rays at around 10 nm. The LPSXs were focused on the surfaces of inorganic materials, using an ellipsoidal mirror that we desined so as to focus LPSXs at around 10 nm efficiently. We found that synthetic quartz glass, fused silica, Pyrex, LiF, CaF2, Al2O3, and LiNbO3 can be machined. Typically, silica glass is ablated at 47 nm/shot, and it has a surface roughness less than 10 nm after 10 shots. To demonstrate lateral resolution, we fabricated a WSi contact mask with 200-nm-pitch line-and-space patterns on quartz glass. After soft X-ray irradiation, trench structures with a width of 70 nm were clearly observed.

Makimura, Tetsuya; Miyamoto, Hisao; Uchida, Satoshi; Fujimori, Takashige; Niino, Hiroyuki; Murakami, Kouichi

2006-06-01

137

Atomic-beam alignment of inorganic materials for liquid-crystal displays  

NASA Astrophysics Data System (ADS)

The technique used to align liquid crystals-rubbing the surface of a substrate on which a liquid crystal is subsequently deposited-has been perfected by the multibillion-dollar liquid-crystal display industry. However, it is widely recognized that a non-contact alignment technique would be highly desirable for future generations of large, high-resolution liquid-crystal displays. A number of alternative alignment techniques have been reported, but none of these have so far been implemented in large-scale manufacturing. Here, we report a non-contact alignment process, which uses low-energy ion beams impinging at a glancing angle on amorphous inorganic films, such as diamond-like carbon. Using this approach, we have produced both laptop and desktop displays in pilot-line manufacturing, and found that displays of higher quality and reliability could be made at a lower cost than the rubbing technique. The mechanism of alignment is explained by adopting a random network model of atomic arrangement in the inorganic films. Order is induced by exposure to an ion beam because unfavourably oriented rings of atoms are selectively destroyed. The planes of the remaining rings are predominantly parallel to the direction of the ion beam.

Chaudhari, P.; Lacey, James; Doyle, James; Galligan, Eileen; Lien, Shui-Chi Alan; Callegari, Alesandro; Hougham, Gareth; Lang, Norton D.; Andry, Paul S.; John, Richard; Yang, Kei-Hsuing; Lu, Minhua; Cai, Chen; Speidell, James; Purushothaman, Sampath; Ritsko, John; Samant, Mahesh; Stöhr, Joachim; Nakagawa, Yoshiki; Katoh, Yoshimine; Saitoh, Yukito; Sakai, Kazumi; Satoh, Hiroyuki; Odahara, Shuichi; Nakano, Hiroki; Nakagaki, Johji; Shiota, Yasuhiko

2001-05-01

138

Polyfunctional inorganic-organic hybrid materials: an unusual kind of NLO active layered mixed metal oxalates with tunable magnetic properties and very large second harmonic generation.  

PubMed

Mixed M(II)/M(III) metal oxalates, as "stripes" connected through strong hydrogen bonding by para-dimethylaminobenzaldeide (DAMBA) and water, form an organic-inorganic 2D network that enables segregation in layers of the cationic organic NLO-phore trans-4-(4-dimethylaminostyryl)-1-methylpyridinium, [DAMS+]. The crystalline hybrid materials obtained have the general formula [DAMS]4[M2M'(C2O4)6].2DAMBA.2H2O (M = Rh, Fe, Cr; M' = Mn, Zn), and their overall three-dimensional packing is non-centrosymmetric and polar, therefore suitable for second harmonic generation (SHG). All the compounds investigated are characterized by an exceptional SHG activity, due both to the large molecular quadratic hyperpolarizability of [DAMS+] and to the efficiency of the crystalline network which organizes [DAMS+] into head-to-tail arranged J-type aggregates. The tunability of the pairs of metal ions allows exploiting also the magnetic functionality of the materials. Examples containing antiferro-, ferro-, and ferri-magnetic interactions (mediated by oxalato bridges) are obtained by coupling proper M(III) ions (Fe, Cr, Rh) with M(II) (Mn, Zn). This shed light on the role of weak next-nearest-neighbor interactions and main nearest-neighbor couplings along "stripes" of mixed M(II)/M(III) metal oxalates of the organic-inorganic 2D network, thus suggesting that these hybrid materials may display isotropic 1D magnetic properties along the mixed M(II)/M(III) metal oxalates "stripes". PMID:17616190

Cariati, Elena; Macchi, Roberto; Roberto, Dominique; Ugo, Renato; Galli, Simona; Casati, Nicola; Macchi, Piero; Sironi, Angelo; Bogani, Lapo; Caneschi, Andrea; Gatteschi, Dante

2007-08-01

139

The chemical composition of inorganic and carbonaceous materials in PM 2.5 in Nanjing, China  

NASA Astrophysics Data System (ADS)

PM 2.5 samples were collected at an urban and a suburban site in Nanjing, China in 2001. They were analyzed for inorganic ions, elemental carbon, organic carbon (OC), water-soluble organic carbon (WSOC), and individual WSOC and nonpolar organic species. Sulfate and organic matter were the two most abundant constituents in these samples. Sulfate accounted for an average of 23% (urban site) and 30% (suburban site) of the identified aerosol mass. Organic matter accounted for an average of 37% (urban) and 28% (suburban) of the identified aerosol mass. WSOC was a significant portion of OC, accounting for about one-third of OC at the urban site and 45% of OC at the suburban site. The suburban-urban gradient in the WSOC/OC ratio also reflected that the aerosol OC was more aged at the suburban location. The correlations of WSOC with sulfate and nitrate suggest that the WSOC fraction was dominated by secondary organics. More than 30 individual WSOC species in the compound classes of organic anions, amino acids, aliphatic amines, and carbohydrates were quantified, accounting for approximately 8% of the WSOC on a carbon mass basis. In addition, 46 individual nonpolar organic compounds in the compound classes of n-alkanes, hopanes, and polycyclic aromatic hydrocarbons were quantified using an in-injection port thermal desorption technique. These nonpolar organic species accounted for less than 7% of the OC on a carbon mass basis. The quantification of individual compounds allowed the identification of major aerosol sources through principal component analysis. Coal combustion, vehicular emissions, secondary inorganic and organic aerosols, and road/sea salt were the major contributing sources to the identified PM 2.5 aerosol mass.

Yang, Hong; Yu, Jian Zhen; Ho, Steven Sai Hang; Xu, Jinhui; Wu, Wai-Shing; Wan, Chun Hong; Wang, Xiaodong; Wang, Xiaorong; Wang, Liansheng

140

Bridged polysilsesquioxanes: A molecular based approach for the synthesis of functional hybrid materials  

SciTech Connect

Bridged polysilsesquioxanes (BPS) are a family of hybrid organic-inorganic materials prepared by sol-gel polymerization of molecular building blocks that contain a variable organic component and at least two trifunctional silyl groups. The resulting xerogels and aerogels have physical and mechanical properties that are strongly influenced by the organic bridging group. This talk focuses on the synthesis of functional bridged polysilsesquioxanes. Incorporation of functional groups that respond to chemical, photochemical, or thermal stimuli can provide handles for modifying bulk morphology and/or provide function. These materials can find use as ion exchange media, chromatographic stationary phases, photoresists and high capacity selective chemical absorbents.

SHEA,KENNETH J.; LOY,DOUGLAS A.

2000-05-09

141

The structures and properties of the new two-dimensional inorganic-organic hybrid materials based on the molybdate chains  

NASA Astrophysics Data System (ADS)

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.

Li, Na; Mu, Bao; Cao, Xinyu; Huang, Rudan

2014-09-01

142

Phosphomolybdate clusters as molecular building blocks in the design of one-, two- and three-dimensional organic inorganic hybrid materials  

NASA Astrophysics Data System (ADS)

An attractive approach to the design of inorganic solids exploits the tethering of inorganic clusters through organic spacers to produce hybrid materials with composite properties. We have recently described a modified strategy in which polyoxometalate clusters are linked through organic subunits to give an anionic hybrid substructure which may be further modified through the introduction of secondary metal-ligand complex (SMLC) cations, serving as a third component building block. In this application, the molybdophosphonate cluster {Mo 5O 15(O 3PR) 2} 4- serves as a secondary building unit (SBU) with alkyl (CH 2) n or aromatic -(C 6H 4) n- tethers providing one-dimensional structural expansion. A binucleating ligand such as tetrapyridylpyrazine (tpyprz) is used to bridge secondary metal sites into a binuclear {Cu 2(tpyprz)} 4+ SBU which may link phosphomolybdate clusters into two- or three-dimensional structures. The influence of a variety of structural determinants is discussed, including the tether length of the diphosphonate ligand, the coordination preferences of the secondary metal, expansion of the ligand component of the SMLC, and substitution of As for P in the oxide SBU.

Gabriel Armatas, N.; Burkholder, Eric; Zubieta, Jon

2005-08-01

143

Inorganic nanotubes reinforced polyvinylidene fluoride composites as low-cost electromagnetic interference shielding materials  

PubMed Central

Novel polymer nanocomposites comprising of MnO2 nanotubes (MNTs), functionalized multiwalled carbon nanotubes (f-MWCNTs), and polyvinylidene fluoride (PVDF) were synthesized. Homogeneous distribution of f-MWCNTs and MNTs in PVDF matrix were confirmed by field emission scanning electron microscopy. Electrical conductivity measurements were performed on these polymer composites using four probe technique. The addition of 2 wt.% of MNTs (2 wt.%, f-MWCNTs) to PVDF matrix results in an increase in the electrical conductivity from 10-16S/m to 4.5 × 10-5S/m (3.2 × 10-1S/m). Electromagnetic interference shielding effectiveness (EMI SE) was measured with vector network analyzer using waveguide sample holder in X-band frequency range. EMI SE of approximately 20 dB has been obtained with the addition of 5 wt.% MNTs-1 wt.% f-MWCNTs to PVDF in comparison with EMI SE of approximately 18 dB for 7 wt.% of f-MWCNTs indicating the potential use of the present MNT/f-MWCNT/PVDF composite as low-cost EMI shielding materials in X-band region. PMID:21711633

2011-01-01

144

Inorganic nanotubes reinforced polyvinylidene fluoride composites as low-cost electromagnetic interference shielding materials.  

PubMed

Novel polymer nanocomposites comprising of MnO2 nanotubes (MNTs), functionalized multiwalled carbon nanotubes (f-MWCNTs), and polyvinylidene fluoride (PVDF) were synthesized. Homogeneous distribution of f-MWCNTs and MNTs in PVDF matrix were confirmed by field emission scanning electron microscopy. Electrical conductivity measurements were performed on these polymer composites using four probe technique. The addition of 2 wt.% of MNTs (2 wt.%, f-MWCNTs) to PVDF matrix results in an increase in the electrical conductivity from 10-16S/m to 4.5 × 10-5S/m (3.2 × 10-1S/m). Electromagnetic interference shielding effectiveness (EMI SE) was measured with vector network analyzer using waveguide sample holder in X-band frequency range. EMI SE of approximately 20 dB has been obtained with the addition of 5 wt.% MNTs-1 wt.% f-MWCNTs to PVDF in comparison with EMI SE of approximately 18 dB for 7 wt.% of f-MWCNTs indicating the potential use of the present MNT/f-MWCNT/PVDF composite as low-cost EMI shielding materials in X-band region. PMID:21711633

Eswaraiah, Varrla; Sankaranarayanan, Venkataraman; Ramaprabhu, Sundara

2011-01-01

145

Inorganic nanotubes reinforced polyvinylidene fluoride composites as low-cost electromagnetic interference shielding materials  

NASA Astrophysics Data System (ADS)

Novel polymer nanocomposites comprising of MnO2 nanotubes (MNTs), functionalized multiwalled carbon nanotubes ( f-MWCNTs), and polyvinylidene fluoride (PVDF) were synthesized. Homogeneous distribution of f-MWCNTs and MNTs in PVDF matrix were confirmed by field emission scanning electron microscopy. Electrical conductivity measurements were performed on these polymer composites using four probe technique. The addition of 2 wt.% of MNTs (2 wt.%, f-MWCNTs) to PVDF matrix results in an increase in the electrical conductivity from 10-16S/m to 4.5 × 10-5S/m (3.2 × 10-1S/m). Electromagnetic interference shielding effectiveness (EMI SE) was measured with vector network analyzer using waveguide sample holder in X-band frequency range. EMI SE of approximately 20 dB has been obtained with the addition of 5 wt.% MNTs-1 wt.% f-MWCNTs to PVDF in comparison with EMI SE of approximately 18 dB for 7 wt.% of f-MWCNTs indicating the potential use of the present MNT/ f-MWCNT/PVDF composite as low-cost EMI shielding materials in X-band region.

Eswaraiah, Varrla; Sankaranarayanan, Venkataraman; Ramaprabhu, Sundara

2011-12-01

146

PREFACE: Functional materials and nanotechnologies (FM&NT-2007)  

NASA Astrophysics Data System (ADS)

The International Baltic Sea Region conference Functional Materials and Nanotechnologies (FM&NT-2007) was held in Riga, 2-4 April 2007 in the Institute of Solid State Physics, University of Latvia (ISSP LU). The conference was organized in co-operation with projects ERANET 'MATERA' and EUREKA 'BIONANOCOMPOSITE'. The purpose of the conference was to bring together scientists, engineers and students from universities, research institutes and related industrial companies active in the field of advanced material science and materials technologies trends and future activities. Scientific themes covered in the conference are:

  • advanced inorganic materials for photonics, energetics and microelectronics
  • organic materials for photonics and nanoelectronics
  • advanced methods for investigation of nanostructures
  • perspective biomaterials and medicine technologies
  • development of technologies for design of nanostructured materials, nanoparticles, and thin films
  • design of functional materials and nanocomposites and development of their technologies
  • The number of registered participants from 14 countries was nearly 110. During three days of the conference 70 oral reports and 58 posters were presented, 50 papers, based on these reports, are included in this volume of Journal of Physics: Conference Series. Additional information about FM&NT-2007 is available in its homepage http://fmnt.lu.lv and http://www.fmnt.lv . The Organizing Committee would like to thank all speakers, contributors, session chairs, referees and meeting staff for their efforts in making the FM&NT-2007 successful. The local Organization Committee would like to acknowledge and thank our sponsors - Latvian Council of Science and the Institute of Solid State Physics, University of Latvia. Andris Sternberg Inta Muzikante Guest editors

    Sternberg, Andris; Muzikante, Inta

    2007-06-01

    147

    Micromachining of inorganic transparent materials using pulsed laser plasma soft x-rays at 10 nm (Invited Paper)  

    NASA Astrophysics Data System (ADS)

    We have investigated micromachining of inorganic transparent materials by direct soft X-ray ablation. The pulsed soft X-rays were generated by irradiation of a Ta target in a vacuum chamber with Nd:YAG laser light at 532 nm, with a pulse duration of 7 ns, at a fluence of 104 J/cm2. The laser plasma soft X-rays (LPSX's) were focused on the surfaces of specimens using an ellipsoidal mirror that is made from silica glass and coated with Au. The ellipsoidal mirror is designed so that LPSX's at arount 10 nm are focused efficiently. The fluence of LPSX's on the specimens is roughly estimated to be 0.1 J/cm2. We found that quartz glass plates are machined by pulsed LPSX's irradiation at a rate of 48 nm/shot. Furthermore, the quartz plates have smooth surfaces with a roughness less thatn 10 nm after 10 shots of LPSX irradiation and sharp edges with a steepness less than 100 nm. In addition to quartz glass, the LPSX processing can be applied to micromachining of a variety of materials such as Pyrex, CaF2, LiF, LiNbO3, Si and silicone. We found a transient state induced by LPSX irradiation of quartz glass. The transient state absorbs 266 nm light. We irradiated quartz glass with 266 nm Nd:YAG laser light and LPSX's simultaneously and found that ablation is enhanced to have a rate of 85 nm/shot. With X-ray imaging optics, nanomachining of inorganic transparent materials should be achieved.

    Makimura, Tetsuya; Kenmotsu, Youichi; Miyamoto, Hisao; Uchida, Satoshi; Niino, Hiroyuki; Murakami, Kouichi

    2005-04-01

    148

    Towards rational design of peptides for selective interaction with inorganic materials  

    E-print Network

    Utilizing molecular recognition and self-assembly, material-specific biomolecules have shown great promise for engineering and ordering materials at the nanoscale. These molecules, inspired from natural biomineralization ...

    Krauland, Eric Mark

    2007-01-01

    149

    Vertically Aligned Nanostructured Arrays of Inorganic Materials: Synthesis, Distinctive Physical Phenomena, and Device Integration  

    NASA Astrophysics Data System (ADS)

    The manifestation of novel physical phenomena upon scaling materials to finite size has inspired new device concepts that take advantage of the distinctive electrical, mechanical, and optical, properties of nanostructures. The development of fabrication approaches for the preparation of their 1D nanostructured form, such as nanowires and nanotubes, has contributed greatly to advancing fundamental understanding of these systems, and has spurred the integration of these materials in novel electronics, photonic devices, power sources, and energy scavenging constructs. Significant progress has been achieved over the last decade in the preparation of ordered arrays of carbon nanotubes, II---VI and III---V semiconductors, and some binary oxides such as ZnO. In contrast, relatively less attention has been focused on layered materials with potential for electrochemical energy storage. Here, we describe the catalyzed vapor transport growth of vertical arrays of orthorhombic V2O 5 nanowires. In addition, near-edge X-ray absorption fine structure (NEXAFS) spectroscopy is used to precisely probe the alignment, uniformity in crystal growth direction, and electronic structure of single-crystalline V2O5 nanowire arrays prepared by a cobalt-catalyzed vapor transport process. The dipole selection rules operational for core-level electron spectroscopy enable angle-dependant NEXAFS spectroscopy to be used as a sensitive probe of the anisotropy of these systems and provides detailed insight into bond orientation and the symmetry of the frontier orbital states. The experimental spectra are matched to previous theoretical predictions and allow experimental verification of features such as the origin of the split-off conduction band responsible for the n-type conductivity of V2O5 and the strongly anisotropic nature of vanadyl-oxygen-derived (V=O) states thought to be involved in catalysis. We have also invested substantial effort in obtaining shape and size control of metal oxide materials to obtain a fundamental understanding of the influence of finite size and surface restructuring on electronic instabilities in the proximity of the Fermi level. We present here a novel synthetic approach that takes advantage of the intrinsic octahedral symmetry of rock-salt-structured VO to facilitate the growth of six-armed nanocrystallites of related, technologically more important binary vanadium oxide V2O5 . The prepared nanostructures exhibit clear six-fold symmetry and most notably show remarkable retention of electronic structure. The latter has been evidenced through extensive X-ray absorption spectroscopy measurements. We have further designed a facile, generalizable, and entirely scalable approach for the fabrication of vertically aligned arrays of Fe2O 3/polypyrrole core---shell nanostructures and polypyrrole nanotubes. Our "all electrochemical" approach is based on the fabrication of ?-Fe 2O3 nanowire arrays by the simple heat treatment of commodity low carbon steel substrates, followed by electropolymerization of conformal polypyrrole sheaths around the nanowires. Subsequently, electrochemical etching of the nanowires yields large-area vertically aligned polypyrrole nanotube arrays on the steel substrate. The developed methodology is generalizable to functionalized pyrrole monomers and represents a significant practical advance of relevance to the technological implementation of conjugated polymer nanostructures in electrochromics, electrochemical energy storage, and sensing. As another variation of this general synthetic route, we have extended the practice of our simple oxidative process for the fabrication of large-area ZnO nanostructures, specifically highly aligned nanowire arrays integrated onto galvanized steel substrates which via a simple device design and additive piezoelectric nanopower generation were measured across the array substrates. The nanomaterial syntheses and device fabrication approaches developed here will enable facile integration of piezoelectric nanogenerators on to structural components.

    Velazquez, Jesus Manuel

    150

    Boundary Element Methods for Functionally Graded Materials  

    NSDL National Science Digital Library

    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.

    Paulino, Glaucio

    2002-05-28

    151

    Preparation of molecular imprinted microspheres based on inorganic-organic co-functional monomer for miniaturized solid-phase extraction of fluoroquinolones in milk.  

    PubMed

    An inorganic-organic co-functional monomer, methacrylic acid-vinyltriethoxysilan (MAA-VTES) was designed for the synthesis of molecularly imprinted microspheres (MIMs). By virtue of the aqueous suspension polymerization and dummy template (pazufloxacin), the obtained MAA-VTES based MIMs exhibited good recognition and selectivity to fluoroquinolones (FQs), and were successfully applied as selective sorbents of a miniaturized home-made solid phase extraction device for the determination of ofloxacin (OFL), lomefloxacin (LOM) and ciprofloxacin (CIP) in milk samples. Under the optimum conditions of the miniaturized molecularly imprinted solid phase extraction (mini-MISPE) coupled with liquid chromatography-ultraviolet detector (LC-UV), good linearities were obtained for three FQs in a range of 0.2-20.0?gmL(-1) and the average recoveries at three spiked levels were ranged from 87.2% to 106.1% with the relative standard deviation (RSD) less than 5.4%. The presented co-functional monomer based mini-MISPE-LC-UV protocol introduced the rigidity and flexibility of inorganic silicon materials, exhibited excellent extraction performance towards targets, and could be potentially applied to the determination of FQs in milk samples. PMID:24448515

    Wang, Hui; Wang, Ruiling; Han, Yehong

    2014-02-15

    152

    Inorganic contents of peats  

    SciTech Connect

    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.

    Raymond, R. Jr.; Bish, D.L.; Cohen, A.D.

    1988-02-01

    153

    Structure and dynamics of interfaces in organic and inorganic materials using atomic level simulation  

    NASA Astrophysics Data System (ADS)

    Interfaces in materials play a key role for industrial applications. The structures and dynamics at various interfaces including ferroelectric domain walls, gas-organic interface, organic-semiconductor interface and metal-gas interface are investigated with different atomic levels of simulation approaches. Ferroelectricity: Due to their unique ferroelectric and nonlinear optical properties, trigonal ferroelectrics such as LiNbO3 and LiTaO 3, are of wide interest for their potential applications in optoelectronics and nonlinear optics. The properties of these materials are heavily influenced by the shape of ferroelectric domains and domain walls. Therefore, investigation of the local structure and energetics of the ferroelectric domain walls and their interaction with defects on atomic scales, which is not clearly understood, is extremely important. The structure and energetics of ferroelectric domain walls in LiNbO 3 are examined using density functional theory (DFT) and molecular dynamics (MD) methods. The energetically favorable structures of 180° domain walls and the activation energy for domain wall motion are determined by atomic level simulations. The variation of polarization due to the presence of domain walls is also discussed. Defects can be pinned by domain walls. Various defects-domain walls interactions and the effects on domain wall motion are described using atomic level simulation methods. Although the structure of LiTaO3 is very similar with LiNbO3, it has been said experimentally that the shapes of domain walls are different with the presence of particular defects. Using both DFT and a newly developed interatomic potential for LiTaO 3, the differences in domain wall structure are understood in terms of the difference in energetics of domain walls between two materials. Polymerization: Surface polymerization by ion-assisted deposition (SPIAD) enables the control of thin film chemistry and morphology on the nanoscale during growth of conductive polymer thin films. This method allows fine tuning of optical band gaps and other optoelectronic properties of a polymer film by controlling the structure and kinetic energy of the depositing ions and neutrals. Thus, a comprehensive understanding of various mechanisms on the atomic level will contribute to optimizing growth conditions during SPIAD. SPIAD simulations are performed to study polymerization and crosslinking behavior of polythiophene molecules at the gas-organic interfaces using DFT-MD method. The growth processes for polythiophene molecules are studied by depositing thiophene molecules with 25 eV kinetic energy on terthiophene surface. The mechanism and various processes for polymerization and crosslinking of polythiophenes will be discussed. The changes in bond chemistry at the polythiophene molecules and at a PbS nanocrystalline quantum dot (organic-semiconductor interface) after a collision of C2H+ molecules with the substrate are also addressed. Surface diffusion: Surface diffusion is a key concept for understanding catalytic behavior at the surface. We develop a new code implementing adaptive kinetic Monte Carlo (AKMC) method with the dimer transition searching mechanism. The code is developed with a simple Lennard-Jones (LJ) potential. A test of dimer method is performed by using 2-dimensional testing potential. Results of surface diffusion processes of an Al adatom on Al (111) surface using AKMC method are presented.

    Lee, Donghwa

    154

    Regulation of responsiveness of phosphorescence toward dissolved oxygen concentration by modulating polymer contents in organic-inorganic hybrid materials.  

    PubMed

    Platinum(II) octaethylporphyrin (PtOEP)-loaded organic-inorganic hybrids were obtained via the microwave-assisted sol-gel condensation with methyltrimethoxysilane and poly(vinylpyrrolidone). From transparent and homogeneous hybrid films, the strong phosphorescence from PtOEP was observed. Next, the resulting hybrids were immersed in the aqueous buffer, and the emission intensity was monitored by changing the dissolved oxygen level in the buffer. When the hybrid with relatively-higher amount of the silica element, the strong phosphorescence was observed even under the aerobic conditions. In contrast, the emission from the hybrids with lower amounts of the silica element was quenched under the hypoxic conditions. This is, to the best of our knowledge, the first example to demonstrate that the responsiveness of the phosphorescence intensity of PtOEP in hybrid films to the dissolved oxygen concentration in water can be modulated by changing the percentage of the contents in the material. PMID:24794749

    Okada, Hiroshi; Tanaka, Kazuo; Chujo, Yoshiki

    2014-06-15

    155

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

    SciTech Connect

    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.

    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

    156

    Flow chemistry meets advanced functional materials.  

    PubMed

    Flow chemistry and continuous processing techniques are beginning to have a profound impact on the production of functional materials ranging from quantum dots, nanoparticles and metal organic frameworks to polymers and dyes. These techniques provide robust procedures which not only enable accurate control of the product material's properties but they are also ideally suited to conducting experiments on scale. The modular nature of flow and continuous processing equipment rapidly facilitates reaction optimisation and variation in function of the products. PMID:25156609

    Myers, Rebecca M; Fitzpatrick, Daniel E; Turner, Richard M; Ley, Steven V

    2014-09-22

    157

    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...

    158

    TRANSPORT OF INORGANIC COLLOIDS THROUGH NATURAL AQUIFER MATERIAL: IMPLICATIONS FOR CONTAMINANT TRANSPORT  

    EPA Science Inventory

    The stability and transport of radiolabeled Fe2O3 particles were studied using laboratory batch and column techniques. Core material collected from a shallow sand and gravel aquifer was used as the immobile column matrix material. Variables in the study incl...

    159

    LABORATORY STUDIES ON THE STABILITY AND TRANSPORT OF INORGANIC COLLOIDS THROUGH NATURAL AQUIFER MATERIAL  

    EPA Science Inventory

    The stability and transport of radio-labeled Fe2O3 particles were studied using laboratory batch and column techniques. Core material collected from shallow sand and gravel aquifer was used as the immobile column matrix material. Variables in the study included flow rate, pH, i...

    160

    3-D molecular assembly of function in titania-based composite material systems.  

    PubMed

    Various examples of composite titania-based nanostructured materials exhibiting cooperative functionalities between different active components are presented. The fabrication of these integrated composite materials is based on one-pot supramolecular templating techniques combined with acidic sol-gel chemistry. The defined 3-D nanoscale organization and integration of various functional components results in advanced optoelectronic and photonic applications such as visible light sensitization of mesoporous titania photocatalysts with cadmium sulfide nanocrystals acting as sensitizing integral part of the mesopore wall structure, narrow bandwidth emission from rare earth ion activated nanocrystalline mesoporous titania films, and mirrorless lasing in dye-doped hybrid organic/inorganic mesostructured titania waveguides. PMID:15835873

    Bartl, Michael H; Boettcher, Shannon W; Frindell, Karen L; Stucky, Galen D

    2005-04-01

    161

    An assessment of inorganic ion-exchange materials for the removal of strontium from simulated Hanford tank wastes  

    SciTech Connect

    Several inorganic ion-exchange materials were evaluated for the removal of strontium from two simulated Hanford tank wastes (NCAW and 101SY-Cs5) using static batch experiments. Sodium titanium silicate, Na{sub 2}Ti{sub 2}O{sub 3}SiO{sub 4} {center_dot} 2H{sub 2}O (NaTS), was the best material in NCAW with a K{sub d} of 2.7 x 10{sup 5} mL/g at a volume-to-mass ratio of 200:1. In the 101SY-Cs5 simulant, strontium extraction was more difficult due to the presence of complexants and consequently K{sub d}s were greatly reduced. Sodium nonatitanate, NaTi, performed best in the presence of these complexants and gave a K{sub d} of 295 mL/g, though none of the materials performed particularly well. Pellets suitable for column studies were synthesized and the ion exchangers evaluated in column studies. Breakthrough curves correlated well with the K{sub d}s obtained from batch experiments with the sodium titanium silicate performing best in NCAW and a pelletized form of sodium nonatitanate performing best in 101SY-Cs5. Both the sodium titanate and the sodium titanosilicate performed better than IONSIV IE-911, a commercially available ion exchanger, in the NCAW simulant, and consequently could be used for the removal of {sup 90}Sr from highly alkaline tank wastes.

    Sylvester, P.; Behrens, E.A.; Graziano, G.M.; Clearfield, A. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry] [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry

    1999-07-01

    162

    All-inorganic nanocrystals as a glue for BiSbTe grains: design of interfaces in mesostructured thermoelectric materials.  

    PubMed

    Nano- and mesostructuring is widely used in thermoelectric (TE) materials. It introduces numerous interfaces and grain boundaries that scatter phonons and decrease thermal conductivity. A new approach has been developed for the rational design of the interfaces in TE materials by using all-inorganic nanocrystals (NCs) that serve as a "glue" for mesoscopic grains. For example, circa 10?nm Bi?NCs capped with (N2H5)4Sb2Te7 chalcogenidometallate ligands can be used as an additive to BiSbTe particles. During heat treatment, NCs fill up the voids between particles and act as a "glue", joining grains in hot-pressed pellets or solution-processed films. The chemical design of NC glue allowed the selective enhancement or decrease of the majority-carrier concentration near the grain boundaries, and thus resulted in doped or de-doped interfaces in granular TE material. Chemically engineered interfaces can be used as to optimize power factor and thermal conductivity. PMID:24852900

    Son, Jae Sung; Zhang, Hao; Jang, Jaeyoung; Poudel, Bed; Waring, Al; Nally, Luke; Talapin, Dmitri V

    2014-07-14

    163

    Trace Metal Availability in Soils Amended with Metal-Fixing Inorganic Materials  

    Microsoft Academic Search

    Immobilization of metals by two materials (zeolite, AZ, and a synthetic, carbonate-rich material, “slovakite”, SL) was tested\\u000a in a pot experiment with two soils from urban areas of Sevilla and two soils affected by a mine spill. Barley (Hordeum vulgare L. Hispanic) was grown in the pots, and metal contents were measured after 31 days in shoots and roots. Available metal

    M. C. Florido

    2009-01-01

    164

    Flagellar filament bio-templated inorganic oxide materials - towards an efficient lithium battery anode  

    NASA Astrophysics Data System (ADS)

    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.

    Beznosov, Sergei N.; Veluri, Pavan S.; Pyatibratov, Mikhail G.; Chatterjee, Abhijit; Macfarlane, Douglas R.; Fedorov, Oleg V.; Mitra, Sagar

    2015-01-01

    165

    Flagellar filament bio-templated inorganic oxide materials – towards an efficient lithium battery anode  

    PubMed Central

    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

    Beznosov, Sergei N.; Veluri, Pavan S.; Pyatibratov, Mikhail G.; Chatterjee, Abhijit; MacFarlane, Douglas R.; Fedorov, Oleg V.; Mitra, Sagar

    2015-01-01

    166

    Flagellar filament bio-templated inorganic oxide materials - towards an efficient lithium battery anode.  

    PubMed

    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

    Beznosov, Sergei N; Veluri, Pavan S; Pyatibratov, Mikhail G; Chatterjee, Abhijit; MacFarlane, Douglas R; Fedorov, Oleg V; Mitra, Sagar

    2015-01-01

    167

    Hydrodynamic cavitation as a tool to control macro-, micro-, and nano-properties of inorganic materials  

    Microsoft Academic Search

    Hydrodynamic cavitation was shown to be a powerful tool for the synthesis of nanostructured catalysts, ceramics, and piezoelectrics in high phase purities. The macro-, micro-, and nano- properties of solid-state materials could be controlled through adjusting the cavitational regime during synthesis by simple mechanical adjustment. The synthesis of nanostructured titania, piezoelectrics, perovskites, supported and unsupported cobalt molybdates, and Pd and

    J. Find; S. C. Emerson; I. M. Krausz; W. R. Mosera

    2001-01-01

    168

    First-principles studies of Ce and Eu doped inorganic materials as candidates for scintillator gamma ray detectors  

    NASA Astrophysics Data System (ADS)

    We have performed high-throughput DFT based (GGA+U) band structure calculations for new Ce and Eu doped wide band gap inorganic materials to determine their potential as candidates for gamma ray scintillator detectors. These calculations are based on determining the 4f ground state level of the Ce and Eu relative to the valence band of the host as well as the position of the Ce and Eu 5d excited state relative to the conduction band of the host. We find many classes of candidate materials where the 5d is in the conduction band preventing scintillation. Even when the Eu and Ce 4f and 5d levels are placed well in the gap of the host, traps on the host can also prevent the energy of the gamma ray transferring to the Eu or Ce. We therefore also performed calculations for host hole traps and electron traps to compare their energies to the Ce and Eu 4f and 5d levels.

    Canning, Andrew; Chourou, Slim; Derenzo, Stephen

    2012-02-01

    169

    Optical switch and luminescence properties of sol gel hybrid organic inorganic materials containing azobenzene groups and doped with neodymium ions  

    NASA Astrophysics Data System (ADS)

    TiO2/?-glycidoxypropyltrimethoxysilane and methyltrimethoxysilane hybrid organic inorganic material, which contains azobenzene groups and is doped with neodymium ions, was prepared by a low temperature sol gel technique. The trans-cis-trans photoisomerization cycles of the hybrid film were investigated by a photoirradiation with UV light followed by visible light. An intense room-temperature upconversion emission at 397 nm was also measured from a hybrid film heated at a low temperature of 80 °C upon excitation with a xenon lamp at a wavelength of 580 nm. The mechanism of the upconversion is proposed and indicates that the sequential two-photon absorption process originating from the long-lived 4 F 3/2 excited state should be responsible for the up-conversion process. These results indicate that the prepared hybrid materials with multifunctional photonic properties are promising candidates for integrated optics and photonic applications, which would allow directly integrating onto a single chip, the upconversion device with the pump source, and optical data storage and optical switching devices.

    Que, Wenxiu; Hu, X.

    2007-09-01

    170

    Hybrid Inorganic-Organic Materials with an Optoelectronically Active Aromatic Cation: (C7H7)2SnI6 and C7H7PbI3.  

    PubMed

    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

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

    2015-01-01

    171

    Sol-gel synthesis of hybrid organic-inorganic materials. Hexylene- and phenylene-bridged polysiloxanes  

    SciTech Connect

    New highly cross-linked polysiloxanes were prepared by sol-gel polymerization of 1,6-bis(diethoxymethylsilyl)hexane (1) and 1,4-bis(diethoxymethylsilyl)benzene (2). Hydrolysis and condensation of 1 and 2 under acidic and basic conditions with 4 equiv of water led to the rapid formation of hexylene- and phenylene-bridged polysiloxane gels. The dry gels (xerogels) were intractable, insoluble materials that were noticeably hydrophobic, exhibiting no swelling in organic solvents or water. Most of the xerogels were high surface area, mesoporous materials. Hexylene-bridged polysiloxanes prepared under acidic conditions were always nonporous regardless of whether they were processed to afford xerogels or supercritically dried as aerogels. Hexylene-bridged polysiloxanes prepared under basic conditions and all of the phenylene-bridged polysiloxanes were mesoporous with surface areas as high as 1025 m{sup 2}/g. 35 refs., 9 figs., 3 tabs.

    Loy, D.A.; Jamison, G.M.; Baugher, B.M.; Myers, S.A.; Assink, R.A.; Shea, K.J. [Sandia National Laboratories, Albuquerque, NM (United States)] [Sandia National Laboratories, Albuquerque, NM (United States); [Univ. of California, Irvine, CA (United States)

    1996-03-01

    172

    Organic and Inorganic Blended Materials for Use as Pop-Up Fertilizer for Cotton Seedlings  

    Microsoft Academic Search

    Various factors such as soil moisture at planting, application rate, and composition of the fertilizer materials have contributed to the erratic results from use of starter and “pop-up” fertilizers. Earlier research with ammonium polyphosphate (11–37–0) has shown some beneficial effects on growth and lint yield of cotton (Gossypium hirsutum L.) when the starter was placed in the seed furrow or

    J. E. Matocha; D. L. Coker

    2012-01-01

    173

    Direct Nanomachining of Inorganic Transparent Materials Using Laser Plasma Soft X-Rays  

    Microsoft Academic Search

    We have investigated micromachining of a variety of materials by irradiation with laser plasma soft X-rays (LPSXs) at around 10 nm. The pulsed LPSXs were generated by irradiation of a Ta target in a vacuum chamber with Nd:YAG laser light at 532 nm, with a pulse duration of 7 ns, at a fluence of ~104 J\\/cm2. The LPSXs were focused

    Tetsuya Makimura; Hisao Miyamoto; Satoshi Uchida; Hiroyuki Niino; Kouichi Murakami

    2007-01-01

    174

    Naked eye detection of cadmium using inorganic–organic hybrid mesoporous material  

    Microsoft Academic Search

    A novel and low-cost optical sensor for the naked eye detection of Cd2+in aqueous media based on mesoporous silica containing 4-(2-pyridylazo)resorcinol (PAR) as a probe molecule anchored by N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (TMAC) was prepared. The effects of various factors such as pH, solvent volume, temperature, reaction\\u000a time, amount of the material, and the presence of various ions were studied in order

    Tatineni Balaji; Manickam Sasidharan; Hideyuki Matsunaga

    2006-01-01

    175

    Sol-gel synthesis of hybrid organic-inorganic materials. Hexylene and phenylene-bridged polysiloxanes  

    Microsoft Academic Search

    New highly cross-linked polysiloxanes were prepared by sol-gel polymerization of 1,6-bis(diethoxymethylsilyl)hexane (1) and 1,4-bis(diethoxymethylsilyl)benzene (2). Hydrolysis and condensation of 1 and 2 under acidic and basic conditions with 4 equiv of water led to the rapid formation of hexylene- and phenylene-bridged polysiloxane gels. The dry gels (xerogels) were intractable, insoluble materials that were noticeably hydrophobic, exhibiting no swelling in organic

    Douglas A. Loy; Gregory M. Jamison; Brigitta M. Baugher; Sharon A. Myers; Roger A. Assink; Kenneth J. Shea

    1996-01-01

    176

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

    NASA Astrophysics Data System (ADS)

    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

    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

    177

    Direct Nanomachining of Inorganic Transparent Materials Using Laser Plasma Soft X-Rays  

    NASA Astrophysics Data System (ADS)

    We have investigated micromachining of a variety of materials by irradiation with laser plasma soft X-rays (LPSXs) at around 10 nm. The pulsed LPSXs were generated by irradiation of a Ta target in a vacuum chamber with Nd:YAG laser light at 532 nm, with a pulse duration of 7 ns, at a fluence of ~104 J/cm2. The LPSXs were focused on the surfaces of samples using an ellipsoidal mirror that is designed so that LPSXs at around 10 nm are focused efficiently. We found that quartz glass plates are ablated by LPSX irradiation at a typical rate of 48 nm/shot. Furthermore, the ablated regions have smooth surfaces with a roughness less than 10 nm after 10 shots of LPSX irradiation. It is demonstrated that quartz glass is machined with a lateral resolution higher than 100 nm. In addition to quartz glass, the LPSX processing can be applied to micromachining of a variety of materials such as Pyrex, CaF2, LiF, LiNbO3, Si and silicone.

    Makimura, Tetsuya; Miyamoto, Hisao; Uchida, Satoshi; Niino, Hiroyuki; Murakami, Kouichi

    2007-04-01

    178

    Naked eye detection of cadmium using inorganic-organic hybrid mesoporous material.  

    PubMed

    A novel and low-cost optical sensor for the naked eye detection of Cd2+ in aqueous media based on mesoporous silica containing 4-(2-pyridylazo)resorcinol (PAR) as a probe molecule anchored by N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (TMAC) was prepared. The effects of various factors such as pH, solvent volume, temperature, reaction time, amount of the material, and the presence of various ions were studied in order to optimize operating conditions. The detection was based on the color change of PAR from orange-yellow to purple as a result of complexation with Cd2+. The intensity of the Cd-PAR complex varies linearly with the Cd2+ concentration, from zero to 1.78x10(-7) mol dm(-3). The detection and quantification limits for the method when determining Cd2+ were 1.75x10(-8) and 5.77x10(-8) mol dm(-3), respectively, with a correlation coefficient of 0.99. Good chemical stability of the material was observed for a period of five months. The developed sensor was applied to the analysis of various industrial effluents and tap water samples. PMID:16341850

    Balaji, Tatineni; Sasidharan, Manickam; Matsunaga, Hideyuki

    2006-01-01

    179

    Experimental Synthesis of Organic Compounds From Inorganic Materials by the Simulated Impact on the Early Earth  

    NASA Astrophysics Data System (ADS)

    How to prepare prebiotic organic molecules on the early Earth has been debated vigorously. One of points of debates is how to overcome the difficulty to produce prebiotic organic molecules under moderately oxidizing CO2 and N2-rich early atmosphere. Previous investigators suggested the existence of early oceans well before 4.0 Ga, late heavy bombardments at around 4.0 Ga, and the earliest life at 3.8 Ga. In order to connect these geological evidences, we hypothesized that meteorite impacts, which brought many reductants, on the early oceans followed by interaction with the atmosphere were responsible for production of prebiotic organic molecules. In order to simulate the impact reaction, we performed shock-recovery experiments with single-stage propellant gun. The shocked materials are composed of mixture of iron, nickel, carbon, water and gaseous nitrogen or dissolved ammonia. The carbon in the starting materials is enriched in 99% of 13C so that the C-bearing products can be distinguished from contaminants. These mixtures were encapsulated in metal containers and then shocked with impact velocities of 1 km/s. Analyses of the experimental products were performed using the state-of-the-art LC/MS and GC/MS. Various organic molecules including bio molecules composed only of 13C are detected, verifying syntheses of those organic molecules during the shock experiments. This result further suggests that the late heavy bombardment on the early oceans, dynamic high-pressure conditions, triggered to form a large mass and variety of prebiotic organic molecules on the early Earth.

    Furukawa, Y.; Sekine, T.; Oba, M.; Kakegawa, T.; Nakazawa, H.

    2008-12-01

    180

    Physical state and acidity of inorganic sulfate can regulate the production of secondary organic material from isoprene photooxidation products.  

    PubMed

    The production of secondary organic material (SOM) by the reactive uptake of isoprene photooxidation products was investigated using partially to wholly neutralized sulfuric acid particles. The experiments were performed at a relative humidity (RH) of <5% and a temperature of 20 °C. The extent X of neutralization was adjusted from that of sulfuric acid (X = 0) to that of ammonium sulfate (X = 1). Significant SOM production was observed only for X < 0.7. The threshold of 0.7 corresponded to the transition point of the sulfate particles from aqueous to solid for <5% RH. The phase transition of inorganic sulfate therefore regulated the particle-phase reactions that produce isoprene SOM, at least for the investigated conditions. For aqueous particles, a decreasing extent of neutralization was associated with increasing production of SOM, including increased production of oligomers and organosulfates. These results can underpin treatments of phase-dependent SOM production within chemical transport models, thereby improving the accuracy of simulations of biogenic-anthropogenic interactions in the atmosphere and the associated impacts of aerosol particles on climate and air quality. PMID:25623937

    Kuwata, Mikinori; Liu, Yingjun; McKinney, Karena; Martin, Scot T

    2015-02-10

    181

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

    NASA Astrophysics Data System (ADS)

    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.

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

    2010-09-01

    182

    Electron Microscopy Localization and Characterization of Functionalized Composite Organic-Inorganic SERS Nanoparticles on Leukemia Cells  

    PubMed Central

    We demonstrate the use of electron microscopy as a powerful characterization tool to identify and locate antibody-conjugated composite organic-inorganic (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 cases, the backscattered electron detector (BSE) was used to detect and identify the silver constituents in COINs due to its high sensitivity to atomic number variations within a specimen. The imaging and analytical capabilities in the SEM were further complemented by higher resolution Transmission Electron Microscope (TEM) images and Scanning Auger Electron Spectroscopy (AES) data to give reliable and high-resolution information about nanoparticles and their binding to cell surface antigens. PMID:18995965

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

    2008-01-01

    183

    Study of high resistance inorganic coatings on graphite fibers. [for graphite-epoxy composite materials  

    NASA Technical Reports Server (NTRS)

    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.

    Galasso, F. S.; Veltri, R. D.; Scola, D. A.

    1979-01-01

    184

    Functional polarity of the tentacle of the sea anemone Anemonia viridis: role in inorganic carbon acquisition.  

    PubMed

    The oral epithelial layers of anthozoans have a polarized morphology: photosynthetic endosymbionts live within endodermal cells facing the coelenteric cavity and are separated from the external seawater by the ectodermal layer and the mesoglea. To study if this morphology plays a role in the supply of inorganic carbon for symbiont photosynthesis, we measured the change in pH and the rate of OH- (H+) fluxes induced by each cell layer on a tentacle of the sea anemone Anemonia viridis. Light-induced pH increase of the medium bathing the endodermal layers led to the generation of a transepithelial pH gradient of approximately 0.8 pH units across the tentacle, whereas darkness induced acidification of this medium. The light-induced pH change was associated with an increase of total alkalinity. Only the endodermal layer was able to induce a net OH- secretion (H+ absorption). The light-induced OH- secretion by the endodermal cell layer was dependent on the presence of HCO3- in the compartment facing the ectoderm and was sensitive to several inhibitors of ion transport. [14C] HCO3- incorporation into photosynthates confirmed the ectodermal supply, the extent of which varied from 25 to > 90%, according to HCO3- availability. Our results suggest that the light-induced OH- secretion by the endodermal cell layer followed the polarized transport of HCO3- and its subsequent decarboxylation within the endodermal cell layer. This polarity may play a significant role both in inorganic carbon absorption and in the control of light-enhanced calcification in scleractinian corals. PMID:9486285

    Furla, P; Bénazet-Tambutté, S; Jaubert, J; Allemand, D

    1998-02-01

    185

    Modeling Bamboo as a Functionally Graded Material  

    SciTech Connect

    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.

    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

    186

    Functionally graded materials produced by laser cladding  

    Microsoft Academic Search

    AlSi40 functionally graded materials (FGMs) were produced by a one-step laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surrounded by ?-Al dendritic halos and by Al\\/Si eutectic. The Si particles exhibit a continuous increase in

    Y. T. Pei; J. Th. M. De Hosson

    2000-01-01

    187

    Inorganic separator technology program  

    NASA Technical Reports Server (NTRS)

    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.

    Smatko, J. S.; Weaver, R. D.; Kalhammer, F. R.

    1973-01-01

    188

    Flexible hydrogel-based functional composite materials  

    DOEpatents

    A composite having a flexible hydrogel polymer formed by mixing an organic phase with an inorganic composition, the organic phase selected from the group consisting of a hydrogel monomer, a crosslinker, a radical initiator, and/or a solvent. A polymerization mixture is formed and polymerized into a desired shape and size.

    2013-10-08

    189

    In situ modification of the silica backbone leading to highly porous monolithic hybrid organic-inorganic materials via ambient pressure drying.  

    PubMed

    We report the synthesis of monolithic porous hybrid organic-inorganic materials based on tetraethoxysilane (TEOS) and a bifunctional precursor synthesized from 3-aminopropyltriethoxysilane (APTES) and 3-glycidoxypropyltrimethoxysilane (GLYMO) via base catalysis. To compensate for the slower hydrolysis and condensation rate of the organically modified silane in basic media, it was prehydrolysed prior to adding it to the silane solution. This process leads to a lower shrinkage and stable monoliths with densities as low as 200 kg/m(3). Analysis of the samples supports the assumption that the porous monolithic materials derived via ambient pressure drying of the gels consist of a network of homogeneous hybrid primary particles. These particles are larger than their inorganic counterparts in classical silica gels and therefore the capillary forces while drying the gels at ambient pressure are reduced. This leads to less shrinkage and thus lower densities of the materials derived via ambient pressure drying. An inorganic xerogel with the same low density can be achieved by a subsequent oxidation step that decomposes the organic moieties. PMID:24354277

    Noisser, Theresa; Reichenauer, Gudrun; Hüsing, Nicola

    2014-01-22

    190

    Love wave propagation in functionally graded piezoelectric material layer  

    E-print Network

    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

    Wang, Ji

    191

    Magnetic spectroscopy and microscopy of functional materials  

    SciTech Connect

    Heusler intermetallics Mn{sub 2}Y Ga and X{sub 2}MnGa (X; Y =Fe, Co, Ni) undergo tetragonal magnetostructural transitions that can result in half metallicity, magnetic shape memory, or the magnetocaloric effect. Understanding the magnetism and magnetic behavior in functional materials is often the most direct route to being able to optimize current materials for todays applications and to design novel ones for tomorrow. Synchrotron soft x-ray magnetic spectromicroscopy techniques are well suited to explore the the competing effects from the magnetization and the lattice parameters in these materials as they provide detailed element-, valence-, and site-specifc information on the coupling of crystallographic ordering and electronic structure as well as external parameters like temperature and pressure on the bonding and exchange. Fundamental work preparing the model systems of spintronic, multiferroic, and energy-related compositions is presented for context. The methodology of synchrotron spectroscopy is presented and applied to not only magnetic characterization but also of developing a systematic screening method for future examples of materials exhibiting any of the above effects. The chapter progression is as follows: an introduction to the concepts and materials under consideration (Chapter 1); an overview of sample preparation techniques and results, and the kinds of characterization methods employed (Chapter 2); spectro- and microscopic explorations of X{sub 2}MnGa/Ge (Chapter 3); spectroscopic investigations of the composition series Mn{sub 2}Y Ga to the logical Mn{sub 3}Ga endpoint (Chapter 4); and a summary and overview of upcoming work (Chapter 5). Appendices include the results of a Think Tank for the Graduate School of Excellence MAINZ (Appendix A) and details of an imaging project now in progress on magnetic reversal and domain wall observation in the classical Heusler material Co{sub 2}FeSi (Appendix B).

    Jenkins, C.A.

    2011-01-28

    192

    Gold nanoparticles-induced enhancement of the analytical response of an electrochemical biosensor based on an organic-inorganic hybrid composite material.  

    PubMed

    The design and characterization of a new organic-inorganic hybrid composite material for glucose electrochemical sensing are described. This material is based on the entrapment of both gold nanoparticles (AuNPs) and glucose oxidase, which was chosen as a model, into a sol-gel matrix. The addition of spectroscopic grade graphite to this system, which confers conductivity, leads to the development of a material particularly attractive for electrochemical biosensor fabrication. The characterization of the hybrid composite material was performed using atomic force microscopy and scanning electron microscopy techniques. This composite material was applied to the determination of glucose in presence of hydroxymethylferrocene as a redox mediator. The system exhibits a clear electrocatalytic activity towards glucose, allowing its determination at 250 mV vs Ag/AgCl. The performance of the resulting enzyme biosensor was evaluated in terms of sensitivity, detection limit, linear response range, stability and accuracy. Finally, the enhancement of the analytical response of the resulting biosensor induced by the presence of gold nanoparticles was evaluated by comparison with a similar organic-inorganic hybrid composite material without AuNPs. PMID:19836554

    Barbadillo, M; Casero, E; Petit-Domínguez, M D; Vázquez, L; Pariente, F; Lorenzo, E

    2009-12-15

    193

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

    PubMed

    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

    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

    194

    Gen IV Materials Handbook Functionalities and Operation  

    SciTech Connect

    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.

    Ren, Weiju [ORNL

    2009-12-01

    195

    Long-term effects of inorganic fertilizers on microbial biomass and community functional diversity in a paddy soil derived from quaternary red clay  

    Microsoft Academic Search

    Long-term effects of inorganic fertilizers on microbial biomass and community functional diversity were investigated in a paddy soil derived from quaternary red clay in the Red Soil Ecological Experimental Station of the Chinese Academy of Sciences. The original soil is extremely eroded, characterized by low pH and deficiencies of available nutrients, particularly phosphorus and nitrogen. After 13 years application of

    W. H. Zhong; Z. C. Cai

    2007-01-01

    196

    Synthesis and Characterization of a Layered Manganese Oxide: Materials Chemistry for the Inorganic or Instrumental Methods Lab  

    ERIC Educational Resources Information Center

    A three-week laboratory project involving synthesis and characterization of a layered manganese oxide provides an excellent vehicle for teaching important concepts of inorganic chemistry and instrumental methods related to non-molecular systems. Na-birnessite is an easily prepared manganese oxide with a 7 A interlayer spacing and Na[superscript +]…

    Ching, Stanton; Neupane, Ram P.; Gray, Timothy P.

    2006-01-01

    197

    Inorganic Nanoparticles for Multimodal Molecular Imaging  

    PubMed Central

    Multimodal molecular imaging can offer a synergistic improvement of diagnostic ability over a single imaging modality. Recent development of hybrid imaging systems has profoundly impacted the pool of available multimodal imaging probes. In particular, much interest has been focused on biocompatible, inorganic nanoparticle–based multimodal probes. Inorganic nanoparticles offer exceptional advantages to the field of multimodal imaging owing to their unique characteristics, such as nanometer dimensions, tunable imaging properties, and multifunctionality. Nanoparticles mainly based on iron oxide, quantum dots, gold, and silica have been applied to various imaging modalities to characterize and image specific biologic processes on a molecular level. A combination of nanoparticles and other materials such as biomolecules, polymers, and radiometals continue to increase functionality for in vivo multimodal imaging and therapeutic agents. In this review, we discuss the unique concepts, characteristics, and applications of the various multimodal imaging probes based on inorganic nanoparticles. PMID:21303611

    Swierczewska, Magdalena; Lee, Seulki; Chen, Xiaoyuan

    2013-01-01

    198

    Fabrication of functional materials in microfluidics  

    NASA Astrophysics Data System (ADS)

    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.

    Shum, Ho Cheung

    199

    Functional Hydrogel Materials Inspired by Amyloid  

    NASA Astrophysics Data System (ADS)

    Protein assembly resulting in the formation of amyloid fibrils, assemblies rich in cross beta-sheet structure, is normally thought of as a deleterious event associated with disease. However, amyloid formation is also involved in a diverse array of normal biological functions such as cell adhesion, melanin synthesis, insect defense mechanism and modulation of water surface tension by fungi and bacteria. These findings indicate that Nature has evolved to take advantage of large, proteinaceous fibrillar assemblies to elicit function. We are designing functional materials, namely hydrogels, from peptides that self-assembled into fibrillar networks, rich in cross beta-sheet structure. These gels can be used for the direct encapsulation and delivery of small molecule-, protein- and cell-based therapeutics. Loaded gels exhibit shear-thinning/self-healing mechanical properties enabling their delivery via syringe. In addition to their use for delivery, we have found that some of these gels display antibacterial activity. Although cytocompatible towards mammalian cells, the hydrogels can kill a broad spectrum of bacteria on contact.

    Schneider, Joel

    2012-02-01

    200

    Hybrid nanoscale inorganic cages  

    NASA Astrophysics Data System (ADS)

    Cage structures exhibit inherent high symmetry and beauty, and both naturally occurring and synthetic molecular-scale cages have been discovered. Their characteristic high surface area and voids have led to their use as catalysts and catalyst supports, filtration media and gas storage materials. Nanometre-scale cage structures have also been synthesized, notably noble-metal cube-shaped cages prepared by galvanic displacement with promising applications in drug delivery and catalysis. Further functionality for nanostructures in general is provided by the concept of hybrid nanoparticles combining two disparate materials on the same system to achieve synergistic properties stemming from unusual material combinations. We report the integration of the two powerful concepts of cages and hybrid nanoparticles. A previously unknown edge growth mechanism has led to a new type of cage-structured hybrid metal-semiconductor nanoparticle; a ruthenium cage was grown selectively on the edges of a faceted copper(I) sulphide nanocrystal, contrary to the more commonly observed facet and island growth modes of other hybrids. The cage motif was extended by exploiting the open frame to achieve empty cages and cages containing other semiconductors. Such previously unknown nano-inorganic cage structures with variable cores and metal frames manifest new chemical, optical and electronic properties and demonstrate possibilities for uses in electrocatalysis.

    MacDonald, Janet E.; Bar Sadan, Maya; Houben, Lothar; Popov, Inna; Banin, Uri

    2010-10-01

    201

    ESR dosimetry using inorganic materials: a case study of Li2CO3 and CaSO4:Dy as prospective dosimeters.  

    PubMed

    The CO2- radical ion, detected by ESR technique in bones and teeth enamel, was proved to be invaluable in high level and retrospective dosimetry. In these matrices, impurity carbonate (at phosphate sites) was the precursor to CO2-. With a view to investigate the possibility of using inorganic materials such as lithium carbonate as ESR dosimeters, studies were carried out on gamma-irradiated Li2CO3. The intensity of radiation-induced ESR signals of Li2CO3 at g = 2.0036 (CO3-) and g = 2.0006 (CO2-) was followed as a function of gamma dose in the low dose range of 1-1350 Gy. It was observed that the intensity of the ESR signal at g = 2.0036 (CO3-) was in a linear relation with the radiation dose in the dose range 10-800 Gy and the signal at g = 2.0006 (CO2-) showed linear response in the dose range 5-800 Gy. The lowest dose that could be detected in the present studies using the signal of CO2- in Li2CO3 powder samples (approximately 50 mg) is 3.2 Gy. ESR studies were also carried out on the widely used TL dosimetric material CaSO4:Dy and in pure CaSO4 after gamma irradiation. The TL materials were used in powder as well as pellet forms. The linearity of ESR response with dose for powder and pellet forms of CaSO4: Dy was also studied using the signals at g = 2.0030 (SO3-) and at g = 2.0139 (SO4-). It was observed that the range of linearity of dose response extended between 20 and 1200 Gy, for SO3- signals. The results of dosimetric study indicate that the ESR-Li2CO3 system could be used in dosimetric applications in radiotherapy. However, for the actual applications further advancement is needed to lower the detection limit. The TL phosphor, CaSO4:Dy in powder and pellet forms, could be used as ESR dosimeter in the dose range 20-600 Gy. PMID:11393767

    Murali, S; Natarajan, V; Venkataramani, R; Pushparaja; Sastry, M D

    2001-08-01

    202

    Catalytical Functions of Metallic Nanostructures and Nanostructured Materials  

    E-print Network

    Catalytical Functions of Metallic Nanostructures and Nanostructured Materials T. Diemant1 , R: Functional Nanostructures, T. Schimmel and H. v. Loehneysen (Eds.) (Springer-Verlag Berlin, Heidelberg New

    Pfeifer, Holger

    203

    29 CFR 1208.4 - Material relating to representation function.  

    Code of Federal Regulations, 2011 CFR

    ...2011-07-01 false Material relating to representation function. 1208.4 Section 1208... § 1208.4 Material relating to representation function. (a) The documents...evidence submitted in connection with a representation dispute and the investigatory...

    2011-07-01

    204

    29 CFR 1208.4 - Material relating to representation function.  

    Code of Federal Regulations, 2010 CFR

    ...2010-07-01 false Material relating to representation function. 1208.4 Section 1208... § 1208.4 Material relating to representation function. (a) The documents...evidence submitted in connection with a representation dispute and the investigatory...

    2010-07-01

    205

    29 CFR 1208.4 - Material relating to representation function.  

    Code of Federal Regulations, 2012 CFR

    ...2012-07-01 false Material relating to representation function. 1208.4 Section 1208... § 1208.4 Material relating to representation function. (a) The documents...evidence submitted in connection with a representation dispute and the investigatory...

    2012-07-01

    206

    Indirectly detected through-bond chemical shift correlation NMR spectroscopy in solids under fast MAS: Studies of organic-inorganic hybrid materials  

    NASA Astrophysics Data System (ADS)

    Indirectly detected, through-bond NMR correlation spectra between 13C and 1H nuclei are reported for the first time in solid state. The capabilities of the new method are demonstrated using naturally abundant organic-inorganic mesoporous hybrid materials. The time performance is significantly better, almost by a factor of 10, than in the corresponding 13C detected experiment. The proposed scheme represents a new analytical tool for studying other solid-state systems and the basis for the development of more advanced 2D and 3D correlation methods.

    Mao, Kanmi; Wiench, Jerzy W.; Lin, Victor S.-Y.; Pruski, Marek

    2009-01-01

    207

    Indirectly detected through-bond chemical shift correlation NMR spectroscopy in solids under fast MAS: Studies of organic-inorganic hybrid materials  

    SciTech Connect

    Indirectly detected, through-bond NMR correlation spectra between {sup 13}C and {sup 1}H nuclei are reported for the first time in solid state. The capabilities of the new method are demonstrated using naturally abundant organic-inorganic mesoporous hybrid materials. The time performance is significantly better, almost by a factor of 10, than in the corresponding {sup 13}C detected experiment. The proposed scheme represents a new analytical tool for studying other solid-state systems and the basis for the development of more advanced 2D and 3D correlation methods.

    Mao, Kanmi; Wiench, Jerzy; Lin, Victor S.-Y.; Pruski, Marek

    2008-10-12

    208

    Functional organic materials for electronics industries  

    NASA Technical Reports Server (NTRS)

    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.

    Shibayama, K.; Ono, H.

    1982-01-01

    209

    Potential of hybrid functionalized meso-porous materials for the separation and immobilization of radionuclides  

    SciTech Connect

    Functionalized meso-porous materials are a class of hybrid organic-inorganic material in which a meso-porous metal oxide framework is functionalized with multifunctional organic molecules. These molecules may contain one or more anchor groups that form strong bonds to the pore surfaces of the metal oxide framework and free functional groups that can impart and or modify the functionality of the material such as for binding metal ions in solution. Such materials have been extensively studied over the past decade and are of particular interest in absorption applications because of the tremendous versatility in choosing the composition and architecture of the metal oxide framework and the nature of the functional organic molecule as well as the efficient mass transfer that can occur through a well-designed hierarchically porous network. A sorbent for nuclear applications would have to be highly selective for particular radio nuclides, it would need to be hydrolytically and radiolytically stable, and it would have to possess reasonable capacity and fast kinetics. The sorbent would also have to be available in a form suitable for use in a column. Finally, it would also be desirable if once saturated with radio nuclides, the sorbent could be recycled or converted directly into a ceramic or glass waste form suitable for direct repository disposal or even converted directly into a material that could be used as a transmutation target. Such a cradle-to- grave strategy could have many benefits in so far as process efficiency and the generation of secondary wastes are concerned.This paper will provide an overview of work done on all of the above mentioned aspects of the development of functionalized meso-porous adsorbent materials for the selective separation of lanthanides and actinides and discuss the prospects for future implementation of a cradle-to-grave strategy with such materials. (author)

    Luca, V. [Programa Nacional de Gestion de Residuos Radiactivos, Comision Nacional de Energia Atomica, Centro Atomico Constituyentes, Av. General, Paz 1499, 1650 San Martin, Provincia de Buenos Aires (Argentina)

    2013-07-01

    210

    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

    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

    Galloway, Joel M.

    2008-01-01

    211

    Simulating functional magnetic materials on supercomputers.  

    PubMed

    The recent passing of the petaflop per second landmark by the Roadrunner project at the Los Alamos National Laboratory marks a preliminary peak of an impressive world-wide development in the high-performance scientific computing sector. Also, purely academic state-of-the-art supercomputers such as the IBM Blue Gene/P at Forschungszentrum Jülich allow us nowadays to investigate large systems of the order of 10(3) spin polarized transition metal atoms by means of density functional theory. Three applications will be presented where large-scale ab initio calculations contribute to the understanding of key properties emerging from a close interrelation between structure and magnetism. The first two examples discuss the size dependent evolution of equilibrium structural motifs in elementary iron and binary Fe-Pt and Co-Pt transition metal nanoparticles, which are currently discussed as promising candidates for ultra-high-density magnetic data storage media. However, the preference for multiply twinned morphologies at smaller cluster sizes counteracts the formation of a single-crystalline L1(0) phase, which alone provides the required hard magnetic properties. The third application is concerned with the magnetic shape memory effect in the Ni-Mn-Ga Heusler alloy, which is a technologically relevant candidate for magnetomechanical actuators and sensors. In this material strains of up to 10% can be induced by external magnetic fields due to the field induced shifting of martensitic twin boundaries, requiring an extremely high mobility of the martensitic twin boundaries, but also the selection of the appropriate martensitic structure from the rich phase diagram. PMID:21828528

    Gruner, Markus Ernst; Entel, Peter

    2009-07-22

    212

    Dynamic stability characteristics of functionally graded materials shallow spherical shells  

    Microsoft Academic Search

    Here, the dynamic stability behavior of a clamped functionally graded materials spherical shell structural element subjected to external pressure load is studied. The material properties are graded in the thickness direction according to the power-law distribution in terms of volume fractions of the constituents of the material. The effective material properties are evaluated using a homogenization method. The structural model

    M. Ganapathi

    2007-01-01

    213

    Density functional theory in materials science  

    PubMed Central

    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

    Neugebauer, Jörg; Hickel, Tilmann

    2013-01-01

    214

    Inorganic salts interact with oxalic acid in submicron particles to form material with low hygroscopicity and volatility  

    NASA Astrophysics Data System (ADS)

    Volatility and hygroscopicity are two key properties of organic aerosol components, and both are strongly related to chemical identity. While the hygroscopicities of pure salts, di-carboxylic acids (DCA), and DCA salts are known, the hygroscopicity of internal mixtures of these components, as they are typically found in the atmosphere, has not been fully characterized. Here we show that inorganic-organic component interactions typically not considered in atmospheric models can lead to very strongly bound metal-organic complexes and greatly affect aerosol volatility and hygroscopicity; in particular, the bi-dentate binding of DCA to soluble inorganic ions. We have studied the volatility of pure, dry organic salt particles and the hygroscopicity of internal mixtures of oxalic acid (OxA, the dominant DCA in the atmosphere) and a number of salts, both mono- and di-valent. The formation of very low volatility organic salts was confirmed, with minimal evaporation of oxalate salt particles below 75 °C. Dramatic increases in the cloud condensation nuclei (CCN) activation diameter for particles with di-valent salts (e.g., CaCl2) and relatively small particle volume fractions of OxA indicate that standard volume additivity rules for hygroscopicity do not apply. Thus small organic compounds with high O : C ratios are capable of forming low-volatility and very low hygroscopicity particles. Given current knowledge of the formation mechanisms of OxA and M-Ox salts, surface enrichment of insoluble M-Ox salts is expected. The resulting formation of an insoluble coating of metal-oxalate salts can explain low-particle hygroscopicities. The formation of particles with a hard coating could offer an alternative explanation for observations of glass-like particles without the need for a phase transition.

    Drozd, G.; Woo, J.; Häkkinen, S. A. K.; Nenes, A.; McNeill, V. F.

    2014-05-01

    215

    Engineering multiferroic materials and new functionalities in materials  

    NASA Astrophysics Data System (ADS)

    This dissertation details the synthesis and properties of thin films and devices based on multiferroic materials. The primary advances made as a result of the work described herein are the growth and characterization of thin films of the candidate multiferroic PbVO3, the growth and nanoscale domain control of the model multiferroic BiFeO3 through a number of methods, the growth and detailed characterization of exchange heterostructures based on Co0.9Fe0.1/BiFeO 3, the correlation of ferroelectric domain structure in BiFeO3 to the exchange bias properties exhibited, discussion of the mechanism for these varied properties, and the first evidence for electrical control of ferromagnetism with a multiferroic material at room temperature.

    Martin, Lane Wyatt

    216

    Nanocomposites of polymer and inorganic nanoparticles for optical and magnetic applications  

    PubMed Central

    This article provides an up-to-date review on nanocomposites composed of inorganic nanoparticles and the polymer matrix for optical and magnetic applications. Optical or magnetic characteristics can change upon the decrease of particle sizes to very small dimensions, which are, in general, of major interest in the area of nanocomposite materials. The use of inorganic nanoparticles into the polymer matrix can provide high-performance novel materials that find applications in many industrial fields. With this respect, frequently considered features are optical properties such as light absorption (UV and color), and the extent of light scattering or, in the case of metal particles, photoluminescence, dichroism, and so on, and magnetic properties such as superparamagnetism, electromagnetic wave absorption, and electromagnetic interference shielding. A general introduction, definition, and historical development of polymer–inorganic nanocomposites as well as a comprehensive review of synthetic techniques for polymer–inorganic nanocomposites will be given. Future possibilities for the development of nanocomposites for optical and magnetic applications are also introduced. It is expected that the use of new functional inorganic nano-fillers will lead to new polymer–inorganic nanocomposites with unique combinations of material properties. By careful selection of synthetic techniques and understanding/exploiting the unique physics of the polymeric nanocomposites in such materials, novel functional polymer–inorganic nanocomposites can be designed and fabricated for new interesting applications such as optoelectronic and magneto-optic applications. PMID:22110855

    Li, Shanghua; Meng Lin, Meng; Toprak, Muhammet S.; Kim, Do Kyung; Muhammed, Mamoun

    2010-01-01

    217

    Surface functionalization of semiconductor and oxide nanocrystals with small inorganic oxoanions (PO4(3-), MoO4(2-)) and polyoxometalate ligands.  

    PubMed

    In this work, we study the functionalization of the nanocrystal (NC) surface with inorganic oxo ligands, which bring a new set of functionalities to all-inorganic colloidal nanomaterials. We show that simple inorganic oxoanions, such as PO4(3-) and MoO4(2-), exhibit strong binding affinity to the surface of various II-VI and III-V semiconductor and metal oxide NCs. ?-Potential titration offered a useful tool to differentiate the binding affinities of inorganic ligands toward different NCs. Direct comparison of the binding affinity of oxo and chalcogenidometallate ligands revealed that the former ligands form a stronger bond with oxide NCs (e.g., Fe2O3, ZnO, and TiO2), while the latter prefer binding to metal chalcogenide NCs (e.g., CdSe). The binding between NCs and oxo ligands strengthens when moving from small oxoanions to polyoxometallates (POMs). We also show that small oxo ligands and POMs make it possible to tailor NC properties. For example, we observed improved stability upon Li(+)-ion intercalation into the films of Fe2O3 hollow NCs when capped with MoO4(2-) ligands. We also observed lower overpotential and enhanced exchange current density for water oxidation using Fe2O3 NCs capped with [P2Mo18O62](6-) ligands and even more so for [{Ru4O4(OH)2(H2O)4}(?-SiW10O36)2] with POM as the capping ligand. PMID:25181260

    Huang, Jing; Liu, Wenyong; Dolzhnikov, Dmitriy S; Protesescu, Loredana; Kovalenko, Maksym V; Koo, Bonil; Chattopadhyay, Soma; Shenchenko, Elena V; Talapin, Dmitri V

    2014-09-23

    218

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

    PubMed

    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. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25476948

    Yin, Xijie; Chen, Zhigang

    2014-12-01

    219

    Thiol functionalized polymers for dielectric materials.  

    SciTech Connect

    The development of functionalized polymer dielectrics based on poly(norbornene) and poly(PhONDI) (PhONDI = N-phenyl-7-oxanorbornene-5,6-dicarboximide) is presented. Functionalization of the polymer backbones by the thiol-ene reaction was examined to determine if thiol addition improved dielectric properties. Poly(norbornene) was not amenable to functionalization due to the propensity to crosslink under the reaction conditions studied. Poly(PhONDI) could be successfully functionalized, and the functionalized polymer was found to have increased breakdown strength as well as improved solution stability. Initial studies on the development of thiol-functionalized silica/poly(PhONDI) nanocomposites and their dielectric properties will also be discussed.

    Appelhans, Leah

    2010-11-01

    220

    Polyoxometalates Macroanions: From Self-Recognition to Functional Materials  

    NASA Astrophysics Data System (ADS)

    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.

    Yin, Panchao

    221

    Physicochemical characterization of silylated functionalized materials.  

    PubMed

    Silylation of several materials where the surface area arises from the internal pores (MCM-41 and FSM-16) or is essentially external (silica gel, and clays) was performed using three organosilanes: (3-aminopropyl)triethoxysilane (APTES), 4-(triethoxysilyl)aniline (TESA) and (3-mercaptopropyl)trimethoxysilane (MPTS). The materials were characterized by nitrogen adsorption-desorption at -196 degrees C, powder XRD, XPS, bulk chemical analysis, FTIR and (29)Si and (13)C MAS NMR. For MCM-41 and FSM-16 the highest amounts of organosilane are obtained for APTES, while for the remaining materials the highest amounts are for MPTS; TESA always anchored with the lowest percentage. In terms of surface chemical analysis, TESA anchored with the highest contents irrespectively of the material, and the opposite is registered for MPTS. Comparison of bulk vs surface contents indicate that TESA is mainly anchored at the material external surface. Moreover, with N or S (surface and bulk) contents expressed per unit of surface area, MCM-41 and FSM-16 (internal porosity) show the lowest amounts of silane; the highest amounts of silane per unit of surface area are obtained for the clays. Grafting of the organosilanes to the surface hydroxyl groups was corroborated by FTIR and (29)Si and (13)C MAS NMR. Furthermore, NMR data suggested that TESA and APTES grafted mostly through a bidentate approach, whereas MPTS grafted by a monodentate mechanism. PMID:20129614

    Borrego, Tiago; Andrade, Marta; Pinto, Moisés L; Silva, Ana Rosa; Carvalho, Ana P; Rocha, João; Freire, Cristina; Pires, João

    2010-04-15

    222

    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)

    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.

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

    2011-05-01

    223

    Validation of noninvasive monitoring of adrenocortical endocrine activity in ground-feeding aardwolves (Proteles cristata): exemplifying the influence of consumption of inorganic material for fecal steroid analysis.  

    PubMed

    Biologically inert material in feces may confound interpretations of noninvasive fecal endocrine data, because it may induce variance related to differences in foraging behavior rather than to differences in endocrine activity. We evaluated two different enzyme immunoassays (EIAs) for the noninvasive evaluation of adrenocortical activity in ground-feeding aardwolves (Proteles cristata) and tested the influence of soil content in aardwolf feces on the interpretation of fecal glucocorticoid metabolite data. Using adrenocorticotropic hormone (ACTH) challenges for validation, we successfully identified a cortisol EIA suitable for assessing adrenocortical activity in aardwolves. An alternatively tested 11-oxoetiocholanolone EIA failed to detect a biologically relevant signal after ACTH administration. Although the proportion of inorganic content in aardwolf feces did not alter qualitative conclusions from the endocrine data, the data related to mass of organic content had a larger amount of variance attributed to relevant biological contrasts and a lower amount of variance attributed to individual variation, compared with data related to total dry mass of extracted material. Compared with data expressed as dry mass of extracted material, data expressed as mass of organic content may provide a more refined and statistically powerful measure of endocrine activity in species that ingest large amounts of indigestible material. PMID:22418711

    Ganswindt, André; Muilwijk, Charlotte; Engelkes, Monique; Muenscher, Stefanie; Bertschinger, Henk; Paris, Monique; Palme, Rupert; Cameron, Elissa Z; Bennett, Nigel C; Dalerum, Fredrik

    2012-01-01

    224

    Ion-Conducting Organic/Inorganic Polymers  

    NASA Technical Reports Server (NTRS)

    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.

    Kinder, James D.; Meador, Mary Ann B.

    2007-01-01

    225

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

    E-print Network

    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, ...

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

    2011-01-01

    226

    The influence of humic acid on the adsorption of europium onto inorganic colloids as a function of pH  

    Microsoft Academic Search

    The effect of pH (2–10) and humic acid (HA) concentration on the adsorption of HA onto a range of pure-phase inorganic colloids (?-alumina, haematite, manganese dioxide, amorphous silica and titanium dioxide) has been studied, and the influence of HA on the colloidal zeta-potential has been investigated. The results showed a decrease in the adsorption of HA with increasing pH, due

    Andrew J Fairhurst; Peter Warwick; Steve Richardson

    1995-01-01

    227

    PREFACE: Annual Conference on Functional Materials and Nanotechnologies - FM&NT 2011  

    NASA Astrophysics Data System (ADS)

    The International Conference Functional Materials and Nanotechnologies (FM&NT-2011) was held in Riga, 5-8 April 2011 in the Institute of Solid State Physics, University of Latvia (ISSP LU). The conference was organized in co-operation with projects ERANET 'MATERA' and National Research programme in Materials Science and Information Technologies. The purpose of the conference was to bring together scientists, engineers and students from universities, research institutes and related industrial companies active in the field of advanced material science and materials technologies trends and future activities. Scientific themes covered in the conference are: theoretical research and modelling of processes and materials; materials for energetics, renewable energy technologies and phtovoltaics; multifunctional inorganic, organic and hybrid materials for photonic, micro and nanoelectronic applications and innovative methods for research of nanostructures; advanced technologies for synthesis and research of nanostructured materials, nanoparticles, thin films and coatings; application of innovative materials in science and economics. The number of registered participants from 17 countries was nearly 300. During three days of the conference 22 invited, 69 oral reports and 163 posters were presented. 40 papers, based on these reports, are included in this volume of IOP Conference Series: Materials Science and Engineering. Additional information about FM&NT-2011 is available in its homepage http://www.fmnt.lu.lv. The Organizing Committee would like to thank all speakers, contributors, session chairs, referees and meeting staff for their efforts in making the FM&NT-2011 successful. The Organizing Committee sincerely hopes that that the conference gave all participants new insights into the widespread development of functional materials and nanotechnologies and would enhance the circulation of information released at the meeting. Andris Sternberg Inta Muzikante Janis Zicans Conference photograph ERAF logo International Organizing Committee Andris Sternberg (chairperson), Institute of Solid State Physics, University of Latvia, Latvia, MATERA Juras Banys, Vilnius University, Lithuania Gunnar Borstel, University of Osnabrück, Germany Niels E Christensen, University of Aarhus, Denmark Robert A Evarestov, St. Petersburg State University, Russia Claes-Goran Granqvist, Uppsala University, Sweden Dag Høvik, The Research Council of Norway, Norway, MATERA Marco Kirm, Institute of Physics, University of Tartu, Estonia Vladislav Lemanov, Ioffe Physical Technical Institute, Russia Witold Lojkowski, Institute of High Pressure Physics, Poland Ergo Nommiste, University of Tartu, Estonia Helmut Schober, Institut Laue-Langevin, France Sisko Sipilä, Finnish Funding Agency for Technology and Innovation, Finland, MATERA Ingólfur Torbjörnsson, Icelandic Centre for Research, Iceland, MATERA Marcel H Van de Voorde, University of Technology Delft, The Netherlands International Program Committee Inta Muzikante (chairperson), Institute of Solid State Physics, University of Latvia, Latvia, MATERA Liga Berzina-Cimdina, Institute of Biomaterials and Biomechanics, Riga Technical University, Latvia Janis Grabis, Institute of Inorganic Chemistry, Riga Technical University, Latvia Leonid V Maksimov, Vavilov State Optical Institute, Russia Linards Skuja, Institute of Solid State Physics, University of Latvia, Latvia Maris Springis, Institute of Solid State Physics, University of Latvia, Latvia Ilmars Zalite, Institute of Inorganic Chemistry, Riga Technical University, Latvia Janis Zicans, Institute of Polymers, Riga Technical University Local Committee: Liga Grinberga, Anatolijs Sarakovskis, Jurgis Grube, Raitis Siatkovskis, Maris Kundzins, Anna Muratova, Maris Springis, Aivars Vembris, Krisjanis Smits, Andris Fedotovs, Dmitrijs Bocarovs, Anastasija Jozepa, Andris Krumins.

    Sternberg, Andris; Muzikante, Inta; Zicans, Janis

    2011-06-01

    228

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

    Microsoft Academic Search

    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 m² swine manure pond at the Ohio Agricultural Research and Development Center Western Branch

    Chin-Min Cheng; Wei Tu; Behrad Zand; Tarunjit Butalia; William Wolfe; Harold Walker

    2007-01-01

    229

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

    SciTech Connect

    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 those materials with that of commercially available ion exchangers. The equilibrium uptake data presented in this report are useful for identifying potential materials that are capable of removing cesium and strontium from 105-KE Basin water. The data show the relative selectivities of the ion exchange materials under similar operating conditions. Additional flow studies are needed to predict material capacities and to develop complete ion exchange process flow sheets. The materials investigated in this study include commercially available ion exchangers such as IONSIV{reg_sign} IE-911 (manufactured by UOP), clinoptilolite (a naturally occurring zeolite), and materials produced on an experimental basis by AlliedSignal (biotites and nonatitanates), 3M (hexacyanoferrates), Selion Technologies, Inc. (hexacyanoferrates and titanates), and Texas A&M University (pharmacosiderites, biotites, and nonatitanates). In all, the performance of 14 ion exchange materials was evaluated at two solution-to-exchanger mass ratios (i.e., 10{sup 4} and 10{sup 5}) using actual 105-KE Basin water. Evaluation consisted of determining cesium and strontium batch distribution coefficients, loading, and decontamination factors. Actual 105-KE Basin water was obtained from a sample collected during the sludge dissolution work conducted by PNNL in FY 1996. This sample was taken from the bottom of the basin and contained significantly higher concentrations of the radioactive constituents than do samples taken from the top of the basin.

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

    1997-10-01

    230

    Surface functionalized mesoporous material and method of making same  

    DOEpatents

    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 all but one or two layers of water molecules on the internal surface of a pore. Suitable functional molecule precursor is then applied to permeate the hydrated pores and the precursor then undergoes condensation to form the functional molecules on the interior surface(s) of the pore(s).

    Feng, Xiangdong (West Richland, WA) [West Richland, WA; Liu, Jun (West Richland, WA) [West Richland, WA; Fryxell, Glen E. (Kennewick, WA) [Kennewick, WA

    2001-12-04

    231

    Inorganic salts interact with organic di-acids in sub-micron particles to form material with low hygroscopicity and volatility  

    NASA Astrophysics Data System (ADS)

    Volatility and hygroscopicity are two key properties of organic aerosol components, and both are strongly related to chemical identity. Here we show that inorganic-organic component interactions typically not considered in atmospheric models may strongly affect aerosol volatility and hygroscopicity. In particular, bi-dentate binding of di-carboxylic acids (DCA) to soluble inorganic ions can lead to very strongly bound metal-organic complexes with largely undetermined hygroscopicity and volatility. These reactions profoundly impact particle hygroscopicity, transforming hygroscopic components into irreversibly non-hygroscopic material. While the hygroscopicities of pure salts, DCA, and DCA salts are known, the hygroscopicity of internal mixtures of hygroscopic salts and DCA, as they are typically found in the atmosphere, has not been fully characterized. We have studied the volatility of pure, dry organic salt particles and the hygroscopicity of internal mixtures of oxalic acid (OxA, the dominant DCA in the atmosphere) and a number of salts, both mono- and di-valent. The formation of very low volatility organic salts was confirmed, with minimal evaporation of oxalate salt particles below 75 °C. Dramatic increases in the CCN activation diameter for particles with divalent salts (e.g. CaCl2) and relatively small particle mass fractions of OxA indicate that standard volume additivity rules for hygroscopicity do not apply. Thus small organic compounds with high O:C are capable of forming low volatility and very low hygroscopicity particles. Given current knowledge of the formation mechanisms of OxA and M-Ox salts, surface enrichment of insoluble M-Ox salts is expected. The resulting formation of an insoluble coating of metal-oxalate salts can explain low particle hygroscopicities. The formation of particles with a hard coating could offer an alternative explanation for observations of glass-like particles with very low viscosity.

    Drozd, G.; Woo, J.; Häkkinen, S. A. K.; Nenes, A.; McNeill, V. F.

    2013-11-01

    232

    Method of making nanopatterns and nanostructures and nanopatterned functional oxide materials  

    DOEpatents

    Method for nanopatterning of inorganic materials, such as ceramic (e.g. metal oxide) materials, and organic materials, such as polymer materials, on a variety of substrates to form nanopatterns and/or nanostructures with control of dimensions and location, all without the need for etching the materials and without the need for re-alignment between multiple patterning steps in forming nanostructures, such as heterostructures comprising multiple materials. The method involves patterning a resist-coated substrate using electron beam lithography, removing a portion of the resist to provide a patterned resist-coated substrate, and spin coating the patterned resist-coated substrate with a liquid precursor, such as a sol precursor, of the inorganic or organic material. The remaining resist is removed and the spin coated substrate is heated at an elevated temperature to crystallize the deposited precursor material.

    Dravid, Vinayak P; Donthu, Suresh K; Pan, Zixiao

    2014-02-11

    233

    Harvesting Vibrational Energy Using Material Work Functions  

    NASA Astrophysics Data System (ADS)

    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.

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

    2014-10-01

    234

    Harvesting vibrational energy using material work functions.  

    PubMed

    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

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

    2014-01-01

    235

    The features of self-assembling organic bilayers important to the formation of anisotropic inorganic materials in microgravity conditions  

    NASA Technical Reports Server (NTRS)

    Materials with directional properties are opening new horizons in a variety of applications including chemistry, electronics, and optics. 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. The new applications and the need for model particles in scientific investigations are rapidly out-distancing the ability to synthesize anisotropic particles with specific chemistries and narrowly distributed physical characteristics (e.g. size distribution, shape, and aspect ratio).

    Talham, Daniel R.; Adair, James H.

    2005-01-01

    236

    Inorganic membranes: The new industrial revolution  

    SciTech Connect

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

    Fain, D.E. [Martin Merietta Energy Systems, Oak Ridge, TN (United States)

    1994-12-31

    237

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

    E-print Network

    (Cr2O3) passivation layer formed on the surface of stainless steel in oxi- dizing environments is one protection of stainless steel [9­13]. In spite of all the advantages of sol-gel processing, sol-gel oxide for corrosion protection of stainless steel T. P. CHOU Department of Materials Science and Engineering

    Cao, Guozhong

    238

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

    Microsoft Academic Search

    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

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

    1997-01-01

    239

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

    PubMed

    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

    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

    240

    Synthesis and Characterization of Novel Materials, Tin Potassium Vanadate and Zirconium Potassium Vanadate Inorganic MultiComponent Ion Exchangers  

    Microsoft Academic Search

    Nano polyoxometallate-cation exchangers, tin potassium vanadate (TPV), and zirconium potassium vanadate (ZPV), with stereoregular particulate structures have been chemically synthesized using a homogeneous precipitation technique under a variety of conditions. The experimental parameters such as mixing, volume ratio, order of mixing and pH were established for the synthesis of the materials and fairly compromised to optimize the ion exchange properties

    G. M. Ibrahim; B. El-Gammal; I. M. El-Naggar

    2011-01-01

    241

    Ionic liquids coated Fe3O4 based inorganic-organic hybrid materials and their application in the simultaneous determination of DNA bases.  

    PubMed

    Ionic liquids (ILs) coated Fe3O4 based inorganic-organic hybrid materials (represented as Fe3O4/ILs) were synthesized. ILs such as methylimidazolium chloride ([Hmim][Cl]) and 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) were investigated. For comparative study, quaternary ammonium salts such as choline chloride, cetyltrimethylammonium bromide [C16H33N(CH3)3][Br], and trimethylstearylammonium chloride [C18H37N(CH3)3][Cl] were also investigated. Materials were characterized by X-ray diffraction, nitrogen sorption, Fourier transform infrared and scanning/transmission electron microscopy. Electrochemical sensors based on Fe3O4/ILs modified glassy carbon electrodes were fabricated for the simultaneous determination of all four DNA bases. The electrochemical behavior of DNA bases was investigated in detail. Various reaction parameters such as effect of scan rate, number of electrons involved in the rate determining step, electron transfer coefficient, surface adsorbed concentration, and the electrode reaction standard rate constant were investigated. Catalytic activity obtained at various Fe3O4/ILs modified electrodes was explained using DFT calculation. The analytical performance of the sensor was demonstrated in the simultaneous determination of guanine, adenine, thymine, and cytosine in calf thymus DNA sample. PMID:24703634

    Kaur, Balwinder; Srivastava, Rajendra

    2014-06-01

    242

    Swelling in organic-inorganic multilayer systems  

    NASA Astrophysics Data System (ADS)

    We have investigated the swelling of organic-inorganic structures based on fluorocarbon polymer (CF2) layers sandwiched by two layers of inorganic ionic (HfO2) and inorganic covalent (CdS) materials. The swelling of the CF2 layer produces cracks on the uppermost inorganic layer. The cracks form a network of hexagonal defects with random distribution. The extension of the pattern and the mean unit size have been measured for different solvents by using a purposely developed optical profilometer. We show that the swelling phenomenon strongly depends on the polar forces between the molecules of the solvent and those of the inorganic layers. The electric dipole moment of the solvents and the ionicity of the inorganic materials are thus the crucial parameters influencing the crack density and shape.

    Convertino, A.; Valentini, A.; De Vittorio, M.; Cingolani, R.

    1998-08-01

    243

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

    Microsoft Academic Search

    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

    J. J. Petrovic; K. J. McClellan

    1998-01-01

    244

    Surface Intensive Materials Processing for Multi-Functional Purposes  

    SciTech Connect

    We have chosen silicon carbide (SiC) as a multi-functional material to demonstrate the application of surface intensive processing for device fabrication. We will highlight two devices which are produced in house at the Center for Irradiation of materials of Alabama A and M university: (A) High temperature electronic gas sensor, (B) High temperature optical properties/sensor.

    Ila, D.; Williams, E.K.; Muntele, C.I.; George, M.A.; Poker, D.B.; Hensley, D.K.; Larkin, D.J.

    2000-03-06

    245

    Functional and Smart Materials Structural Evolution and Structure Analysis  

    E-print Network

    .13.3 Piezoelectric property #12;ii 1.13.4 Ferroelectric property 1.13.5 Optical property 1.13.6 Electric property 1.4 Functional materials with perovskite-like structures 3.4.1 Ferroelectricity and ferroelectric compounds 3 actuator materials 3.4.6 Optically switchable compounds 3.5 Doping and oxygen vacancies 3.6 Giant

    Wang, Zhong L.

    246

    Evaluation of naturally occurring radioactive materials (NORMs) in inorganic and organic oilfield scales from the Middle East.  

    PubMed

    The distribution of natural nuclide gamma-ray activities and their respective annual effective dose rates, produced by potassium-40 (??K), uranium-238 (²³?U), thorium-232 (²³²Th), and radium-226 (²²?Ra), were determined for 14 oilfield scale samples from the Middle East. Accumulated radioactive materials concentrate in tubing and surface equipment, and workers at equipment-cleaning facilities and naturally occurring radioactive materials (NORMs) disposal facilities are the population most at risk for exposure to NORM radiation. Gamma-spectra analysis indicated that photo-gamma lines represent the parents of 10 radioactive nuclides: ²³?Th, plutonium-239, actinium-228, ²²?Ra, lead-212 (²¹²Pb), ²¹?Pb, thallium-238 (²??Tl), bismuth-212 (²¹²Bi), ²¹?Bi, and ??K. These nuclides represent the daughters of the natural radioactive series ²³?U and ²³²Th with ??K as well. The mean activity concentration of ²³?U, ²³²Th, and ??K were found to be 25.8 ± 11.6, 18.3 ± 8.1, and 4487.2 ± 2.5% Bq kg?¹ (average values for 14 samples), respectively. The annual effective dose rates and the absorbed doses in air, both indoor and outdoor, for the samples were obtained as well. The results can be used to assess the respective hazard on workers in the field and represent a basis for revisiting current engineering practices. PMID:21892762

    Bassioni, Ghada; Abdulla, Fareed; Morsy, Zeinab; El-Faramawy, Nabil

    2012-04-01

    247

    FACULTY POSITION IN INORGANIC CHEMISTRY Department of Chemistry  

    E-print Network

    FACULTY POSITION IN INORGANIC CHEMISTRY Department of Chemistry Syracuse University The Department of Chemistry at Syracuse University invites applications for a tenure track faculty position at the Assistant Professor level in inorganic chemistry with specialization in materials chemistry (broadly defined

    Doyle, Robert

    248

    Use of inorganic ion-exchange materials for the treatment of liquid wastes -- Cerium (IV) antimonate matrix  

    SciTech Connect

    The removal of radioactive elements Na{sup +}, Cs{sup +}, Sr{sup 2+}, o{sup +2} and Eu{sup 3+} was carried out either by chemical precipitation in situ or by using preformed precipitate of cerium (IV) antimonate. Characterization of the produced materials using X-ray diffraction, thermal and infrared analyses was conducted. Capacity, equilibria measurements, selectivity patterns for Na, Cs, Sr, Co and Eu were determined on these matrices at different conditions. The distribution coefficients of cerium (IV) antimonate for strontium and europium are high, nearly 7 {times} 10{sup 3} and 9 {times} 10{sup 3} at a nitric acid concentration below 0.1 and 0.5 M, respectively. The effect of high concentrations of sodium nitrate, boric acid, sodium citrate and EDTA on the sorption of Eu{sup 3+} has been studied. Cerium (IV) antimonate can be used for the separation and consolidation of radwaste into suitable waste form.

    El-Naggar, I.M.; El-Dessouky, M.I.; Aly, H.F. [Atomic Energy Authority, Cairo (Egypt). Hot Lab. and Waste Management Center

    1993-12-31

    249

    Development and investigation of functional hierarchical hybrid materials  

    NASA Astrophysics Data System (ADS)

    In this dissertation, a series of hierarchical hybrid materials were developed and their process-morphology-activity relationship was studied. In this context, zinc oxide was used as a model metal-oxide semiconductor for the development of branched hierarchical nanostructures on various flexible substrates including cotton, nylon, and electrospun organic and inorganic nanofibers. In all cases, well-defined, radially oriented, highly dense, uniform, and single crystalline arrays of ZnO nanostructures were successfully grown using an optimized hydrothermal growth strategy. This process involves seed solution treatment of a substrate with ZnO nanocrystals that will form nucleation sites for subsequent anisotropic growth of single crystalline ZnO nanowires by incubation in the growth solution. All ZnO nanowires exhibit wurtzite crystal structure oriented along the c-axis which was confirmed by XRD analysis. Seed-to-growth solution concentration ratio ([S]/[G]) was determined to be the most important process parameter on the morphology of the resulting nanostructures when applied to cotton and nylon surfaces. Increase in the [S]/[G] values resulted in the amount of ZnO grown on the surfaces to drop significantly, which also resulted in a morphological transform from nanorods to needle-like structures. Consequently, a strong dependency of the physical, optical, and electrochemical properties of the resulting materials was observed. In addition, room temperature photoluminescence measurements revealed that the band-gap of ZnO widened as the morphology changed from nanorods to nanoneedles. Additional analyses revealed that cotton bearing ZnO nanorods exhibits a lower propensity for contact transfer of E. coli than unmodified cotton fabric. Moreover, studies with nonwoven nanofibers generated by electrospinning revealed that the morphology of the branched nanostructures was also controlled by the density of the underlying fibrous platform. The amount of ZnO nanorods grown over electrospun nanofibers was higher than that of cotton and nylon fabrics, due to the increased surface area-to-volume ratio. Organic and inorganic based electrospun nanofibers such as cellulose acetate, amide, and TiO 2 have been employed as the primary platform upon which the secondary nanostructures were grown. ZnO nanowires grown on electrospun fibers were found to be highly effective photocatalysts, as indicated by the almost complete removal of the model compound methylene blue in 30 min. With the ZnO nanorods-electrospun TiO2 hierarchical systems, more effective charge transfer capacity was achieved due to enhanced state of heterojunctions and directionality of the charge carriers.

    Athauda, Thushara J.

    250

    New Functional Materials for Fluid Control and Sensing in Microfluidic  

    E-print Network

    Spiropyran - + Slide 12 ·OPTICALLY ACTUATE BETWEEN TWO DISTINCT ISOMERS ·CONTROL PHYSICO-CHEMICAL PROPERTIES OF SYSTEMNew Functional Materials for Fluid Control and Sensing in Microfluidic Devices Fernando Benito SCIENCE, FUNCTIONAL POLYMERS, DEVICE PROTOTYPING, ENERGY MANAGEMENT, ADAPTIVE MIDDLEWARE, WEARABLE SENSORS

    Lee, Hyowon

    251

    Function and Manipulation Knowledge of Tools 1 Supplementary Online Materials  

    E-print Network

    Function and Manipulation Knowledge of Tools 1 Supplementary Online Materials Experiment 1 Inverse): function decisions were significantly faster than manipulation decisions. There was a main effect as in the response time analysis in Experiment 1. Manipulation judgments with words were slower than manipulation

    Mahon, Bradford Z.

    252

    First three-dimensional inorganic-organic hybrid material constructed from an "inverted Keggin" polyoxometalate and a copper(I)-organic complex.  

    PubMed

    A new polyoxometalate (POM) based on a flexible bidentate ligand and "inverted Keggin" inorganic building block, namely, [Cu(8)L(8)[Mo(12)O(46)(AsPh)(4)](2)]·H(2)O (1), where L is 1,3-bis(1,2,4-triazol-1-yl)propane, has been synthesized under hydrothermal condition. In 1, the "inverted Keggin" [Mo(12)O(46)(AsPh)(4)](4-) building blocks are linked by the one-dimensional (1D) zigzag [Cu(I)(trans-L)](+) chains and [Cu(I)(4)(cis-L)(4)](4+) macrocycles to yield a three-dimensional (3D) framework. The compound 1 represents the first 3D "inverted Keggin" polyoxometalate modified by a transition-metal complex. Topologically, the 3D framework can be considered as an 8-connected net with a Schläfli symbol of 4(22)·6(6). As far as we know, compound 1 is the highest-connected uninodal network topology presently known for POM-based materials. The compound was characterized by its IR spectrum, UV-vis spectrum, thermogravimetric analysis (TGA), and powder X-ray diffraction (XRD) patterns. Remarkably, compound 1 exhibits photocatalytic activity for dye degradation under visible light irradiation and shows good stability toward visible-light photocatalysis. PMID:21842843

    Liu, Bo; Yu, Zhen-Tao; Yang, Jin; Hua, Wu; Liu, Ying-Ying; Ma, Jian-Fang

    2011-09-19

    253

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

    Microsoft Academic Search

    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

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

    2007-01-01

    254

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

    PubMed

    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

    Schramm, Christian; Rinderer, Beate; Tessadri, Richard

    2014-05-25

    255

    Efficient inorganic-organic hybrid perovskite solar cells based on pyrene arylamine derivatives as hole-transporting materials.  

    PubMed

    A set of three N,N-di-p-methoxyphenylamine-substituted pyrene derivatives have successfully been synthesized and characterized by (1)H/(13)C NMR spectroscopy, mass spectrometry, and elemental analysis. The optical and electronic structures of the pyrene derivatives were adjusted by controlling the ratio of N,N-di-p-methoxyphenylamine to pyrene, and investigated by UV/vis spectroscopy and cyclic voltammetry. The pyrene derivatives were employed as hole-transporting materials (HTMs) in fabricating mesoporous TiO2/CH3NH3PbI3/HTMs/Au solar cells. The pyrene-based derivative Py-C exhibited a short-circuit current density of 20.2 mA/cm(2), an open-circuit voltage (Voc) of 0.886 V, and a fill factor of 69.4% under an illumination of 1 sun (100 mW/cm(2)), resulting in an overall power conversion efficiency of 12.4%. The performance is comparable to that of the well-studied spiro-OMeTAD, even though the Voc is slightly lower. Thus, this newly synthesized pyrene derivative holds promise as a HTM for highly efficient perovskite-based solar cells. PMID:24313292

    Jeon, Nam Joong; Lee, Jaemin; Noh, Jun Hong; Nazeeruddin, Mohammad Khaja; Grätzel, Michael; Seok, Sang Il

    2013-12-26

    256

    Some functional properties of composite material based on scrap tires  

    NASA Astrophysics Data System (ADS)

    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.

    Plesuma, Renate; Malers, Laimonis

    2013-09-01

    257

    PREFACE: International Conference on Functional Materials and Nanotechnologies (FM&NT2012)  

    NASA Astrophysics Data System (ADS)

    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 together scientists, researchers, engineers and students from universities, research institutes and related industrial companies working in the field of advanced material science, energy and materials technologies. The contributions of the participants were grouped according to three main topics of the conference: 1. Multifunctional Materials including advanced inorganic, organic and hybrid materials; ferroics; multiscale and multiphenomenal material modeling and simulation 2. Nanotechnologies including progressive methods, technologies and design for investigation of nanoparticles, nanostructures, nanocomposites, thin films and coatings; 3. Energy including perspective materials and technologies for renewable and hydrogen energy, fuel cells, photovoltaics and developing diverse energy systems. A special section devoted to Organic Materials was organized to commemorate a long-time organizer of the FM&NT conference series, Dr. habil. phys, academician Inta Muzikante who passed away on 15 February 2012. The number of registered participants from 21 countries was nearly 300. During the three days of the conference 2 plenary, 16 invited, 54 oral reports and 184 posters were presented. 64 papers, based on these reports, are included in this volume of IOP Conference Series: Materials Science and Engineering. Additional information about FM&NT-2012 is available at its homepage http://www.fmnt.lu.lv. The Organizing Committee would like to thank all the speakers, contributors, session chairs, referees and other involved staff for their efforts in making the FM&NT-2012 successful. The Organizing Committee sincerely hopes that the Conference gave all the participants new insights into the widespread development of functional materials and nanotechnologies and would enhance the circulation of the information released at the meeting. Inta Muzikante Andris Sternberg Liga Grinberga Anatolijs Sarakovskis Conference photograph The manuscripts are published thanks to the financial support from ERAF project 'Atbalsts starptautiskas sadarbibas projektiem zinatne un tehnologijas LU Cietvielu fizikas instituta' Nr.2010/0204/2DP/2.1.1.2.0./10/APIA/VIAA/010 Sponsors Sponsors flag Sponsors logo International Organizing Committee 1. Andris Sternberg (chairperson), Institute of Solid State Physics, University of Latvia, Latvia 2. Juras Banys, Vilnius University, Lithuania 3. Gunnar Borstel, University of Osnabrück, Germany 4. Niels E Christensen, University of Aarhus, Denmark 5. Robert A Evarestov, St. Petersburg State University, Russia 6. Claes-Goran Granqvist, Uppsala University, Sweden 7. Dag Høvik, The Research Council of Norway, Norway 8. Marco Kirm, Institute of Physics, University of Tartu, Estonia 9. Jiri Kulda, Institut Laue-Langevin, France 10. Witold Lojkowski, Institute of High Pressure Physics, Poland 11. Ergo Nommiste, University of Tartu, Estonia 12. Ingólfur Torbjörnsson, Icelandic Centre for Research, Iceland 13. Marcel H. Van de Voorde, University of Technology Delft, The Netherlands International Program Committee 1. Liga Grinberga (chairperson), Institute of Solid State Physics, University of Latvia, Latvia 2. Eugene Kotomin, Max Planck Institute for Solid State Research, Germany 3. Martins Rutkis, Institute of Solid State Physics, University of Latvia, Latvia 4. Inta Muzikante, Institute of Solid State Physics, University of Latvia, Latvia 5. Liga Berzina-Cimdina, Institute of Biomaterials and Biomechanics, Riga Technical University, Latvia 6. Janis Grabis, Institute of Inorganic Chemistry, Riga Technical University, Latvia 7. Linards Skuja, Institute of Solid State Physics, University of Latvia, Latvia 8. Maris Spr

    Sternberg, Andris; Muzikante, Inta; Sarakovskis, Anatolijs; Grinberga, Liga

    2012-08-01

    258

    Functionalized Materials From Elastomers to High Performance Thermoplastics  

    SciTech Connect

    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.

    Laura Ann Salazar

    2003-05-31

    259

    Inorganic membranes and solid state sciences  

    NASA Astrophysics Data System (ADS)

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

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

    2000-05-01

    260

    Hybrid organic/inorganic complexes based on electroactive tetrathiafulvalene-functionalized diphosphanes tethered to C(3)-symmetrized Mo(3)Q(4) (Q = S, Se) clusters.  

    PubMed

    A two-step procedure for the preparation of hybrid complexes based on electroactive tetrathiafulvalene (TTF)- functionalized o-P(2) diphosphanes (o-P(2) = 3,4-dimethyl-3,4-bis(diphenylphosphino)tetrathiafulvalene) and inorganic C(3)-symmetrized Mo(3)Q(4) (Q = S, Se) clusters, namely, [Mo(3)S(4)Cl(3)(o-P(2))(3)]PF(6) ([1]PF(6)) and [Mo(3)Se(4)Cl(3)(o-P(2))(3)]PF(6) ([2]PF(6)), is reported. Their molecular and electronic structures are also described on the basis of X-ray diffraction experiments and density functional theory (DFT) calculations aimed at understanding the interactions established between both the organic and the inorganic parts. Cyclic voltammograms of compounds [1]PF(6) and [2]PF(6) display reduction features associated to the Mo(3)Q(4) core and oxidation characteristics due to the TTF skeleton. The oxidation chemistry of [1]PF(6) and [2]PF(6) in solution is also investigated by means of in situ electrospray ionization (ESI) mass spectrometry, UV-vis, and, electron paramagnetic resonance (EPR) measurements. Upon addition of increasing amounts of NOPF(6) (less than 3 equiv), the sequential formation of 1(n+) (n = 1-4) species was observed whereas addition of a 3-fold excess of NOPF(6) allows to access the three-electron oxidized [Mo(3)S(4)Cl(3)(o-P(2))(3)](4+) (1(4+)) and [Mo(3)Se(4)Cl(3)(o-P(2))(3)](4+) (2(4+)) cations. These 1(4+) and 2(4+) cations represent still rare examples of complexes with oxidized TTF-ligands that are remarkably stable either toward diphosphane dissociation or phosphane oxidation. Polycrystalline samples of compound [1](PF(6))(4) were obtained by oxidation of compound [1]PF(6) using NOPF(6) which were analyzed by solid state absorption, UV-vis, and Raman spectroscopies. PMID:20085305

    Avarvari, Narcis; Kiracki, Kaplan; Llusar, Rosa; Polo, Victor; Sorribes, Ivan; Vicent, Cristian

    2010-02-15

    261

    Inorganic Fullerenes, Onions, and Tubes  

    ERIC Educational Resources Information Center

    Buckminsterfullerene, which is in the shape of a soccer-ball was first discovered in 1985, has many applications as a good lubricant, or as a new superconductor. The synthesis of these inorganic fullerenes involves a great deal of interdisciplinary research between physicists, material scientists, engineers and chemists from various fields.

    York, Andrew P. E.

    2004-01-01

    262

    Inorganic Reaction Mechanisms. Part I  

    ERIC Educational Resources Information Center

    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)

    Cooke, D. O.

    1976-01-01

    263

    A mesoporous 3D hybrid material with dual functionality for Hg2+ detection and adsorption.  

    PubMed

    Dual-function hybrid material U1 was designed for simultaneous chromofluorogenic detection and removal of Hg(2+) in an aqueous environment. Mesoporous material UVM-7 (MCM41 type) with homogeneously distributed pores of about 2-3 nm in size, a large specific surface area exceeding 1000 m(2) g(-1), and nanoscale particles was used as an inorganic support. The mesoporous solid is decorated with thiol groups that were treated with squaraine dye III to give a 2,4-bis(4-dialkylaminophenyl)-3-hydroxy-4-alkylsulfanylcyclobut-2-enone (APC) derivative that is covalently anchored to the inorganic silica matrix. The solid was characterised by various techniques including X-ray diffraction, transmission electron microscopy, Raman spectroscopy, and nitrogen adsorption. This hybrid solid is the chemodosimeter for Hg(2+) detection. Hg(2+) reacts with the APC fragment in U1 with release of the squaraine dye into the solution, which turns deep blue and fluoresces strongly. Naked-eye Hg(2+) detection is thus accomplished in an easy-to-use procedure. In contrast, U1 remains silent in the presence of other thiophilic transition metal ions, alkali and alkaline earth metal ions, or anions ubiquitously present in water such as chloride, carbonate, sulfate, and phosphate. Material U1 acts not only as chemodosimeter that signals the presence of Hg(2+) down to parts-per-billion concentrations, but at the same time is also an excellent adsorbent for the removal of mercury cations from aqueous solutions. The amount of adsorbed mercury ranges from 0.7 to 1.7 mmol g(-1), depending on the degree of functionalisation. In addition, hybrid material U1 can be regenerated for both sensing and removal purposes. As far as we know, U1 is the first example of a promising new class of polyfunctional hybrid supports that can be used as both remediation and alarm systems by selective signalling and removal of target species of environmental importance. Model compounds based on silica gel (G1), fumed silica (F1), and micrometre-sized MCM-41 scaffolds (M1) were also prepared and studied for comparative purposes. PMID:18666295

    Ros-Lis, José V; Casasús, Rosa; Comes, María; Coll, Carmen; Marcos, M Dolores; Martínez-Máñez, Ramón; Sancenón, Félix; Soto, Juan; Amorós, Pedro; El Haskouri, Jamal; Garró, Nuria; Rurack, Knut

    2008-01-01

    264

    Self-organization of functional materials in confinement.  

    PubMed

    This Account aims to describe our experience in the use of patterning techniques for addressing the self-organization processes of materials into spatially confined regions on technologically relevant surfaces. Functional properties of materials depend on their chemical structure, their assembly, and spatial distribution at the solid state; the combination of these factors determines their properties and their technological applications. In fact, by controlling the assembly processes and the spatial distribution of the resulting structures, functional materials can be guided to technological and specific applications. We considered the principal self-organizing processes, such as crystallization, dewetting and phase segregation. Usually, these phenomena produce defective molecular films, compromising their use in many technological applications. This issue can be overcome by using patterning techniques, which induce molecules to self-organize into well-defined patterned structures, by means of spatial confinement. In particular, we focus our attention on the confinement effect achieved by stamp-assisted deposition for controlling size, density, and positions of material assemblies, giving them new chemical/physical functionalities. We review the methods and principles of the stamp-assisted spatial confinement and we discuss how they can be advantageously exploited to control crystalline order/orientation, dewetting phenomena, and spontaneous phase segregation. Moreover, we highlight how physical/chemical properties of soluble functional materials can be driven in constructive ways, by integrating them into operating technological devices. PMID:25068634

    Gentili, Denis; Valle, Francesco; Albonetti, Cristiano; Liscio, Fabiola; Cavallini, Massimiliano

    2014-08-19

    265

    Preparation and applications of hybrid organic-inorganic monoliths: a review.  

    PubMed

    This review presents an overview of the properties of hybrid organic-inorganic monolithic materials and summarizes the recent developments in the preparation and applications of these hybrid monolithic materials. Hybrid monolithic materials with porosities, surface functionalities, and fast dynamic transport have developed rapidly, and have been used in a wide range of applications owing to the low cost, good stability, and excellent performance. Basically, these materials can be divided into two major types according to the chemical composition: hybrid silica-based monolith (HSM) and hybrid polymer-based monolith (HPM). Compared to the HPM, HSM monolith has been attracting most wide attentions, and it is commonly synthesized by the sol-gel process. The conventional preparation procedures of two type's hybrid organic-inorganic monoliths are addressed. Applications of hybrid organic-inorganic monoliths in optical devices, capillary microextraction (CME), capillary electrochromatography (CEC), high performance liquid chromatography (HPLC), and chiral separation are also reviewed. PMID:22733509

    Zhu, Tao; Row, Kyung Ho

    2012-06-01

    266

    Ionic self-assembly for functional hierarchical nanostructured materials.  

    PubMed

    CONSPECTUS: The challenge of constructing soft functional materials over multiple length scales can be addressed by a number of different routes based on the principles of self-assembly, with the judicious use of various noncovalent interactions providing the tools to control such self-assembly processes. It is within the context of this challenge that we have extensively explored the use of an important approach for materials construction over the past decade: exploiting electrostatic interactions in our ionic self-assembly (ISA) method. In this approach, cooperative assembly of carefully chosen charged surfactants and oppositely charged building blocks (or tectons) provides a facile noncovalent route for the rational design and production of functional nanostructured materials. Generally, our research efforts have developed with an initial focus on establishing rules for the construction of novel noncovalent liquid-crystalline (LC) materials. We found that the use of double-tailed surfactant species (especially branched double-tailed surfactants) led to the facile formation of thermotropic (and, in certain cases, lyotropic) phases, as demonstrated by extensive temperature-dependent X-ray and light microscopy investigations. From this core area of activity, research expanded to cover issues beyond simple construction of anisotropic materials, turning to the challenge of inclusion and exploitation of switchable functionality. The use of photoactive azobenzene-containing ISA materials afforded opportunities to exploit both photo-orientation and surface relief grating formation. The preparation of these anisotropic LC materials was of interest, as the aim was the facile production of disposable and low-cost optical components for display applications and data storage. However, the prohibitive cost of the photo-orientation processes hampered further exploitation of these materials. We also expanded our activities to explore ISA of biologically relevant tectons, specifically deoxyguanosine monophosphate. This approach proved, in combination with block copolymer (BCP) self-assembly, very fruitful for the construction of complex and hierarchical functional materials across multiple length scales. Molecular frustration and incommensurability, which played a major role in structure formation in combination with nucleotide assembly, have now become important tools to tune supramolecular structure formation. These concepts, that is, the use of BCP assembly and incommensurability, in combination with metal-containing polymeric materials, have provided access to novel supramolecular morphologies and, more importantly, design rules to prepare such constructs. These design rules are now also being applied to the assembly of electroactive oligo(aniline)-based materials for the preparation of highly ordered functional soft materials, and present an opportunity for materials development for applications in energy storage. In this Account, we therefore discuss investigations into (i) the inclusion and preparation of supramolecular photoactive and electroactive materials; (ii) the exploitation and control over multiple noncovalent interactions to fine-tune function, internal structure, and long-range order and (iii) exploration of construction over multiple length scales by combination of ISA with well-known BCP self-assembly. Combination of ISA with tuning of volume fractions, mutual compatibility, and molecular frustration now provides a versatile tool kit to construct complex and hierarchical functional materials in a facile noncovalent way. A direct challenge for future ISA activities would certainly be the construction of functional mesoscale objects. However, within a broader scientific context, the challenge would be to exploit this powerful assembly tool for application in areas of research with societal impact, for example, energy storage and generation. The hope is that this Account will provide a platform for such future research activities and opportunities. PMID:25191750

    Faul, Charl F J

    2014-12-16

    267

    Functionalized apertures for the detection of chemical and biological materials  

    DOEpatents

    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.

    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

    268

    Aeroelastic Tailoring of a Plate Wing with Functionally Graded Materials  

    NASA Technical Reports Server (NTRS)

    This work explores the use of functionally graded materials for the aeroelastic tailoring of a metallic cantilevered plate-like wing. Pareto trade-off curves between dynamic stability (flutter) and static aeroelastic stresses are obtained for a variety of grading strategies. A key comparison is between the effectiveness of material grading, geometric grading (i.e., plate thickness variations), and using both simultaneously. The introduction of material grading does, in some cases, improve the aeroelastic performance. This improvement, and the physical mechanism upon which it is based, depends on numerous factors: the two sets of metallic material parameters used for grading, the sweep of the plate, the aspect ratio of the plate, and whether the material is graded continuously or discretely.

    Dunning, Peter D.; Stanford, Bret K.; Kim, H. Alicia; Jutte, Christine V.

    2014-01-01

    269

    A plant proton-pumping inorganic pyrophosphatase functionally complements the vacuolar ATPase transport activity and confers bafilomycin resistance in yeast.  

    PubMed

    V-ATPases (vacuolar H+-ATPases) are a specific class of multi-subunit pumps that play an essential role in the generation of proton gradients across eukaryotic endomembranes. Another simpler proton pump that co-localizes with the V-ATPase occurs in plants and many protists: the single-subunit H+-PPase [H+-translocating PPase (inorganic pyrophosphatase)]. Little is known about the relative contribution of these two proteins to the acidification of intracellular compartments. In the present study, we show that the expression of a chimaeric derivative of the Arabidopsis thaliana H+-PPase AVP1, which is preferentially targeted to internal membranes of yeast, alleviates the phenotypes associated with V-ATPase deficiency. Phenotypic complementation was achieved both with a yeast strain with its V-ATPase specifically inhibited by bafilomycin A1 and with a vma1-null mutant lacking a catalytic V-ATPase subunit. Cell staining with vital fluorescent dyes showed that AVP1 recovered vacuole acidification and normalized the endocytic pathway of the vma mutant. Biochemical and immunochemical studies further demonstrated that a significant fraction of heterologous H+-PPase is located at the vacuolar membrane. These results raise the question of the occurrence of distinct proton pumps in certain single-membrane organelles, such as plant vacuoles, by proving yeast V-ATPase activity dispensability and the capability of H+-PPase to generate, by itself, physiologically suitable internal pH gradients. Also, they suggest new ways of engineering macrolide drug tolerance and outline an experimental system for testing alternative roles for fungal and animal V-ATPases, other than the mere acidification of subcellular organelles. PMID:21612578

    Pérez-Castiñeira, José R; Hernández, Agustín; Drake, Rocío; Serrano, Aurelio

    2011-07-15

    270

    Development of pillared M(IV) phosphate phosphonate inorganic organic hybrid ion exchange materials for applications in separations found in the nuclear fuel cycle  

    NASA Astrophysics Data System (ADS)

    This dissertation focuses on key intergroup and intragroup separations found in the back end of the nuclear fuel cycle, specifically americium from lanthanides and americium from other actinides, most importantly americium from curium. Our goal is to implement a liquid-solid separation process to reduce waste and risk of contamination by the development of metal(IV) phosphate phosphonate inorganic organic hybrid ion exchange materials with the ideal formula of M(O6P2C6H4)0.5 (O3POA) ·nH2O, where M = Zr or Sn, A = H or Na. These materials have previously shown to have high affinity for Ln, this work will expand on the previous studies and provide methods for the above target separation, exploiting oxidation state and ion charge to drive the separation process. The optimum hydrothermal reaction conditions were determined by adjusting parameters such as reaction temperature and time, as well as the phosphonate to phosphate (pillar-to-spacer) ligands ratio. Following these results four bulk syntheses were performed and their ion exchange properties were thoroughly examined. Techniques such as inductively coupled mass spectrometry and liquid scintillation counting were used to determine the affinity of the materials towards Na+, Cs+, Ca2+, Sr 2+, Ni2+, Nd3+, Sm3+, Ho3+, Yb3+, NpO2+, Pu4+, PuO22+, Am3+, AmO2+, and Cm3+. Separation factors in the thousands have been observed for intergroup separations of the Ln from the alkali, alkaline earth, and low valent transition metals. A new method for Am oxidation was developed, which employed Na 2S2O8 as the oxidizing agent and Ca(OCl) 2 as the stabilizing agent for AmO2+ synthesis. Separation factors of 30-60 for Nd3+ and Eu3+ from AmO2+, as well as 20 for Cm3+ from AmO2+ were observed at pH 2. The work herein shows that a liquid-solid separation can be carried out for these difficult separations by means of oxidation and ion exchange.

    Burns, Jonathan David

    271

    Inorganic spark chamber frame and method of making the same  

    NASA Technical Reports Server (NTRS)

    A spark chamber frame, manufactured using only inorganic materials is described. The spark chamber frame includes a plurality of beams formed from inorganic material, such as ceramic or glass, and are connected together at ends with inorganic bonding material having substantially the same thermal expansion as the beam material. A plurality of wires formed from an inorganic composition are positioned between opposed beams so that the wires are uniformly spaced and form a grid. A plurality of hold down straps are formed of inorganic material such as ceramic or glass having substantially the same chemical and thermal properties as the beam material. Hold down straps overlie wires extending over the beams and are bonded thereto with inorganic bonding material.

    Heslin, T. M. (inventor)

    1982-01-01

    272

    Alkoxide routes to Inorganic Materials  

    SciTech Connect

    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.

    Thomas, George H [ORNL

    2007-12-01

    273

    Organic/Inorganic Composite Latexes: The Marriage of Emulsion Polymerization and Inorganic Chemistry  

    NASA Astrophysics Data System (ADS)

    This review article describes recent advances in the synthesis and properties of waterborne organic/inorganic colloids elaborated through conventional emulsion polymerization, a well-established technology. These materials can be defined as aqueous suspensions of composite latex particles made up of organic and inorganic domains organized into well-defined core-shell, multinuclear, raspberry-like, multipod-like, or armored morphologies. Particular emphasis is placed on the synthetic strategies for fabrication of these colloidal materials. Two main approaches are described: the polymerization of organic monomers in the presence of preformed inorganic particles, and the reverse approach by which inorganic materials are synthesized in the presence of preformed polymer latexes. The list of examples provided in this review is by no means exhaustive but rather intends to give an overview of synthetic methods for selected inorganic compounds (e.g., silica, iron oxide, pigments, clays, quantum dots, and metals), and briefly reports on potential applications of the resulting materials.

    Bourgeat-Lami, Elodie; Lansalot, Muriel

    274

    Speciation of dissolved inorganic arsenic by diffusive gradients in thin films: selective binding of AsIII by 3-mercaptopropyl-functionalized silica gel.  

    PubMed

    A diffusive gradients in thin films (DGT) technique for selectively measuring As(III) utilizes commercially available 3-mercaptopropyl-functionalized silica gel. Deployment of the new technique alongside the Metsorb-DGT for total inorganic arsenic allows the calculation of As(III) directly and As(V) by difference. Uptake of As(III) by mercapto-silica was quantitative and elution with a mixture of 1 mol L(-1) HNO(3) and 0.01 mol L(-1) KIO(3) gave a recovery of 85.6 ± 1.7%. DGT validation experiments showed linear accumulation of As(III) over time (R(2) > 0.998). Accumulation was unaffected by varying ionic strength (0.0001-0.75 mol L(-1) NaNO(3)) and pH (3.5-8.5). Deployment of mercapto-silica DGT and Metsorb DGT in seawater spiked with As(III) and As(V) demonstrated the ability of the combined approach to accurately quantify both species in the presence of potential competing ions. Ferrihydrite DGT, which has been previously reported for the measurement of total inorganic arsenic, was evaluated in seawater and shown to underestimate both As(III) and As(V) at longer deployment times (72 h). Reproducibility of the new mercapto-silica DGT technique was good (relative standard deviations < 9%), and the average method detection limit was sufficiently low to allow quantification of ultratrace concentrations of As(III) (0.03 ?g L(-1); 72 h deployment). PMID:21967720

    Bennett, William W; Teasdale, Peter R; Panther, Jared G; Welsh, David T; Jolley, Dianne F

    2011-11-01

    275

    EXTENDED FINITE ELEMENTS FOR FRACTURE ANALYSIS OF FUNCTIONALLY GRADED MATERIALS  

    Microsoft Academic Search

    Summary. In this paper we develop a numerical strategy to follow crack propagation in quasi-brittle functionally graded materials (FGMs), endowed with assigned spatially varying elastic and fracture properties. A cohesive model is used within the context of the extended finite element method, formulated to account for continuous elastic and fracture energy gradation. This work addresses some computational issues concerning failure

    Claudia Comi; Stefano Mariani

    276

    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

    277

    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...

    278

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

    SciTech Connect

    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.

    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

    279

    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...

    280

    Materials Science Volume 7, Number 2  

    E-print Network

    Materials Science Volume 7, Number 2 A Review of Mesoporous TiO2 Thin Films Synthesis of MeltingThrough Ultrasonic Spray Pyrolysis Advanced Inorganic Materials for Solid State Lighting Building Up for Tomorrow of new materials. Recent advances in the area of functional materials include the development of porous

    Suslick, Kenneth S.

    281

    Functional and Multifunctional Polymers: Materials for Smart Structures  

    NASA Technical Reports Server (NTRS)

    The ultimate goal of the research in smart structures and smart materials is the development of a new generation of products/devices which will perform better than products/devices built from passive materials. There are a few examples of multilayer polymer systems which function as smart structures, e.g. a synthetic muscle which is a multilayer assembly of a poly(ethylene) layer, a gold layer, and a poly(pyrrole) layer immersed in a liquid electrolyte. Oxidation and reductions of the active pyrrole layer causes the assembly to reversibly deflect and mimic biological muscles. The drawback of such a setup is slow response times and the use of a liquid electrolyte. We have developed multifunctional polymers which will eliminate the use of a liquid electrolyte, and also because the functionalities of the polymers are within a few hundred angstroms, an improved response time to changes in the external field should be possible. Such multifunctional polymers may be classified as the futuristic 'smart materials.' These materials are composed of a number of different functionalities which work in a synergistic fashion to function as a device. The device performs on the application of an external field and such multifunctional polymers may be scientifically labeled as 'field responsive polymers.' Our group has undertaken a systematic approach to develop functional and multifunctional polymers capable of functioning as field responsive polymers. Our approach utilizes multicomponent polymer systems (block copolymers and graft copolymers), the strategy involves the preparation of block or graft copolymers where the functionalities are limited to different phases in a microphase separated system. Depending on the weight (or volume) fractions of each of the components, different microstructures are possible. And, because of the intimate contact between the functional components, an increase in the synergism between the functionalities may be observed. In this presentation, three examples of multifunctional polymers developed in our labs will be reported. The first class of multifunctional polymers are the microphase separated mixed (ionic and electronic) conducting or MIEC block copolymers. The second class being developed in our labs are the biocompatible conductive materials and the conductive fluids. The final class may be considered microwave active smart polymers.

    Arnold, S.; Pratt, L. M.; Li, J.; Wuagaman, M.; Khan, I. M.

    1996-01-01

    282

    Incorporating microorganisms into polymer layers provides bioinspired functional living materials.  

    PubMed

    Artificial two-dimensional biological habitats were prepared from porous polymer layers and inoculated with the fungus Penicillium roqueforti to provide a living material. Such composites of classical industrial ingredients and living microorganisms can provide a novel form of functional or smart materials with capability for evolutionary adaptation. This allows realization of most complex responses to environmental stimuli. As a conceptual design, we prepared a material surface with self-cleaning capability when subjected to standardized food spill. Fungal growth and reproduction were observed in between two specifically adapted polymer layers. Gas exchange for breathing and transport of nutrient through a nano-porous top layer allowed selective intake of food whilst limiting the microorganism to dwell exclusively in between a confined, well-enclosed area of the material. We demonstrated a design of such living materials and showed both active (eating) and waiting (dormant, hibernation) states with additional recovery for reinitiation of a new active state by observing the metabolic activity over two full nutrition cycles of the living material (active, hibernation, reactivation). This novel class of living materials can be expected to provide nonclassical solutions in consumer goods such as packaging, indoor surfaces, and in biotechnology. PMID:22198770

    Gerber, Lukas C; Koehler, Fabian M; Grass, Robert N; Stark, Wendelin J

    2012-01-01

    283

    Inorganic Nanoparticle Nucleation on Polymer Matrices  

    NASA Astrophysics Data System (ADS)

    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.

    Kosteleski, Adrian John

    284

    Acid Functionalized Mesoporous Ordered Materials for the Production of 5-Hydroxymethyfurfural from Carbohydrates  

    NASA Astrophysics Data System (ADS)

    Solid acid catalysts were designed for the conversion of fructose to 5-hydroxymethylfurfural (HMF). Some of the catalysts incorporate thioether groups to promote the tautomerization of fructose to its furanose form, as well as sulfonic acid groups to catalyze its dehydration. A bifunctional silane, 3-((3-(trimethoxysilyl)propyl)thio)propane-1-sulfonic acid (TESAS), was designed for incorporation into SBA-15-type silica by co-condensation. To achieve mesopore ordering in the functionalized silica, the standard SBA-15 synthetic protocol was modified, resulting in well-formed hexagonal particles. Functional groups incorporated into mesoporous silica by co-condensation are more robust under the reaction conditions than those grafted onto a non-porous silica. In a variation, the thioether group of TESAS was oxidized by H2O 2 to the sulfone during the synthesis of the modified SBA-15. The materials were tested in batch reactors and compared in the selective dehydration of fructose to 5-hydroxymethylfurfural (HMF). Compared to benchmark catalysts, the thioether-containing TESAS-SBA-15 showed the highest activity in the dehydration of aqueous fructose, as well as the highest selectivity towards HMF (71 % at 84 % conversion). In addition, the stability of several supported acid catalysts was evaluated in tubular reactors designed to produce 5-hydroxymethylfurfural (HMF) continuously. The reactors, packed with the solid catalysts, were operated at 403 K for extended periods, up to 180 h. The behaviors of three propylsulfonic acid-functionalized, ordered porous silicas (one inorganic SBA-15-type silica, and two ethane-bridged SBA-15-type organosilicas) were compared with that of a propylsulfonic acid-modified, non-ordered porous silica. The HMF selectivity of the catalysts with ordered pore structures ranged from 60 to 75 %, while the selectivity of the non-ordered catalyst peaked at 20 %. The latter was also the least stable, deactivating with a first-order rate constant of 0.152 h-1. The organosilicas are more hydrothermally stable and maintained a steady catalytic activity longer than inorganic SBA-15-type silica. The organosilica with an intermediate framework ethane content of 45 mol % was the most stable, with a first-order deactivation rate constant of only 0.012 h-1. Deactivation under flow conditions is caused primarily by hydrolytic cleavage of acid sites, which can be (to some extent) recaptured by the free surface hydroxyl groups of the silica surface.

    Crisci, Anthony J.

    285

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

    SciTech Connect

    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.

    Kutsuzawa, K. [Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan); Shizuoka Cancer Center Research Institute, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Chowdhury, E.H. [Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan); Shizuoka Cancer Center Research Institute, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Nagaoka, M. [Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan); Maruyama, K. [Shizuoka Cancer Center Research Institute, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Akiyama, Y. [Shizuoka Cancer Center Research Institute, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Akaike, T. [Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501 (Japan) and Shizuoka Cancer Center Research Institute, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan)]. E-mail: takaike@bio.titech.ac.jp

    2006-11-24

    286

    Expression and functional roles of Bradyrhizobium japonicum genes involved in the utilization of inorganic and organic sulfur compounds in free-living and symbiotic conditions.  

    PubMed

    Strains of Bradyrhizobium spp. form nitrogen-fixing symbioses with many legumes, including soybean. Although inorganic sulfur is preferred by bacteria in laboratory conditions, sulfur in agricultural soil is mainly present as sulfonates and sulfur esters. Here, we show that Bradyrhizobium japonicum and B. elkanii strains were able to utilize sulfate, cysteine, sulfonates, and sulfur-ester compounds as sole sulfur sources for growth. Expression and functional analysis revealed that two sets of gene clusters (bll6449 to bll6455 or bll7007 to bll7011) are important for utilization of sulfonates sulfur source. The bll6451 or bll7010 genes are also expressed in the symbiotic nodules. However, B. japonicum mutants defective in either of the sulfonate utilization operons were not affected for symbiosis with soybean, indicating the functional redundancy or availability of other sulfur sources in planta. In accordance, B. japonicum bacteroids possessed significant sulfatase activity. These results indicate that strains of Bradyrhizobium spp. likely use organosulfur compounds for growth and survival in soils, as well as for legume nodulation and nitrogen fixation. PMID:21190435

    Sugawara, Masayuki; Shah, Gopit R; Sadowsky, Michael J; Paliy, Oleg; Speck, Justin; Vail, Andrew W; Gyaneshwar, Prasad

    2011-04-01

    287

    An integration technique for evaluating confluent hypergeometric functions and its application to functionally graded materials  

    Microsoft Academic Search

    A novel numerical integral technique is proposed for evaluating confluent hypergeometric functions (CHFs), which arise from a wave propagation problem in functionally graded material (FGM). In the present method, a part of the integrand in the integral representation of the CHFs is approximated by piecewise polynomials, so that the integral can be carried out analytically in each sub-region. Using this

    G. R. Liu; X. Han; K. Y. Lam

    2001-01-01

    288

    Importance of spin-orbit coupling in hybrid organic/inorganic perovskites for photovoltaic  

    E-print Network

    1 Importance of spin-orbit coupling in hybrid organic/inorganic perovskites for photovoltaic, optoelectronics, titanateoxyde, density functional theory Photovoltaic (PV) solar electricity is one of the key, nanostructured materials, and thin films. Various approaches ranging from high-cost/high-performance III

    Boyer, Edmond

    289

    Piezoelectric materials mimic the function of the cochlear sensory epithelium  

    PubMed Central

    Cochlear hair cells convert sound vibration into electrical potential, and loss of these cells diminishes auditory function. In response to mechanical stimuli, piezoelectric materials generate electricity, suggesting that they could be used in place of hair cells to create an artificial cochlear epithelium. Here, we report that a piezoelectric membrane generated electrical potentials in response to sound stimuli that were able to induce auditory brainstem responses in deafened guinea pigs, indicating its capacity to mimic basilar membrane function. In addition, sound stimuli were transmitted through the external auditory canal to a piezoelectric membrane implanted in the cochlea, inducing it to vibrate. The application of sound to the middle ear ossicle induced voltage output from the implanted piezoelectric membrane. These findings establish the fundamental principles for the development of hearing devices using piezoelectric materials, although there are many problems to be overcome before practical application. PMID:22025702

    Inaoka, Takatoshi; Shintaku, Hirofumi; Nakagawa, Takayuki; Kawano, Satoyuki; Ogita, Hideaki; Sakamoto, Tatsunori; Hamanishi, Shinji; Wada, Hiroshi; Ito, Juichi

    2011-01-01

    290

    Interfacial properties and design of functional energy materials.  

    PubMed

    Conspectus 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 and performance. 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 noncovalent (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, for example, lithographic, approach. However, while function in simple systems such as single crystals can often be evaluated a priori, 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 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 support substrates. Typical molecular self-assembly involves noncovalent intermolecular and substrate-molecule interactions. These interactions remain poorly understood, due to the combination of many-body interactions compounded by local or collective influences from the substrate atomic lattice and electronic structure. Progress toward unraveling the underlying physicochemical processes that control the structure and macroscopic physical, chemical, 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. Theory, modeling, and simulation can accelerate the process of materials understanding and design by providing atomic level understanding of the underlying physicochemical phenomena (illuminating connections between experiments). It can also provide the ability to explore new materials and conditions before they are realized in the laboratory. With tight integration and feedback with experiment, it becomes feasible to identify promising materials or processes for targeted energy applications. In this Account, we highlight recent advances and success in using an integrated approach based on electronic structure simulations and scanning probe microscopy techniques to study and design functional materials formed from the self-assembly of molecules into supramolecular or polymeric architectures on substrates. PMID:24963787

    Sumpter, Bobby G; Liang, Liangbo; Nicolaï, Adrien; Meunier, Vincent

    2014-11-18

    291

    The Resolution of a Completely Inorganic Coordination Compound.  

    ERIC Educational Resources Information Center

    Discussed is a technique used by Alfred Werner to resolve inorganic coordination compounds. The materials, procedures and analysis necessary for undergraduates to repeat this procedure are described. (CW)

    Yasui, Takaji; And Others

    1989-01-01

    292

    Supersonic flutter analysis of thin cracked functionally graded material plates  

    E-print Network

    In this paper, the flutter behaviour of simply supported square functionally graded material plates immersed in a supersonic flow is studied. An enriched 4-noded quadrilateral element based on field consistency approach is used for this study and the crack is modelled independent of the underlying mesh. The material properties are assumed to be temperature dependent and graded only in the thickness direction. The effective material properties are estimated using the rule of mixtures. The formulation is based on the first order shear deformation theory and the shear correction factors are evaluated employing the energy equivalence principle. The influence of the crack length, the crack orientation, the flow angle and the gradient index on the aerodynamic pressure and the frequency are numerically studied. The results obtained here reveal that the critical frequency and the critical pressure decreases with increase in crack length and it is minimum when the crack is aligned to the flow angle.

    Natarajan, S; Bordas, S

    2012-01-01

    293

    Butterfly effects: novel functional materials inspired from the wings scales.  

    PubMed

    Through millions of years of evolutionary selection, nature has created biological materials with various functional properties for survival. Many complex natural architectures, such as shells, bones, and honeycombs, have been studied and imitated in the design and fabrication of materials with enhanced hardness and stiffness. Recently, more and more researchers have started to research the wings of butterflies, mostly because of their dazzling colors. It was found that most of these iridescent colors are caused by periodic photonic structures on the scales that make up the surfaces of these wings. These materials have recently become a focus of multidiscipline research because of their promising applications in the display of structural colors, and in advanced sensors, photonic crystals, and solar cells. This paper review aims to provide a perspective overview of the research inspired by these wing structures in recent years. PMID:25087928

    Zhang, Wang; Gu, Jiajun; Liu, Qinglei; Su, Huilan; Fan, Tongxiang; Zhang, Di

    2014-10-01

    294

    Approximate Green's function methods for HZE transport in multilayered materials  

    NASA Astrophysics Data System (ADS)

    A nonperturbative analytic solution of the high charge and energy (HZE) Green's function is used to implement a computer code for laboratory ion beam transport in multilayered materials. The code is established to operate on the Langley nuclear fragmentation model used in engineering applications. Computational procedures are established to generate linear energy transfer (LET) distributions for a specified ion beam and target for comparison with experimental measurements. The code was found to be highly efficient and compared well with the perturbation approximation.

    Wilson, John W.; Badavi, Francis F.; Shinn, Judy L.; Costen, Robert C.

    1993-10-01

    295

    Applications of inorganic nanoparticles as therapeutic agents  

    NASA Astrophysics Data System (ADS)

    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.

    Kim, Taeho; Hyeon, Taeghwan

    2014-01-01

    296

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

    SciTech Connect

    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.

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

    1998-12-31

    297

    Material-specific transfer function model and SNR in CT  

    NASA Astrophysics Data System (ADS)

    This study presents an analytical model for the edge spread function (ESF) of a clinical CT system that allows reliable fits of noisy ESF data. The model was used for the calculation of the material-specific transfer function TF and an estimation of the signal transfer and the signal-to-noise ratio (SNR) in 2D. Images of the Catphan phantom were acquired with a clinical Siemens Somatom Sensation Cardiac 64 CT scanner combining four different x-ray tube outputs (40, 150, 250 and 350 mAs) with four different reconstruction filters, which covered the range from very smooth (B10s) to very sharp (B70s). The images of the high- and mid-contrast cylinders of the phantom’s ‘Geometry and Sensitometry’ module (air, Teflon, Delrin and PMP) were used to sample material-specific ESF curves. The ESF curves were fitted with the analytical model we developed based on a linear combination of Boltzmann and Gaussian functions. The analytical model of the ESF was used to obtain the Fourier-based material-specific transfer function TF, as well as the spatial-domain point spread function (PSF). TF was subsequently used to estimate the signal transfer, which was compared to the actual reconstructed image of a 3.0 mm diameter Teflon pin. The noise power spectrum (NPS) was calculated from images of a uniform water phantom under the same technique parameters. The task-specific SNR was calculated for all technique parameters from the model-based TF, the measured NPS and simulated 3 mm diameter disc signals modeling the aforementioned materials. Bootstrapping was performed to estimate the standard deviation of the TF and the SNR. The analytical model we developed accurately captured the features of the CT ESF data. The coefficient of determination R2, a metric that describes the goodness of the fit, had a median value of 0.9995, and decreased for low tube output, low contrast and the sharp reconstruction filter. Our analysis showed that ESF, PSF and TF depended not only on the reconstruction filter, but also on the tube output and the material of the cylinders. For B40s and B70s, the TF of Delrin was significantly higher than the TF of other materials in the frequency range of 0.4-0.9 mm-1. The estimated signal transfer agreed well with the actual reconstructed image of the Teflon pin. For the technique parameters we used the SNR values ranged between [64, 320], [64, 281], [37, 137] and [33, 117] for air, Teflon, Delrin and PMP respectively. While for high-contrast materials the smoothest reconstruction filter resulted in the highest SNR, for mid-contrast materials the standard filter gave the best results. The presented approach provides an accurate, analytical description of the material-specific ESF, PSF and TF as well as an estimate of the signal transfer. The transfer function TF together with the NPS and simulated signals allow the calculation of a task-specific SNR.

    Brunner, Claudia C.; Kyprianou, Iacovos S.

    2013-10-01

    298

    Detonation Properties Measurements for Inorganic Explosives  

    Microsoft Academic Search

    Many commonly available explosive materials have never been quantitatively or theoretically characterized in a manner suitable for use in analytical models. This includes inorganic explosive materials used in spacecraft ordnance, such as zirconium potassium perchlorate (ZPP). Lack of empirical information about these materials impedes the development of computational techniques. We have applied high fidelity measurement techniques to experimentally determine the

    Brent A. Morgan; Angel Lopez

    2005-01-01

    299

    Combining form with function--the dawn of phosphole-based functional materials.  

    PubMed

    Phosphole-based ?-conjugated compounds have recently attracted significant attention due their unique electronic properties. It is now well established that the versatile phosphorus chemistry offers great opportunities for efficient fine-tuning of the properties of ?-conjugated systems from a fundamental point of view; a feature that pure carbon-based ?-conjugated materials cannot provide. This perspective highlights the recent progress using phosphole-based ?-conjugated building blocks towards applied materials with multiple and diverse functionalities. PMID:22414898

    Ren, Yi; Baumgartner, Thomas

    2012-07-14

    300

    10 CFR 1023.1 - Introductory material on the Board and its functions.  

    Code of Federal Regulations, 2011 CFR

    ...Introductory material on the Board and its functions. 1023.1 Section 1023.1...APPEALS Overview: Organization, Functions and Authorities § 1023.1 ...Introductory material on the Board and its functions. (a) The Energy Board of...

    2011-01-01

    301

    Gas separations using inorganic membranes  

    Microsoft Academic Search

    Two potential industrially important applications of inorganic membranes are of particular interest: (1) recovery of Hâ from synthesis gas at high temperature and in a chemically harsh environment; and (2) removal of acid gases from raw synthesis gas at temperatures in the 1200-1800\\/degree\\/F range. Hydrogen is an important and valuable raw material that has numerous uses in the chemical and

    B. Z. Egan; S. P. N. Singh; D. E. Fain; G. J. Kidd

    1988-01-01

    302

    PREFACE Surface Modifications and Functionalization of Materials for Biomedical Applications  

    NASA Astrophysics Data System (ADS)

    Conference photograph This special issue contains selected papers which were presented as invited and contributed communications at the workshop entitled 'Surface modification and functionalization of materials for biomedical applications' (BIO-COAT 2010) which was held on 24 June 2010 in Zaragoza (Spain). The surface of a material plays a major role in its interaction with the biological medium. Processes related to the mechanical stability of articular devices in contact, osseointegration, thrombogenicity, corrosion and leaching, or the inflammatory response of rejection of a material, are clearly conditioned by the surface properties. Therefore, the modification or functionalization of surfaces can have an important impact on these issues. New techniques for functionalization by thin film deposition or surface treatments help to improve superficial properties, while understanding the interaction of the surface-biological medium is critical for their application in new devices. Jointly organized by the Spanish Materials Research Society, BIO-COAT 2010 provided an open forum to discuss the progress and latest developments in thin film processing and the engineering of biomaterials. Invited lectures were particularly aimed at providing overviews on scientific topics and were given by recognized world-class scientists. Two of them have contributed with a proceedings article to this selected collection (articles 012001 and 012008). The contributed communications were focused on particular cutting-edge aspects of thin film science and functionalization technologies for biomaterials, showing the major scientific push of Spanish research groups in the field. The 2010 BIO-COAT conference was organized along four main topics: (1) functionalization and texture on surfaces, (2) tribology and corrosion, (3) the surface modification of biomaterials, and (4) surface-biological environment interactions. The papers published in this volume were accepted for publication after peer-review as are regular papers. The editor of this proceedings volume gratefully acknowledges all referees for their valuable work, sometimes working to quite short deadlines. Finally, BIO-COAT 2010 would not have been successful without the strong involvement and input of the local organizing committee in Zaragoza, and the support of the University of Zaragoza. We sincerely thank them all for their efforts. Jose L Endrino (Editor) Jose A Puértolas (Chairman) Jose M Albella (Chairman)

    Endrino, Jose Luis; Puértolas, Jose A.; Albella, Jose M.

    2010-11-01

    303

    Functionalized Cyclophanes Incorporated into Molecular Architectures and Mechanized Materials  

    NASA Astrophysics Data System (ADS)

    Supramolecular chemistry, the chemistry of the noncovalent bond beyond the molecule, has been utilized historically to organize the formation of novel compounds and topologies, including mechanically interlocked molecules (MIMs). Specifically, the host-guest complex between the cyclophane cyclobis(paraquat-p-phenylene) (CBPQT4+) and electron-rich guests has been exploited to template the formation of catenanes, rotaxanes and other topologically interesting molecules. By equipping CBPQT 4+ with new functional handles, previously unattainable topologies can be accessed. Moving beyond the synthesis of MIMs in solution, functionalizing the cyclophane enables the marriage of these existing topologies to different materials. In doing so, new properties can be obtained and new functions can be elicited. In this thesis, the functionalization of CBPQT4+ is featured in respect to a bioconjugate device that utilizes the cyclophane and a molecular Figure-of-Eight (Fo8). The DNA bioconjugate device is constructed characterized, and recognition properties are examined here. The donor-acceptor Fo8 is also synthesized and characterized here. The Fo8 possesses a structure that could not be attainable without the functionalized CBPQT4+ host. Furthermore, the resulting stereochemical implications and consequences of the Fo8 structure are presented.

    Boyle, Megan Marie

    304

    Low work function material development for the microminiature thermionic converter.  

    SciTech Connect

    Thermionic energy conversion in a miniature format shows potential as a viable, high efficiency, micro to macro-scale power source. A microminiature thermionic converter (MTC) with inter-electrode spacings on the order of microns has been prototyped and evaluated at Sandia. The remaining enabling technology is the development of low work function materials and processes that can be integrated into these converters to increase power production at modest temperatures (800 - 1300 K). The electrode materials are not well understood and the electrode thermionic properties are highly sensitive to manufacturing processes. Advanced theoretical, modeling, and fabrication capabilities are required to achieve optimum performance for MTC diodes. This report describes the modeling and fabrication efforts performed to develop micro dispenser cathodes for use in the MTC.

    Zavadil, Kevin Robert; Battaile, Corbett Chandler; Marshall, Albert Christian; King, Donald Bryan; Jennison, Dwight Richard

    2004-03-01

    305

    Peptide Self-Assembly for Crafting Functional Biological Materials  

    PubMed Central

    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

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

    2011-01-01

    306

    Ion Beams: A Powerful Tool for Making New Functional Materials  

    SciTech Connect

    It is well known that ion beams play an important role in semiconductor industry, which utilizes ion implantation and irradiation for materials modification. Ion sputtering technique is used to fabricate multifunctional coatings and multilayers. Using ion implantation, there is a continued effort for fabrication of quantum bit structures for future quantum computers. Availability of focused ion beams (FIBs) has widened the applications of ion beams and nanostructured functional materials are being fabricated using FIBs. Various quantum structures can be fabricated using FIB. Ferromagnetism can either be induced or destroyed in special layered structures using ion irradiation. The magnetic exchange bias phenomenon is of tremendous utility in magnetic recording. Issues of lateral diffusion in nanoscale doping of semiconductors by FIB and an example of exchange bias enhancement by ion irradiation are discussed.

    Dev, B. N. [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

    2010-12-01

    307

    Fabrication and application of advanced functional materials from lignincellulosic biomass  

    NASA Astrophysics Data System (ADS)

    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.

    Hu, Sixiao

    308

    Hybrid materials of MCM-41 functionalized by lanthanide (Tb{sup 3+}, Eu{sup 3+}) complexes of modified meta-methylbenzoic acid: Covalently bonded assembly and photoluminescence  

    SciTech Connect

    Novel organic-inorganic mesoporous hybrid materials were synthesized by linking lanthanide (Tb{sup 3+}, Eu{sup 3+}) complexes to the mesoporous MCM-41 through the modified meta-methylbenzoic acid (MMBA-Si) using co-condensation method in the presence of the cetyltrimethylammonium bromide (CTAB) surfactant as template. The luminescence properties of these resulting materials (denoted as Ln-MMBA-MCM-41, Ln=Tb, Eu) were characterized in detail, and the results reveal that luminescent mesoporous materials have high surface area, uniformity in the ordered mesoporous structure. Moreover, the mesoporous material covalently bonded Tb{sup 3+} complex (Tb-MMBA-MCM-41) exhibits the stronger characteristic emission of Tb{sup 3+} and longer lifetime than Eu-MMBA-MCM-41 due to the triplet state energy of organic legend MMBA-Si matches with the emissive energy level of Tb{sup 3+} very well. - Graphical abstract: Novel organic-inorganic mesoporous luminescent materials were synthesized by linking lanthanide (Tb{sup 3+}, Eu{sup 3+}) complexes to covalently bond the functionalized ordered mesoporous MCM-41 with modified meta-methylbenzoic acid (MMBA)-Si by co-condensation of tetraethoxysilane (TEOS) in the presence of the cetyltrimethylammonium bromide (CTAB) surfactant as template.

    Li Ying [Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092 (China); Yan Bing [Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092 (China)], E-mail: byan@tongji.edu.cn

    2008-05-15

    309

    Stress Recovery and Dynamic Analysis of Functionally Graded Materials  

    NASA Astrophysics Data System (ADS)

    A macroelement recovery technique for the strain field of a functionally graded material (FGM), based on the residual dynamic equilibrium equation for elasticity, is proposed. The derivatives are recovered by solving a local variational problem, using the superconvergence points. The basic idea is to utilize post-processing to achieve a more accurate approximation of the stresses while considering the dynamic nature of the problem. The development includes dynamic modeling of FGM and can be applied to direct and inverse problems. A numerical simulation is presented to better demonstrate the proposed methodology.

    Paulino, Rivânia H.; Romero, Juan S.; Menandro, Fernando C. M.

    2008-02-01

    310

    Analysis of the Elastic Field in Functionally Graded Materials  

    NASA Astrophysics Data System (ADS)

    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.

    Mohammadi, Mohsen

    311

    Soft materials design via self assembly of functionalized icosahedral particles  

    NASA Astrophysics Data System (ADS)

    In this work we simulate self assembly of icosahedral building blocks using a coarse grained model of the icosahedral capsid of virus 1m1c. With significant advancements in site-directed functionalization of these macromolecules [1], we propose possible application of such self-assembled materials for drug delivery. While there have been some reports on organization of viral particles in solution through functionalization, exploiting this behaviour for obtaining well-ordered stoichiometric structures has not yet been explored. Our work is in well agreement with the earlier simulation studies of icosahedral gold nanocrystals, giving chain like patterns [5] and also broadly in agreement with the wet lab works of Finn, M.G. et al., who have shown small predominantly chain-like aggregates with mannose-decorated Cowpea Mosaic Virus (CPMV) [22] and small two dimensional aggregates with oligonucleotide functionalization on the CPMV capsid [1]. To quantify the results of our Coarse Grained Molecular Dynamics Simulations I developed analysis routines in MATLAB using which we found the most preferable nearest neighbour distances (from the radial distribution function (RDF) calculations) for different lengths of the functional groups and under different implicit solvent conditions, and the most frequent coordination number for a virus particle (histogram plots further using the information from RDF). Visual inspection suggests that our results most likely span the low temperature limits explored in the works of Finn, M.G. et al., and show a good degree of agreement with the experimental results in [1] at an annealing temperature of 4°C. Our work also reveals the possibility of novel stoichiometric N-mer type aggregates which could be synthesized using these capsids with appropriate functionalization and solvent conditions.

    Muthukumar, Vidyalakshmi Chockalingam

    312

    Dynamic fracture of functionally graded magnetoelectroelastic composite materials  

    NASA Astrophysics Data System (ADS)

    The stress, magnetic and electric field analysis of multifunctional composites, weakened by impermeable cracks, is of fundamental importance for their structural integrity and reliable service performance. The aim is to study dynamic behavior of a plane of functionally graded magnetoelectroelastic composite with more than one crack. The coupled material properties vary exponentially in an arbitrary direction. The plane is subjected to anti-plane mechanical and in-plane electric and magnetic load. The boundary value problem described by the partial differential equations with variable coefficients is reduced to a non-hypersingular traction boundary integral equation based on the appropriate functional transform and frequency-dependent fundamental solution derived in a closed form by Radon transform. Software code based on the boundary integral equation method (BIEM) is developed, validated and inserted in numerical simulations. The obtained results show the sensitivity of the dynamic stress, magnetic and electric field concentration in the cracked plane to the type and characteristics of the dynamic load, to the location and cracks disposition, to the wave-crack-crack interactions and to the magnitude and direction of the material gradient.

    Stoynov, Y.; Dineva, P.

    2014-11-01

    313

    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...

    314

    Magnetic Alignment and Charge Transport Improvement in Functional Soft Materials  

    NASA Astrophysics Data System (ADS)

    The realization of nanostructured functional materials by self-assembly in polymers and polymer nanocomposites is adversely affected by persisting structural defects which greatly diminish the performance of the material. The use of magnetic fields to impose long-range order is investigated in three distinct systems - ion-conducting block copolymers, semiconducting nanowire-polymer composites and lyotropic surfactant mesophases. The alignment process is quantitatively studied with X-ray scattering and microscopic methods. Time and temperature resolved data collected in situ during the magnetic experiments provide an insight into the thermodynamic and kinetic aspects of the process. These data together with simultaneous electrical conductivity measurements allow relating fundamental structural properties (e.g., morphology and long-range order) to transport properties (i.e., conductivity). In particular, it is demonstrated that magnetic fields offer a viable route for improvement of electric conductivity in these systems. More than an order of magnitude increase in conductivity is recorded in magnetically-annealed materials. The resulting aligned nanostructured systems are attractive for ordered solid polymer electrolyte membranes, heterojunction photovoltaic devices and generally help to understand charge transport mechanisms in anisotropic heterogeneous systems.

    Majewski, Pawel W.

    315

    Inorganic-organic separators for alkaline batteries  

    NASA Technical Reports Server (NTRS)

    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.

    Sheibley, D. W. (inventor)

    1978-01-01

    316

    Gas separations using inorganic membranes  

    SciTech Connect

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

    Egan, B.Z.; Singh, S.P.N. (Oak Ridge National Lab., TN (United States)); Fain, D.E.; Roettger, G.E.; White, D.E. (Oak Ridge K-25 Site, TN (United States))

    1992-04-01

    317

    Design of Functional Materials with Hydrogen-Bonded Host Frameworks  

    NASA Astrophysics Data System (ADS)

    The properties of molecular crystals are governed by the attributes of their molecular constituents and their solid-state arrangements, making control of crystal packing paramount when designing new materials with targeted functions. One effective strategy involves the use of robust host frameworks that encapsulate functional guests in molecular-scale cavities with tailored shapes, sizes, and chemical environments that enable systematic regulation of solid state properties. This approach promises to simplify the synthesis of molecular materials by decoupling the design of structure, provided by the host framework, from function, introduced by the guests. This thesis has reported a series of crystalline, structurally robust hosts based on guanidinium cations (G = (C(NH2) 3 +) and the sulfonate moieties of organodisulfonate anions (DS; S = -O3S-R-SO3 -). The host framework is based on layers of 2-D GS sheet, which are interconnected by the organic residues (pillars) of the disulfonates, thereby producing a lamellar architecture with inclusion cavities, occupied by guest molecules, between the sheets. Notably, the GDS inclusion compounds exhibit numerous architectures such as bilayer, simple brick, and zigzag brick -- each endowed with uniquely sized and shaped cavities, suggesting that the aggregation motifs of the included guests can be controlled within the host lattice. Furthermore, the selectivity toward different architectures is governed by the relative size of the pillars and guests, allowing the construction of a "structural phase diagram" which can be used to predict the solid-state architecture of untested host-guest combination. Consequently, a variety of functional molecules have been included in order to exploit these features. Chapter 3 reports the inclusion of polyconjugated molecules within the GDS hosts, generating various guest aggregation motifs -- edge-to-edge to face-to-edge to end-to-end. The effects of the various host and/or guest aggregation motifs on the optical properties of the confined guests are manifested in the bathochromic shifts in the absorption and emission spectra relative to those in dilute solution. The shifts in the absorption bands were corroborated by ab initio computations (using TDDFT at the PBE0/6-311G(d,p) level) based on the structures of the host-guest aggregates observed in the crystalline state. Chapter 4 describes the inclusion of several coumarin-based laser dyes. GDS hosts with the bilayer architectures include the dye as monomers, whereas those with the brick architectures include the dye as dimers. The ability to tune the emission wavelength through choice of dye and adjustment of framework architectures enables the design of a new class of efficient laser dye crystals. Furthermore, the excited state lifetime of some of the confined dyes in the host matrix were extended by up to ten times longer than those in dilute solutions -- an important characteristic for producing efficient lasing crystals. Chapter 5 details the inclusion of a variety of TEMPO-based radicals, whose molecular arrangement can be controlled depending on the host framework architecture. GDS hosts with the simple brick architecture generate 1-D channels which organize the radical guests into a two-leg ladder, whereas GDS hosts with the zigzag brick architecture distribute the radical guests into a 2-D square-planar lattice. Although magnetic susceptibility measurements indicate long-range antiferromagnetic ordering in these materials, the ability to form 1-D or 2-D spin systems in these frameworks may allow the design of low-dimensional magnets. Collectively, this thesis demonstrates the ability of the GDS hosts to regulate the solid-state structure of functional guest molecules, which suggests a route to the design and synthesis of materials with future applications in areas as diverse as optoelectronics, magnetics, and confined reactions.

    Soegiarto, Airon Cosanova

    318

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

    SciTech Connect

    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.

    Coker, Eric Nicholas

    2010-11-01

    319

    Harvesting bioenergy with rationally designed complex functional materials  

    NASA Astrophysics Data System (ADS)

    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.

    Kuang, Liangju

    320

    Molten salt battery having inorganic paper separator  

    Microsoft Academic Search

    A high-temperature secondary battery comprises an anode containing lithium, a cathode containing a chalcogen or chalcogenide, a molten salt electrolyte containing lithium ions, and a separator comprising a porous sheet comprising a homogenous mixture of 2 to 20 wt percent chrysotile asbestos fibers and the remainder inorganic material nonreactive with the battery components. The nonreactive material is present as fibers,

    R. D. Jr

    1977-01-01

    321

    Size and crystallinity in protein-templated inorganic nanoparticles  

    PubMed Central

    Protein cages such as ferritins and virus capsids have been used as containers to synthesize a wide variety of protein-templated inorganic nanoparticles. While identification of the inorganic crystal phase has been successful in some cases, very little is known about the detailed nanoscale structure of the inorganic component. We have used pair distribution function analysis of total X-ray scattering to measure the crystalline domain size in nanoparticles of ferrihydrite, ?-Fe2O3, Mn3O4, CoPt, and FePt grown inside 24-meric ferritin cages from H. sapiens and P. furiosus. The material properties of these protein-templated nanoparticles are influenced by processes at a variety of length scales: the chemistry of the material determines the precise arrangement of atoms at very short distances, while the interior volume of the protein cage constrains the maximum nanoparticle size attainable. At intermediate length scales, the size of coherent crystalline domains appears to be constrained by the arrangement of crystal nucleation sites on the interior of the cage. Based on these observations, some potential synthetic strategies for the control of crystalline domain size in protein-templated nanoparticles are suggested. PMID:23997427

    Jolley, Craig C.; Uchida, Masaki; Reichhardt, Courtney; Harrington, Richard; Kang, Sebyung; Klem, Michael T.; Parise, John B.; Douglas, Trevor

    2013-01-01

    322

    Enzyme-polymer hybrids for highly stanle functional materials and self-cleaning coatings.  

    E-print Network

    ??Being deployed originally for biosynthesis or biodegradation, enzymes have also shown great potentials for development of functional materials. One particular challenge in deriving enzyme-based functional… (more)

    Wu, Songtao

    2011-01-01

    323

    ATRP in the design of functional materials for biomedical applications  

    PubMed Central

    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

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

    2013-01-01

    324

    Work Function of Cathode Emitter Materials Obtained by Ab-initio Quantum Mechanical Modeling  

    Microsoft Academic Search

    The work function of a material is a very important figure of merit in determining the material's applicability as an efficient electron emitter. Consequently, the work function of a variety of materials utilized in both thermionic and field-assisted cathodes for electron emission was investigated computationally using ab-initio quantum mechanical modeling methods based on the density functional theory (DFT) approach (Hohenberg

    V. Viaho; E. F. Holby; A. K. Berta; D. D. Morgan; J. H. Booske

    2006-01-01

    325

    Advanced Density Functional Theory Methods for Materials Science  

    NASA Astrophysics Data System (ADS)

    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.

    Demers, Steven

    326

    Acquisition of Instructional Material Information as a Function of Manual Design and Material Complexity.  

    ERIC Educational Resources Information Center

    The study, with 52 preservice special education teachers, focused on effects of two types of teacher manual design and two levels of material complexity on comprehension of instructional materials utilization. Two materials were selected from an instructional materials collection for less complex material and for more complex material,…

    Altman, Reuben; And Others

    327

    Metal-organic frameworks as functional, porous materials  

    NASA Astrophysics Data System (ADS)

    The research presented in this thesis investigates the use of metal carboxylates as permanently porous materials called metal-organic frameworks (MOFs). The project has focused on three broad areas of study, each which strives to develop a further understanding of this class of materials. The first topic is concerned with the synthesis and structural characterization of MOFs. Our group and others have found that the reaction of metal salts with carboxylic acids in polar solvents at elevated temperatures often leads the formation of crystalline MOF materials that can be examined by single crystal X-ray diffraction. Specifically, Chapter 2 reports on some of the first examples of magnesium MOFs, constructed from formate or aryldicarboxylate ligands. The magnesium formate MOF, [Mg3(O2CH) 6] was found to be a permanently porous 3-D material capable of selective uptake and exchange of small molecules. Once the synthesis and structures of some of these materials was known, their physical properties were studied. The magnesium formate MOF, [Mg 3(O2CH)6], was found to be permanently porous and able to reversibly adsorb both N2 and H2 gas. Furthermore, the material was also capable of taking up a variety of organic molecules to form new inclusion compounds that were characterized by XRD studies. Size exclusion was shown for cyclohexane and larger molecules. Chapters 3, 5, and 6 attempt to build off of the synthetic findings reported in Chapter 2. Specifically, the ability of these materials to take up guest molecules is expanded by the attempted synthesis of porous, homochiral MOFs using enantiopure carboxylic acids in the synthesis. It was found that under the appropriate synthetic conditions, both L-tartaric acid and (+)-camphoric acid were robust linkers for the formation of homochiral MOFs. Of the compounds synthesized, the most interesting were the set of compounds, [Zn2(Cam) 2(bipy)?3DMF] and [Zn2(Cam)2(apyr)?2DMF]. These compounds formed isoreticular cubic networks in which the pore size was dependent on the size of the linker molecule (bipy or apyr). Additonally, the compounds [Zn2(Cam)2(bipy)?3DMF] and [Zn2(Cam)2(apyr)?2DMF] were found to be capable of guest exchange. Due to their chiral nature, these materials were screened for the enanatioselective separation of racemic alcohols. No selectivity was seen with either MOF, likely owing to factors such as large pore size and disorder in the chiral camphorate ligand. [Zn2(Cam)2(bipy)?3DMF] contained large voids and preliminary studies showed that free-radical polymerization of methylmethacrylate could take place within the channels of the material. The amino group of the apyr ligand in [Zn2(Cam)2(apyr)?2DMF] was able to be functionaled with acetaldehyde by treatment of the porous MOF with the bulk organic reagent. A further area of study detailed in this work deals with a central question in MOF chemistry, concerning the assembly process of these extended materials from solution. Chapter 3 reveals that the trimeric species Mg2(HCam) 3+, the SBU for the formation of the MOF [Mg2(Hcam) 3?3H2O]?NO3?MeCN, can be identified using ESI-MS on the the reaction solution prior to crystallization. Further studies showed that the addition of chelating additives led to new solid-state structures and new ions in the mass spectrum, indicating that the Mg 2(HCam)3+ ion is likely present in solution prior to MOF formation. Chapter 4 discusses extension of these ESI-MS studies on various other MOF and organometallic systems. Finally, Chapter 7 discusses the synthesis and structures of magnesium imides. These compounds were originally investigated for use as SBUs in network synthesis. This strategy proved to be unsuccessful, as the compounds form molecular clusters in the solid state. The coordination chemistry and computational studies regarding the adopted aggregation state is detailed.

    Rood, Jeffrey A.

    328

    A Mapping of the Electron Localization Function for Earth Materials  

    SciTech Connect

    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.

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

    2005-06-01

    329

    Inorganic mass spectrometry  

    SciTech Connect

    Inorganic mass spectrometry is enjoying a resurgence of interest among analytical chemists. Dramatic improvements in existing techniques, rapid development and commercialization of new methods, and successful application to increasingly difficult analytical problems are all factors responsible for the renewal of interest in MS as applied to inorganic, elemental, and isotopic analysis. Given the level of recent activity in this field, the book is both timely and needed. Edited by three faculty members of the University of Antwerp in Belgium, the book contains chapters contributed by these editors and other established mass spectrometrists. It fills a void that has existed too long in MS. Too many recent texts purporting to survey the technique of MS in general have ignored inorganic applications altogether. As the title implies, this book turns the tables somewhat and is devoted entirely to the importance of MS in inorganic analysis. The book contains detailed chapters on both established and newer methods of inorganic MS analysis, including spark source, glow discharge, secondary ion, laser microprobe, ICP source, and isotope dilution MS techniques. Introductory and concluding chapters discuss the historical and future roles of inorganic MS, respectively; this historical synopsis is particularly interesting and informative. The discussion of spark source MS includes an excellent and up-to-date treatment of the physics and dynamics of the spark discharge phenomenon as well as a thorough review of the technique's features.

    Adams, F.; Gijbels, R.; Van Grieken, R. (eds.)

    1988-01-01

    330

    Inorganic Chemistry Solutions to Semiconductor Nanocrystal Problems  

    SciTech Connect

    The optoelectronic and chemical properties of semiconductor nanocrystals heavily depend on their composition, size, shape and internal structure, surface functionality, etc. Available strategies to alter these properties through traditional colloidal syntheses and ligand exchange methods place a premium on specific reaction conditions and surfactant combinations. In this invited review, we apply a molecular-level understanding of chemical precursor reactivity to reliably control the morphology, composition and intimate architecture (core/shell vs. alloyed) of semiconductor nanocrystals. We also describe our work aimed at achieving highly selective, low-temperature photochemical methods for the synthesis of semiconductor–metal and semiconductor–metal oxide photocatalytic nanocomposites. In addition, we describe our work on surface modification of semiconductor nanocrystal quantum dots using new approaches and methods that bypass ligand exchange, retaining the nanocrystal's native ligands and original optical properties, as well as on spectroscopic methods of characterization useful in determining surface ligand organization and chemistry. Using recent examples from our group and collaborators, we demonstrate how these efforts have lead to faster, wider and more systematic application of semiconductor nanocrystal-based materials to biological imaging and tracking, and to photocatalysis of unconventional substrates. We believe techniques and methods borrowed from inorganic chemistry (including coordination, organometallic and solid state chemistry) have much to offer in reaching a better understanding of the synthesis, functionalization and real-life application of such exciting materials as semiconductor nanocrystals (quantum dots, rods, tetrapods, etc.).

    Alvarado, Samuel R. [Ames Laboratory; Guo, Yijun [Ames Laboratory; Ruberu, T. Purnima A. [Ames Laboratory; Tavasoli, Elham [Ames Laboratory; Vela, Javier [Ames Laboratory

    2014-03-15

    331

    Functional materials from self-assembled bis-urea macrocycles.  

    PubMed

    CONSPECTUS: This Account highlights the work from our laboratories on bis-urea macrocycles constructed from two C-shaped spacers and two urea groups. These simple molecular units assembled with high fidelity into columnar structures guided by the three-centered urea hydrogen bonding motif and aryl stacking interactions. Individual columns are aligned and closely packed together to afford functional and homogeneous microporous crystals. This approach allows for precise and rational control over the dimensions of the columnar structure simply by changing the small molecular unit. When the macrocyclic unit lacks a cavity, columnar assembly gives strong pillars. Strong pillars with external functional groups such as basic lone pairs can expand like clays to accept guests between the pillars. Macrocycles that contain sizable interior cavities assemble into porous molecular crystals with aligned, well-defined columnar pores that are accessible to gases and guests. Herein, we examine the optimal design of the macrocyclic unit that leads to columnar assembly in high fidelity and probe the feasibility of incorporating a second functional group within the macrocycles. The porous molecular crystals prepared through the self-assembly of bis-urea macrocycles display surface areas similar to zeolites but lower than MOFs. Their simple one-dimensional channels are well-suited for studying binding, investigating transport, diffusion and exchange, and monitoring the effects of encapsulation on reaction mechanism and product distribution. Guests that complement the size, shape, and polarity of the channels can be absorbed into these porous crystals with repeatable stoichiometry to form solid host-guest complexes. Heating or extraction with an organic solvent enables desorption or removal of the guest and subsequent recovery of the solid host. Further, these porous crystals can be used as containers for the selective [2 + 2] cycloadditions of small enones such as 2-cyclohexenone or 3-methyl-cyclopentenone, while larger hosts bind and facilitate the photodimerization of coumarin. When the host framework incorporates benzophenone, a triplet sensitizer, UV-irradiation in the presence of oxygen efficiently generates singlet oxygen. Complexes of this host were employed to influence the selectivity of photooxidations of 2-methyl-2-butene and cumene with singlet oxygen. Small systematic changes in the channel and bound reactants should enable systematic evaluation of the effects of channel dimensions, guest dimensions, and channel-guest interactions on the processes of absorption, diffusion, and reaction of guests within these nanochannels. Such studies could help in the development of new materials for separations, gas storage, and catalysis. PMID:24784767

    Shimizu, Linda S; Salpage, Sahan R; Korous, Arthur A

    2014-07-15

    332

    Exploration Life Support: ELS Functions and Materials Interfaces  

    NASA Technical Reports Server (NTRS)

    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.

    Duffield, Bruce

    2007-01-01

    333

    Functional Graphenic Materials Via a Johnson?Claisen Rearrangement  

    E-print Network

    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, ...

    Swager, Timothy M.

    334

    New and extended parameterization of the thermodynamic model AIOMFAC: calculation of activity coefficients for organic-inorganic mixtures containing carboxyl, hydroxyl, carbonyl, ether, ester, alkenyl, alkyl, and aromatic functional groups  

    NASA Astrophysics Data System (ADS)

    We present a new and considerably extended parameterization of the thermodynamic activity coefficient model AIOMFAC (Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients) at room temperature. AIOMFAC combines a Pitzer-like electrolyte solution model with a UNIFAC-based group-contribution approach and explicitly accounts for interactions between organic functional groups and inorganic ions. Such interactions constitute the salt-effect, may cause liquid-liquid phase separation, and affect the gas-particle partitioning of aerosols. The previous AIOMFAC version was parameterized for alkyl and hydroxyl functional groups of alcohols and polyols. With the goal to describe a wide variety of organic compounds found in atmospheric aerosols, we extend here the parameterization of AIOMFAC to include the functional groups carboxyl, hydroxyl, ketone, aldehyde, ether, ester, alkenyl, alkyl, aromatic carbon-alcohol, and aromatic hydrocarbon. Thermodynamic equilibrium data of organic-inorganic systems from the literature are critically assessed and complemented with new measurements to establish a comprehensive database. The database is used to determine simultaneously the AIOMFAC parameters describing interactions of organic functional groups with the ions H+, Li+, Na+, K+, NH4+, Mg2+, Ca2+, Cl-, Br-, NO3-, HSO4-, and SO42-. Detailed descriptions of different types of thermodynamic data, such as vapor-liquid, solid-liquid, and liquid-liquid equilibria, and their use for the model parameterization are provided. Issues regarding deficiencies of the database, types and uncertainties of experimental data, and limitations of the model, are discussed. The challenging parameter optimization problem is solved with a novel combination of powerful global minimization algorithms. A number of exemplary calculations for systems containing atmospherically relevant aerosol components are shown. Amongst others, we discuss aqueous mixtures of ammonium sulfate with dicarboxylic acids and with levoglucosan. Overall, the new parameterization of AIOMFAC agrees well with a large number of experimental datasets. However, due to various reasons, for certain mixtures important deviations can occur. The new parameterization makes AIOMFAC a versatile thermodynamic tool. It enables the calculation of activity coefficients of thousands of different organic compounds in organic-inorganic mixtures of numerous components. Models based on AIOMFAC can be used to compute deliquescence relative humidities, liquid-liquid phase separations, and gas-particle partitioning of multicomponent mixtures of relevance for atmospheric chemistry or in other scientific fields.

    Zuend, A.; Marcolli, C.; Booth, A. M.; Lienhard, D. M.; Soonsin, V.; Krieger, U. K.; Topping, D. O.; McFiggans, G.; Peter, T.; Seinfeld, J. H.

    2011-05-01

    335

    New and extended parameterization of the thermodynamic model AIOMFAC: calculation of activity coefficients for organic-inorganic mixtures containing carboxyl, hydroxyl, carbonyl, ether, ester, alkenyl, alkyl, and aromatic functional groups  

    NASA Astrophysics Data System (ADS)

    We present a new and considerably extended parameterization of the thermodynamic activity coefficient model AIOMFAC (Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients) at room temperature. AIOMFAC combines a Pitzer-like electrolyte solution model with a UNIFAC-based group-contribution approach and explicitly accounts for interactions between organic functional groups and inorganic ions. Such interactions constitute the salt-effect, may cause liquid-liquid phase separation, and affect the gas-particle partitioning of aerosols. The previous AIOMFAC version was parameterized for alkyl and hydroxyl functional groups of alcohols and polyols. With the goal to describe a wide variety of organic compounds found in atmospheric aerosols, we extend here the parameterization of AIOMFAC to include the functional groups carboxyl, hydroxyl, ketone, aldehyde, ether, ester, alkenyl, alkyl, aromatic carbon-alcohol, and aromatic hydrocarbon. Thermodynamic equilibrium data of organic-inorganic systems from the literature are critically assessed and complemented with new measurements to establish a comprehensive database. The database is used to determine simultaneously the AIOMFAC parameters describing interactions of organic functional groups with the ions H+, Li+, Na+, K+, NH4+, Mg2+, Ca2+, Cl-, Br-, NO3-, HSO4-, and SO42-. Detailed descriptions of different types of thermodynamic data, such as vapor-liquid, solid-liquid, and liquid-liquid equilibria, and their use for the model parameterization are provided. Issues regarding deficiencies of the database, types and uncertainties of experimental data, and limitations of the model, are discussed. The challenging parameter optimization problem is solved with a novel combination of powerful global minimization algorithms. A number of exemplary calculations for systems containing atmospherically relevant aerosol components are shown. Amongst others, we discuss aqueous mixtures of ammonium sulfate with dicarboxylic acids and with levoglucosan. Overall, the new parameterization of AIOMFAC agrees well with a large number of experimental datasets. However, due to various reasons, for certain mixtures important deviations can occur. The new parameterization makes AIOMFAC a versatile thermodynamic tool. It enables the calculation of activity coefficients of thousands of different organic compounds in organic-inorganic mixtures of numerous components. Models based on AIOMFAC can be used to compute deliquescence relative humidities, liquid-liquid phase separations, and gas-particle partitioning of multicomponent mixtures of relevance for atmospheric chemistry or in other scientific fields.

    Zuend, A.; Marcolli, C.; Booth, A. M.; Lienhard, D. M.; Soonsin, V.; Krieger, U. K.; Topping, D. O.; McFiggans, G.; Peter, T.; Seinfeld, J. H.

    2011-09-01

    336

    Synthesis of nanostructured materials in inverse miniemulsions and their applications  

    NASA Astrophysics Data System (ADS)

    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.

    Cao, Zhihai; Ziener, Ulrich

    2013-10-01

    337

    Pulse thermal processing of functional materials using directed plasma arc  

    DOEpatents

    A method of thermally processing a material includes exposing the material to at least one pulse of infrared light emitted from a directed plasma arc to thermally process the material, the pulse having a duration of no more than 10 s.

    Ott, Ronald D. (Knoxville, TN); Blue, Craig A. (Knoxville, TN); Dudney, Nancy J. (Knoxville, TN); Harper, David C. (Kingston, TN)

    2007-05-22

    338

    Nanoporous Delafossite CuAlO2 from Inorganic/Polymer Double Gels: A Desirable High-Surface-Area p-Type Transparent Electrode Material.  

    PubMed

    Nanoporous structures of a p-type semiconductor, delafossite CuAlO2, with a high crystallinity have been fabricated through an inorganic/polymer double-gel process and characterized for the first time via Mott-Schottky measurements. The effect of the precursor concentration, calcination temperature, and atmosphere were examined to achieve high crystallinity and photoelectrochemical properties while maximizing the porosity. The optical properties of the nanoporous CuAlO2 are in good agreement with the literature with an optical band gap of 3.9 eV, and the observed high electrical conductivity and hole concentrations conform to highly crystalline and well-sintered nanoparticles observed in the product. The Mott-Schottky plot from the electrochemical impedance spectroscopy studies indicates a flat-band potential of 0.49 V versus Ag/AgCl. It is concluded that CuAlO2 exhibits band energies very close to those of NiO but with electrical properties very desirable in the fabrication of photoelectrochemical devices including dye-sensitized solar cells. PMID:25584858

    Das, Barun; Renaud, Adèle; Volosin, Alex M; Yu, Lei; Newman, Nathan; Seo, Dong-Kyun

    2015-02-01

    339

    Improvements in quantification accuracy of inorganic time-of-flight secondary ion mass spectrometric analysis of silicate materials by using C60 primary ions.  

    PubMed

    Time-of-flight secondary ion mass spectrometry is a very useful tool for the comprehensive characterization of samples by in situ measurements. A pulsed primary ion beam is used to sputter secondary ions from the surface of a sample and these are then recorded by a time-of-flight mass spectrometer. The parallel detection of all elements leads to very efficient sample usage allowing the comprehensive analysis of sub-micrometre sized samples. An inherent problem is accurate quantification of elemental abundances which mainly stems from the so-called matrix effect. This effect consists of changes in the sputtering and ionization efficiencies of the secondary neutrals and ions due to different sample compositions, different crystal structure or even different crystallographic orientations. Here we present results obtained using C60 molecules as a new primary ion species for inorganic analyses. The results show an improvement in quantification accuracy of elemental abundances, achieving relative errors as small as the certified uncertainties for the analyzed silicate standards. This improvement is probably due to the different sputter mechanism for C60+ primary ions from that for single atomic primary ions such as Ga+, Cs+ or Ar+. The C60+ cluster breaks up on impact, distributing the energy between its constituent carbon atoms. In this way it excavates nano-craters, rather than knocking out single atoms or molecules from the surface via a collision cascade, leading to a more reproducible sputter process and much improved quantification. PMID:19780063

    Henkel, Torsten; Rost, Detlef; Lyon, Ian C

    2009-11-01

    340

    Study of nonproportionality in the light yield of inorganic scintillators  

    SciTech Connect

    Using a phenomenological approach, the light yield is derived for inorganic scintillators as a function of the rates of linear, bimolecular, and Auger processes occurring in the electron track initiated by an x ray or a {gamma}-ray photon. A relation between the track length and incident energy is also derived. It is found that the nonproportionality in the light yield can be eliminated if either nonlinear processes of interaction among the excited electrons, holes, and excitons can be eliminated from occurring or the high density situation can be relieved by diffusion of carriers from the track at a faster rate than the rate of activation of nonlinear processes. The influence of the track length and radius on the yield nonproportionality is discussed in view of the known experimental results. Inventing new inorganic scintillating materials with high carrier mobility can lead to a class of proportional inorganic scintillators. Results agree qualitatively with experimental results for the dependence of light yield on the incident energy.

    Singh, Jai [School of Engineering and IT, B-purple-12, Faculty of EHSE, Charles Darwin University, Darwin, Northern Territory 0909 (Australia)

    2011-07-15

    341

    Identifying Optimal Inorganic Nanomateirals for Hybrid Solar Cells  

    SciTech Connect

    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.

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

    2009-01-01

    342

    Preparation and use of hybrid organic–inorganic catalysts  

    Microsoft Academic Search

    Various approaches towards the immobilization of molecular homogeneous catalysts are introduced, focusing on catalysts where an organic molecule is attached to the surface of an inorganic support material via a covalent bond forming the so-called hybrid organic–inorganic catalysts. The application of this new class of catalysts in a wide variety of organic reactions is reviewed.

    Michael H. Valkenberg; Wolfgang F. Hölderich

    2002-01-01

    343

    GC/MS analytical procedure for the characterization of glycerolipids, natural waxes, terpenoid resins, proteinaceous and polysaccharide materials in the same paint microsample avoiding interferences from inorganic media.  

    PubMed

    An innovative GC/MS procedure for the characterization of organic materials in samples from works of art was developed. It is based on a multistep chemical pretreatment of the samples based on the ammonia extraction of proteins and polysaccharide materials, in order to separate them from lipid and resinous materials. The extraction is then followed by the separation and purification of proteinaceous and polysaccharide materials before hydrolysis, based on the use of monolithic sorbent tip technology with a C4 stationary phase. Lipids and resins are saponified/salified separately. Three fractions are generated and analyzed separately by GC/MS, thus enabling a quantitative analysis to be performed on aldoses and uronic acids, amino acids, mono- and dicarboxylic aliphatic acids, to determine polysaccharide, proteinaceous, and glycerolipid materials and molecular pattern recognition for the natural resin and wax components. With this analytical procedure, for the first time, glycerolipids, natural waxes, and proteinaceous, resinous, and polysaccharide materials can be simultaneously characterized in the same microsample from painted works of art. This new analytical approach prevents any analytical difficulties arising when the sample is divided into several different aliquots to be chemically processed separately, in order to characterize the various classes of organic materials. The procedure was successfully applied to samples from paintings from the Bamiyan Buddhas and a panel painting from the 15th century, highlighting the occurrence of glycerolipids, animal and plant resins, proteinaceous and polysaccharide materials. PMID:19954203

    Lluveras, Anna; Bonaduce, Ilaria; Andreotti, Alessia; Colombini, Maria Perla

    2010-01-01

    344

    Surface science aspects on inorganic biomaterials  

    Microsoft Academic Search

    The chemical interaction between a foreign inorganic material, such as an implant, and living tissue takes place at an interface whose width initially is only about 1 nm. The processes at the interface, such as corrosion, ion diffusion, denaturing of proteins, etc., will eventually widen the interface until, at best, a dynamic quasiequilibrium is established. Since the chemical role of

    B. Kasemo; J. Lausmaa

    1986-01-01

    345

    Inorganic bonding of semiconductor strain gages  

    NASA Technical Reports Server (NTRS)

    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.

    Woodruff, N. L.

    1970-01-01

    346

    FT-IR spectra of inorganic borohydrides.  

    PubMed

    Inorganic compounds with BH4(-) ions are the subject of many recent investigations in the context of potential hydrogen storage materials. In this work, Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectra of a series of reference and research compounds (including deuterated samples) are collected and made available to the research community. PMID:24717677

    D'Anna, Vincenza; Spyratou, Alexandra; Sharma, Manish; Hagemann, Hans

    2014-07-15

    347

    Supplementary material to "Curvature and frontier orbital energies in density functional theory", by Stein et al.  

    E-print Network

    Supplementary material to "Curvature and frontier orbital energies in density functional theory and frontier orbital energies in density functional theory", by Stein et al. 2. Calculation of curvature from: [{ }] [{ }] #12;Supplementary material to "Curvature and frontier orbital energies in density functional theory

    Baer, Roi

    348

    The Study for Improving the Dielectric Strength and Lowering the Low-molecular-weight Siloxane of PDMS based Materials by Organic-inorganic Hybrid Method  

    NASA Astrophysics Data System (ADS)

    We have investigated the thermal endurance and electrical insulating properties and mechanical properties of PDMS-based hybrid materials made from ethoxy-terminated PDMS and various metal alkoxides for application as electrical insulating encapsulants. The materials exhibited good thermal stability and good electrical insulating properties. The amount of all dimethyl cyclic siloxanes evaporated at 200°C from PDMS based hybrid were found to be much lower than silicone rubber.

    Aoki, Yusuke; Kubo, Hidenori; Shindou, Takuya

    349

    Functional Group Compositions of Carbonaceous Materials of Hayabusa-Returned Samples  

    NASA Astrophysics Data System (ADS)

    We have analyzed the functional group compositions of the carbonaceous materials of Hayabusa-returned samples by STXM-XANES, in order to identify whether the materials are terrestrial or extraterrestrial.

    Yabuta, H.; Uesugi, M.; Naraoka, H.; Ito, M.; Kilcoyne, D.; Sandford, S. A.; Kitajima, F.; Mita, H.; Takano, Y.; Yada, T.; Karouji, Y.; Ishibashi, Y.; Okada, T.; Abe, M.

    2014-09-01

    350

    Functional Nanofibers via Electospinning: New Materials and Processes  

    NASA Astrophysics Data System (ADS)

    Cyclodextrins are fascinating, amphiphilic molecules that are of considerable interest due to their ability to be used in a variety of applications ranging from pharmaceuticals and cosmetics to foods and agriculture. These are ring-shaped sugar molecules possess a hydrophobic cavity and a hydrophilic exterior which imparts them water solubility. There are three main types of naturally occurring cyclodextrins namely alpha-, beta- and gamma- CD which have 6, 7 and 8 member rings, respectively. Owing to their hydrophobic interior, cyclodextrin molecules encapsulate hydrophobic guest molecules (from small to macromolecules) to form host-guest supermolecular structures. Chemically modified CDs are often preferred to the natural forms, particularly methylated (MbetaCD) and hydroxypropylated (HPbetaCD) cyclodextrins, for their enhanced solubility and chemical stability. Electrostatic spinning (electrospinning) of nanofibers has drawn significant research attention in recent decades. This technique involves the stretching of a polymer solution or melt in a high electric field to produce fibers on the nanoscale. These 1-Dimensional nanostructures possess extraordinary surface-to-weight ratio and find applications that vary from filtration membranes and tissue scaffolding materials to drug delivery and many others. The scope of this research attempts to leverage the unique features of CDs with the high aspect ratio of nanofibers to create functional nanomaterials. The present study can be divided into three sections. In the first part, we establish that CDs can be electrospun without the need for a "carrier" polymer. This discovery may serve to extend the horizon of what is currently considered "electrospinnable" from macromolecules now to small molecules. The ability to electrospin CDs led to their incorporation of other polymers to create bicomponent fibers with poly (vinyl alcohol) (PVA) and polyacrylonitrile (PAN). In the case of PVA we demonstrate the ability to not only to control the fiber properties based on PVA/CD ratio, but also crosslink these fibers to create water resistant fiber mats. Furthermore, the use of these fibers as rapid dissolving membranes for drug delivery is explored. Additionally, CDs are investigated for use as a porogen for PAN and carbon fibers. We find that CDs are particularly good candidates for us as porogens due to their amorphous nature and versatility to be dissolved in various solvent system. By nature, solution electrospinning is a low-throughput, solvent intensive process. In the last part we attempt to alleviate this issue by designing an extrusion based melt electrospinning device. We show that submicron fibers of polycaprolactone are possible through this technique without the use of organic solvents.

    Manasco, Joshua Lee

    351

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

    PubMed Central

    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

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

    2013-01-01

    352

    Nanomoulding of functional materials, a versatile complementary pattern replication method to nanoimprinting.  

    PubMed

    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

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

    2013-01-01

    353

    Functionalized organic-inorganic nanostructured N-p-carboxy benzyl chitosan-silica-PVA hybrid polyelectrolyte complex as proton exchange membrane for DMFC applications.  

    PubMed

    Chitosan was modified into N-p-carboxy benzyl chitosan (NCBC) by introducing an aromatic ring grafted with carboxylic acid as the proton conducting group. A preparation procedure of highly conductive and stable organic-inorganic nanostructured NCBC-silica-poly(vinyl alcohol) (PVA), proton exchange membrane (PEM) for direct methanol fuel cell (DMFC), by the sol-gel method in aqueous media has been reported. These PEMs were developed by cross-linking and designed to consist of weak proton conducting (-COOH) groups at organic segments and strong proton conducting (-SO3H) groups at inorganic segments to achieve high charge density and stabilities. Cross-linking density and NCBC-silica content in the membrane matrix were systematically optimized to control their nanostructure, thermal, mechanical, and chemical stabilities, as well as proton and fuel transport properties. Developed PEMs were extensively characterized by studying their physicochemical and electrochemical properties under DMFC operating conditions. As these PEMs were well processed as self-supporting film, they showed high stabilities and proton conductivity and low methanol permeability. Moreover, among all synthesized membranes, PCS-3-3 hybrid PEM exhibited quite a high selectivity parameter in comparison to Nafion117 membrane for DMFC applications. PMID:19368033

    Tripathi, Bijay P; Shahi, Vinod K

    2008-12-11

    354

    New functional polymers for sensors, smart materials and solar cells  

    E-print Network

    Organic polymers can be used as the active component of sensors, smart materials, chemical-delivery systems and the active layer of solar cells. The rational design and modification of the chemical structure of polymers ...

    Lobez Comeras, Jose Miguel

    2012-01-01

    355

    DesignofFunctionallyGradedPiezocomposite MaterialsUsingTopologyOptimization  

    E-print Network

    Electrical Energy Piezoelectric Material Applications:ultrasonictransducers,actuators,pressure sensorsEquations: Examples: · Quartz(natural) · Ceramic(PZT5A,PMN) · Polymer(PVDF) piezoceramic + piezoceramic #12;ASME

    Paulino, Glaucio H.

    356

    Molten salt battery having inorganic paper separator  

    Microsoft Academic Search

    A high temperature secondary battery comprises an anode containing lithium, a cathode containing a chalcogen or chalcogenide, a molten salt electrolyte containing lithium ions, and a separator comprising a porous sheet comprising a homogenous mixture of 2-20 wt.% chrysotile asbestos fibers and the remainder inorganic material non-reactive with the battery components. The non-reactive material is present as fibers, powder, or

    Robert D

    1977-01-01

    357

    Environmental Inorganic Geochemistry Group  

    E-print Network

    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

    Tobar, Michael

    358

    Inorganic Tracer Use - Lake Fryxell  

    NSF Publications Database

    Title : Inorganic Tracer Use - Lake Fryxell Type : Antarctic EAM NSF Org: OD / OPP Date : June 27 ... Action Memorandum (Inorganic Tracer Use at Lake Fryxell) To: Files (S.7 - Environment) Manager ...

    359

    Polyelectrolyte multilayers as nanostructured templates for inorganic synthesis  

    E-print Network

    Thin film nanocomposites consisting of inorganic matter embedded within a soft polymeric matrix on the nanometer length scale are an important class of materials with potential application in optoelectronics and photonics, ...

    Wang, Tom Chih-Hung, 1973-

    2002-01-01

    360

    Functional properties of whey protein and its application in nanocomposite materials and functional foods  

    NASA Astrophysics Data System (ADS)

    Whey is a byproduct of cheese making; whey proteins are globular proteins which can be modified and polymerized to add functional benefits, these benefits can be both nutritional and structural in foods. Modified proteins can be used in non-foods, being of particular interest in polymer films and coatings. Food packaging materials, including plastics, can linings, interior coatings of paper containers, and beverage cap sealing materials, are generally made of synthetic petroleum based compounds. These synthetic materials may pose a potential human health risk due to presence of certain chemicals such as Bisphenol A (BPA). They also add to environmental pollution, being difficult to degrade. Protein-based materials do not have the same issues as synthetics and so can be used as alternatives in many packaging types. As proteins are generally hydrophilic they must be modified structurally and their performance enhanced by the addition of waterproofing agents. Polymerization of whey proteins results in a network, adding both strength and flexibility. The most interesting of the food-safe waterproofing agents are the (large aspect ratio) nanoclays. Nanoclays are relatively inexpensive, widely available and have low environmental impact. The clay surface can be modified to make it organophilic and so compatible with organic polymers. The objective of this study is the use of polymerized whey protein (PWP), with reinforcing nanoclays, to produce flexible surface coatings which limit the transfer of contents while maintaining food safety. Four smectite and kaolin type clays, one treated and three natural were assessed for strengthening qualities and the potential waterproofing and plasticizing benefits of other additives were also analyzed. The nutritional benefits of whey proteins can also be used to enhance the protein content of various foodstuffs. Drinkable yogurt is a popular beverage in the US and other countries and is considered a functional food, especially when produced with probiotic bacteria. Carbonation was applied to a drinkable yogurt to enhance its benefits. This process helps reduce the oxygen levels in the foodstuff thus potentially being advantageous to the microaerophilic probiotic bacteria while simultaneously producing a product, somewhat similar to kefir, which has the potential to fill a niche in the functional foods market. Yogurt was combined with a syrup to reduce its viscosity, making it drinkable, and also to allow infusion of CO2. This dilution reduced the protein content of the drink and so whey protein concentrate was added to increase levels in the final product. High-methoxyl pectins were used to provide stability by reducing the tendency of the proteins to sediment out. The objectives of this study were to develop a manufacturing technology for drinkable carbonated symbiotic yogurts, and to evaluate their physicochemical properties. Two flavors of yogurt drink, pomegranate and vanilla, were formulated containing inulin as prebiotic, along with probiotic bacteria, producing symbiotic dairy beverages.

    Walsh, Helen

    361

    Optimal Experiment Design for Thermal Characterization of Functionally Graded Materials  

    NASA Technical Reports Server (NTRS)

    The purpose of the project was to investigate methods to accurately verify that designed , materials meet thermal specifications. The project involved heat transfer calculations and optimization studies, and no laboratory experiments were performed. One part of the research involved study of materials in which conduction heat transfer predominates. Results include techniques to choose among several experimental designs, and protocols for determining the optimum experimental conditions for determination of thermal properties. Metal foam materials were also studied in which both conduction and radiation heat transfer are present. Results of this work include procedures to optimize the design of experiments to accurately measure both conductive and radiative thermal properties. Detailed results in the form of three journal papers have been appended to this report.

    Cole, Kevin D.

    2003-01-01

    362

    A parametric study of thermomechanical behavior of functionally gradient materials  

    E-print Network

    distance of a functionally gradient cylinder for 5 seconds. . . . . 31 . . . . 36 Temperature distributions through the thickness at the center of the plate. . . . . . . 38 Transverse displacements along the x-direction . 10 Temperature variations... at the ceramic rich end of a functionally gradient Ti-6Al-4V/Zr02 cylinder with various power exponents for 50 seconds. Temperature distributions along the radius of a functionally gradient Ti-6AI-4V/Zr02 cylinder with metal volume fraction, V?, = r, for 20...

    Chin, Che-Doong

    2012-06-07

    363

    Anisotropic Materials Properties: Functional Forms for Multiscale Modeling  

    NASA Astrophysics Data System (ADS)

    Atomistic simulations provide effective means for evaluating surface energies, grain boundary toughness, dislocation migration barriers, etc., for particular orientations, external conditions, and strain fields. As inputs for models on longer length scales, one needs interpolations to "connect the dots" between these particular calculations, often demanding functions of many independent parameters. We describe our use of simple, physics-based functional forms which faithfully represent the singularities and symmetries, and show that they can reproduce the full behavior remarkably well.

    Cretegny, Thierry; Bailey, Nicholas P.; Myers, Christopher R.; Sethna, James P.

    2001-03-01

    364

    Research Profile The Functional Materials Laboratory (FML) is committed to  

    E-print Network

    simple in-vitro cytotoxicity tests. We would like to be able to classify nanoparticles according. Additionally, we study the use of nanomate- rials/nanoparticles for medicinal applications, as catalysts of metal nanoparticles­ (reducing flame) Bone substitute materials­ In-vitro­­ toxicity study

    Sandoghdar, Vahid

    365

    Using biological inspiration to engineer functional nanostructured materials.  

    PubMed

    Humans have always looked to nature for design inspiration, and material design on the molecular level is no different. Here we explore how this idea applies to nanoscale biomimicry, specifically examining both recent advances and our own work on engineering lipid and polymer membrane systems with cellular processes. PMID:17192981

    Wendell, David W; Patti, Jordan; Montemagno, Carlo D

    2006-11-01

    366

    A review of organic and inorganic biomaterials for neural interfaces.  

    PubMed

    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

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

    2014-03-26

    367

    Design of novel inorganic-organic hybrid materials based on iron-chloranilate mononuclear complexes: characteristics of hydrogen-bond-supported layers toward the intercalation of guests.  

    PubMed

    Novel intercalation compounds constructed from the common two-dimensional hydrogen-bond-supported layers and functional guests [(H(0.5)phz)(2)[Fe(CA)(2)(H(2)O)(2)].2H(2)O](n)(1), ([Fe(Cp)(2)][Fe(CA)(2)(H(2)O)(2)])(n)(2), ([Fe(Cp*)(2)][Fe(CA)(2)(H(2)O)(2)])(n)(3), and [(TTF)(2)[Fe(CA)(2)(H(2)O)(2)

    Nagayoshi, Kunimitsu; Kabir, Md Khayrul; Tobita, Hiroshi; Honda, Kenji; Kawahara, Mitsuhiro; Katada, Motomi; Adachi, Keiichi; Nishikawa, Hiroyuki; Ikemoto, Isao; Kumagai, Hitoshi; Hosokoshi, Yuko; Inoue, Katsuya; Kitagawa, Susumu; Kawata, Satoshi

    2003-01-01

    368

    DOI: 10.1002/anie.200902228 The Marriage of Inorganic and Organic Building Blocks  

    E-print Network

    with "hard" inorganics,[2] for example, high conductivity and magnetic properties, with those of "soft composites · rotaxanes · self-assembly The synthesis of functional organic­inorganic hybrid archi- tectures the physical and chemical properties of both "hard" inorganic and "soft" organic building blocks.[1] This goal

    Leigh, David A.

    369

    Functionalization of biomedical materials using plasma and related technologies  

    NASA Astrophysics Data System (ADS)

    Plasma techniques are important to biomedical engineering and surface modification. By modifying selective surface characteristics, conventional materials can be designed with superior biological properties while the favorable bulk materials properties can be retained. In this mini-review, recent progress pertaining to surface modification of Mg-based and polymer-based biomaterials by plasma-based techniques such as gas or metal ion implantation, dual metal and gas ion implantation, as well as plasma immersion ion implantation and deposition is described. Plasma-based surface modification is promising in elevating the cell biocompatibility, blood compatibility, and antibacterial properties of Mg-based and polymer-based biomaterials and expected to be extensively applied to biomaterials.

    Zhao, Ying; Yeung, Kelvin W. K.; Chu, Paul K.

    2014-08-01

    370

    Structure-based design of functional amyloid materials.  

    PubMed

    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

    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

    371

    Supported inorganic membranes  

    DOEpatents

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

    Sehgal, Rakesh (Albuquerque, NM); Brinker, Charles Jeffrey (Albuquerque, NM)

    1998-01-01

    372

    Materials Design and Discovery with High-Throughput Density Functional Theory: The Open Quantum Materials Database (OQMD)  

    NASA Astrophysics Data System (ADS)

    High-throughput density functional theory (HT DFT) is fast becoming a powerful tool for accelerating materials design and discovery by the amassing tens and even hundreds of thousands of DFT calculations in large databases. Complex materials problems can be approached much more efficiently and broadly through the sheer quantity of structures and chemistries available in such databases. Our HT DFT database, the Open Quantum Materials Database (OQMD), contains over 200,000 DFT calculated crystal structures and will be freely available for public use at http://oqmd.org. In this review, we describe the OQMD and its use in five materials problems, spanning a wide range of applications and materials types: (I) Li-air battery combination catalyst/electrodes, (II) Li-ion battery anodes, (III) Li-ion battery cathode coatings reactive with HF, (IV) Mg-alloy long-period stacking ordered (LPSO) strengthening precipitates, and (V) training a machine learning model to predict new stable ternary compounds.

    Saal, James E.; Kirklin, Scott; Aykol, Muratahan; Meredig, Bryce; Wolverton, C.

    2013-11-01

    373

    Synthesis of Porous Inorganic Hollow Fibers without Harmful Solvents.  

    PubMed

    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

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

    2015-01-01

    374

    Density functional studies of functionalized graphitic materials with late transition metals for Oxygen Reduction Reactions.  

    PubMed

    Low-temperature fuel cells are appealing alternatives to the conventional internal combustion engines for transportation applications. However, in order for them to be commercially viable, effective, stable and low-cost electrocatalysts are needed for the Oxygen Reduction Reaction (ORR) at the cathode. In this contribution, on the basis of Density Functional Theory (DFT) calculations, we show that graphitic materials with active sites composed of 4 nitrogen atoms and transition metal atoms belonging to groups 7 to 9 in the periodic table are active towards ORR, and also towards Oxygen Evolution Reaction (OER). Spin analyses suggest that the oxidation state of those elements in the active sites should in general be +2. Moreover, our results verify that the adsorption behavior of transition metals is not intrinsic, since it can be severely altered by changes in the local geometry of the active site, the chemical nature of the nearest neighbors, and the oxidation states. Nonetheless, we find that these catalysts trend-wise behave as oxides and that their catalytic activity is limited by exactly the same universal scaling relations. PMID:21796295

    Calle-Vallejo, Federico; Martínez, José Ignacio; Rossmeisl, Jan

    2011-09-14

    375

    Functionalized mesoporous materials for adsorption and release of different drug molecules: A comparative study  

    SciTech Connect

    The adsorption capacity and release properties of mesoporous materials for drug molecules can be improved by functionalizing their surfaces with judiciously chosen organic groups. Functionalized ordered mesoporous materials containing various types of organic groups via a co-condensation synthetic method from 15% organosilane and by post-grafting organosilanes onto a pre-made mesoporous silica were synthesized. Comparative studies of their adsorption and release properties for various model drug molecules were then conducted. Functional groups including 3-aminopropyl, 3-mercaptopropyl, vinyl, and secondary amine groups were used to functionalize the mesoporous materials while rhodamine 6G and ibuprofen were utilized to investigate the materials' relative adsorption and release properties. The self-assembly of the mesoporous materials was carried out in the presence of cetyltrimethylammonium bromide (CTAB) surfactant, which produced MCM-41 type materials with pore diameters of {approx}2.7-3.3 nm and moderate to high surface areas up to {approx}1000 m{sup 2}/g. The different functional groups introduced into the materials dictated their adsorption capacity and release properties. While mercaptopropyl and vinyl functionalized samples showed high adsorption capacity for rhodamine 6G, amine functionalized samples exhibited higher adsorption capacity for ibuprofen. While the diffusional release of ibuprofen was fitted on the Fickian diffusion model, the release of rhodamine 6G followed Super Case-II transport model. - Graphical abstract: The adsorption capacity and release properties of mesoporous materials for various drug molecules are tuned by functionalizing the surfaces of the materials with judiciously chosen organic groups. This work reports comparative studies of the adsorption and release properties of functionalized ordered mesoporous materials containing different hydrophobic and hydrophilic groups that are synthesized via a co-condensation and post-grafting methods for various model drug molecules.

    Wang Gang; Otuonye, Amy N.; Blair, Elizabeth A.; Denton, Kelley; Tao Zhimin [Department of Chemistry, 111 College Place, Syracuse University, Syracuse, New York 13244 (United States); Asefa, Tewodros, E-mail: tasefa@syr.ed [Department of Chemistry, 111 College Place, Syracuse University, Syracuse, New York 13244 (United States)

    2009-07-15

    376

    Density functional methods as computational tools in materials design  

    Microsoft Academic Search

    This article gives a brief overview of density functional theory and discusses two specific implementations: a numerical localized basis approach (DMol) and the pseudopotential plane-wave method. Characteristic examples include Cu, clusters, CO and NO dissociation on copper surfaces, Li-, K-, and O-endohedral fullerenes, tris-quaternary ammonium cations as zeolite template, and oxygen defects in bulk SiO2. The calculations reveal the energetically

    Y. S. Li; M. A. Daelen; M. Wrinn; D. King-Smith; J. M. Newsam; B. Delley; E. Wimmer; T. Klitsner; M. P. Sears; G. A. Carlson; J. S. Nelson; D. C. Allan; M. P. Teter

    1994-01-01

    377

    Functionalized mesoporous materials for adsorption and release of different drug molecules: A comparative study  

    NASA Astrophysics Data System (ADS)

    The adsorption capacity and release properties of mesoporous materials for drug molecules can be improved by functionalizing their surfaces with judiciously chosen organic groups. Functionalized ordered mesoporous materials containing various types of organic groups via a co-condensation synthetic method from 15% organosilane and by post-grafting organosilanes onto a pre-made mesoporous silica were synthesized. Comparative studies of their adsorption and release properties for various model drug molecules were then conducted. Functional groups including 3-aminopropyl, 3-mercaptopropyl, vinyl, and secondary amine groups were used to functionalize the mesoporous materials while rhodamine 6G and ibuprofen were utilized to investigate the materials' relative adsorption and release properties. The self-assembly of the mesoporous materials was carried out in the presence of cetyltrimethylammonium bromide (CTAB) surfactant, which produced MCM-41 type materials with pore diameters of ˜2.7-3.3 nm and moderate to high surface areas up to ˜1000 m 2/g. The different functional groups introduced into the materials dictated their adsorption capacity and release properties. While mercaptopropyl and vinyl functionalized samples showed high adsorption capacity for rhodamine 6G, amine functionalized samples exhibited higher adsorption capacity for ibuprofen. While the diffusional release of ibuprofen was fitted on the Fickian diffusion model, the release of rhodamine 6G followed Super Case-II transport model.

    Wang, Gang; Otuonye, Amy N.; Blair, Elizabeth A.; Denton, Kelley; Tao, Zhimin; Asefa, Tewodros

    2009-07-01

    378

    Work function determination of promising electrode materials for thermionic converters  

    NASA Technical Reports Server (NTRS)

    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.

    Jacobson, D.

    1977-01-01

    379

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

    SciTech Connect

    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.

    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

    380

    Natural material adsorbed onto a polymer to enhance immune function  

    PubMed Central

    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

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

    2012-01-01

    381

    Laser ablation particle beam glow discharge time of flight mass spectrometry for the analysis of halogenated polymers and inorganic solid material  

    NASA Astrophysics Data System (ADS)

    A laser ablation particle beam pulsed glow discharge mass spectrometer (LA-PB-GD-TOFMS) was designed and used for fundamental studies. The instrument consists of a three stage aerodynamic lens system, a hollow cathode pulsed glow discharge and a time-of-flight mass spectrometer. The particle beam interface was constructed to provide an efficient particle transfer into the hollow cathode. Calculations showed that particles between 1 and 3000 nm in diameter are able to pass through this interface. Glass and metal (SRM NIST610 and CRM JK37) ablated by laser ablation and introduced into a pulsed, He glow discharge showed no ionization, even for major elements such as 27Al +, 28Si +, 23Na + or 56Fe +. This can be explained by the low gas temperature of a pulsed glow discharge which is not sufficient to vaporize particles with high melting and vaporization points. In contrast, ablated particles of soft materials such as PTFE or PVC polymers were vaporized and ionized in a pulsed glow discharge. Ion signals for elements such as carbon ( 12C +), hydrogen ( 1H 3+), fluorine ( 19F +) and chlorine ( 35/37Cl +) were detected when generating an aerosol by laser ablation and introduced into the hollow cathode. Furthermore, various fragments such as 12C x1H v19F y+ and 12C x1H v35/37Cl y+ were identified and provide a "fingerprint" of the ablated polymer. The influence of the laser fluence and glow discharge voltage was investigated with respect to the ratio of fragments to elemental ion signals. The decrease in laser energy leads to an increase of the 12C +/ 12C 19F x+ ratio. Lowering the glow discharge plasma power favors the appearance of fragments such as 12C 19F x+ whereas higher plasma power favors the ion signals of the elements, such as 12C + and 19F +. A set of experiments comparing different PVC polymers with increasing PVC content was evaluated with respect to the 12C +/ 35Cl + ratio. A correlation between the ratio and the concentration of the PVC in the sample was determined and indicates the capability for quantitative analysis of halogens in organic particulate matter by LA-PB-GD-TOFMS.

    Fliegel, Daniel; Günther, Detlef

    2009-05-01

    382

    Descriptive Inorganic Chemistry (by Geoff Rayner-Canham)  

    NASA Astrophysics Data System (ADS)

    Geoff Rayner-Canham. W. H. Freeman: New York, 1996. 492 pp. ISBN: 0-7167-2819-2. $67.95. There are plenty of good inorganic chemistry books on the market, from venerable reference works (e.g., Cotton and Wilkinson's Advanced Inorganic Chemistry, Greenwood and Earnshaw's Chemistry of the Elements) to "comprehensive" two-semester textbooks (e.g., Huheey, Keiter, and Keiter's Inorganic Chemistry: Principles of Structure and Reactivity, Douglas, McDaniel, and Alexander's Concepts and Models of Inorganic Chemistry). Undergraduate students, especially those new to inorganic chemistry, frequently find these books overwhelming in depth and length (not to mention weight!). Alternatively, some shorter books with less ambitious goals present an oversimplified view of the field or sacrifice conceptual material on behalf of sections on environmental, industrial, or biological chemistry. Rayner-Canham's Descriptive Inorganic Chemistry, a one-semester book aimed specifically at the introductory (sophomore) level, provides an excellent balance of theory and descriptive material, with a fresh look at traditional and current areas of interest in inorganic chemistry.

    Rabinovich, Daniel

    1998-06-01

    383

    Analytical electron microscopy of biogenic and inorganic carbonates  

    NASA Technical Reports Server (NTRS)

    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.

    Blake, David F.

    1989-01-01

    384

    Density functional methods as computational tools in materials design  

    NASA Astrophysics Data System (ADS)

    This article gives a brief overview of density functional theory and discusses two specific implementations: a numerical localized basis approach (DMol) and the pseudopotential plane-wave method. Characteristic examples include Cu, clusters, CO and NO dissociation on copper surfaces, Li-, K-, and O-endohedral fullerenes, tris-quaternary ammonium cations as zeolite template, and oxygen defects in bulk SiO2. The calculations reveal the energetically favorable structures (estimated to be within ± 0.02 Å of experiment), the energetics of geometric changes, and the electronic structures underlying the bonding mechanisms. A characteristic DMo1 calculation on a 128-node nCUBE 2 parallel computer shows a speedup of about 107 over a single processor. A plane-wave calculation on a unit cell with 64 silicon atoms using 1024 nCUBE 2 processors runs about five times faster than on a single-processor CRAY YMP.

    Li, Y. S.; van Daelen, M. A.; Wrinn, M.; King-Smith, D.; Newsam, J. M.; Delley, B.; Wimmer, E.; Klitsner, T.; Sears, M. P.; Carlson, G. A.; Nelson, J. S.; Allan, D. C.; Teter, M. P.

    1994-04-01

    385

    Inorganic: the other mercury.  

    PubMed

    There is a broad array of mercury species to which humans may be exposed. While exposure to methylmercury through fish consumption is widely recognized, the public is less aware of the sources and potential toxicity of inorganic forms of mercury. Some oral and laboratory thermometers, barometers, small batteries, thermostats, gas pressure regulators, light switches, dental amalgam fillings, cosmetic products, medications, cultural/religious practices, and gold mining all represent potential sources of exposure to inorganic forms of mercury. The route of exposure, the extent of absorption, the pharmacokinetics, and the effects all vary with the specific form of mercury and the magnitude and duration of exposure. If exposure is suspected, a number of tissue analyses can be conducted to confirm exposure or to determine whether an exposure might reasonably be expected to be biologically significant. By contrast with determination of exposure to methylmercury, for which hair and blood are credible indicators, urine is the preferred biological medium for the determination of exposure to inorganic mercury, including elemental mercury, with blood normally being of value only if exposure is ongoing. Although treatments are available to help rid the body of mercury in cases of extreme exposure, prevention of exposure will make such treatments unnecessary. Knowing the sources of mercury and avoiding unnecessary exposure are the prudent ways of preventing mercury intoxication. When exposure occurs, it should be kept in mind that not all unwanted exposures will result in adverse health consequences. In all cases, elimination of the source of exposure should be the first priority of public health officials. PMID:18044248

    Risher, John F; De Rosa, Christopher T

    2007-11-01

    386

    PREFACE: 3rd International Symposium on Functional Materials 2009 (ISFM 2009) 3rd International Symposium on Functional Materials 2009 (ISFM 2009)  

    NASA Astrophysics Data System (ADS)

    The 3rd International Symposium on Functional Materials 2009 (ISFM 2009) and its preconference, Advances in Functional Materials 2009 (AFM 2009), were successfully held in the Republic of Korea from 15-18 June 2009 and in the People's Republic of China from 8-12 June 2009, respectively. The two conferences attracted over 300 oral and poster presentations from over 12 countries including Australia, Canada, China, Germany, Japan, India, Israel, Korea, The Netherlands, Thailand, the UK and the USA. In the two conferences, eight keynote lectures were delivered by S Miyazaki, S A Akbar, D J Singh, C Suryanarayana, M~Greenblatt, H Zhang, T Sato and J Ding. This topical issue of Physica Scripta contains papers presented at the ISFM 2009 and AFM 2009. Keyan Li from Dalian University, People's Republic of China, presents some empirical formulae to estimate the elastic moduli of rocksalt-, zincblende- and chalcopyrite-structured crystals, on the basis of electronegativities of bonded atoms in the crystallographic frame. Min-Jung Kim from Hanyang University, Korea, reports on the preparation and characterization of carboxyl functionalization of magnetite nanoparticles for oligonucleotide immobilization. F Yan from the National University of Singapore studies the fabrication of Bi(Fe0.5Sc0.5)O3-PbTiO3 (BSF-PT) thin films by pulsed laser deposition, and the enhanced magnetic moment with respect to BiFeO3-PbTiO3. Dong-Gil Lee from Pusan National University, Korea, reports on the sterilization of enteropathogenic Escherichia coli using nanofiber TiO2 films prepared by the electrostatic spray method. Sang-Eun Park from the Korea Institute of Science and Technology reports on the study of encapsulated Fe3O4 nanoparticles with a silica thin layer with a reversible capacity of about 363 mAhg-1. Other researchers report on many other exiting achievements in the fields of ferromagnetic materials, magneto-optical materials, thermoelectric materials, shape memory materials, fuel-cell and battery materials, and other related advanced functional materials. The 4th International Symposium on Functional Materials 2011 (ISFM 2011) will be held in Sendai, Japan, from 2-6 August 2011 just before the Sendai Tanabata Festival. Its preconference (AFM 2011) will be held at Jeju Island, Korea, just before ISFM 2011. We look forward to meeting you in Jeju and Sendai.

    Kiwon, Kim; Li, Lu; Taehyun, Nam; Jouhyeon, Ahn

    2010-05-01

    387

    Crystallization at Inorganic-Organic Interfaces: Biominerals and Biomimetic Synthesis  

    NASA Astrophysics Data System (ADS)

    Crystallization is an important process in a wide range of scientific disciplines including chemistry, physics, biology, geology, and materials science. Recent investigations of biomineralization indicate that specific molecular interactions at inorganic-organic interfaces can result in the controlled nucleation and growth of inorganic crystals. Synthetic systems have highlighted the importance of electrostatic binding or association, geometric matching (epitaxis), and stereochemical correspondence in these recognition processes. Similarly, organic molecules in solution can influence the morphology of inorganic crystals if there is molecular complementarity at the crystal-additive interface. A biomimetic approach based on these principles could lead to the development of new strategies in the controlled synthesis of inorganic nanophases, the crystal engineering of bulk solids, and the assembly of organized composite and ceramic materials.

    Mann, Stephen; Archibald, Douglas D.; Didymus, Jon M.; Douglas, Trevor; Heywood, Brigid R.; Meldrum, Fiona C.; Reeves, Nicholas J.

    1993-09-01

    388

    Crystallization at Inorganic-organic Interfaces: Biominerals and Biomimetic Synthesis.  

    PubMed

    Crystallization is an important process in a wide range of scientific disciplines including chemistry, physics, biology, geology, and materials science. Recent investigations of biomineralization indicate that specific molecular interactions at inorganic-organic interfaces can result in the controlled nucleation and growth of inorganic crystals. Synthetic systems have highlighted the importance of electrostatic binding or association, geometric matching (epitaxis), and stereochemical correspondence in these recognition processes. Similarly, organic molecules in solution can influence the morphology of inorganic crystals if there is molecular complementarity at the crystal-additive interface. A biomimetic approach based on these principles could lead to the development of new strategies in the controlled synthesis of inorganic nanophases, the crystal engineering of bulk solids, and the assembly of organized composite and ceramic materials. PMID:17731856

    Mann, S; Archibald, D D; Didymus, J M; Douglas, T; Heywood, B R; Meldrum, F C; Reeves, N J

    1993-09-01

    389

    Inorganic Crystal Structure Database (ICSD)  

    National Institute of Standards and Technology Data Gateway

    SRD 84 FIZ/NIST Inorganic Crystal Structure Database (ICSD) (PC database for purchase)   The Inorganic Crystal Structure Database (ICSD) is produced cooperatively by the Fachinformationszentrum Karlsruhe(FIZ) and the National Institute of Standards and Technology (NIST). The ICSD is a comprehensive collection of crystal structure data of inorganic compounds containing more than 140,000 entries and covering the literature from 1915 to the present.

    390

    Early Transition Metal Oxides as Catalysts: Crossing Scales from Clusters to Single Crystals to Functioning Materials  

    SciTech Connect

    The overall goal of this program is to investigate the electronic structure and chemical bonding of early transition metal oxide clusters and use them as well-defined molecular models to obtain insight into properties and mechanisms of oxide catalysts, as well as to provide accurate spectroscopic and molecular information to verify theoretical methods used to predict materials properties. A laser vaporization cluster source is used to produce metal oxide clusters with different sizes, structures, and compositions. Well-defined inorganic polyoxometalate clusters in solution are transported in the gas phase using electrospray. Two state-of-the-art photoelectron spectroscopy apparatuses are used to interrogate the oxide clusters and polyoxometalate anions in the gas phase to obtain spectroscopic and electronic structure information. The experimental effort is assisted by theoretical calculations to understanding the structures, chemical bonding, and catalytical properties of the transition metal oxide clusters. The research approach combines novel and flexible experimental techniques and advanced theoretical/computational methodologies and seeks molecular-level information to aiding the design of new catalysts, as well as mechanistic understanding. We have focused on the investigation of tungsten oxide clusters containing three W atoms: W{sub 3}O{sub x}{sup -} (x = 7-11). A number of interesting findings have been made. We observed that the oxygen-poor W{sub 3}O8 cluster contains a localized W{sup 4+} center, which can be used as a molecular model for O-deficient defect sites. A chemisorption energy was obtained through density functional calculations for W{sub 3}O8 + O{sub 2} {yields} W{sub 3}O{sub 10} as -78 kcal/mol. We further found that the neutral stoichiometric W{sub 2}O{sub 6} and W{sub 3}O{sub 9} clusters do not react with O{sub 2} and they only form physi-sorbed complexes, W{sub 2}O{sub 6}(O{sub 2}) and W{sub 3}O{sub 9}(O{sub 2}). However, the negatively charged W{sub 2}O{sub 6}{sup -} and W{sub 3}O{sub 9}{sup -} clusters are found to form chemisorbed complexes due to the presence of the extra electron. Thus, the W{sub 2}O{sub 6}{sup -} and W{sub 3}O{sub 9}{sup -} negative clusters can be viewed as models for O{sub 2} interaction with a reduced W site (W{sup 5+}) on the oxide surface. These studies also led to the surprising observation of the first d-orbital aromatic clusters in W{sub 3}O{sub 9}{sup 2-} and Mo{sub 3}O{sub 9}{sup 2-}, which each contains a completely delocalized three-center two-electron bond made entirely made of the metal d orbitals. This last result was highlighted in both Chem & Eng. News and Nature. We further studied a series of small metalate anions using electrospray, including the hydroxo and methoxo oxometalate MO{sub 3}(OH){sup -} and MO{sub 3}(OCH{sub 3}){sup -}, and the dimetalates: M{sub 2}O{sub 7}{sup 2-}, MM{prime}O{sub 7}{sup 2-}, and M{sub 2}O{sub 7}{sup -} (M, M{prime} = Cr, Mo, and W).

    Lai-Sheng Wang

    2009-07-07

    391

    Interconversion of linearly viscoelastic material functions expressed as Prony series: a closure  

    NASA Astrophysics Data System (ADS)

    Interconversion of viscoelastic material functions is a longstanding problem that has received attention since the 1950s. There is currently no accepted methodology for interconverting viscoelastic material functions due to the lack of stability and accuracy of the existing methods. This paper presents a new exact, analytical interconversion method for linearly viscoelastic material functions expressed as Prony series. The new algorithm relies on the equations of the thermodynamics of irreversible processes used for defining linearly viscoelastic constitutive theories. As a result, interconversion is made possible for unidimensional and tridimensional materials for arbitrary material symmetry. The algorithm has been tested over a broad range of cases and was found to deliver accurate interconversion in all cases. Based on its accuracy and stability, the authors believe that their algorithm provides a closure to the interconversion of linearly viscoelastic constitutive theories expressed with Prony series.

    Luk-Cyr, Jacques; Crochon, Thibaut; Li, Chun; Lévesque, Martin

    2013-02-01

    392

    A Review on the Finite Element Methods for Heat Conduction in Functionally Graded Materials  

    NASA Astrophysics Data System (ADS)

    The review presented in this paper focuses mainly on the application of finite element methods for investigating the effect of heat transfer, variation of temperature and other parameters in the functionally graded materials. Different methods have been investigated for thermal conduction in functionally graded materials. The use of FEM for steady state heat transfer has been addressed in this work. The authors have also discussed the utilization of FEM based shear deformation theories and FEM in combination with other methods for the problems involving complexity of the shape and geometry of functionally graded materials. Finite element methods proved to be effective for the solution of heat transfer problem in functionally graded materials. These methods can be used for steady state heat transfer and as well as for transient state.

    Sharma, R.; Jadon, V. K.; Singh, B.

    2015-01-01

    393

    Multifunctional organic-inorganic hybrid nanophotonic devices  

    NASA Astrophysics Data System (ADS)

    The emergence of optical applications, such as lasers, fiber optics, and semiconductor based sources and detectors, has created a drive for smaller and more specialized devices. Nanophotonics is an emerging field of study that encompasses the disciplines of physics, engineering, chemistry, biology, applied sciences and biomedical technology. In particular, nanophotonics explores optical processes on a nanoscale. This dissertation presents nanophotonic applications that incorporate various forms of the organic polymer N-isopropylacrylamide (NIPA) with inorganic semiconductors. This includes the material characterization of NIPA, with such techniques as ellipsometry and dynamic light scattering. Two devices were constructed incorporating the NIPA hydrogel with semiconductors. The first device comprises a PNIPAM---CdTe hybrid material. The PNIPAM is a means for the control of distances between CdTe quantum dots encapsulated within the hydrogel. Controlling the distance between the quantum dots allows for the control of resonant energy transfer between neighboring quantum dots. Whereby, providing a means for controlling the temperature dependent red-shifts in photoluminescent peaks and FWHM. Further, enhancement of photoluminescent due to increased scattering in the medium is shown as a function of temperature. The second device incorporates NIPA into a 2D photonic crystal patterned on GaAs. The refractive index change of the NIPA hydrogel as it undergoes its phase change creates a controllable mechanism for adjusting the transmittance of light frequencies through a linear defect in a photonic crystal. The NIPA infiltrated photonic crystal shows greater shifts in the bandwidth per °C than any liquid crystal methods. This dissertation demonstrates the versatile uses of hydrogel, as a means of control in nanophotonic devices, and will likely to lead to development of other hybrid applications. The development of smaller light based applications will facilitate the need to augment the devices with control mechanism and will play an increasing important role in the future.

    Garner, Brett William

    394

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

    PubMed

    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 sl