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1

Inorganic materials: The quest for new functionality  

NASA Astrophysics Data System (ADS)

Building on our understanding of the chemical bond, advances in synthetic chemistry, and large-scale computation, materials design has now become a reality. From a pool of 400 unknown compositions, 15 new compounds have been realized that adopt the predicted structures and properties.

Walsh, Aron

2015-04-01

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

Functionalized coating materials based on inorganic-organic polymers  

Microsoft Academic Search

ORMOCER®s (ORMOCER® Trademark of Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.) as inorganic-organic polymers synthesized by a two-step sol-gel processing method can be applied as thin transparent coatings on various substrates (polymers, metals, ceramics). The curing of ORMOCER®s is performed thermally (at temperatures below 200°C) or by UV-radiation. Their high abrasion resistance and good chemical stability led to several actual

Karl-Heinz Haas; Sabine Amberg-Schwab; Klaus Rose

1999-01-01

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

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

NASA Astrophysics Data System (ADS)

This dissertation describes the design, fabrication, and characterization of organic-inorganic hybrid materials. Several classes of bridged polysilsesquioxanes are presented. The first class is a membrane material suitable for fuel cell technology as a proton conducting polyelectrolyte. The second class includes hybrid nanoparticles for display device applications and chromatographic media. Chapter 1 is an introduction to hybrid organic-inorganic materials. Sol-gel chemistry is discussed, followed by a survey of prominent examples of silica hybrids. Examples of physical organic-silica blends and covalent organo-silicas, including ORMOCERSRTM, polyhedral oligomeric silsesquioxanes, and bridged polysilsesquioxanes are discussed. Bridged polysilsesquioxanes are described in great detail. Monomer synthesis, sol-gel chemistry, processing, characterization, and physical properties are included. Chapter 2 describes the design of polyelectrolyte bridged polysilsesquioxane membranes. The materials contain covalently bound sulfonic acid groups originating from the corresponding disulfides. These organic-inorganic hybrid materials integrate a network supporting component which is systematically changed to fine-tune their physical properties. The membranes are characterized as PEM fuel cell electrolytes, where proton conductivities of 4-6 mS cm-1 were measured. In Chapter 3 techniques for the preparation of bridged polysilsesquioxane nanoparticles are described. An inverse water-in-oil microemulsion polymerization method is developed to prepare cationic nanoparticles, including viologen-bridged materials with applications in electrochromic display devices. An aqueous ammonia system is used to prepare neutral nanoparticles containing hydrocarbon bridging groups, which have potential applications as chromatographic media. Chapter 4 describes electrochromic devices developed in collaboration with the Heflin group of Virginia Tech, which incorporate viologen bridged nanoparticles described in Chapter 3. The devices are prepared via the layer-by-layer deposition technique and characterized by voltammetry and transmission spectroscopy. Contrast ratios between yellow and violet states were 45-50% with switching times of 3-3.5 seconds. Finally, Appendix I describes the resolution of racemic 3,3.3',3'-Tetramethyl-1,1"-spirobisindane-5,5',6,6'-tetrol by diastereomeric complex formation with (8S,9R)-(-)-N-benzylcinchonidinium chloride. Enantiomerically pure bisspirocatechol is used to prepare a chiral polymer, which exhibits differences in solid state packing from polymer made with the racemic monomer. Preliminary results on the use of the chiral polymer in enantioselective membrane separations technology are described.

Khiterer, Mariya

2007-05-01

7

Inorganic-organic materials incorporating alumoxane nanoparticles  

Microsoft Academic Search

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

Cullen Taylor Vogelson

2000-01-01

8

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

9

Inorganic immobilisation of waste materials  

Microsoft Academic Search

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

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

1997-01-01

10

Plasma chemistry for inorganic materials  

NASA Technical Reports Server (NTRS)

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

Matsumoto, O.

1980-01-01

11

RETROSPECTIVE MONITORING OF INORGANIC MATERIALS  

EPA Science Inventory

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

12

Oxide materials for electronics Inorganic Materials and Ceramics Research Group  

E-print Network

Oxide materials for electronics Inorganic Materials and Ceramics Research Group Sverre M. Selbach annually #12;Inorganic and ceramic materials research group Professor Mari-Ann Einarsrud (1988) Professor, selbach@material.ntnu.no Department of Materials Science and Engineering, NTNU NorTex Nano Summit Oct. 12

13

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

14

Combinatorial synthesis of inorganic or composite 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 or, alternatively, allowing the components to interact to form at least two different materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, nonbiological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

Goldwasser, Isy (Palo Alto, CA); Ross, Debra A. (Mountain Ranch, CA); Schultz, Peter G. (La Jolla, CA); Xiang, Xiao-Dong (Danville, CA); Briceno, Gabriel (Baldwin Park, CA); Sun, Xian-Dong (Fremont, CA); Wang, Kai-An (Cupertino, CA)

2010-08-03

15

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

16

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

17

X-ray Spectroscopy of Inorganic Materials  

Microsoft Academic Search

X-ray spectroscopies have been applied on different inorganic materials with a main focus on 3d-metal materials and iron compounds in particular. Different theoretical treatments of x-ray absorption spectroscopy (XAS) are compared with each other and with experimental data. XAS calculations have been performed for iron to study the XAS shapes of different spin states of iron as well as the

P. S. Miedema

2012-01-01

18

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

19

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

20

Combinatorial solid-state chemistry of inorganic materials  

NASA Astrophysics Data System (ADS)

Throughout history, scientists and engineers have relied on the slow and serendipitous trial-and-error process for discovering and developing new materials. In contrast, an emerging theme in modern materials science is the notion of intelligent design of materials. Pioneered by the pharmaceutical industry and adapted for the purposes of materials science and engineering, the combinatorial approach represents a watershed in the process of accelerated discovery, development and optimization of materials. To survey large compositional landscapes rapidly, thousands of compositionally varying samples may be synthesized, processed and screened in a single experiment. Recent developments have been aided by innovative rapid characterization tools, and by advanced materials synthesis techniques such as laser molecular beam epitaxy which can be used to perform parallel-processed design and control of materials down to the atomic scale. Here we review the fast-growing field of combinatorial materials science, with an emphasis on inorganic functional materials.

Koinuma, Hideomi; Takeuchi, Ichiro

2004-07-01

21

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

NASA Astrophysics Data System (ADS)

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

Ziegler, Christopher R.

22

Sol–gel-derived organic–inorganic hybrid materials  

Microsoft Academic Search

Optically transparent organic–inorganic hybrid coating materials have been prepared by a sol–gel process. Four different types of the coating material produced by TWI in Cambridge, UK using the patented Vitresyn® method, all identical in terms of the starting materials, but differing in terms of their relative proportions, have been examined. Tetraethoxysilane was used as the primary inorganic precursor and urethane

Yung-Hoe Han; Alan Taylor; Mick D. Mantle; Kevin M. Knowles

2007-01-01

23

Characteristics of colored inorganic–organic hybrid materials  

Microsoft Academic Search

Inorganic–organic hybrid glasses are relatively new nanometric materials of Ormosil’s group (organic modified silicates). There co-existence, on a molecular scale, exists between inorganic structures in the form of silica-oxide network and organic structures based on carbon links. Properties of these materials are intermediate between those of inorganic glasses (hardness, chemical and thermal resistance) and organic polymers (low temperature of obtaining,

K. Wojtach; M. Laczka; K. Cholewakowalska; Z. Olejniczak; J. Sokolowska

2007-01-01

24

Computer information resources of inorganic chemistry and materials science  

NASA Astrophysics Data System (ADS)

Information systems used in inorganic chemistry and materials science are considered. The following basic trends in the development of modern information systems in these areas are highlighted: access to information via the Internet, merging of documental and factual databases, involvement of experts in the evaluation of the data reliability, supplementing databases with information analysis tools on the properties of inorganic substances and materials.

Kiselyova, N. N.; Dudarev, V. A.; Zemskov, V. S.

2010-02-01

25

Organic/inorganic hybrid materials: challenges for ab initio methodology.  

PubMed

CONSPECTUS: Organic/inorganic hybrid structures are most exciting since one can expect new properties that are absent in either of their building blocks. They open new perspectives toward the design and tailoring of materials with desired features and functions. Prerequisite for real progress is, however, the in-depth understanding of what happens on the atomic and electronic scale. In this respect, hybrid materials pose a challenge for electronic-structure theory. Methods that proved useful for describing one side may not be applicable for the other one, and they are likely to fail for the interfaces. In this Account, we address the question to what extent we can quantitatively describe hybrid materials and where we even miss a qualitative description. We note that we are dealing with extended systems and thus adopt a solid-state approach. Therefore, density-functional theory (DFT) and many-body perturbation theory (MBPT), the GW approach for charged and the Bethe-Salpeter equation for neutral excitations, are our methods of choice. We give a brief summary of the used methodology, focusing on those aspects where problems can be expected when materials of different character meet at an interface. These issues are then taken up when discussing hybrid materials. We argue when and why, for example, standard DFT may fall short when it comes to the electronic structure of organic/metal interfaces or where the framework of MBPT can or must take over. Selected examples of organic/inorganic interfaces, structural properties, electronic bands, optical excitation spectra, and charge-transport properties as obtained from DFT and MBPT highlight which properties can be reliably computed for such materials. The crucial role of van der Waals forces is shown for sexiphenyl films, where the subtle interplay between intermolecular and molecule-substrate interactions is decisive for growth and morphologies. With a PTCDA monolayer on metal surfaces we discuss the performance of DFT in terms of interfacial electronic structure. We face the problem of a so far hidden variable, namely, electron-vibrational coupling, regarding level alignment at interfaces between organic and inorganic semiconductors. Poly(para-phenylene) adsorbed on graphene and encapsulated in carbon nanotubes represent case studies to demonstrate the impact of polarization effects and exciton delocalization in optoelectronic excitations, respectively. Polaron-induced band narrowing and its consequences for charge transport in organic crystals is exemplified for the HOMO bandwidth in naphthalene crystals. On the basis of these prototypical systems, we discuss what is missing to reach predictive power on a quantitative level for organic/inorganic hybrid materials and, thus, open a perspective toward the computational discovery of new materials for optoelectronic applications. PMID:25171272

Draxl, Claudia; Nabok, Dmitrii; Hannewald, Karsten

2014-11-18

26

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

27

Cationic inorganic materials for anionic pollutant trapping and catalysis.  

PubMed

Despite their vast industrial importance, almost all extended inorganic synthetic structures and naturally occurring minerals adopt a neutral or anionic charge. This tutorial review describes the current knowledge of inorganic materials that bear a positive charge on the host. The best-known example is the family of clays known as layered double hydroxides, and other limited examples also exist. Our research efforts have given rise to a series of new cationic inorganic materials, oxides and fluorides of heavy p-block metals. Organic-based cationic materials will also be briefly discussed. Interest in these materials is widespread, with potential applications in many areas including anionic pollutant trapping, exchange, selective catalysis, polymer hybrids and nanocomposites, and biomaterials for drug or DNA delivery. PMID:19551168

Oliver, Scott R J

2009-07-01

28

Combinatorial Measurement Methods for Inorganic Materials  

E-print Network

) devices, or the Seebeck coefficients of thermoelectric materials for vehicular waste heat recovery devices such as Intel and Micron, as well as GM and Honda for the use of thermoelectrics for vehicular waste heat. At present, this tool produces library films for our thermoelectric materials and advanced MOS gate stack

29

UV curing of organic–inorganic hybrid coating materials  

Microsoft Academic Search

The effect of UV-curing time on the mechanism of interaction between the various precursor phases in a novel sol–gel-derived\\u000a organic–inorganic hybrid coating material and the resulting mechanical and thermal properties of this material when coated\\u000a onto substrates in thin film form have been examined using a variety of chemical and physical characterisation methods. Microstructurally,\\u000a the hybrid coating materials examined were

Yung-Hoe Han; Alan Taylor; Michael D. Mantle; Kevin M. Knowles

2007-01-01

30

Generalized synthesis of periodic surfactant\\/inorganic composite materials  

Microsoft Academic Search

THE recent synthesis of silica-based mesoporous materials1,2 by the cooperative assembly of periodic inorganic and surfactant-based structures has attracted great interest because it extends the range of molecular-sieve materials into the very-large-pore regime. If the synthetic approach can be generalized to transition-metal oxide mesostructures, the resulting nanocomposite materials might find applications in electrochromic or solid-electrolyte devices3,4, as high-surface-area redox catalysts5

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

1994-01-01

31

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

32

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

33

STABILITY AND TRANSPORT OF INORGANIC COLLOIDS THROUGH CONTAMINATED AQUIFER MATERIAL  

EPA Science Inventory

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

34

Pattern Replication in Organic-Inorganic Hybrid Materials  

E-print Network

. I could not have achieved this without you!. Mihaela Contents 1 Introduction 1 1.1 Patterning of Organic and Inorganic Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 History of Solar Cells... . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 4 Experimental Techniques 51 4.1 Atomic Force Microscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 4.2 Magnetic Force Microscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 4.3 X-Ray Di#11;raction...

Nedelcu, Mihaela

2014-05-27

35

Screening combinatorial arrays of inorganic materials with spectroscopy or microscopy  

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.; Xiang, Xiaodong; Goldwasser, Isy

2004-02-03

36

Nano Engineered Organic-Inorganic Material Systems for Photovoltaics  

Microsoft Academic Search

Organic-inorganic photovoltaic systems which attempt to integrate\\u000a benefits of both material types in terms of ease of fabrication,\\u000a stability and efficiency are reviewed. Three broad categories;\\u000a inorganic-small molecule systems, carbon naotube incorporated organic\\u000a photovoltaics and nanostructured organic surfaces-based photovoltaics\\u000a have been discussed with reference to recent literature.\\u000a Nanocrystal-organic systems are designed to improve broadband photon\\u000a collection possibilty, nanostructred organic surfaces-based

A. A. D. T. Adikaari; D. M. N. M. Dissanayake; N. K. Mudugamuwa; S. R. P. Silva

2009-01-01

37

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

38

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

Microsoft Academic Search

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

Marina Sofos; D. A. Stone D. K. Goswami; J. S. Okasinski; H. Jin; M. J. Bedzyk; S. I. Stupp

2008-01-01

39

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

40

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

41

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

42

Abrasion resistant inorganic\\/organic coating materials prepared by the sol-gel method  

Microsoft Academic Search

Novel abrasion resistant coating materials prepared by the sol-gel method have been developed and applied on the polymeric substrates bisphenol-A polycarbonate and diallyl diglycol carbonate resin (CR-39). These coatings are inorganic\\/organic hybrid network materials synthesized from 3-isocyanatopropyltriethoxysilane functionalized organics and metal alkoxide. The organic components are 3,3'-iminobispropylamine (IMPA), resorcinol (RSOL), diethylenetriamine (DETA), poly(ethyleneimine) (PEI), glycerol and a series of diols.

J. Wen; V. J. Vasudevan; G. L. Wilkes

1995-01-01

43

Use of pulp mill inorganic wastes as alternative liming materials.  

PubMed

A laboratory aerobic incubation study was performed during 18 weeks under controlled conditions to assess the effects of applying different doses of pulp mill inorganic wastes on the physical-chemical properties of an acid Dystric Cambissol. Three different inorganic wastes were tested - wood ash, dregs and grits, and an agriculture limestone was used as reference. Results showed that increasing the dose applied of the different inorganic wastes tested always led to significant raises of soil pH at different incubation times demonstrating that its use as alternative-liming materials could be a valid and less expensive option to the use of commercial agricultural limestone. Moreover, no immediate concerns seem to be expected related to soil exchangeable sodium (Na) content, at least for the doses needed to increase soil pH until the targeted value 6.5. Particularly for wood ash a pronounced increase on soil extractable potassium and phosphorous was observed, indicating that besides the liming effect this waste can contribute to improve soil fertility by supplying significant available amounts of these nutrients. Finally, metals do not seem to be a limiting factor for the application to land of these by-products. PMID:18406609

Cabral, F; Ribeiro, H M; Hilário, L; Machado, L; Vasconcelos, E

2008-11-01

44

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

45

Novel inorganic materials for polymer electrolyte and alkaline fuel cells  

NASA Astrophysics Data System (ADS)

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

Tadanaga, Kiyoharu

2012-06-01

46

Hybrid exciton recombination dynamics in inorganic-organic materials  

SciTech Connect

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

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

2013-12-16

47

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

NASA Astrophysics Data System (ADS)

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

Hicks, Jason Christopher

48

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

NASA Astrophysics Data System (ADS)

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

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

49

Electrospray ionization mass spectrometry of organic-inorganic materials: identification and gas-phase reactivity of functionalized octahedral rhenium(III) clusters.  

PubMed

Electrospray ionization mass spectrometry was used for the analysis of functionalized rhenium clusters such as [Re6Se8(o-Me2TTFPPh2)6]2+ (1), {Re6Se8[(o-Me2TTF)2PPh]6}2+ (2) and [Re6Se8(MePPh2)6]2+ (3). The high-resolution mass spectra of the intact clusters, performed in dichloromethane, confirm the identification of the compounds by comparison with the theoretical isotopic distributions. Low-resolution full-scan mass spectra recorded at increasing desolvation cone voltage values allow the study of the intrinsic reactivity of ionic species. The survival yield curves illustrating the bimolecular reactivity of 1 and 2 suggest that a bisdimethyltetrathiafulvalene(phenyl)phosphine ligand increases the stability of the functionalized ML6(2+) cluster 2. In the case of the 3, instead of loss of a neutral ligand, ligand exchange is observed either with traces of water present in dichloromethane or with acetonitrile used as solvent. PMID:15584011

Rondeau, David; Perruchas, Sandrine; Avarvari, Narcis; Batail, Patrick; Vékey, Karoly

2005-01-01

50

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

51

Organic inorganic materials for fabrication of integrated optical circuits  

NASA Astrophysics Data System (ADS)

In the last few years, ORganically MOdified SIlicates (ORMOSILS) [R xSi(OR) 4- x] prepared by sol-gel process were particularly attractive for integrated optics fabrication. A composition based on 3-(trimethoxysilyl)propylmethacrylate (MAPTMS) has already allowed the industrial fabrication of optical integrated devices. For this kind of materials, the polymerization of the organic network is typical of free radical curing. In this work, we try to obtain waveguides with another hybrid precursor [2-(3,4-epoxycyclohexylethyltrimethoxysilane)] using cationic polymerization. The main advantage of cationic polymerization is its ability to allow spontaneous cure reaction in presence of oxygen, in contrast with radical polymerization. We choose cycloaliphatic compounds because of their well-known high polymerization rates. The polymerization of the organic network of this hybrid material requires a cationic photoinitiator. The purpose of this paper is dedicated to the inorganic part of the material. Hydrolysis and polycondensation are followed by 29Si NMR. The main objective is to obtain the highest reactive multifunctional oligomer with the lowest OH groups content. Based on our results, we obtained 3D waveguides with a cross-section of 5 ?m × 5 ?m.

Jabbour, J.; Calas-Etienne, S.; Smaïhi, M.; Gatti, S.; Kribich, R.; Pille, G.; Moreau, Y.; Etienne, P.

2007-07-01

52

Interfacial slippage of inorganic electronic materials on plastic substrates  

Microsoft Academic Search

The stretchable and flexible electronics with the structure of inorganic films on plastic substrate has recently attracted an increasing interest. Interfacial failure inevitably occurs when the structure is subject to repeated bending or stretching in application. An analysis is presented in this letter on the slipping failure mechanism for the interface between inorganic film and plastic substrate. The critical radius

Longchao Dai; Xue Feng; Bin Liu; Daining Fang

2010-01-01

53

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

54

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

55

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

PubMed

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

2014-07-29

56

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

57

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

58

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

SciTech Connect

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

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

1999-11-11

59

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

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

60

Characterization of nanoscale inorganic solid state materials synthesized by means of alkalide reduction  

Microsoft Academic Search

The discovery and development of new inorganic materials is crucial to the continuing advancement of technology. Such materials play important roles in catalysis, information storage, microwave technology, superconductors, magnetic refrigeration, and even audio\\/visual applications, to name a few. A recent surge of interest has placed more emphasis on nanoscale materials, which often demonstrate marked property differences from their bulk counterparts.

Kim Ellen Mooney

2004-01-01

61

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

62

Preparation and characterization of photopolymerizable organic–inorganic hybrid materials by the sol-gel method  

Microsoft Academic Search

A series of UV-curable organic–inorganic hybrid materials were prepared by the sol-gel technique and coated onto Plexiglass® substrate. The effects of the content of EGDMA and the content of the inorganic part on various properties of the coatings,\\u000a such as tensile strength, hardness, gloss, and cross-cut adhesion, were investigated. It was found that the properties of\\u000a the coating were improved

Sevim Karata?; Zuhal Ho?gör; Nilhan-Kayaman Apohan; Atilla Güngör

2010-01-01

63

Combinatorial solid-state chemistry of inorganic materials  

Microsoft Academic Search

Throughout history, scientists and engineers have relied on the slow and serendipitous trial-and-error process for discovering and developing new materials. In contrast, an emerging theme in modern materials science is the notion of intelligent design of materials. Pioneered by the pharmaceutical industry and adapted for the purposes of materials science and engineering, the combinatorial approach represents a watershed in the

Hideomi Koinuma; Ichiro Takeuchi

2004-01-01

64

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

65

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

66

Engineered biomolecular interactions with inorganic materials : sequence, binding, and assembly  

E-print Network

Nanobiotechnology aims to exploit biomolecular recognition and self-assembly capabilities for integrating advanced materials into medicine and electronics. In particular, peptides have exhibited the ability to specifically ...

Peelle, Beau R

2005-01-01

67

Construction & characterization of organic-inorganic hybrid materials for applications in nanotechnology  

NASA Astrophysics Data System (ADS)

The use of soft matter to direct the organization of hard materials into functional geometries has been a paradigm inspired by nature. Polymer based systems can be engineered to reproducibly adopt nano-scale architectures. Designing interactions between such polymer templates and inorganic nanoparticles gives rise to nano-scale hybrid materials that may be deployable in applications ranging from magnetism to optoelectronics and lasing. In particular, hybrid one dimensional nanostructures exhibit a strong anisotropy in their physical properties. This anisotropy may be utilized for applications that require a directional transfer of signals or an orientation dependent physical response. The construction of one dimensional nanoparticle arrays via polymer based templates is detailed. Nano-scale arrays have been created using self-assembling peptide templates. Peptides adopt secondary and higher order hierarchical conformations in solution. The ability to engineer different types of functionality at precise locations in the assembled architecture presents possibilities of patterning matter at length scales inaccessible by lithographic techniques. Micro-scale particle arrays have been constructed via electrospinning, an electric-field assisted solution spinning technique. Correlations between the structural morphology and the optical behavior of these polymer-particle hybrid arrays have been investigated. Magnetic nanoparticle arrays displaying orientation dependent magnetic behavior have been constructed by coaxial electrospinning.

Sharma, Nikhil

68

Graded porous inorganic materials derived from self-assembled block copolymer templates  

NASA Astrophysics Data System (ADS)

Graded porous inorganic materials directed by macromolecular self-assembly are expected to offer unique structural platforms relative to conventional porous inorganic materials. Their preparation to date remains a challenge, however, based on the sparsity of viable synthetic self-assembly pathways to control structural asymmetry. Here we demonstrate the fabrication of graded porous carbon, metal, and metal oxide film structures from self-assembled block copolymer templates by using various backfilling techniques in combination with thermal treatments for template removal and chemical transformations. The asymmetric inorganic structures display mesopores in the film top layers and a gradual pore size increase along the film normal in the macroporous sponge-like support structure. Substructure walls between macropores are themselves mesoporous, constituting a structural hierarchy in addition to the pore gradation. Final graded structures can be tailored by tuning casting conditions of self-assembled templates as well as the backfilling processes. We expect that these graded porous inorganic materials may find use in applications including separation, catalysis, biomedical implants, and energy conversion and storage.Graded porous inorganic materials directed by macromolecular self-assembly are expected to offer unique structural platforms relative to conventional porous inorganic materials. Their preparation to date remains a challenge, however, based on the sparsity of viable synthetic self-assembly pathways to control structural asymmetry. Here we demonstrate the fabrication of graded porous carbon, metal, and metal oxide film structures from self-assembled block copolymer templates by using various backfilling techniques in combination with thermal treatments for template removal and chemical transformations. The asymmetric inorganic structures display mesopores in the film top layers and a gradual pore size increase along the film normal in the macroporous sponge-like support structure. Substructure walls between macropores are themselves mesoporous, constituting a structural hierarchy in addition to the pore gradation. Final graded structures can be tailored by tuning casting conditions of self-assembled templates as well as the backfilling processes. We expect that these graded porous inorganic materials may find use in applications including separation, catalysis, biomedical implants, and energy conversion and storage. Electronic supplementary information (ESI) available: Additional SEM images, supporting experimental details, TGA analyses and XRD pattern. See DOI: 10.1039/c4nr07492k

Gu, Yibei; Werner, Jörg G.; Dorin, Rachel M.; Robbins, Spencer W.; Wiesner, Ulrich

2015-03-01

69

Light wave coupled flat panel displays and solid-state lighting using hybrid inorganic\\/organic materials  

Microsoft Academic Search

We present a review of light-emitting materials and devices that combine inorganic and organic lumophores and hosts. The essence of this hybrid inorganic\\/organic (I\\/O) approach is to combine materials, structures and devices from each category in such a way as to obtain best-of-both-worlds performance. The combination of high power\\/high efficiency inorganic light pump sources with high conversion efficiency organic lumophores

Andrew J. Steckl; Jason Heikenfeld; Steven C. Allen

2005-01-01

70

Functionally Graded Materials Database  

NASA Astrophysics Data System (ADS)

Functionally Graded Materials Database (hereinafter referred to as FGMs Database) was open to the society via Internet in October 2002, and since then it has been managed by the Japan Aerospace Exploration Agency (JAXA). As of October 2006, the database includes 1,703 research information entries with 2,429 researchers data, 509 institution data and so on. Reading materials such as "Applicability of FGMs Technology to Space Plane" and "FGMs Application to Space Solar Power System (SSPS)" were prepared in FY 2004 and 2005, respectively. The English version of "FGMs Application to Space Solar Power System (SSPS)" is now under preparation. This present paper explains the FGMs Database, describing the research information data, the sitemap and how to use it. From the access analysis, user access results and users' interests are discussed.

Kisara, Katsuto; Konno, Tomomi; Niino, Masayuki

2008-02-01

71

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

72

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

73

Mn-Substituted Inorganic-Organic Hybrid Materials Based on ZnSe  

E-print Network

Mn-Substituted Inorganic-Organic Hybrid Materials Based on ZnSe: Nanostructures That May Lead of Zn for Mn in the ZnSe(L)0.5 systems. The latter are composed of perfectly ordered ZnSe semiconductor to semiconductor quantum wells (QWs), these structures are composed of II-VI nanolayers. However, the II-VI nano

Li, Jing

74

INORGANIC NANOPARTICLES AS PHASE-CHANGE MATERIALS FOR LARGE-SCALE THERMAL ENERGY STORAGE  

E-print Network

INORGANIC NANOPARTICLES AS PHASE-CHANGE MATERIALS FOR LARGE- SCALE THERMAL ENERGY STORAGE Miroslaw storage performance. The expected immediate outcome of this effort is the demonstration of high-energy generation at high efficiency could revolutionize the development of solar energy. Nanoparticle-based phase

Pennycook, Steve

75

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

76

Hybrid organic-inorganic sol-gel materials and components for integrated optoelectronics  

NASA Astrophysics Data System (ADS)

On the technical platform of hybrid organic-inorganic sol-gel, the integrated optoelectronics in the forms of heterogeneous integration between the hybrid sol-gel waveguide and the high refractive index semiconductors and the nonlinear functional doping of disperse red chromophore into hybrid sol-gel is developed. The structure of hybrid sol-gel waveguide on high index semiconductor substrate is designed with BPM-CAD software. A hybrid sol-gel based on MAPTMS and TEOS suitable for lower cladding for the waveguide is developed. The multi-layer hybrid sol-gel waveguide with good mode confinement and low polarization dependence is fabricated on Si and InP. As proof of concept, a 1 x 12 beam splitter based on multimode interference is fabricated on silicon substrate. The device shows excess loss below 0.65 dB and imbalance below 0.28 dB for both TE and TM polarization. A nonlinear active hybrid sol-gel doped with disperse red 13 has been developed by simple co-solvent method. It permits high loading concentration and has low optical loss at 1550 nm. The second-order nonlinear property of the active sol-gel is induced with corona poling and studied with second harmonic generation. A 3-fold of enhancement in the poling efficiency is achieved by blue light assisted corona poling. The chromophore alignment stability is improved by reducing the free volume of the formed inorganic network from the sol-gel condensation reaction. An active sol-gel channel waveguide has been fabricated using active and passive hybrid sol-gel materials by only photopatterning and spin-coating. An amplitude modulator based on the active sol-gel containing 30 wt.% of DR13 shows an electro-optic coefficient of 14 pm/V at 1550 nm and stable operation within the observation time of 24 days.

Lu, Dong

77

INORGANIC ION-EXCHANGE MATERIALS FOR WATER PURIFICATION IN CVTR  

Microsoft Academic Search

Hydrous zirconium phosphate and oxide, were selected for intensive ; evaluation as candidate materials for high temperature, nuclear reactor water ; puriffcation. Experiments with unfired zirconium phosphate and zircorium oxide ; gels seemed to indicate the existence of a polyolated structure. When these ; polymeric gels were exposed to sufficiently high temperatures, crystallization ; resulted and characteristic x-ray diffraction patterns

N. Michael; W. D. Fletcher; M. J. Bell; D. E. Croucher

1961-01-01

78

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

79

Characterization of the photopolymerization - kinetics of inorganic-organic nanocomposite materials by photo-DSC  

SciTech Connect

Organic-inorganic sol-gel derived composites with poly(methylmethacrylate) chains formed by polymerization already have shown their usefulness for many optical applications including embossing and holography technics to produce aspherical lenses, optical lattices and coatings for optical fibers. They can combine relatively low shrinkage with efficient photopolymerization and show overall properties being superior to those of pure methacrylate based polymers. The investigation of the kinetics of the radical polymerization however of methacrylate precursors containing hydrolyzable alkoxysilane groupings in sol-gel composite materials is more difficult due to the high inorganic crosslinking and the resulting high insolubility. For these reasons, Photo-DSC was assumed to be a useful method to investigate the kinetics of precursor systems, together with appropriate photoinitiators. The purpose of this work is to investigate the influence of the inorganic network formation on the kinetics of free radical polymerization reaction in methacryloxypropyltrimethoxysilane (MPTS) systems.

Becker, C.; Zahnhausen, M.; Krug, H.; Schmidt, H.

1995-12-31

80

Graded porous inorganic materials derived from self-assembled block copolymer templates.  

PubMed

Graded porous inorganic materials directed by macromolecular self-assembly are expected to offer unique structural platforms relative to conventional porous inorganic materials. Their preparation to date remains a challenge, however, based on the sparsity of viable synthetic self-assembly pathways to control structural asymmetry. Here we demonstrate the fabrication of graded porous carbon, metal, and metal oxide film structures from self-assembled block copolymer templates by using various backfilling techniques in combination with thermal treatments for template removal and chemical transformations. The asymmetric inorganic structures display mesopores in the film top layers and a gradual pore size increase along the film normal in the macroporous sponge-like support structure. Substructure walls between macropores are themselves mesoporous, constituting a structural hierarchy in addition to the pore gradation. Final graded structures can be tailored by tuning casting conditions of self-assembled templates as well as the backfilling processes. We expect that these graded porous inorganic materials may find use in applications including separation, catalysis, biomedical implants, and energy conversion and storage. PMID:25758193

Gu, Yibei; Werner, Jörg G; Dorin, Rachel M; Robbins, Spencer W; Wiesner, Ulrich

2015-03-19

81

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

82

Hybrid organic-inorganic materials: Synthesis and characterization of organic bridged polysilsesquioxanes  

NASA Astrophysics Data System (ADS)

Hybrid organic-inorganic materials are designed to combine the favorable physical properties of organic polymers and inorganic oxides. This dissertation focuses on the synthesis and characterization of hybrid organic-inorganic materials in which the organic and inorganic portions are contained within the same molecular precursors. These organic bridged polysilsesquioxanes are prepared by the sol-gel polymerization of alpha,omega-bis(triethoxysilyl) substituted monomers. Chapter 2 focuses upon the application of organic bridged polysilsequioxanes to second order nonlinear optical (NLO) materials. Since the magnitude of the NLO response is directly related to the extent of conjugation between the electron donor and acceptor portion on the NLO active organic chromophore, chromophores with extended conjugation were synthesized. Thus, a more efficient synthesis of 4-nitro-N,N-bis((3-triethoxysilyl)propyl) aniline 10 (82.5% vs. 3.2%) was achieved. Optical quality thin films were synthesized and the NLO properties of these films were probed by Second Harmonic Generation. Chapter 3 describes the synthesis of materials that combine the characteristics of polyimides and silica. Polymerizations of the bridged bisimide triethoxysilyl monomers occurred rapidly (<5 min) at ambient temperature in THF under acidic (HCl) conditions to give transparent or translucent xerogels. Thin films were cast at ambient temperatures and later cured under moderate temperatures (100sp°C). The thermal stability was measured by Thermal Gravimetric Analysis (TGA) and the hardness was measured by a Vickers Hardness Determination. Finally, Chapter 4 details the influence of the nature of the bridging organic spacer upon the surface area and porosity of hybrid organic inorganic polysilsesquioxanes. This was accomplished by the synthesis and polymerization of a variety of novel sol-gel processable monomers. Variables in the organic bridging group included changes in the hydrophobicity of the bridging organic spacer, polymerization solvent, along with the effect of inserting a double bond in the hydrocarbon bridge.

Hobson, Stephen Terrence

83

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

84

Direct access to hierarchically porous inorganic oxide materials with three-dimensionally interconnected networks.  

PubMed

Hierarchically porous oxide materials have immense potential for applications in catalysis, separation, and energy devices, but the synthesis of these materials is hampered by the need to use multiple templates and the associated complicated steps and uncontrollable mixing behavior. Here we report a simple one-pot strategy for the synthesis of inorganic oxide materials with multiscale porosity. The inorganic precursor and block copolymer are coassembled into an ordered mesostructure (microphase separation), while the in situ-polymerized organic precursor forms organic-rich macrodomains (macrophase separation) around which the mesostructure grows. Calcination generates hierarchical meso/macroporous SiO2 and TiO2 with three-dimensionally interconnected pore networks. The continuous 3D macrostructures were clearly visualized by nanoscale X-ray computed tomography. The resulting TiO2 was used as the anode in a lithium ion battery and showed excellent rate capability compared with mesoporous TiO2. This work is of particular importance because it (i) expands the base of BCP self-assembly from mesostructures to complex porous structures, (ii) shows that the interplay of micro- and macrophase separation can be fully exploited for the design of hierarchically porous inorganic materials, and therefore (iii) provides strategies for researchers in materials science and polymer science. PMID:25338137

Hwang, Jongkook; Jo, Changshin; Hur, Kahyun; Lim, Jun; Kim, Seongseop; Lee, Jinwoo

2014-11-12

85

New Class of Biodegradable Polymers Formed from Reactions of an Inorganic Functional Group  

E-print Network

New Class of Biodegradable Polymers Formed from Reactions of an Inorganic Functional Group Jun Yoo functional groups into polymer chemistry allows the fabrication of polymers with new properties a polymer with a new functional group along its backbone that renders it stable at physiological pH but also

Salem, Aliasger K.

86

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

87

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

88

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

89

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

90

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

91

Micromachining of Inorganic Materials using Laser Plasma Soft X-Rays  

Microsoft Academic Search

We have investigated nanomachining of inorganic materials using laser plasma soft X-rays. The soft X-ray was generated by irradiating Ta targets with pulsed Nd:YAG laser light. The laser plasma soft X-rays were focused using an ellipsoidal mirror, which is designed so as to focus soft X-rays at around 10 nm efficiently. The focused soft X-rays were incident to the surfaces

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

2007-01-01

92

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

93

Affinity and Selectivity of Peptides for Inorganic Materials: A Thermodynamic Discussion of the Role of Conformational Flexibility  

NASA Astrophysics Data System (ADS)

The recognition of inorganic materials by polypeptides is a technologically relevant and scientifically intriguing phenomenon. Several features of the polypeptide determine the affinity for a given surface and, possibly, its selectivity among a set of materials or among various crystal planes of the same material. Different amino acids have different intrinsic affinities for a given surface; the geometrical features of the surface are also relevant in the recognition process. By means of a minimal, analytically solvable thermodynamic model for the polypeptide-surface interaction, we discuss the role of the conformational flexibility in determining affinity and selectivity of polypeptides for surfaces. In particular, the interplay between geometrical matching of polypeptide-surface features and the presence in the polypeptide of amino acids able to bind the target surface is analyzed as a function of the flexibility. A discussion of literature data in the light of this minimal model is also given.

Corni, Stefano

2015-03-01

94

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

95

Atomic layer deposition of organic-inorganic hybrid materials based on saturated linear carboxylic acids.  

PubMed

Atomic layer deposition (ALD) has successfully provided thin films of organic-inorganic hybrid materials based on saturated linear carboxylic acids and trimethylaluminium (TMA). Films were grown for seven carboxylic acids: oxalic, malonic, succinic, glutaric, pimelic, suberic and sebacic acid, i.e. ranging from 2 to 10 carbon atoms in the molecular structure. These processes show exceptionally high growth rates; up to 4.3 nm/cycle for the pimelic acid-TMA system. Quartz crystal microbalance measurements of the growth dynamics indicate that all systems are of a self limiting ALD-type. Nevertheless, temperature dependent growth was observed in several systems. The width of the ALD windows shows correlations with the length of the carbon chains. Fourier transform infrared spectroscopy clearly proved that the deposited films are of a hybrid character, where the carboxylic acids primarily form bidentate complexes, though bridging complexes may also form. All films are X-ray amorphous as deposited. The films were further analyzed by atomic force microscopy for surface roughness and topography, UV-Vis spectroscopy and ellipsometry for optical properties, and the goniometer method for measuring sessile drops for surface wetting properties. Apart from the oxalic and malonic acid-TMA systems, the films are stable in contact with water. The films are generally smooth, transparent and have a refractive index close to 1.5. The complete coverage and accurate growth control offered by the ALD technique is here proven to provide surface-functionalized hybrid materials resembling metal-organic frameworks (MOF), probably as rather dense structures, yet with substantial potential for applications. PMID:21442116

Klepper, Karina Barnholt; Nilsen, Ola; Hansen, Per-Anders; Fjellvåg, Helmer

2011-05-01

96

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

97

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

98

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

SciTech Connect

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

Simon, N.J.

1994-12-01

99

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

100

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

101

Recent achievements on inorganic electrode materials for lithium-ion batteries.  

PubMed

The lithium-ion battery technology is rooted in the studies of intercalation of guest ions into inorganic host materials developed ca. 40 years ago. It further turned into a commercial product, which will soon blow its 25th candle. Intense research efforts during this time have resulted in the development of a large spectrum of electrode materials together with deep understanding of the underlying structure-property relationships that govern their performance. This has enabled an ever increasing electrochemical yield together with the diversification of the technology into several subfamilies, tailoring materials to application requirements. The present paper aims at providing a global and critical perspective on inorganic electrode materials for lithium-ion batteries categorized by their reaction mechanism and structural dimensionality. Specific emphasis is put on recent research in the field, which beyond the chemistry and microstructure of the materials themselves also involves considering interfacial chemistry concepts alongside progress in characterization techniques. Finally a short personal perspective is provided on some plausible development of the field. PMID:25679823

Croguennec, Laurence; Palacin, M Rosa

2015-03-11

102

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

103

Function Materialization in Object Bases  

Microsoft Academic Search

We describe function materialization as an optimizationconcept in object-oriented databases. Exploiting theobject-oriented paradigm---namely classification, objectidentity , and encapsulation---facilitates a rather easy incorporationof function materialization into (existing)object-oriented systems. Furthermore, the exploitationof encapsulation (information hiding) and object identityprovides for additional performance tuning measureswhich drastically decrease the rematerialization...

Alfons Kemper; Christoph Kilger; Guido Moerkotte

1991-01-01

104

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

NASA Astrophysics Data System (ADS)

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

Goel, Divya

105

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

106

Standard absolute entropy, S degrees 298 values from volume or density. 1. Inorganic materials.  

PubMed

Standard absolute entropies of many inorganic materials are unknown; this precludes a full understanding of their thermodynamic stabilities. It is shown here that formula unit volume, V(m)(), can be employed for the general estimation of standard entropy, S degrees 298 values for inorganic materials of varying stoichiometry (including minerals), through a simple linear correlation between entropy and molar volume. V(m)() can be obtained from a number of possible sources, or alternatively density, rho, may be used as the source of data. The approach can also be extended to estimate entropies for hypothesized materials. The regression lines pass close to the origin, with the following formulas: For inorganic ionic salts, S degrees 298 /J K(-)(1) mol(-)(1) = 1360 (V(m)()/nm(3) formula unit(-)(1)) + 15 or = 2.258 [M/(rho/g cm(-)(3))] + 15. For ionic hydrates, S degrees 298 /J K(-)(1) mol(-)(1) = 1579 (V(m)()/nm(3) formula unit(-)(1)) + 6 or = 2.621 [M/(rho/g cm(-)(3))] + 6. For minerals, S degrees 298 /J K(-)(1) mol(-)(1) = 1262 (V(m)()/nm(3) formula unit(-)(1)) + 13 or = 2.095 [M/(rho/g cm(-)(3))] + 13. Coupled with our published procedures, which relate volume to other thermodynamic properties via lattice energy, the correlation reported here complements our development of a predictive approach to thermodynamics and ultimately permits the estimation of Gibbs energy data. Our procedures are simple, robust, and reliable and can be used by specialists and nonspecialists alike. PMID:14686847

Jenkins, H Donald Brooke; Glasser, Leslie

2003-12-29

107

The organic-inorganic hybrid material 1-cyclohexylpiperazine-1,4-diium tetrachloridozincate.  

PubMed

In the crystal structure of the title organic-inorganic hybrid material, (C10H22N2)[ZnCl4], the tetrachloridozincate anions and 1-cyclohexylpiperazine-1,4-diium dications are interconnected via N-H...Cl and C-H...Cl hydrogen bonds to form layers parallel to the (001) plane. The cyclohexyl groups from adjacent chains interdigitate, thus building the three-dimensional structure. The piperazinium and cyclohexyl rings exhibit regular spatial chair conformations. The title salt was also characterized by FT-IR and Raman spectroscopic analyses. PMID:24192176

Soudani, Sarra; Aubert, Emmanuel; Jelsch, Christian; Ben Nasr, Cherif

2013-11-01

108

Micromachining of Inorganic Materials using Laser Plasma Soft X-Rays  

NASA Astrophysics Data System (ADS)

We have investigated nanomachining of inorganic materials using laser plasma soft X-rays. The soft X-ray was generated by irradiating Ta targets with pulsed Nd:YAG laser light. The laser plasma soft X-rays were focused using an ellipsoidal mirror, which is designed so as to focus soft X-rays at around 10 nm efficiently. The focused soft X-rays were incident to the surfaces of inorganic materials such as silica glass, LiF, CaF2 and LiNbO3. It is found that these materials are ablated by soft X-ray irradiation. In particular, silica glass can be ablated at rates of 0.2-150 nm/shot, which can be controlled by the intensity of soft X-rays. It is remarkable that silica can be ablated smoothly with a roughness of 1 nm after 10 shots of soft X-ray irradiation at a rate of 50 nm/shot. In order to demonstrate nanomachining of silica glass, we used contact masks on top of silica glass plates fabricated by electron beam lithography technique. The silica glass plates were irradiated with laser plasma soft X-rays through the windows of the contact masks. We found that nanofabrication of trenches with a width of 70 nm are performed clearly.

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

109

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

Microsoft Academic Search

The use of nanostructured, hybrid materials possesses great future potential. Many examples of nanostructured materials exist within nature, such as animal bone, animal teeth, and seashells. This research, inspired by nature, strove to mimic salient properties of natural materials, utilizing methods observed within nature to produce materials. Further, this research increased the functionality of the templates from \\

Christopher Ryan Lubeck

2007-01-01

110

Cracks in functionally graded materials  

Microsoft Academic Search

A semi-infinite crack in a strip of an isotropic, functionally graded material under edge loading and in-plane deformation conditions is analyzed. Mixed mode stress intensity factors are analytically solved for up to a numerically determined parameter. The effects of material gradients on the mode I and mode II stress intensity factors and the phase angle used to measure mode mixity

Pei Gu; R. J. Asaro

1997-01-01

111

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

112

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

113

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

PubMed

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

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

2012-01-01

114

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

PubMed

In this work, a homogeneity study of a corn flour reference material candidate for inorganic analysis is presented. Seven kilograms of corn flour were used to prepare the material, which was distributed among 100 bottles. The elements Ca, K, Mg, P, Zn, Cu, Fe, Mn and Mo were quantified by inductively coupled plasma optical emission spectrometry (ICP OES) after acid digestion procedure. The method accuracy was confirmed by analyzing the rice flour certified reference material, NIST 1568a. All results were evaluated by analysis of variance (ANOVA) and principal component analysis (PCA). In the study, a sample mass of 400mg was established as the minimum mass required for analysis, according to the PCA. The between-bottle test was performed by analyzing 9 bottles of the material. Subsamples of a single bottle were analyzed for the within-bottle test. No significant differences were observed for the results obtained through the application of both statistical methods. This fact demonstrates that the material is homogeneous for use as a laboratory reference material. PMID:25704713

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

2015-07-01

115

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

NASA Astrophysics Data System (ADS)

The special features of synchrotron X-radiation and the types of instrumentation required for a range of synchrotron X-ray diffraction experiments are outlined. A diverse range of applications to inorganic and heterogeneous catalyst systems are discussed. Grazing incidence X-ray diffraction experiments have revealed a number of surface structures and followed surface phase transformations; similar studies of boundary and interfacial structures are cited. Experiments on catalytic metals dispersed on supports have exploited anomalous scattering effects. High-resolution powder diffraction has assisted phase identifications, provided quantitative data on peak broadening (such as arise from particle size effects or stacking disorder), enabled studies of subtle superstructures and a growing number of ab initio structure solutions, and permitted Rietveld refinements of a range of inorganic materials. The potential for performing measurements on individual crystallites in the micrometre size regime has been demonstrated; a small number of successful single-crystal structure refinements have been described. Single-crystal Laue methods have been also applied successfully to structure refinements and solutions; this configuration potentially permits data sufficient for structure definition to be recorded on a nano-microsecond time scale. A range of studies that are time-resolved (currently on somewhat longer scales), and various studies under non-ambient conditions (such as at high or low temperatures, at extreme pressures, or under applied magnetic and electric fields) have also been described. These various applications of synchrotron X-ray diffraction techniques to inorganic and heterogeneous catalyst systems both illustrate already substantial contributions to our understanding, and promise still greater advances from future applications.

Newsam, J. M.; Liang, K. S.

116

Comparison of the NH3 Removal Characteristics by Trickle-Bed Air Biofilter Packed with Four Inorganic Packing Materials  

Microsoft Academic Search

Four inorganic packing materials were evaluated in terms of their availability as a packing material in trickle-bed air biofilter (TBAB) of biological NH3 removal characteristics. The nitrification rate is in the order of zeolite > active carbon > ceramic pellets > multi-face ball. The highest nitrification rate for zeolite, polypropylene multi-face ball, ceramic pellets and active carbon were 275, 136,

Jiao Zhang

2010-01-01

117

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

NASA Astrophysics Data System (ADS)

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

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

1986-04-01

118

Inorganic Graphenylene: A Porous Two-Dimensional Material With Tunable Band Gap  

E-print Network

By means of ab initio calculations we investigate the possibility of existence of a boron nitride (BN) porous two-dimensional nanosheet which is geometrically similar to the carbon allotrope known as biphenylene carbon. The proposed structure, which we called Inorganic Graphenylene (IGP), is formed spontaneously after selective dehydrogenation of the porous Boron Nitride (BN) structure proposed by Ding et al. We study the structural and electronic properties of both porous BN and IGP and it is shown that, by selective substitution of B and N atoms with carbon atoms in these structures, the band gap can be significantly reduced, changing their behavior from insulators to semiconductors, thus opening the possibility of band gap engineering for this class of two-dimensional materials.

Perim, Eric; Atreto, Pedro Alves da Silva; Galvão, Douglas

2014-01-01

119

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

NASA Astrophysics Data System (ADS)

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

Imam, Hisham; Elsayed, Khaled; Madkour, Fatma

2011-06-01

120

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

121

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-Ar2PC6H4SO2O with Ar = 2-MeOC6H4) (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)CH2CH3}] and [(P^O)Pd{?(2)-C,O-CH2CH(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

122

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

PubMed

In this study, a facile and effective strategy is presented for the preparation of a series of zwitterionic poly(sulfobetaine methacrylate) (pSBMA)-grafted organic and inorganic biomaterials with well-controlled haemocompatibility via intuitive thermal-induced graft polymerization. The research focused on the effects of zwitterionic surface packing density on human blood compatibility by varying the SBMA monomer concentration on the silanized silicon wafer substrates. A 0.2M SBMA monomer solution was found to not only produce Si wafer surfaces with ideal zwitterionic surface packing density and uniform, evenly distributed pSBMA grafting coverage but also yield optimal hydrophilicity and haemocompatibility. SBMA monomer concentrations lower and greater than 0.2M yielded a zwitterionic surface with low grafting coverage. This study also demonstrated that the same, intuitive thermal-induced graft polymerization strategy could be applied to a variety of organic polymeric, inorganic ceramic and metal oxide biomaterials to improve haemocompatibility. Among the tested organic and inorganic materials, however, it was found that inorganic biomaterials demonstrated greater resistance to protein and platelet adhesions. It was hypothesized that the ozone treatment, which generated an abundance of hydroxide groups on inorganic substrate interfaces, might have given the inorganic biomaterials a more stable silanized layer yielding a preferable reaction state and resulted in sturdier and more durable pSBMA grafting. PMID:25638723

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

2015-03-01

123

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

SciTech Connect

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

Catauro, Michelina, E-mail: michelina.catauro@unina2.it [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Bollino, Flavia [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Cristina Mozzati, Maria [Department of Physics, CNISM and INSTM, University of Pavia, Via Bassi 6, 27100 Pavia (Italy); Ferrara, Chiara; Mustarelli, Piercarlo [Department of Chemistry, Section of Physical Chemistry, University of Pavia and INSTM, Via Taramelli 16, 27100 Pavia (Italy)

2013-07-15

124

An ultrafast nickel-iron battery from strongly coupled inorganic nanoparticle/nanocarbon hybrid materials.  

PubMed

Ultrafast rechargeable batteries made from low-cost and abundant electrode materials operating in safe aqueous electrolytes could be attractive for electrochemical energy storage. If both high specific power and energy are achieved, such batteries would be useful for power quality applications such as to assist propelling electric vehicles that require fast acceleration and intense braking. Here we develop a new type of Ni-Fe battery by employing novel inorganic nanoparticle/graphitic nanocarbon (carbon nanotubes and graphene) hybrid materials as electrode materials. We successfully increase the charging and discharging rates by nearly 1,000-fold over traditional Ni-Fe batteries while attaining high energy density. The ultrafast Ni-Fe battery can be charged in ~2 min and discharged within 30 s to deliver a specific energy of 120 Wh kg(-1) and a specific power of 15 kW kg(-1). These features suggest a new generation of Ni-Fe batteries as novel devices for electrochemical energy storage. PMID:22735445

Wang, Hailiang; Liang, Yongye; Gong, Ming; Li, Yanguang; Chang, Wesley; Mefford, Tyler; Zhou, Jigang; Wang, Jian; Regier, Tom; Wei, Fei; Dai, Hongjie

2012-01-01

125

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

126

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

127

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

SciTech Connect

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

Wang Hualin [School of Chemical Technology, Hefei University of Technology, Hefei, Anhui 230009 (China); Shi Tiejun [School of Chemical Technology, Hefei University of Technology, Hefei, Anhui 230009 (China)]. E-mail: stjdean@hfut.edu.cn; Yang Shanzhong [School of Chemical Technology, Hefei University of Technology, Hefei, Anhui 230009 (China); Hang Guopei [School of Chemical Technology, Hefei University of Technology, Hefei, Anhui 230009 (China)

2006-02-02

128

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

Microsoft Academic Search

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

Reshef Tenne; C. N. R. Rao

2004-01-01

129

Intrinsically fluorescent nanoparticles with excellent stability based on a highly crosslinked organic-inorganic hybrid polyphosphazene material.  

PubMed

A series of intrinsically fluorescent particles were synthesized, including nanoparticles with independently tunable diameters, nanotubes and microspheres, based on a highly crosslinked organic-inorganic hybrid polyphosphazene material. The nanoparticles exhibit high fluorescent intensity and excellent thermal and photobleaching stability, and can be well dispersed in both aqueous and organic media. PMID:21947021

Liu, Wei; Huang, Xiaobin; Wei, Hao; Tang, Xiaozhen; Zhu, Lu

2011-11-01

130

Organic-inorganic hybrid materials constructed from inorganic lanthanide sulfate skeletons and organic 4,5-imidazoledicarboxylic acid.  

PubMed

Five different types of the lanthanide sulfate-carboxylates family, [La(2)(SO(4))(Himdc)(2)(H2O)2] , [Gd(2)(SO(4))(2)(Himdc)(H2O)3].H2O , [Ln(2)(SO(4))(2)(Himdc)(H2O)(3)].H2O (Ln = Gd3a, Eu3b), [Eu(6)Cu(SO(4))(6)(Himdc)(4)(H2O)(14)] , and [Ln(Himc)(SO(4))(H2O)] (Ln = Eu5a, Gd5b, Tb5c, Dy5d, Er5e); H(2)imc = 4-imidazolecarboxylic acid, H(3)imdc = 4,5-imidazoledicarboxylic acid) have been obtained by hydrothermal reactions of Ln(2)O(3), transition metal sulfates and H(3)imdc at 170 degrees C and characterized by means of elemental analyses, IR, TG analysis, luminescence spectroscopy and single crystal X-ray diffraction. The 3D structure of 1 is constructed from alternately linkages of organic {La(Himdc)} layers and inorganic {La(2)O(2)(SO(4))} layers, with the La atoms as hinges. 2 and 3a/3b both contain alternately arranged 1D left- and right-handed helical {Ln(imdc)} chains bridged by SO(4)(2-) anions to form a 3D framework with 1D rectangle-like channels along the b axis. The structural differences of 2 and 3a/3b lie in the linkages of the SO(4)(2-) anions. Complex 4 consists of 2D tubular Eu-sulfate layers pillared by {Cu(Himdc)(2)} units to generate a 3D network. Complexes 5a-5e possess 2D bamboo-raft-like layer structures based on helical tubes. Interestingly, H(2)imc comes from the in-situ decarboxylation of H(3)imdc in the hydrothermal reactions. The luminescence properties of the complexes 3a, 4, 5a 5c, 5d were investigated in solid state at room temperature. PMID:17712443

Sun, Yan-Qiong; Yang, Guo-Yu

2007-09-14

131

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

NASA Astrophysics Data System (ADS)

This dissertation is concerned with controlling the flux synthesis and ensuing physical properties of mixed-valence metal oxides. Molten alkali metal nitrates and hydroxides have been explored to determine and exploit their variable redox chemistries for the synthesis of mixed-valent oxide materials. Cationic and anionic additives have been utilized in these molten salts to control the relative concentrations of the redox-active species present to effectively tune and cap the electrochemical potential of the flux. Atoms like bismuth, copper, and manganese are capable of providing different numbers of electrons for bonding. With appropriate doping near the metal-insulator transition, many of these mixed-valent inorganic metal oxides exhibit extraordinary electronic and magnetic properties. Traditionally, these materials have been prepared by classical high temperature solid state routes where microscopic homogeneity is hard to attain. In these routes, the starting composition dictates the doping level, and in turn, the formal oxidation state achieved. Molten flux syntheses developed in this work have provided the potential for preparing single-phase, homogeneous, and crystalline materials. The redox-active fluxes provide a medium for enhanced doping and mixed-valency control in which the electrochemical potential adjusts the formal oxidation state, and the doping takes place to maintain charge neutrality. The two superconductor systems investigated are: (1) the potassium-doped barium bismuth oxides, and (2) the alkali metal- and alkaline earth metal-doped lanthanum copper oxides. Controlled oxidative doping has been achieved in both systems by two different approaches. The superconducting properties of these materials have been assessed, and the materials have been characterized by powder X-ray diffraction and e-beam microprobe elemental analyses. In the course of these studies, several other materials have been identified. Analysis of these materials, and the conditions necessary to prepare them, have further aided in developing a model for use in controlling the electrochemical potential of the flux. The alkali metal hydroxide fluxes have large electrochemical windows, and a variety of chemical reducers have been explored in the copper system. Control of the electrochemical potential has been developed through compositional control of the flux whereby the entire range of copper oxidation states, including the metal, has been achieved at a single temperature, in a single flux system. Environmentally-friendly copper ore mimics have been prepared for thermodynamic analysis to aid in mineral transport modeling. The hydrothermally-prepared homogeneous copper- and cobalt-doped birnessites have been structurally, compositionally, and physically analyzed.

Schrier, Marc David

132

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.

133

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

134

Discovery and application of peptides that bind to proteins and solid state inorganic materials  

NASA Astrophysics Data System (ADS)

A series of three projects was undertaken on the theme of peptide-based molecular recognition. In the first project, a messenger RNA (mRNA) display selection was carried out against the II-VI semiconductors zinc sulfide (ZnS), zinc selenide (ZnSe), and cadmium sulfide (CdS). Sequence analysis of 18-mer semiconductor-binding peptides (SBPs) following four rounds of selection indicated that the amino acid sequences were enriched in polar residues compared to the naive library, suggesting that hydrogen-bonding interactions are a dominant mode of interaction between the SBPs and their cognate inorganic surfaces. Select peptides were expressed as fusions of the green fluorescent protein (GFP) to visualize their recognition of semiconductor crystals. Interpretation of the results was complicated by a high fluorescence background that was observed with certain control GFP fusions. Additional experiments, including cross-specificity binding assays, are needed to characterize the peptides that were isolated in this selection. A second project described the practical application of a known inorganic-binding and nucleating peptide. Peptide A3, which was previously isolated by phage display, was chemically conjugated to a short DNA strand using the heterobifunctional linker succinimidyl 4-[N-maleimidomethyl]cyclohexane-1-carboxylate (SMCC). The resulting peptide-DNA conjugate was hybridized to ten complementary single-stranded capture probes extending outward from the surface of an origami DNA nanotube. A gold precursor solution was added to initiate nucleation and growth of gold nanoparticles at the site of the peptide. Transmission electron microscopy (TEM) was used to visualize the gold nanoparticle-decorated nanostructures. This approach holds immense promise for organizing compositionally-diverse materials at the nanoscale. In a third project, a novel non-iterative approach to mRNA display called covalent capture was demonstrated. Using human transferrin as a target protein, peptides with low-nanomolar affinity were isolated from a combinatorial library of one trillion distinct 12-mer peptide sequences by using UV light to covalently crosslink the peptides to a photoreactive arm that was displayed on the protein surface. The best peptide isolated from this screen exhibited a binding affinity constant (Kd) of 3 nM, which is equivalent to some of the best peptides isolated after many rounds of traditional bead-based selection. The approach itself is general and could be applied to many different types of problems in molecular biology.

Stearns, Linda A.

135

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

136

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...

137

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

NASA Astrophysics Data System (ADS)

Organic-inorganic nanocomposite materials have been synthesized via sol-gel. They consist of an inorganic SiO2 matrix, in which different percentages of poly(?-caprolactone) (PCL) have been incorporated. The formation of H-bonds among the carbonyl groups of the polymer chains and Si-OH group of the inorganic matrix has been proved by means of Fourier transform infrared spectroscopy (FT-IR) analysis and has been confirmed by solid-state nuclear magnetic resonance (NMR). X-Ray diffraction (XRD) analysis highlighted the amorphous nature of the synthesized materials. Scanning electron microscope (SEM) micrograph and atomic force microscope (AFM) topography showed their homogeneous morphology and nanostructure nature. Considering the opportunity to synthesize these hybrid materials under microgravity conditions by means of magnetic levitation, superconducting quantum interference device (SQUID) magnetometry has been used to quantify their magnetic susceptibility. This measure has shown that the SiO2/PCL hybrid materials are diamagnetic and that their diamagnetic susceptibility is independent of temperature and increases with the PCL amount.

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

2013-07-01

138

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

139

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

140

Microwave-assisted Synthesis and Biomedical Applications of Inorganic Nanostructured Materials  

NASA Astrophysics Data System (ADS)

Inorganic nanostrucured materials have attracted much attention owing to their unique features and important applications in biomedicine. This thesis describes the development of rapid and efficient approaches to synthesize inorganic nanostructures, and introduces some potential applications. Magnetic nanostructures, such as necklace-like FeNi3 magnetic nanochains and magnetite nanoclusters, were synthesized by an efficient microwave-hydrothermal process. They were used as magnetic resonance imaging (MRI) contrast agents. Magnetic FeNi3 nanochains were synthesized by reducing iron(III) acetylacetonate and nickel(II) acetylacetonate with hydrazine in ethylene glycol solution without any template under microwave irradiation. This was a rapid and economical route based on an efficient microwave-hydrothermal process which significantly shortened the synthesis time to mins. The morphologies and size of the materials could be effectively controlled by adjusting the reaction conditions, such as, the reaction time, temperature and concentrations of reactants. The morphology and composition of the as-prepared products were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The size of the aligned nanospheres in the magnetic FeNi 3 chains could be adjusted from 150nm to 550nm by increasing the amounts of the precursors. Magnetic measurements revealed that the FeNi3 nanochains showed enhanced coercivity and saturation magnetization. Toxicity tests by exposure of FeNi3 nanochains to the zebrafish larvae showed that the as-prepared nanochains were biocompatible. In vitro magnetic resonance imaging (MRI) confirms the effectiveness of the FeNi 3 nanochains as sensitive MRI probes. Magnetite nanoclusters were synthesized by reducing iron(III) acetylacetonate with hydrazine in ethylene glycol under microwave irradiation. The nanoclusters showed enhanced T2 relaxivity. In vitro and in vivo MRI confirmed the effectiveness of the magnetite nanoclusters as sensitive MRI probes. We also investigated the biodistribution of the nanoclusters in rat liver and spleen. Bifunctional mesoporous core/shell Ag FeNi3 nanospheres were synthesized by reducing iron(III) chloride, nickel(II) chloride and silver nitrate with hydrazine in ethylene glycol under microwave irradiation. The efficient microwave-hydrothermal process significantly shortened the synthesis time to one minute. The toxicity of Ag FeNi3 nanospheres were tested by exposing to zebrafish, they were less toxic than silver nanoparticles. In vitro MRI confirmed the effectiveness of the Ag FeNi3 nanospheres as sensitive MRI probes. The interaction of Rhodamine Band nanospheres showed greatly enhanced fluorescence over the FeNi3 nanoparticles. A series of interesting core/shell silver/phenol formaldehyde resin (PFR) nano/microstructures were also synthesized through an efficient microwave process by self-assembly growth. Various morphologies, including monodispersed nanospheres, nanocables, and microcages were obtained by changing the fundamental experimental parameters, such as the reaction time and the surfactants (Pluronic P123 or CTAB). The results indicated that the presence of triblock copolymer Pluronic P123 would result in hollow silver/PFR microcages, while CTAB would prefer the formation of ultralong silver/PFR coaxial nanocables. In the absence of surfactants, monodispersed core/shell silver/PFR nanospheres could be obtained. The size of the nanospheres can be controlled in the range of 110 to 450 nm by changing the molar ratio of reagents (phenol:hexamine). The morphology and composition of the as-prepared products were characterized. The formation mechanism of the products was discussed based on the obtained results. Finally, a series of ZnO microarchitectures including monodispersed spindles, branches, flowers, paddies, and sphere-like clusters were prepared by an efficient microwave-hydrothermal process. The ZnO mophologies could be effectively controlled

Jia, Juncai

141

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

SciTech Connect

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

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

2011-09-15

142

Synthesis and characterization of nanocomposite organic/inorganic hybrid materials using living cationic polymerization  

NASA Astrophysics Data System (ADS)

A series of novel chlorosilyl functional initiators have been prepared and applied for the first time in the living cationic polymerization of isobutylene (IB). Well-defined polyisobutylenes (PIBs) carrying mono-, di-, and trichlorosilyl head-group, and a tert-chloro end-group were synthesized using newly designed silyl-functional initiators in conjunction with TiCl4 in Hex:MeCl (60:40, v:v) at -80°C. End-group analysis by 1H NMR spectroscopy verified the product structure and the survival of the Si-Cl head-groups during the polymerization. The chlorosilyl functional initiators and chlorosilyl functional PIBs have been employed for the synthesis of PIB brushes on planar silicate substrates by the "grafting from" and "grafting to" techniques. Structurally well-defined polymer/inorganic nanocomposites were prepared by surface-initiated living cationic polymerization of isobutylene (IB). The living cationic polymerization of IB was initiated from initiators self-assembled on the surface of silica nanoparticles in the presence of additional soluble "free initiator" with TiCl4 in hexanes/CH3Cl (60/40, v/v) at -80°C. The polymerization displayed the diagnostic criteria for living cationic polymerization and provided densely grafted polymers of controlled molecular weight with an approximate graft density of 3.3 chains/nm 2. The surface-initiated polymerization of IB without added "free initiator" also yielded grafted polymer chains with good molecular weight control and narrow molecular weight distribution (Mw/M n). A series of novel hybrid poly(styryl-POSS), poly(isobutylene- b-(styryl-POSS)), and poly(isobutylene-b-(styryl-POSS)- b-isobutylene) are synthesized and characterized. Living cationic polymerization of styryl-POSS macromer was carried out using the 1-chloro-1-(4-methyphenyl)ethane (p-MeStCl)/TiCl4/MeChx:CH3Cl (60:40, v:v)/-80°C system in the presence of DTBP. Using these conditions, we have synthesized AB diblock, and ABA linear triblock copolymers containing polyisobutylene (PIB)-based rubbery mid block (B) with amorphous glassy poly(styryl-POSS) end blocks (A) by living cationic polymerization using sequential monomer addition. Well-defined PIB-b-P(styryl-POSS) and PIB- b-P(styryl-POSS)-b-PIB have been successfully prepared. The styryl-POSS based hybrid polymers were characterized by thermogravimetry and GPC measurements. (Abstract shortened by UMI.)

Kim, Iljin

143

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

PubMed

High-performance catalysts and photovoltaics are required for building an environmentally sustainable society. Because catalytic and photovoltaic reactions occur at the interfaces between reactants and surfaces, the chemical, physical, and structural properties of interfaces have been the focus of much research. To improve the performance of these materials further, inorganic porous materials with hierarchic porous architectures have been fabricated. The breath figure technique allows preparing porous films by using water droplets as templates. In this study, a valuable preparation method for hierarchic porous inorganic materials is shown. Hierarchic porous materials are prepared from surface-coated inorganic nanoparticles with amphiphilic copolymers having catechol moieties followed by sintering. Micron-scale pores are prepared by using water droplets as templates, and nanoscale pores are formed between the nanoparticles. The fabrication method allows the preparation of hierarchic porous films from inorganic nanoparticles of various shapes and materials. PMID:25179786

Saito, Yuta; Shimomura, Masatsugu; Yabu, Hiroshi

2014-09-01

144

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

145

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

SciTech Connect

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

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

2002-02-26

146

Sensors for inorganic vapor detection based on carbon nanotubes and poly( o-anisidine) nanocomposite material  

NASA Astrophysics Data System (ADS)

A gas sensor, fabricated by selective growth of aligned carbon nanotubes (CNTs) by pulsed plasma on Si 3N 4/Si substrates patterned by metallic platinum, is presented for inorganic vapor detection at room temperature. Poly( o-anisidine) (POAS) deposition onto the CNTs device was shown to impart higher sensitivity to the sensor. Upon exposure to HCl the variation of the CNTs sensitivity is less than 4%, while the POAS-coated CNTs devices offer a higher sensitivity (i.e. 28%). The extended detection capability to inorganic vapors is attributed to direct charge transfer with electron hopping effects on intertube conductivity through physically adsorbed POAS between CNTs.

Valentini, L.; Bavastrello, V.; Stura, E.; Armentano, I.; Nicolini, C.; Kenny, J. M.

2004-01-01

147

Inorganic-organic hybrid materials and abrasion resistant coatings based on a sol-gel approach  

SciTech Connect

Attempts to synthesize hybrid materials from polytetramethylene oxide (PTMO) end-functionalized with triethoxy silyl groups and, tetraethylorthosilicate (TEOS) under basic conditions met with only partial success. The films obtained had low mechanical stability. In contrast, films with good mechanical stability were obtained when the TEOS was replaced with tritanium tetraisopropoxide (TIOPR). The microstructure of the TIOPR/PTMO hybrid synthesized under near neutral conditions was generally similar to the acid catalyzed PTMO/TIOPR hybrids. In another closely related study, the effect of subjecting acid catalyzed hybrid materials to aqueous and basic solutions was examined. Two chemically different systems were chosen which were namely the PTMO-TEOS system and the PTMO-TIOPR system. In addition to the difference in the reactivity between the TEOS and TIOPR, another point of differentiation was the relative solubility of the silicon oxide in basic aqueous solutions in contrast to the relative insolubility of the titanium oxide species in all but the very concentrated basic solutions. An application of the hybrid materials in the area of abrasion resistant coatings was also studied. The effects of the various organic structures on abrasion resistance, the extent of reaction and the mechanism of abrasion was examined. Various low molecular weight organics were functionalized triethoxy silyl groups and coated on polycarbonate and cured. They were then subjected to a Taber abrader test. The results showed that all the functionalized organics showed better abrasion resistance than the polycarbonate if sufficiently cured. NMR data showed that the reaction of the functionalized coatings was limited by vitrification and the extent of reaction was influenced by the basicity of the organic backbone. SEM observations of the abraded surfaces showed that the polycarbonate was abraded by a mechanism different from the functionalized coatings.

Betrabet, C.S.

1993-01-01

148

Interactions between cocoa flavanols and inorganic nitrate: Additive effects on endothelial function at achievable dietary amounts.  

PubMed

Dietary intervention studies have shown that flavanols and inorganic nitrate can improve vascular function, suggesting that these two bioactives may be responsible for beneficial health effects of diets rich in fruits and vegetables. We aimed to study interactions between cocoa flavanols (CF) and nitrate, focusing on absorption, bioavailability, excretion, and efficacy to increase endothelial function. In a double-blind randomized, dose-response crossover study, flow-mediated dilation (FMD) was measured in 15 healthy subjects before and at 1, 2, 3, and 4h after consumption of CF (1.4-10.9mg/kg bw) or nitrate (0.1-10mg/kg bw). To study flavanol-nitrate interactions, an additional intervention trial was performed with nitrate and CF taken in sequence at low and high amounts. FMD was measured before (0h) and at 1h after ingestion of nitrate (3 or 8.5mg/kg bw) or water. Then subjects received a CF drink (2.7 or 10.9mg/kg bw) or a micro- and macronutrient-matched CF-free drink. FMD was measured at 1, 2, and 4h thereafter. Blood and urine samples were collected and assessed for CF and nitric oxide (NO) metabolites with HPLC and gas-phase reductive chemiluminescence. Finally, intragastric formation of NO after CF and nitrate consumption was investigated. Both CF and nitrate induced similar intake-dependent increases in FMD. Maximal values were achieved at 1h postingestion and gradually decreased to reach baseline values at 4h. These effects were additive at low intake levels, whereas CF did not further increase FMD after high nitrate intake. Nitrate did not affect flavanol absorption, bioavailability, or excretion, but CF enhanced nitrate-related gastric NO formation and attenuated the increase in plasma nitrite after nitrate intake. Both flavanols and inorganic nitrate can improve endothelial function in healthy subjects at intake amounts that are achievable with a normal diet. Even low dietary intake of these bioactives may exert relevant effects on endothelial function when ingested together. PMID:25530151

Rodriguez-Mateos, Ana; Hezel, Michael; Aydin, Hilal; Kelm, Malte; Lundberg, Jon O; Weitzberg, Eddie; Spencer, Jeremy P E; Heiss, Christian

2015-03-01

149

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

150

Assessment of renal function of workers exposed to inorganic lead, cadmium or mercury vapor  

SciTech Connect

The renal function of workers occupationally exposed to cadmium (n = 148), to mercury vapor (n = 63) or to inorganic lead (n = 25) has been compared with that of workers with no occupational exposure to heavy metals (n = 88). A moderate exposure to lead (Pb-B < 62 ..mu..g/100 ml) does not seem to alter renal function. Excessive exposure to cadmium increases the urinary excretion of both low- and high-molecular-weight proteins and of tubular enzymes. These changes are mainly observed in workers excreting more than 10 ..mu..g Cd/g creatinine or with Cd-B above 1 ..mu..g Cd/100 ml whole blood. Occupational exposure to mercury vapor induces glomerular dysfunction as evidenced by an increased urinary excretion of high-molecular-weight proteins and a slightly increased prevalence of higher ..beta../sub 2/-microglobulin concentration in plasma without concomitant change in urinary ..beta../sub 2/-microglobulin concentration. ..beta..-galactosidase activity in blood and in urine is also increased. The likelihood of these findings is greater in workers with Hg-B and Hg-U exceeding 3 ..mu..g/100 ml whole blood and 50 ..mu..g/g creatinine, respectively. The hypothesis is put forward that the glomerular dysfunction induced by cadmium and mercury might result from an autoimmune mechanism.

Buchet, J.P.; Roels, H.; Bernard, A.; Lauwerys, R.

1980-11-01

151

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

PubMed

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

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

2015-04-01

152

Functionalization and post-functionalization: a step towards polyoxometalate-based materials.  

PubMed

Polyoxometalates (POMs) have remarkable properties and a great deal of potential to meet contemporary societal demands regarding health, environment, energy and information technologies. However, implementation of POMs in various functional architectures, devices or materials requires a processing step. Most developments have considered the exchange of POM counterions in an electrostatically driven approach: immobilization of POMs on electrodes and other surfaces including oxides, embedding in polymers, incorporation into Layer-by-Layer assemblies or Langmuir-Blodgett films and hierarchical self-assembly of surfactant-encapsulated POMs have thus been thoroughly investigated. Meanwhile, the field of organic-inorganic POM hybrids has expanded and offers the opportunity to explore the covalent approach for the organization or immobilization of POMs. In this critical review, we focus on the use of POM hybrids in selected fields of applications such as catalysis, energy conversion and molecular nanosciences and we endeavor to discuss the impact of the covalent approach compared to the electrostatic one. The synthesis of organic-inorganic POM hybrids starting from bare POMs, that is the direct functionalization of POMs, is well documented and reliable and efficient synthetic procedures are available. However, as the complexity of the targeted functional system increases a multi-step strategy relying on the post-functionalization of preformed hybrid POM platforms could prove more appealing. In the second part of this review, we thus survey the synthetic methodologies of post-functionalization of POMs and critically discuss the opportunities it offers compared to direct functionalization. PMID:22782306

Proust, Anna; Matt, Benjamin; Villanneau, Richard; Guillemot, Geoffroy; Gouzerh, Pierre; Izzet, Guillaume

2012-11-21

153

Organic-inorganic electronics  

Microsoft Academic Search

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

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

2001-01-01

154

Crack deflection in functionally graded materials  

Microsoft Academic Search

Small crack deflection in brittle functionally graded materials (FGMs) is studied. The FGMs are modeled as simply nonhomogeneous materials, i.e., the effect of microstructure is neglected and the material property variation is considered to be continuous. Considering local homogeneity and the small scale inelasticity of brittle materials, the toughness is taken to be independent of direction; therefore, the crack propagates

Pei Gu; R. J. Asaro

1997-01-01

155

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

Microsoft Academic Search

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

Kazutoshi Haraguchi

2011-01-01

156

Sensors for inorganic vapor detection based on carbon nanotubes and poly( o-anisidine) nanocomposite material  

Microsoft Academic Search

A gas sensor, fabricated by selective growth of aligned carbon nanotubes (CNTs) by pulsed plasma on Si3N4\\/Si substrates patterned by metallic platinum, is presented for inorganic vapor detection at room temperature. Poly(o-anisidine) (POAS) deposition onto the CNTs device was shown to impart higher sensitivity to the sensor. Upon exposure to HCl the variation of the CNTs sensitivity is less than

L. Valentini; V Bavastrello; E Stura; I Armentano; C Nicolini; J. M Kenny

2004-01-01

157

Azobenzene-functionalized cage silsesquioxanes as inorganic-organic hybrid, photoresponsive, nanoscale, building blocks.  

PubMed

Mono- and octa-azobenzene-functionalized cage silsesquioxanes were easily synthesized by the reaction of 4-bromoazobenzene with monovinyl-substituted octasilsesquioxane and cubic octavinylsilsesquioxane through the Heck coupling reaction. Excited-state energies obtained from time-dependent density functional theory (TDDFT) and the CAM-B3LYP functional correlate very well with experimental trans-cis photoisomerization results from UV/Vis spectroscopy. These azobenzene-functionalized cages exhibit good thermal stability and are fluorescent with maximum emission at approximately 400?nm, making them potential materials for blue-light emission. PMID:25663005

Liu, Yun; Yang, Wenyan; Liu, Hongzhi

2015-03-16

158

Polyester-inorganic nanocomposite materials via sol-gel reactions: Synthesis and characterization of fundamental properties  

NASA Astrophysics Data System (ADS)

A scheme was developed for producing poly(ethylene terephthalate (PET) ionomer)/silicate hybrid materials via polymer-in situ sol-gel reactions for tetraethylorthosilicate (TEOS) using different solvents. Scanning electron microscopy/EDAX studies revealed that silicate structures can be grown deep within PET ionomer films that were melt pressed from silicate-incorporated resin pellets. 29Si solid-state NMR spectroscopy revealed considerable, successful Si-O-Si bond formation, but also a significant fraction of uncondensed SiOH groups. 23Na solid-state NMR spectra suggested the presence of ionic aggregates within the unfilled PET ionomer and that these aggregates do not suffer major structural re-arrangements by silicate incorporation. For an ionomer treated with TEOS using MeCl2 solvent, Na + ions are less self-associated than in the unfilled control, suggesting silicate intrusion between PET-SO3- Na + ion pair associations. The ionomer treated with TEOS + tetrachloroethane had more poorly formed ionic aggregates, which illustrates the influence of solvent type on ionic aggregation. First-scan DSC thermograms for the ionomers demonstrate an increase in crystallinity after the incorporation of silicates, but solvent induced crystallization also appears to be operative. Second-scan DSC thermograms also suggest that the addition of silicate particles is not the only factor implicated in re-crystallization, and that solvent type is important even in second scan behavior. Silicate incorporation does not profoundly affect the second scan Tg vs. solvent type, i.e., chain mobility in the amorphous regions is not severely restricted by silicate incorporation. Re-crystallization and melting in these hybrids appears to be due to an interplay between a solvent induced crystallization that strongly depends on solvent type, and interactions between PET chains and in situ-grown, sol-gel-derived silicate particles. Isothermal studies confirmed that the crystallization rate and melting behavior of PET 5% Na+ ionomers depend on processing conditions. PET ionomer/ORMOSIL composites were formed via in situ sol-gel reactions using the ionic regions of PET as preferential reaction sites. TGA analysis revealed successful uptake for all three different solvents and TEOS:MTES composition ratios. TGA derivative curves suggest that for the THF and MeCl2 carrier solvent systems the MTES-generated network interacts more with the PET ionomer matrix. In the case of TCE, the TEOS-generated network interaction appears to be more operative. First scan DSC traces reveal that the in situ sol-gel processing of ORMOSIL phases induces PET ionomer crystallinity, although systems with higher silicate uptake have reduced induced crystallinity. Second scan DSC traces show that Tg is not effected by the incorporation of silicates into the PET ionomer. Also, for the ORMOSIL phases generated using THF and MeCl2 as the swelling solvent, only the pure silicate networks (synthesized using only TEOS) allow recrystallization and melting during the quick scan timeframe. It is thought that the presence of semi-organic MTES silicate networks do not allow fast nucleation onto the inorganic nuclei. (Abstract shortened by UMI.)

Lambert, Alexander Adam, III

159

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

SciTech Connect

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

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

2010-12-15

160

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

161

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

USGS Publications Warehouse

The concentration and distribution of inorganic Hg was measured using cold-vapor atomic fluorescence spectrometry in samples collected at selected sites on the Sacramento River from below Shasta Dam to Freeport, CA, at six separate times between 1996 and 1997. Dissolved (ultrafiltered, 0.005 ??m equivalent pore size) Hg concentrations remained relatively constant throughout the system, ranging from the detection limit (< 0.4 ng/L) to 2.4 ng/L. Total Hg (dissolved plus colloidal suspended sediment) concentrations ranged from the detection limit at the site below Shasta Dam in September 1996 to 81 ng/L at the Colusa site in January 1997, demonstrating that colloidal sediment plays an important role in the downriver Hg transport. Sequential extractions of colloid concentrates indicate that the greatest amount of Hg associated with sediment Was found in the "residual" (mineral) phase with a significant quantity also occurring in the "oxidizable" phase. Only a minor amount of Hg was observed in the "reducible" phase. Dissolved Hg loads remained constant or increased slightly in the downstream direction through the study area, whereas the total inorganic Hg load increased significantly downstream especially in the reach of the fiver between Bend Bridge and Colusa. Analysis of temporal variations showed that Hg loading was positively correlated to discharge.

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

2001-01-01

162

Continuous spray forming of functionally gradient materials  

SciTech Connect

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

McKechnie, T.N.; Richardson, E.H. [Plasma Processes Inc., Huntsville, AL (United States); Watson, R.D. [Sandia National Labs., Albuquerque, NM (United States)

1995-12-31

163

Oxide nanomaterials Selbach, Inorganic  

E-print Network

Oxide nanomaterials Selbach, Inorganic Materials and Ceramics Research GroupAvity within ceramic engineering, solid state chemistry, nanoparAcles, thin films · Intermediate band solar cells · BaTery materials and tesAng · SOFC and proton

164

Ceramic transactions: Functionally gradient materials. Volume 34  

SciTech Connect

A functionally gradient material (FGM) is a composite that smoothly transitions from one material at one surface to another material at the opposite surface. Metals and ceramics are usually the materials that are combined in a controlled manner to optimize a specific property. The First International Symposium on Functionally Gradient Materials was held in Sendai, Japan, in August 1990. Contained in the present volume are the Proceedings of the Second International Symposium on Functionally Gradient Materials, presented at the Third International Ceramic Science and Technology Congress, held in San Francisco, CA, November 1-4, 1992. The papers presented here are divided into eight sections: the concept of FGM; mathematical modeling; methods of fabrication; material evaluation; applications; joining processes in FGM; process characterization; and design considerations. Separate abstracts are provided for each of the 54 papers.

Holt, J.B.; Koizumi, Mitsue; Hirai, Toshio; Munir, Z.A. (eds.)

1993-01-01

165

MATERIALS AEROMETRIC DATABASE FOR USE IN DEVELOPING MATERIALS DAMAGE FUNCTION  

EPA Science Inventory

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

166

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

167

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

168

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

169

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

170

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

171

Nanoscale Synthesis and Functional Assembly Center for Nanophase Materials  

E-print Network

; Optical, structural and electrical characterization of carbon-based nanomaterials; Charge transport study, sensors. Optical and optoelectronic characterization of organic semiconductor materials (small molecules materials; #12;3. Inorganic/organic nanoscale electronics. Fabrication 1D and 2D nanoscale electronic

Pennycook, Steve

172

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

173

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

NASA Astrophysics Data System (ADS)

A novel type of organic polymer-inorganic hybrid material layered crystalline zinc poly(styrene-phenylvinylphosphonate)-phosphate (ZnPS-PVPP) was synthesized under mild conditions in the absence of any template. And the ZnPS-PVPP were characterized by FT-IR, diffusion reflection UV-vis, AAS, N 2 volumetric adsorption, SEM, TEM and TG. Notably, this method was entirely different from the traditional means used for preparing other zinc phosphonate. Moreover, it could be deduced that ZnPS-PVPP possessed the potential applications for catalyst supports. In the initial catalytic tests, the catalysts immobilized onto ZnPS-PVPP showed comparable or higher activity and enantioselectivity with that of catalysts reported by our group in the asymmetric epoxidation of unfunctional olefins.

Huang, Jing; Fu, Xiangkai; Wang, Gang; Miao, Qiang

2011-09-01

174

Synthesis of novel inorganic-organic hybrid materials for simultaneous adsorption of metal ions and organic molecules in aqueous solution.  

PubMed

In this paper, atom transfer radical polymerization (ATRP) and radical grafting polymerization were combined to synthesize a novel amphiphilic hybrid material, meanwhile, the amphiphilic hybrid material was employed in the absorption of heavy metal and organic pollutants. After the formation of attapulgite (ATP) ATRP initiator, ATRP block copolymers of styrene (St) and divinylbenzene (DVB) were grafted from it as ATP-P(S-b-DVB). Then radical polymerization of acrylonitrile (AN) was carried out with pendent double bonds in the DVD units successfully, finally we got the inorganic-organic hybrid materials ATP-P(S-b-DVB-g-AN). A novel amphiphilic hybrid material ATP-P(S-b-DVB-g-AO) (ASDO) was obtained after transforming acrylonitrile (AN) units into acrylamide oxime (AO) as hydrophilic segment. The adsorption capacity of ASDO for Pb(II) could achieve 131.6 mg/g, and the maximum removal capacity of ASDO towards phenol was found to be 18.18 mg/g in the case of monolayer adsorption at 30°C. The optimum pH was 5 for both lead and phenol adsorption. The adsorption kinetic suited pseudo-second-order equation and the equilibrium fitted the Freundlich model very well under optimal conditions. At the same time FT-IR, TEM and TGA were also used to study its structure and property. PMID:22047723

Jin, Xinliang; Li, Yanfeng; Yu, Cui; Ma, Yingxia; Yang, Liuqing; Hu, Huaiyuan

2011-12-30

175

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

PubMed

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

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

2014-11-15

176

ATR-FTIR characterization of organic functional groups and inorganic ions in ambient aerosols at a rural site  

NASA Astrophysics Data System (ADS)

An Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopic method was used to measure organic functional groups and inorganic ions at Tonto National Monument (TNM), an Interagency Monitoring of Protected Visual Environments (IMPROVE) sampling site in a rural area near Phoenix, Arizona. Functional groups and ions from common aerosol compound classes such as aliphatic and aromatic CH, methylene, methyl, aldehydes/ketones, carboxylic acids, ammonium sulfate and nitrate as well as functional groups from difficult to measure compound classes such as esters/lactones, acid anhydrides, carbohydrate hydroxyl and ethers, amino acids, and amines were quantified. On average, ˜33% of the PM 1.0 mass was composed of organic aerosol. The average (standard deviation) composition of the organic aerosol at TNM was 34% (6%) biogenic functional groups, 21% (5%) oxygenated functional groups, 28% (7%) aliphatic hydrocarbon functional groups (aliphatic CH, methylene and methyl) and 17% (1%) aromatic hydrocarbon functional groups. Compositional analysis, functional group correlations, and back trajectories were used to identify three types of events with source signatures: primary biogenic-influenced, urban-influenced, and regional background. The biogenic-influenced event had high concentrations of amino acids and carbohydrate hydroxyl and ether, as well as aliphatic CH and aromatic CH functional groups and qualitatively high levels of silicate. The urban-influenced events had back trajectories traveling directly from the Phoenix area and high concentrations of hydrocarbons, oxygenated functional groups, and inorganic ions. This aerosol characterization suggests that both primary emissions in Phoenix and secondary formation of aerosols from Phoenix emissions had a major impact on the aerosol composition and concentration at TNM. The regional background source had low concentrations of all functional groups, but had higher concentrations of biogenic functional groups than the urban source.

Coury, Charity; Dillner, Ann M.

177

Functionally graded materials for biomedical applications  

Microsoft Academic Search

Functional gradation is one characteristic feature of living tissue. Bio-inspired materials open new approaches for manufacturing implants for bone replacement. Different routes for new implant materials are presented using the principle of functional gradation. An artificial biomaterial for knee joint replacement has been developed by building a graded structure consisting of ultra-high molecular weight polyethylene (UHMWPE) fibre reinforced high-density polyethylene

W. Pompea; H. Worch; M. Epple; W. Friess; M. Gelinsky; P. Greil; U. Hempel; D. Scharnweber; K. Schulte

2003-01-01

178

Fracture mechanics of functionally graded materials  

Microsoft Academic Search

In this paper, after a brief discussion of the elementary concepts of fracture mechanics in nonhomogeneous materials, a number of typical problem areas relating to the fracture of functionally gradient materials (FGMs) are identified. The main topics considered are the investigation of the nature of stress singularity near the tip of a crack fully embedded in a nonhomogeneous medium, the

F. Erdogan

1995-01-01

179

Work function for inorganic compounds (survey). I. Metallic hydrogen and hydrides of metals  

SciTech Connect

The work function {var_phi} is a parameter that makes it possible to reach fairly definite conclusions (associated with a certain degree of probability) in the analysis of the electronic structures of solids and to predict their properties. Such information is needed in the design and development of various types of materials for electronics and microelectronics, the study and interpretation of catalytic processes and adsorption phenomena, research into the physics and chemistry of solids, chemical and engineering physics, physical chemistry, the behavior of materials in a vacuum, and other applications. An enormous amount of data has been published here and abroad in the last decade. This is a reflection of the intensive ongoing research into traditional (but purer and less defective) and new materials being developed for different high-technology applications (atomic and nuclear power engineering, superconducting devices, laser and plasma technology, etc.). In addition, new research capabilities in the study of solids (both experimental and theoretical) now make it possible to compare electronic-emission properties with chemical composition and parameters of the electronic structure of the interior and surface of materials.

Fomenko, V.S. [Institute of Materials and Science Problems, Kiev (Russian Federation)

1995-09-01

180

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...

181

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...

182

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...

183

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

Microsoft Academic Search

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

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

2010-01-01

184

Functionally graded materials: Design, processing and applications  

SciTech Connect

In a Functionally Graded Material (FGM), the composition and structure gradually change over volume, resulting in corresponding changes in the properties of the material. By applying the many possibilities inherent in the FGM concept, it is anticipated that materials will be improved and new functions for them created. A comprehensive description of design, modeling, processing, and evaluation of FGMs as well as their applications is covered in this book. The contents include: lessons from nature; graded microstructures; modeling and design; characterization of properties; processing and fabrication; applications; and summary and outlook.

Miyamoto, Y. [ed.] [Osaka Univ. (JP); Kaysser, W.A.; Rabin, B.H.; Kawasaki, A.; Ford, R.G. [eds.

1999-09-01

185

Continuous spray forming of functionally gradient materials  

SciTech Connect

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

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

1995-12-01

186

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

187

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

E-print Network

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) * nH2 O, where M = Zr...

Burns, Jonathan

2012-10-02

188

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

189

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

190

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

191

Functionalized SBA-15 materials for bilirubin adsorption  

NASA Astrophysics Data System (ADS)

To investigate the driving force for bilirubin adsorption on mesoporous materials, a comparative study was carried out between pure siliceous SBA-15 and three functionalized SBA-15 mesoporous materials: CH 3-SBA-15 (MS), NH 2-SBA-15 (AS), and CH 3/NH 2-SBA-15 (AMS) that were synthesized by one-pot method. The obtained materials exhibited large surface areas (553-810 m 2/g) and pore size (6.6-7.1 nm) demonstrated by XRD and N 2-ad/desorption analysis. The SEM images showed that the materials had similar fiberlike morphology. The functionalization extent was calculated according to 29Si MAS NMR spectra and it was close to the designed value (10%). The synthesized mesoporous materials were used as bilirubin adsorbents and showed higher bilirubin adsorption capacities than the commercial active carbon. The adsorption capacities of amine functionalized samples AMS and AS were larger than those of pure siliceous SBA-15 and MS, indicating that electrostatic interaction was the dominant driving force for bilirubin adsorption on mesoporous materials. Increasing the ionic strength of bilirubin solution by adding NaCl would decrease the bilirubin adsorption capacity of mesoporous material, which further demonstrated that the electrostatic interaction was the dominant driving force for bilirubin adsorption. In addition, the hydrophobic interaction provided by methyl groups could promote the bilirubin adsorption.

Tang, Tao; Zhao, Yanling; Xu, Yao; Wu, Dong; Xu, Jun; Deng, Feng

2011-05-01

192

Synthesis and application of melamine-based dendrimer/sba-15 hybrid materials  

E-print Network

these criteria by exploiting the physical robustness of porous inorganic materials and the chemical functionality of organic materials. While amorphous oxides are widely used industrially as inorganic supports, disordered pore structures make them difficult...

Lunn, Jonathan David

2007-09-17

193

Optical transmission radiation damage and recovery stimulation of DSB: Ce3+ inorganic scintillation material  

NASA Astrophysics Data System (ADS)

Recently, a new scintillation material DSB: Ce3+ was announced. It can be produced in a form of glass or nano-structured glass ceramics with application of standard glass production technology with successive thermal annealing. When doped with Ce3+, material can be applied as scintillator. Light yield of scintillation is near 100 phe/MeV. Un-doped material has a wide optical window from 4.5eV and can be applied to detect Cherenkov light. Temperature dependence of the light yield LY(T) is 0.05% which is 40 times less than in case of PWO. It can be used for detectors tolerant to a temperature variation between -20° to +20°C. Several samples with dimensions of 15x15x7 mm3 have been tested for damage effects on the optical transmission under irradiation with ?-quanta. It was found that the induced absorption in the scintillation range depends on the doping concentration and varies in range of 0.5-7 m?1. Spontaneous recovery of induced absorption has fast initial component. Up to 25% of the damaged transmission is recuperated in 6 hours. Afterwards it remains practically constant if the samples are kept in the dark. However, induced absorption is reduced by a factor of 2 by annealing at 50°C and completely removed in a short time when annealing at 100°C. A significant acceleration of the induced absorption recovery is observed by illumination with visible and IR light. This effect is observed for the first time in a Ce-doped scintillation material. It indicates, that radiation induced absorption in DSB: Ce scintillation material can be retained at the acceptable level by stimulation with light in a strong irradiation environment of collider experiments.

Borisevich, A.; Dormenev, V.; Korjik, M.; Kozlov, D.; Mechinsky, V.; Novotny, R. W.

2015-02-01

194

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

195

Fracture Analysis of Functionally Graded Materials  

SciTech Connect

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

Zhang, Ch. [Department of Civil Engineering, University of Siegen, D-57068 Siegen (Germany); Gao, X. W. [School of Aeronautics and Astronautics, Dalian University of Technology, Dalian, 116024 (China); Sladek, J.; Sladek, V. [Institute of Construction and Architecture, Slovak Academy of Sciences, 84503 Bratislava (Slovakia)

2010-05-21

196

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

197

A new class of approach for hybrid inorganic\\/organic materials containing semiconductor ZnO  

Microsoft Academic Search

A new route has been developed to prepare ZnO of various shapes using different thiophene acids and ZnO at suitable reaction. Nanosized hybrid materials have a diversity of well-defined morphologies, such as rod-like, star-like sample and particle. The structure and morphology changes of the as-prepared product were investigated by means of transmission electron microscopy (TEM), X-ray powder diffractometry (XRD), infrared

Tonggang Jiu; Huibiao Liu; Haiyang Gan; Yuliang Li; Shengqiang Xiao; Hongmei Li; Yang Liu; Fushen Lu; Lei Jiang; Daoben Zhu

2005-01-01

198

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

E-print Network

of Materials Science and Engineering, University of Virginia 4 Alcoa Professor of Physical Metallurgy as low as 450 °C. Introduction The age hardening of copper-titanium alloys containing 1 ­ 6 atomic percent Ti has been investigated for nearly three quarters of a century [1-3]. Copper-titanium alloys

Laughlin, David E.

199

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

200

Low-Damage Damascene Patterning Using Porous Inorganic Low-Dielectric-Constant Materials  

NASA Astrophysics Data System (ADS)

The degradation of porous low-dielectric-constant (low-k) materials, such as porous methyl silsesquioxane (MSQ) and porous chemical-vapor-deposited SiOCH films, by damascene etch and ash processes has been investigated. The influence of etch damage becomes relatively stronger as ash damage improves. The etch damage to porous low-k dielectric is found particularly at the sidewall of the isolated lines. By investigating the influence of etch conditions on the damage, it is found that O2 and Ar addition causes large sidewall damage. O2-added etch condition, as well as the O2 ash process, produces oxygen radicals, which extract CH3 groups from porous low-k films. On the other hand, Ar plasma does not efficiently extract CH3 groups differently from O2 plasma, but it changes the bonding states of CH3 groups and causes H2O adsorption. This change in film characteristics increases dielectric constant. Finally, we successfully achieved low-damage dual damascene patterning using a porous SiOCH material whose dielectric constant is 2.2.

Yonekura, Kazumasa; Goto, Kinya; Matsuura, Masazumi; Fujiwara, Nobuo; Tsujimoto, Kazunori

2005-05-01

201

Bending behavior of Functionally Gradient Materials  

Microsoft Academic Search

In the last years the suitability of Functionally Gradient Materials (FGM) for monolithic bending actuators was shown. However, there is a lack of detailed models for the bending behavior of FGM. Recently we have developed a analytical model for the calculation of the bending behavior of FGM with an arbitrary gradient of piezoelectric properties. From the modeling it seems to

Tilo Hauke; Azamat Kouvatov; Ralf Steinhausen; Wolfgang Seifert; Horst Beige; Hans Theo; Langhammer; Hans-Peter Abicht

2000-01-01

202

Modelling studies applied to functionally graded materials  

Microsoft Academic Search

This review contains a description of modelling studies relative to functionally graded materials (FGMs). Two principal topics are covered: models for microstructure-dependent thermophysical properties, and models for the design, processing, and performance of FGMs. The former is a particularly important input to FGM modelling because of the wide variety of microstructures that can exist across the graded direction of a

A. J. Markworth; K. S. Ramesh; W. P. Parks

1995-01-01

203

Processing techniques for functionally graded materials  

Microsoft Academic Search

An overview of the achievements of the German priority program “Functionally Graded Materials (FGM)” in the field of processing techniques is given. Established powder processes and techniques involving metal melts are described, and recent developments in the field of graded polymer processing are considered. The importance of modeling of gradient formation, sintering and drying for the production of defect-free parts

B. Kieback; A. Neubrand; H. Riedel

2003-01-01

204

Tungsten hydride complex as a template in organic inorganic hybrid materials  

NASA Astrophysics Data System (ADS)

A tungsten hydride complex, [WH 2( ?2-OOCCH 3)(Ph 2PCH 2CH 2PPh 2) 2][BPh 4], was dispersed in a hybrid matrix synthesized by a sol-gel process. The host matrix of the so-called ureasil is a network of silica to which oligopolyoxyethylene chains [POE, (OCH 2CH 2) n] are grafted by means of urea cross-links. The free complex and sol-gel materials were characterized by thermal analysis (DSC) and spectroscopic methods (FT-IR and UV/Vis). The data gathered indicate that the tungsten(IV) complex is immobilized in the host matrix, and it exhibits structural properties different from those of the free form. These differences could arise either from distortions caused by steric effects imposed by the structure of hybrid matrix or by interactions with the matrix.

Montinho, Isilda; Boev, Victor; Fonseca, António M.; Silva, Carlos J. R.; Neves, Isabel C.

2003-03-01

205

Layered tungsten oxide-based organic/inorganic hybrid materials I: Infrared and Raman study  

E-print Network

Tungsten oxide-organic layered hybrid materials have been studied by infrared and Raman spectroscopy, and demonstrate a difference in bonding nature as the length of the interlayer organic `spacer' molecule is increased. Ethylenediamine-tungsten oxide clearly displays a lack of terminal -NH3+ ammonium groups which appear in hybrids with longer alkane molecules, thus indicating that the longer chains are bound by electrostatic interactions as well as or in place of the hydrogen bonding that must be present in the shorter chain ethylenediamine hybrids. The presence of organic molecules between the tungsten oxide layers, compared with the layered tungstic acid H2WO4, shows a decrease in the apical W=O bond strength, as might be expected from the aforementioned electrostatic interaction.

B. Ingham; S. V. Chong; J. L. Tallon

2004-05-12

206

Energy absorption behaviors of nanoporous materials functionalized (NMF) liquids  

E-print Network

armors, etc. Recently, the high energy absorption efficiency of nanoporous materials functionalized (NMF) liquidsarmors, car bumpers, etc. Recently, the high absorption efficiency of nanoporous materials functionalized (NMF) liquids

Kim, Tae Wan

2011-01-01

207

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

208

Long-term self-assembly of inorganic layered materials influenced by the local states of the interlayer cations.  

PubMed

A wide variety of parameters as, e.g., temperature, humidity, particle size, and cation state are known to influence the agglomeration process of two-dimensional (2D) nanosheets, called self-assembly, in inorganic layered materials. The detailed studies on which parameters are decisive and how they influence the self-assembly, however, have not been performed yet. Here, the long-term self-assembly was studied for layered stevensite and hectorite, and compared with our previous data of saponite for elucidating an influence of local states of the interlayer cations. The results were analyzed with respect to a recently established rheological model, in which 2D nanosheets migrate parallel to the layer direction aided by water molecules as lubricants [K. Sato et al., J. Phys. Chem. C, 2012, 116, 22954]. With decreasing the strength of the local electric fields facing to the interlayer spaces, cation positions split into two or three, which makes the distribution of water molecules more uniformly. These water molecules enhance the rheological motion of the 2D nanosheets parallel to the layer direction, thus accelerating the self-assembly process. PMID:24770790

Sato, Kiminori; Numata, Kazuomi; Dai, Weili; Hunger, Michael

2014-06-14

209

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

210

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

211

Modeling Bamboo as a Functionally Graded Material  

NASA Astrophysics Data System (ADS)

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, Emílio Carlos Nelli; Walters, Matthew C.; Paulino, Glaucio H.

2008-02-01

212

Responses of organic and inorganic materials to intense EUV radiation from laser-produced plasmas  

NASA Astrophysics Data System (ADS)

We have investigated responses of polymers to EUV radiation from laser-produced plasmas beyond ablation thresholds and micromachining. We concentrated on fabricate precise 3D micro-structures of PDMS, PMMA, acrylic block copolymers (BCP), and silica. The micromachining technique can be applied to three-dimensional micro-fluidic and bio-medical devices. The EUV processing is a promising to realize a practical micromachining technique. In the present work, we used two EUV radiation sources; (a) Wide band EUV light in a range of 10{300 eV was generated by irradiation of Ta targets with Nd:YAG laser light at 500 mJ/pulse. (b) Narrow band EUV light at 11 and 13 nm was generated by irradiation of solid Xe and Sn targets, respectively, with pulsed TEA CO2 laser light. The generated EUV light was condensed onto the materials at high power density beyond the ablation thresholds, using ellipsoidal mirrors. We found that through-holes with a diameter of one micrometer an be fabricated in PMMA and PDMS sheets with thicknesses of 4-10 micrometers, at 250 and 230 nm/shot, respectively. The effective ablation of PMMA sheets can be applied to a LIGA-like process for fabricating micro-structures of metals for micro- and nano-molds. PDMS sheets are ablated if it is irradiated with EUV light beyond a distinct threshold power density, while PDMS surfaces were modified at lower power densities. Furthermore, BCP sheets were ablated to have 1-micrometer structures. Thus, we have developed a practical technique for micromachining of PMMA, PDMS and BCP sheets in a micrometer scale.

Makimura, Tetsuya; Torii, Shuichi; Nakamura, Daisuke; Takahashi, Akihiko; Okada, Tatsuo; Niino, Hiroyuki; Murakami, Kouichi

2013-05-01

213

Constructing functional mesostructured materials from colloidal nanocrystal building blocks.  

PubMed

Through synthesizing colloidal nanocrystals (NCs) in the organic phase, chemists gain fine control over their composition, size, and shape. Strategies for arranging them into ordered superlattices have followed closely behind synthetic advances. Nonetheless, the same hydrophobic ligands that help their assembly also severely limit interactions between adjacent nanocrystals. As a result, examples of nanocrystal-based materials whose functionality derives from their mesoscale structure have lagged well behind advances in synthesis and assembly. In this Account, we describe how recent insights into NC surface chemistry have fueled dramatic progress in functional mesostructures. In these constructs, intimate contact between NCs as well as with heterogeneous components is key in determining macroscopic behavior. The simplest mesoscale assemblies we consider are networks of NCs constructed by in situ replacement of their bulky, insulating surface ligands with small molecules. Transistors are a test bed for understanding conductivity, setting the stage for new functionality. For instance, we demonstrated that by electrochemically charging and discharging networks of plasmonic metal oxide NCs, the transmittance of near infrared light can be strongly and reversibly modulated. When we assemble NCs with heterogeneous components, there is an even greater potential for generating complex functionality. Nanocomposites can exhibit favorable characteristics of their component materials, yet the interaction between components can also have a strong influence. Realizing such opportunities requires an intimate linking of embedded NCs to the surrounding matrix phase. We accomplish this link by coordinating inorganic anionic clusters directly to NC surfaces. By exploiting this connection, we found enhanced ionic conductivity in Ag2S-in-GeS2 nanocrystal-in-glass electrodes. In another example, we also found enhanced optical contrast when linking electrochromic niobium oxide to embedded tin-doped indium oxide (ITO) NCs. These dramatic effects emerge from reconstruction of the inorganic glass immediately adjacent to the NC interface. When co-assembling NCs with block copolymers, direct coordination of the polymer to NC surfaces again opens new opportunities for functional mesoscale constructs. We strip NCs of their native ligands and design block copolymers containing a NC tethering domain that bonds strongly, yet dynamically, to the resulting open coordination sites. This strategy enables their co-assembly at high volume fractions of NCs and leads to well-ordered mesoporous NC networks. We find these architectures to be exceptionally stable under chemical transformations driven by cation insertion, removal, and exchange. These developments offer a modular toolbox for arranging NCs deliberately with respect to heterogeneous elements and open space. We have control over metrics that define such architectures from the atomic scale (bonding and crystal structure) through the mesoscale (crystallite shapes and sizes and pore dimensions). By tuning these parameters and better understanding the interactions between components, we look forward to boundless opportunities to employ mesoscale structure, in tandem with composition, to develop functional materials. PMID:24004254

Milliron, Delia J; Buonsanti, Raffaella; Llordes, Anna; Helms, Brett A

2014-01-21

214

Coordination assemblies of polyoxomolybdate cluster framework: from labile building blocks to stable functional materials.  

PubMed

Polyoxomolybdates, an important branch in polyoxometalates chemistry, present complicated solution chemistry and unmatched physicochemical properties, which endows us with both great opportunities and considerable challenges in creating new functional materials. This perspective highlights the recent development on the coordination assembly of transition-metal-substituted heteropolymolybdates by using labile lacunary heteropolymolybdates as inorganic multidentate ligands. A series of strategies have been used to stabilize the lacunary heteropolymolybdate building blocks. Finally, we introduce some researches on the modification of polymolybdates by organic groups in aqueous media, which may shed light on the green chemistry of the functionalization of polyoxomolybdates. PMID:21321727

Li, Fengyan; Xu, Lin

2011-04-28

215

Novel electromagnetic materials from functionalized structures  

NASA Astrophysics Data System (ADS)

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

Xiao, Xiao

216

Organic-inorganic nanocomposite materials prepared by the sol-gel route as new ionic conductors in quasi solid state electrolytes  

Microsoft Academic Search

Nanocomposite organic\\/inorganic materials made through sol-gel method exhibit high values of ionic conductivity when they\\u000a were impregnated with the redox couple I\\u000a 3\\u000a ?\\u000a \\/I? Two different kinds of nanocomposite materials, depending on the different interactions between silica and poly(ethylene)oxide\\u000a or poly(propylene)oxide blends, were prepared by the sol-gel technique in room temperature. Gels, for both nanocomposite materials,\\u000a were obtained by

Elias Stathatos

2005-01-01

217

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

218

Low work function thermionic emission materials  

SciTech Connect

Thermionic energy conversion in a microminiature format shows potential as a viable, high efficiency, on-chip power source. Microminiature thermionic converters (MTC) with inter-electrode spacings on the order of microns are currently being prototyped and evaluated at Sandia. The remaining enabling technology is the development of low work function materials and processes than can be integrated into these converters. In this report, the authors demonstrate a method of incorporating thin film emitters into converters using rf sputtering. They find that the resultant films possess a minimum work function of 1.2 eV. Practical energy conversion is hindered by surface work function non-uniformity. They postulate the source of this heterogeneity to be a result of limited bulk and surface transport of barium. Several methods are proposed for maximizing transport, including increased film porosity and the use of metal terminating layers. They demonstrate a novel method for incorporating film porosity based on metal interlayer coalescence.

Zavadil, K.R.; King, D.B.; Ruffner, J.A.

1999-11-01

219

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

220

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

221

Modular materials synthesis: from structure to function  

NASA Astrophysics Data System (ADS)

The so-called electrostatic layer-by-layer self-assembly method permits to immobilize various functional modules into layered thin film architectures. Adsorption rests primarily on electrostatic interactions of oppositely charged species. Here, we show that immobilization of functional components, such as polyoxometalates (POM), enzymes, or dyes into such multilayers results in layers with interesting properties and devices, including electrochromic windows or sensors. Using this approach it is possible to interface cytochrome c to a surface. The resulting multilayers are electroactive and are interesting model systems to study redox processes and bioelectronic devices. Through the design of the multilayer it is possible to construct materials with polarity gradients capable of vectorial electron transport needed for artificial photosynthesis.

Kurth, Dirk G.; Mohwald, Helmuth

2005-01-01

222

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

223

Experimental Fracture Measurements of Functionally Graded Materials  

NASA Astrophysics Data System (ADS)

The primary objective of this research was to extend established fracture toughness testing methods to a new class of engineering materials known as functionally graded materials (FGMs). Secondary goals were to compare experimental results to those predicted by finite element models and to provide fracture test results as feedback toward optimizing processing parameters for the in-house synthesis of a MoSi2/SiC FGM. Preliminary experiments were performed on commercially pure (CP) Ti and uniform axial tensile tests resulted in mechanical property data including yield strength, 268 MPa, ultimate tensile strength, 470 MPa and Young's modulus, 110 GPa. Results from 3-point bending fracture experiments on CP Ti demonstrated rising R-curve behavior and experimentally determined JQ fracture toughness values ranged between 153 N/mm and 254 N/mm. Similar experimental protocols were used for fracture experiments on a 7- layered Ti/TiB FGM material obtained from Cercom in Vista, California. A novel technique for pre-cracking in reverse 4-point bending was developed for this ductile/brittle FGM material. Fracture test results exhibited rising R-curve behavior and estimated JQ fracture toughness values ranged from 0.49 N/mm to 2.63 N/mm. A 5- layered MoSi2/SiC FGM was synthesized using spark plasma sintering (SPS). Samples of this material were fracture tested and the results again exhibited a rising R-curve with KIC fracture toughness values ranging from 2.7 MPa-m1/2 to 6.0 MPa-m1/2. Finite Element Models predicted rising R-curve behavior for both of the FGM materials tested. Model results were in close agreement for the brittle MoSi2/SiC FGM. For the relatively more ductile Ti/TiB material, results were in close agreement at short crack lengths but diverged at longer crack lengths because the models accounted for fracture toughening mechanisms at the crack tip but not those acting in the crack wake.

Carpenter, Ray Douglas

224

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

225

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

226

46 CFR 153.1045 - Inorganic acids.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Inorganic acids. 153.1045 Section 153.1045...CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations...Procedures § 153.1045 Inorganic acids. When Table 1 refers to...

2010-10-01

227

PROCESSING OF ORGANIC/INORGANIC COMPOSITES BY STEREOLITHOGRAPHY  

E-print Network

of submicron size alumina (A120 3) powdera as the inorganic phase (15% by volume) and a multi-functional composites that are biocompatible from an immunological point of view, as well as mechanically functional, and alumina is used by virtue of its extensive history as a biocom- patible material [3]. The photoinitiator

Aksay, Ilhan A.

228

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

Microsoft Academic Search

Precise positioning of metallic nanostructures on semiconductor surfaces is important for applications such as photovoltaics, metal interconnects, sensing platforms, and many others. The rising cost and complexity with lithographically defined structures demands a parallel fabrication process that enables easy scale up. Surface patterns formed by block copolymers are considered as a promising means to create functional nanoscopic structures needed for

Divya Goel

2009-01-01

229

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

230

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

231

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

232

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

233

Assessment of renal function of workers simultaneously exposed to inorganic lead and cadmium  

SciTech Connect

The renal function of a group of workers (n = 62) exposed simultaneously to lead and to cadmium was examined. The results were compared with those obtained in an earlier study of three groups of workers - one exposed to lead only, one exposed to cadmium only, and one not exposed to either of these metals (control group). No interaction between lead and cadmium is evidenced. The signs of renal dysfunction found in the group exposed simultaneously to lead and to cadmium can be ascribed to cadmium only. The results of this study have confirmed the authors' previous observations, that is, a moderate exposure to lead (plumbemia < 62 ..mu..g/100 ml and average duration of exposure = 13.2 years) does not seem to influence renal function; in adult male workers the critical levels of cadmium in blood and in urine are 1 ..mu..g/100 ml whole blood and 10 ..mu..g/g creatinine respectivly; the renal dysfunction induced by cadmium is both glomerular and tubular.

Buchet, J.P.; Roels, H.; Bernard, A. Jr.; Lauwerys, R.

1981-05-01

234

Love wave propagation in functionally graded piezoelectric material layer  

Microsoft Academic Search

An exact approach is used to investigate Love waves in functionally graded piezoelectric material (FGPM) layer bonded to a semi-infinite homogeneous solid. The piezoelectric material is polarized in z-axis direction and the material properties change gradually with the thickness of the layer. We here assume that all material properties of the piezoelectric layer have the same exponential function distribution along

Jianke Du; Xiaoying Jin; Ji Wang; Kai Xian

2007-01-01

235

Inorganic photovoltaic cells  

Microsoft Academic Search

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

Robert W. Miles; Guillaume Zoppi; Ian Forbes

2007-01-01

236

Functional ceramic materials database: an online resource for materials research.  

PubMed

We present work on the creation of a ceramic materials database which contains data gleaned from literature data sets as well as new data obtained from combinatorial experiments on the London University Search Instrument. At the time of this writing, the database contains data related to two main groups of materials, mainly in the perovskite family. Permittivity measurements of electroceramic materials are the first area of interest, while ion diffusion measurements of oxygen ion conductors are the second. The nature of the database design does not restrict the type of measurements which can be stored; as the available data increase, the database may become a generic, publicly available ceramic materials resource. PMID:18232678

Scott, D J; Manos, S; Coveney, P V; Rossiny, J C H; Fearn, S; Kilner, J A; Pullar, R C; Alford, N Mc N; Axelsson, A-K; Zhang, Y; Chen, L; Yang, S; Evans, J R G; Sebastian, M T

2008-02-01

237

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

238

Hybrid inorganic-organic materials: Novel poly(propylene oxide)-based ceramers, abrasion-resistant sol-gel coatings for metals, and epoxy-clay nanocomposites, with an additional chapter on: Metallocene-catalyzed linear polyethylene  

NASA Astrophysics Data System (ADS)

The sol-gel process has been employed to generate hybrid inorganic-organic network materials. Unique ceramers were prepared based on an alkoxysilane functionalized soft organic oligomer, poly(propylene oxide (PPO), and tetramethoxysilane (TMOS). Despite the formation of covalent bonds between the inorganic and organic constituents, the resulting network materials were phase separated, composed of a silicate rich phase embedded in a matrix of the organic oligomer chains. The behavior of such materials was similar to elastomers containing a reinforcing filler. The study focused on the influence of initial oligomer molecular weight, functionality, and tetramethoxysilane, water, and acid catalyst content on the final structure, mechanical and thermal properties. The sol-gel approach has also been exploited to generate thin, transparent, abrasion resistant coatings for metal substrates. These systems were based on alkoxysilane functionalized diethylenetriamine (DETA) with TMOS, which generated hybrid networks with very high crosslink densities. These materials were applied with great success as abrasion resistant coatings to aluminum, copper, brass, and stainless steel. In another study, intercalated polymer-clay nanocomposites were prepared based on various epoxy networks montmorillonite clay. This work explored the influence of incorporated clay on the adhesive properties of the epoxies. The lap shear strength decreased with increasing day content This was due to a reduction in the toughness of the epoxy. Also, the delaminated (or exfoliated) nanocomposite structure could not be generated. Instead, all nanocomposite systems possessed an intercalated structure. The final project involved the characterization of a series of metallocene catalyzed linear polyethylenes, produced at Phillips Petroleum. Polyolefins synthesized with such new catalyst systems are becoming widely available. The influence of molecular weight and thermal treatment on the mechanical, rheological, and thermal behavior was probed. Although the behavior of this series of metallocene polyethylenes was not unlike that of traditionally catalyzed materials, this work is one of the first comprehensive studies of these new linear polyethylenes. The main distinction between the metallocene, and traditional Ziegler-Natta catalyzed polyethylenes is the narrow molecular weight distributions produced by the former (for this series of materials, 2.3 materials, 2.3 < M¯w/M¯n < 3.6).

Jordens, Kurt

1999-12-01

239

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

NASA Astrophysics Data System (ADS)

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

Gupta, Mohit

240

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

NASA Astrophysics Data System (ADS)

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

Coury, Charity; Dillner, Ann M.

241

Electrophoretic forming of functionally-graded materials  

SciTech Connect

Electrophoretic deposition (EPD) is a colloidal forming process where electrically charged particles are deposited onto an oppositely-charged electrode from an electrostatically stabilized suspension by the application of a dc electric field. It is a cheap and facile technique to fabricate complicated ceramic shapes. EPD is very effective method to synthesize ceramic/ceramic and metal/ceramic composites, eg.; dispersed, laminar, fibre reinforced, and functionally graded materials (FGM) etc. By EPD it is possible to synthesize step FGMs and continuous profile FGMs. The compositional profile of the FGM can be controlled by deposition current density, second component flow rate, suspension concentration etc. Step and continuous profile Al{sub 2}O{sub 3}/YSZ and continuous profile Al{sub 2}O{sub 3}/MoSi{sub 2}, Al{sub 2}O{sub 3}/Ni and YSZ/Ni fabrication is reported herein. The microstructures of the FGMs produced were characterized by optical/electron microscopy and micro-indentation was used to quantify the Vicker`s hardness and fracture toughness variation across The FGM sections.

Sarkar, P.; Datta, S.; Nicholson, P.S. [McMaster Univ., Hamilton, Ontario (Canada)

1997-12-31

242

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

243

M13 bacteriophage displaying DOPA on surfaces: fabrication of various nanostructured inorganic materials without time-consuming screening processes.  

PubMed

M13 bacteriophage (phage) was engineered for the use as a versatile template for preparing various nanostructured materials via genetic engineering coupled to enzymatic chemical conversions. First, we engineered the M13 phage to display TyrGluGluGlu (YEEE) on the pVIII coat protein and then enzymatically converted the Tyr residue to 3,4-dihydroxyl-l-phenylalanine (DOPA). The DOPA-displayed M13 phage could perform two functions: assembly and nucleation. The engineered phage assembles various noble metals, metal oxides, and semiconducting nanoparticles into one-dimensional arrays. Furthermore, the DOPA-displayed phage triggered the nucleation and growth of gold, silver, platinum, bimetallic cobalt-platinum, and bimetallic iron-platinum nanowires. This versatile phage template enables rapid preparation of phage-based prototype devices by eliminating the screening process, thus reducing effort and time. PMID:25317741

Park, Joseph P; Do, Minjae; Jin, Hyo-Eon; Lee, Seung-Wuk; Lee, Haeshin

2014-11-12

244

Hybrid organic-inorganic rotaxanes and molecular shuttles.  

PubMed

The tetravalency of carbon and its ability to form covalent bonds with itself and other elements enables large organic molecules with complex structures, functions and dynamics to be constructed. The varied electronic configurations and bonding patterns of inorganic elements, on the other hand, can impart diverse electronic, magnetic, catalytic and other useful properties to molecular-level structures. Some hybrid organic-inorganic materials that combine features of both chemistries have been developed, most notably metal-organic frameworks, dense and extended organic-inorganic frameworks and coordination polymers. Metal ions have also been incorporated into molecules that contain interlocked subunits, such as rotaxanes and catenanes, and structures in which many inorganic clusters encircle polymer chains have been described. Here we report the synthesis of a series of discrete rotaxane molecules in which inorganic and organic structural units are linked together mechanically at the molecular level. Structural units (dialkyammonium groups) in dumb-bell-shaped organic molecules template the assembly of essentially inorganic 'rings' about 'axles' to form rotaxanes consisting of various numbers of rings and axles. One of the rotaxanes behaves as a 'molecular shuttle': the ring moves between two binding sites on the axle in a large-amplitude motion typical of some synthetic molecular machine systems. The architecture of the rotaxanes ensures that the electronic, magnetic and paramagnetic characteristics of the inorganic rings-properties that could make them suitable as qubits for quantum computers-can influence, and potentially be influenced by, the organic portion of the molecule. PMID:19295605

Lee, Chin-Fa; Leigh, David A; Pritchard, Robin G; Schultz, David; Teat, Simon J; Timco, Grigore A; Winpenny, Richard E P

2009-03-19

245

Biomineralized structural materials with functional optical properties  

E-print Network

Many biological structural materials exhibit "mechanical property amplification" through their intricate hierarchical composite designs. In the past several decades, significant progress has been achieved in elucidating ...

Li, Ling, Ph. D. Massachusetts Institute of Technology

2014-01-01

246

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

247

Data-mined similarity function between material compositions  

NASA Astrophysics Data System (ADS)

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

Yang, Lusann; Ceder, Gerbrand

2013-12-01

248

Function Materialization in Object Bases: Design, Realization, and Evaluation  

Microsoft Academic Search

View materialization is a well-known optimization technique of relational database systems. We present a similar, yet more powerful, optimization concept for object-oriented data models: function materialization. Exploiting the object-oriented paradigm-namely, classification, object identity, and encapsulation-facilitates a rather easy incorporation of function materialization into (existing) object-oriented systems. Only those types (classes) whose instances are involved in some materialization are appropriately modified

Alfons Kemper; Christoph Kilger; Guido Moerkotte

1994-01-01

249

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

250

Functionally graded materials for sensor and energy applications  

Microsoft Academic Search

Principles, preparation, characterisation, and application of functional materials containing a gradient of their functional properties are surveyed, with main emphasis on thermoelectric (TE) materials for application in sensors and thermogenerators. Further examples of the implementation of functionally graded materials (FGM) presented are dielectric thin-film stacks for capacitors with low temperature coefficient, microwave-processed structural gradients in fuel cell electrodes, and zone-melted

E Müller; ? Drašar; J Schilz; W. A Kaysser

2003-01-01

251

Synthesis and structural characterization of a new chiral porous hybrid organic–inorganic material based on ?-zirconium phosphates and L-(+)-phosphoserine  

SciTech Connect

In the present work, a chiral layered derivative of ?-zirconium phosphate (?-ZrP) containing L-(+)-phosphoserine (?-ZrP-PS*) covalently attached to inorganic layers has been prepared by means of topotactic exchange reaction. This organic–inorganic derivative is characterized by X-ray diffractometry, Solid {sup 13}C–NMR and FT-IR spectrophotometries and thermal analyses. A maximum level of topotactic replacement of 20% is achieved. Under both the acidic environment of the interlayer region of ?-ZrP and the acidic synthesis conditions, the hydrolysis of the ester bond of PS* is expected to take place to some extent. For this reason, it was impossible to exceed the recent percentage, which in turn reflects the relative moderate stability of the above mentioned bond under these conditions. In order to be more certain with regard to an expected further hydrolysis for this bond after separation, a sample of ?-ZrP-PS* was stored in a desiccator over a saturated solution of BaCl{sub 2} (90% relative humidity) for three months, and then the sample re-analyzed once again. Surprisingly, the results show that the sample still keeps almost the same level of exchange (i.e., 20%). Second, it is revealed that the sample almost gives the same spectroscopic and thermal behavior. This could be attributed to the less acidic character of the partially exchanged inorganic layers of the sample in comparison with that of the precursor ?-ZrP. Therefore, the PS* molecules persist and stay there into the interlayer gallery without further hydrolysis. - Graphical abstract: • Red: oxygen • White: zirconium • Cyan: carbon • Yellow: phosphorus • Blue: nitrogen. Highlights: ? L-(+)-Phosphoserine (PS*) is exchanged with ?-ZrP by means of topotactic exchange. ? The maximum exchange level is 20%. ? ?-ZrP is functionalized with chiral amino acid group. ? ?-ZrP-PS* has large chiral space for huge guest molecules to be intercalated.

Alhendawi, Hussein M.H., E-mail: hussein.alhendawi@yahoo.com [Department of Chemistry, Faculty of Science, Al-Azhar University of Gaza, 1277 Gaza, Palestine (Country Unknown)

2013-05-15

252

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

253

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

E-print Network

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

Kwan, Phoebe Hoi-Ying, 1978-

2005-01-01

254

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. PMID:25476948

Yin, Xijie; Chen, Zhigang

2014-12-01

255

PREFACE: IUMRS-ICA 2008 Symposium 'AA. Rare-Earth Related Material Processing and Functions'  

NASA Astrophysics Data System (ADS)

Rare-earth related materials have been widely used in various advanced technologies and devices because of their novel functions such as excellent magnetic and optical properties. For the fabrication of the next generation of new rare-earth related materials with novel functions, it is necessary to design a wide range of materials from nano-scale to macro-scale and to develop novel techniques realizing such designs. Indeed, there has been great progress in the preparation, processing and characterization of new rare-earth materials covering magnetic alloys, inorganic and organic fluorescence materials. In the International Union of Materials Research Societies International Conference in Asia 2008 (IUMRS-ICA2008) (9-13 December, Nagoya, Japan), the symposium on 'AA: Rare-Earth Related Material Processing and Functions' was organized to provide an interdisciplinary forum for the discussion of recent advances in fabrication processing and applications of rare-earth related materials with various scaled and unique morphologies. Many papers were presented in the symposium, and some papers were accepted to be published in this proceeding after review. Editors: Takayuki KOMATSU (Nagaoka University of Technology, Japan) Tsugio SATO (Tohoku University, Japan) Ken-ichi MACHIDA (Osaka University, Japan) Hirotoshi FUKUNAGA (Nagasaki University, Japan) Jiro YAMASAKI (Kyushu Institute of Technology, Japan) Honjie ZHANG (Chinese Academy of Sciences, China) Chun Hua YAN (Peking University, China) Jianrong QIU (Zhejiang University, China) Jong HEO (Pohang University, Korea) Setsuhisa TANABE (Kyoto University, Japan) Hiroshi TATEWAKI (Nagoya City University, Japan) Tomokatsu HAYAKAWA (Nagoya Institute of Technology, Japan) Yasufumi FUJIWARA (Osaka University, Japan)

Komatsu, Takayuki; Sato, Tsugio; Machida, Ken-ichi; Fukunaga, Hirotoshi

2009-02-01

256

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

257

Micromechanics-Based Interfacial Debonding Model of Functionally Graded Materials  

E-print Network

Micromechanics-Based Interfacial Debonding Model of Functionally Graded Materials G. H. Paulino", H of California, Irvine, CA 92697 Abstract. This study develops a micromechanical damage model for two. Keywords: Functionally graded composites; Micromechanical modeling; Effective elasticity; Damage mechanics

Paulino, Glaucio H.

258

Love waves in functionally graded piezoelectric materials  

Microsoft Academic Search

To investigate the features of Love waves in a layered functionally graded piezoelectric structure, the mathematical model is established on the basis of the elastic wave theory, and the WKB method is applied to solve the coupled electromechanical field differential equation. The solutions of the mechanical displacement and electrical potential function are obtained for the piezoelectric layer and elastic substrate.

X. Y. Li; Z. K. Wang; S. H. Huang

2004-01-01

259

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

260

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

261

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

262

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

263

Fractal Geometric Characterization of Functionally Graded Materials  

E-print Network

graded materials (FGM) is studied from the standpoint of fractal geometry. First, upon introducing the fineness as the number of grains of either phase across the FGM, the two-phase FGM is char- acterized using in local fractal dimension is considered across or along the FGM domain, and it is characterized by Fourier

Ostoja-Starzewski, Martin

264

THE MATERIAL BONE: Structure-Mechanical Function Relations  

Microsoft Academic Search

The term bone refers to a family of materials, all of which are built up of mineralized collagen fibrils. They have highly complex structures, described in terms of up to 7 hierarchical levels of organization. These materials have evolved to fulfill a variety of mechanical functions, for which the structures are presumably fine-tuned. Matching structure to function is a challenge.

S. Weiner; H. D. Wagner

1998-01-01

265

Directed deposition of inorganic oxide networks on patterned polymer templates  

NASA Astrophysics Data System (ADS)

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

Ford, Thomas James Robert

266

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

267

4th International Symposium on Functional Materials (ISFM2011)  

Microsoft Academic Search

The 4th International Symposium on Functional Materials (ISFM2011) was held in Sendai, Japan, on 2–6 August 2011. This Special Issue of Journal of Physics: Conference Series (JPCS) consists of partial manuscripts which were presented at ISFM2011. Advanced materials have experienced a dramatic increase in demand for research, development and applications. The aim of the International Symposium on Functional Materials (ISFM)

Shu Yin; Tohru Sekino; Shun-ichiro Tanaka; Tsugio Sato; Li Lu; Dongfeng Xue

2012-01-01

268

Block Copolymer Patterning of Functional Materials  

E-print Network

.sc.doe.gov/bes/reports/abstracts.html. iiE. Cartlidge. Bright outlook for solar cells. Physics World, 20(7):2024, 2007. Contents 1 Excitonic Solar Cells 1 1.1 Photovoltaics and Conventional Solar Energy Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Organic Solar... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 Chapter 1 Excitonic Solar Cells The following chapter will give an overview of the important concepts in photovoltaic devices incor- porating novel and low-cost material systems. These approaches have in common the application of semiconductor...

Crossland, Edward

2014-05-27

269

New materials and functionality in spintronics devices  

NASA Astrophysics Data System (ADS)

The next generation of electronics devices, known as spintronics, which incorporate the spin property of the carriers in combination with their charge degree of freedom is the focus of to-date research. Therefore, exciting new classes of materials have been emerging for the last few years for the development of spintronics devices. This study has been carried out to understand/control various properties of such materials at the fundamental level which is important for the spintronics devices applications. Materials studied here include magnetic semiconductors, magnetostrictive alloys and magnetic tunnel junctions (MTJ) based sensors. In the first part, a comparative study of the room temperature ferromagnetism of Co doped ZnO and CeO2 is presented with emphasis on the role of dopant, defects and host oxide. Systemic structural, magnetic, and transport analyses reveal that the nature of donor defects and host oxide plays a vital role in establishing ferromagnetism. This study provides an insight into the underlying mechanisms responsible for the ferromagnetism in Co-ZnO and Co-CeO 2. Moreover, the discussed exchange mechanisms are in good agreement with the electronic structure calculation of magnetic impurity ions and defects. Composite materials with strong magneto-electric (ME) coupling require magnetic thin films with large saturation magnetostriction constant at low magnetic fields. In the second part of this dissertation, we have studied FeGa alloys where changes in their microstructure with the incorporation of boron occur. These changes make this material a soft magnetic alloy (coercivity ˜ 2 Oe) which has a narrow ferromagnetic resonance (FMR) line width, large magnetostriction and high saturation magnetization. The anisotropy values have been extracted from study of the angular dependence of FMR. This work highlights the role of crystalline anisotropy and induced uniaxial anisotropy which determine the magnetic softness and enhanced magnetostriction at small magnetic fields. In addition, the effects of rapid thermal annealing on the structure and magnetic properties of the crystalline as well as amorphous FeGaB thin films have been studied. Additionally, new electrode materials within the magnetic tunneling junction (MTJ) have been developed using FeGaB which serve as the sensing magnetic layer. This provides a method to measure mechanical strain or stress with high sensitivity. It has been shown that TMR of greater than 12% at room temperature could be achieved in CoFeB/MgO/FeGaB based junctions. This suggests that FeGaB could be a new magnetic electrode for MTJs based pressure devices. The ability of magnetoresistive (MR) material to sense very weak magnetic fields at room temperature can be used for the magnetic sensor's design. In the third part, the Al2O3 based sensors have been studied where the shape anisotropy in the free magnetic electrode has been observed to results in a linear and hysteresis free magnetoresistance (MR) curve. Moreover, Al2O3 based sensor have 28 - 30% TMR and sensitivity up to 0.4 %/Oe over a magnetic field range of -40 Oe to 40 Oe whereas the MgO-based sensor with superparamagnetic free layer has about 90 % TMR and sensitivity of 1.1 %/Oe over the same field range.

Shah, Lubna R.

270

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

271

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

E-print Network

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

Hautier, Geoffroy (Geoffroy T. F.)

2011-01-01

272

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

273

Organic-inorganic hybrid materials based on N=C=O functionalised silan modified with titanium and zirconium  

Microsoft Academic Search

This work investigates the influence of the precursor trimethylsilil isocyanate on the sol-gel synthesis of hybrid materials.\\u000a The obtained Si?O?C?N network is additionally modified by titanium and zirconium alcoxypropoxides in the range of 10 to 30\\u000a wt. %. The structure of the obtained hybrid materials before and after pyrolysis up to 1100°C was investigated by methods\\u000a of XRD, FTIR and

Yordanka Y. Ivanova; Yanko B. Dimitriev; Tsvetelina I. Gerganova; Raina G. Bryaskova; Maria H. V. Fernandes; Isabel M. Miranda Salvado

2005-01-01

274

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

275

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

E-print Network

investigated for use in photovoltaic solar cells for the past years. At present, almost all photovoltaic device Meeting; Symposium E, Photovoltaic Technologies, Devices and Systems Based on Inorganic Materials, Small). Development of indium-rich InGaN epilayers for integrated tandem solar cells A. G. Melton1 , B. Kucukgok1 , B

Dietz, Nikolaus

276

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

277

Harvesting Vibrational Energy Using Material Work Functions  

PubMed Central

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

278

Fatigue Crack Growth Analysis Models for Functionally Graded Materials  

SciTech Connect

The objective of this study is to develop crack growth analysis methods for functionally graded materials (FGMs) subjected to mode I cyclic loading. The study presents finite elements based computational procedures for both two and three dimensional problems to examine fatigue crack growth in functionally graded materials. Developed methods allow the computation of crack length and generation of crack front profile for a graded medium subjected to fluctuating stresses. The results presented for an elliptical crack embedded in a functionally graded medium, illustrate the competing effects of ellipse aspect ratio and material property gradation on the fatigue crack growth behavior.

Dag, Serkan [Department of Mechanical Engineering, Middle East Technical University, Ankara 06531 (Turkey); Yildirim, Bora [Department of Mechanical Engineering, Hacettepe University, Ankara 06800 (Turkey); Sabuncuoglu, Baris

2008-02-15

279

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

280

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

Microsoft Academic Search

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

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

2007-01-01

281

Functional oxide nanobelts - from materials to nanodevices  

NASA Astrophysics Data System (ADS)

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

Lin, Zhong; Wang

2003-11-01

282

Advances in hybrid organic\\/inorganic optoelectronic integration  

Microsoft Academic Search

We report on advances in the hybrid organic\\/inorganic integration of passive and active optical functions. The integration approaches include chip-to-chip attach, flip-chip mounting, and insertion of films in slots formed in planar lightwave circuits. The materials integrated include polymer, silica, silicon, silicon oxynitride, lithium niobate, indium phosphide, gallium arsenide, yttrium iron garnet, and neodymium iron boron. The functions enabled by

Louay A. Eldada; Antonije M. Radojevic; Junichiro Fujita; Tomoyuki Izuhara; Reinald Gerhardt

2004-01-01

283

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

ERIC Educational Resources Information Center

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

Boffa, Vittorio; Yue, Yuanzheng; He, Wen

2012-01-01

284

A study of rheology, processing and phase behavior of engineered inorganic glass-organic polymer hybrid materials  

Microsoft Academic Search

Due to the consequence of expensive development costs that arise with manufacturing and synthesizing new polymers, interest in polymer blends has gained considerable attention in recent years. It is well known that the production of miscible and immiscible blends of polymers can lead to composite materials with special chemical, thermal, mechanical, and rheological properties. The morphology of immiscible polymer blends

Peter Christopher Guschl

2002-01-01

285

CR3: Cornerstone to the sustainable inorganic materials management (SIM2) research program at K.U.Leuven  

NASA Astrophysics Data System (ADS)

TMS has forged cooperative agreements with several carefully selected organizations that actively work to benefit the materials science community. In this occasional series, JOM will provide an update on the activities of these organizations. This installment features the Center for Resource Recovery & Recycling (CR3), a research center established by Worcester Polytechnic Institute, Colorado School of Mines, and K.U. Leuven

Jones, P. T.; van Gerven, T.; van Acker, K.; Geysen, D.; Binnemans, K.; Fransaer, J.; Blanpain, B.; Mishra, B.; Apelian, D.

2011-12-01

286

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

287

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

Microsoft Academic Search

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

L. Yin; G. K. Ananthasuresh

2001-01-01

288

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

289

Teaching with Functional Materials: The Problem of Stress and Intonation.  

ERIC Educational Resources Information Center

A discussion of techniques for teachers to best use functional materials focuses on providing practice in recognizing and manipulating stress and intonation variations to produce attitudinally appropriate utterances. Lesson planning ideas for beginner and intermediate levels are included. (MSE)

Roberts, Jon

1983-01-01

290

A parametric study of thermomechanical behavior of functionally gradient materials  

E-print Network

The dynamic thermoelastic response of functionally gradient cylinders and plates is studied. Thermomechanical coupling is significant in these materials when they are used in high temperature applications, and hence, the coupling is included...

Chin, Che-Doong

1996-01-01

291

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

USGS Publications Warehouse

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

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

2001-01-01

292

EDITORIAL: The 2nd International Symposium on Functional Materials  

NASA Astrophysics Data System (ADS)

Following the success of the 1st International Symposium on Functional Materials held in Kuala Lumpur, Malaysia, 5-8 December 2005, the second symposium was held in the beautiful city of Hangzhou, People's Republic of China, 16-19 May 2007. The latter symposium was a gathering of about 200 renowned researchers from 16 countries around the world. The conference consisted of 24 symposia, 5 keynote papers, 21 invited papers, 108 oral presentations and about 160 poster papers covering the frontier areas of materials science and technology of functional materials. They included topics such as energy storage materials, ferroelectric materials, ferromagnetic materials, ferroelectric thin films, applications of functional materials, nanofabrication, computational design, shape memory alloys, application of shape memory materials, ferroelectrics and thermoelectrics, advances in characterizations, magneto-optical materials, Zn and Ti oxides, synthesis of nanopowders and wires, and many other advanced functional materials. With the receipt of more than 396 abstracts, this conference was a gathering of great minds in one place to discuss the research frontiers and discoveries in functional materials. The Organizing Committee would like to express its sincere thanks to the members of the International Advisory Committee for their invaluable contributions to the symposium. The committee is also grateful for the generous support from the many sponsors. A word of sincere thanks needs to go to Professor Roger Wäppling, Editor-in-Chief and the editorial staff of IOP Publishing for the publication of selected papers in this special issue of Physica Scripta. Finally, our deepest gratitude should be directed to the National University of Singapore, Zhejiang University and the General Research Institute for Nonferrous Metals, People's Republic of China for, without their support, the conference would not have been a success.

Lu, L.; Lai, M. O.

2007-12-01

293

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

294

Self-Assembly of biologically inspired complex functional materials  

Microsoft Academic Search

Nature combines hard and soft materials, often in hierarchical architectures, to get synergistic, optimized properties with proven, complex functionalities. Emulating such natural designs in robust engineering materials using efficient processing approaches represents a fundamental challenge to materials chemists. This presentation will review progress on understanding so-called 'evaporation-induced silica\\/surfactant self-assembly' (EISA) as a simple, general means to prepare porous thin-film nanostructures.

Brinker; C. Jeffrey

2004-01-01

295

Gap Wave Propagation in Functionally Graded Piezoelectric Material Structures  

E-print Network

-space and a piezoceramic plate were investigated in [3]. A new-style material called functionally graded material (FGM) was proposed to solve problems in the thermal-protection systems of a space-plane in 1980s. From then on, FGM has attracted interest of investigators from many kinds of disciplines. Today, FGM can be used

Wang, Ji

296

A model of structure optimization for a functionally graded material  

Microsoft Academic Search

A simple model is developed for the spatial variation of composition of a metal\\/ceramic functionally graded material. The composition profile is optimized, subject to certain constraints, such that the flow of heat through the material is either maximized or minimized. Normal thermal-stress profiles are calculated and are found to exhibit unusual behavior in some cases.

Alan J. Markworth; James H. Saunders

1995-01-01

297

A crack in functionally gradient materials under thermal shock  

Microsoft Academic Search

This paper deals with the problem of two bonded semi-infinite functionally gradient material plates with a crack at the interface under thermal shock loading conditions. All material properties are supposed to be exponentially dependent on the distance from the crack line. By using both the Laplace transform and the Fourier transform, the problem is reduced to a singular integral equation

N. Noda; Z.-H. Jin

1994-01-01

298

Time-dependent stress analysis in functionally graded materials  

Microsoft Academic Search

In this article, a joined cylinder with a functionally graded material (FGM) is considered. An analytical solution for the calculation of stresses in FGM is presented for the elastic and creep behavior of the materials. This analytical solution can be used to study the time and temperature dependence of the stresses in a structure with FGM.

Y. Y. Yang

2000-01-01

299

Numerical Calculation of Stress Intensity Factors in Functionally Graded Materials  

Microsoft Academic Search

The finite element method is studied for its use in cracked and uncracked plates made of functionally graded materials. The material property variation is discretized by assigning different homogeneous elastic prop- erties to each element. Finite Element results are compared to existing analytical results and the effect of mesh size is discussed. Stress intensity factors are calculated for an edge-cracked

G. ANLAS; M. H. SANTARE; J. LAMBROS

2000-01-01

300

Production of modern functional materials based on renewable vegetable resources  

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

301

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

USGS Publications Warehouse

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

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

1991-01-01

302

Organic\\/Inorganic bioactive materials Part II: in vitro bioactivity of Collagen-Calcium Phosphate Silicate\\/Wollastonite hybrids  

Microsoft Academic Search

In the present study, novel hybrid materials of Collagen (C) and Calcium Phosphate Silicate\\/Wollastonite (CPS\\/W) were synthesized.\\u000a The CPS\\/W ceramic was prepared via polystep sol-gel method. The dissolution test of CPS\\/W ceramic was filled with TRIS-HCl buffer. FTIR depicts that hydroxyl\\u000a carbonate apatite (OHCO3HA) was observed after 3 days of immersion in TRIS-HCl buffer. Biohybrids of C-CPS\\/W were produced from

Lachezar Radev; Vladimir Hristov; Bisserka Samuneva; Dimitrina Ivanova

2009-01-01

303

Capillary electrophoresis of inorganic anions.  

PubMed

This review deals with the separation mechanisms applied to the separation of inorganic anions by capillary electrophoresis (CE) techniques. It covers various CE techniques that are suitable for the separation and/or determination of inorganic anions in various matrices, including capillary zone electrophoresis, micellar electrokinetic chromatography, electrochromatography and capillary isotachophoresis. Detection and sample preparation techniques used in CE separations are also reviewed. An extensive part of this review deals with applications of CE techniques in various fields (environmental, food and plant materials, biological and biomedical, technical materials and industrial processes). Attention is paid to speciations of anions of arsenic, selenium, chromium, phosphorus, sulfur and halogen elements by CE. PMID:10189691

Kaniansky, D; Masár, M; Marák, J; Bodor, R

1999-02-26

304

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

PubMed

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

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

2014-06-01

305

Macroscopic analysis of axisymmetric functionally gradient material under thermal loading  

SciTech Connect

The axisymmetric functionally gradient materials (FGMs) subject to nonuniform temperature variations were studied with the combined use of homogenization and inhomogeneous eigenstrained media analysis. The material properties and the temperature variations were assumed to depend on the radial coordinate only. The inhomogeneous material properties of the FGM cylinder can be obtained by modulating the concentration level of spherical alumina particles in an aluminum matrix. The resulting stresses due to the temperature variation are presented for numerous distribution functions of alumina particles. It is shown that the particle distribution extensively influences the intensity and profile of the thermal stresses.

Kwon, P.; Dharan, C.K.H.; Ferrari, M. (Univ. of California, Berkeley, CA (United States))

1994-06-01

306

Higher-order theory for functionally graded materials  

Microsoft Academic Search

This paper presents the full generalization of the Cartesian coordinate-based higher-order theory for functionally graded materials developed by the authors during the past several years. This theory circumvents the problematic use of the standard micromechanical approach, based on the concept of a representative volume element, commonly employed in the analysis of functionally graded composites by explicitly coupling the local (microstructural)

J. Aboudi; M.-J. Pindera; S. M. Arnold

1999-01-01

307

A mode III crack in functionally graded piezoelectric materials  

Microsoft Academic Search

This paper considers the mode III crack problem in functionally graded piezoelectric materials. The mechanical and the electrical properties of the medium are considered for a class of functional forms for which the equilibrium equations have an analytical solution. The problem is solved by means of singular integral equation technique. Both a single crack and a series of collinear cracks

B. L. Wang

2003-01-01

308

Catalytic Modification of Polymers: Hydrogenation Routes to Amine Functional Materials  

E-print Network

Catalytic Modification of Polymers: Hydrogenation Routes to Amine Functional Materials Amine Polymers Introduction Amine functional polymers and the copolymers have been widely used in application practices, and nanocomposite study. The usefulness of amine polymers is derived from the nature of the amine

309

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

310

46 CFR 153.555 - Special requirements for inorganic acids.  

Code of Federal Regulations, 2010 CFR

...Special requirements for inorganic acids. 153.555 Section 153.555...CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and...Special requirements for inorganic acids. When Table 1 refers to...

2010-10-01

311

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.

312

Higher-Order Theory for Functionally Graded Materials  

NASA Technical Reports Server (NTRS)

Functionally graded materials (FGM's) are a new generation of engineered materials wherein the microstructural details are spatially varied through nonuniform distribution of the reinforcement phase(s). Engineers accomplish this by using reinforcements with different properties, sizes, and shapes, as well as by interchanging the roles of the reinforcement and matrix phases in a continuous manner (ref. 1). The result is a microstructure that produces continuously or discretely changing thermal and mechanical properties at the macroscopic or continuum scale. This new concept of engineering the material's microstructure marks the beginning of a revolution both in the materials science and mechanics of materials areas since it allows one, for the first time, to fully integrate the material and structural considerations into the final design of structural components. Functionally graded materials are ideal candidates for applications involving severe thermal gradients, ranging from thermal structures in advanced aircraft and aerospace engines to computer circuit boards. Owing to the many variables that control the design of functionally graded microstructures, full exploitation of the FGM's potential requires the development of appropriate modeling strategies for their response to combined thermomechanical loads. Previously, most computational strategies for the response of FGM's did not explicitly couple the material's heterogeneous microstructure with the structural global analysis. Rather, local effective or macroscopic properties at a given point within the FGM were first obtained through homogenization based on a chosen micromechanics scheme and then subsequently used in a global thermomechanical analysis.

Aboudi, J.; Pindera, M. J.; Arnold, Steven M.

2001-01-01

313

Using flowerlike polymer-copper nanostructure composite and novel organic-inorganic hybrid material to construct an amperometric biosensor for hydrogen peroxide.  

PubMed

A new type of amperometric hydrogen peroxide biosensor was fabricated by entrapping horseradish peroxidase (HRP) in the organic-inorganic hybrid material composed of zirconia-chitosan sol-gel and Au nanoparticles (ZrO2-CS-AuNPs). The sensitivity of the biosensor was enhanced by a flowerlike polymer-copper nanostructure composite (pPA-FCu) which was prepared from co-electrodeposition of CuSO4 solution and 2,6-pyridinediamine solution. Several techniques, including UV-vis absorption spectroscopy, scanning electron microscopy, cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy were employed to characterize the assembly process and performance of the biosensor. The results showed that this pPA-FCu nanostructure not only had excellent redox electrochemical activity, but also had good catalytic efficiency for hydrogen peroxide. Also the ZrO2-CS-AuNPs had good film forming ability, high stability and good retention of bioactivity of the immobilized enzyme. The resulting biosensors showed a linear range from 7.80 x 10(-7) to 3.7 x 10(-3) mol L(-1), with a detection limit of 3.2 x 10(-7) mol L(-1) (S/N=3) under optimized experimental conditions. The apparent Michaelis-Menten constant was determined to be 0.32 mM, showing good affinity. In addition, the biosensor which exhibits good analytical performance, acceptable stability and good selectivity, has potential for practical applications. PMID:19836213

Wang, Jinfen; Yuan, Ruo; Chai, Yaqin; Li, Wenjuan; Fu, Ping; Min, Ligen

2010-02-01

314

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

315

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

316

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

317

Smart and functional polymer materials for smart and functional microfluidic instruments  

NASA Astrophysics Data System (ADS)

As microfluidic systems evolve from "chip-in-the-lab" to true portable lab-on-a-chip (LoC) or lab-in-a-package (LiP) microinstrumentation, there is a need for increasingly miniaturized sensors, actuators, and integration/interconnect technologies with high levels of functionality and self-direction. Furthermore, as microfluidic instruments are increasingly realized in polymer-based rather than glass- or silicon- based platforms, there is a need to realize these highly functional components in materials that are polymer-compatible. Polymers that are altered to possess basic functionality, and even higher-functioning "smart" polymer materials, may help to realize high-functioning and selfdirecting portable microinstrumentation. Stimuli-responsive hydrogels have been recognized for over a decade as beneficial to the development of smart microfluidics systems and instrumentation. In addition, functional materials such as conductive and magnetic composite polymers are being increasingly employed to push microfluidics systems to greater degrees of functionality, portability, and/or flexibility for wearable/implantable systems. Functional and smart polymer materials can be employed to realize electrodes, electronic routing, heaters, mixers, valves, pumps, sensors, and interconnect structures in polymer-based microfluidic systems. Stimuli for such materials can be located on-chip or in a small package, thus greatly increasing the degree of portability and the potential for mechanical flexibility of such systems. This paper will examine the application of functional polymer materials to the development of high-functioning microfluidics instruments with a goal towards self-direction.

Gray, Bonnie L.

2014-04-01

318

Force-controlled inorganic crystallization lithography.  

PubMed

Lithography plays a key role in integrated circuits, optics, information technology, biomedical applications, catalysis, and separation technologies. However, inorganic lithography techniques remain of limited utility for applications outside of the typical foci of integrated circuit manufacturing. In this communication, we have developed a novel stamping method that applies pressure on the upper surface of the stamp to regulate the dewetting process of the inorganic buffer and the evaporation rate of the solvent in this buffer between the substrate and the surface of the stamp. We focused on generating inorganic microstructures with specific locations and also on enabling the ability to pattern gradients during the crystallization of the inorganic salts. This approach utilized a combination of lithography with bottom-up growth and assembly of inorganic crystals. This work has potential applications in a variety of fields, including studying inorganic material patterning and small-scale fabrication technology. PMID:16967953

Cheng, Chao-Min; LeDuc, Philip R

2006-09-20

319

THE MATERIAL BONE: Structure-Mechanical Function Relations  

NASA Astrophysics Data System (ADS)

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

Weiner, S.; Wagner, H. D.

1998-08-01

320

A micromechanical study of residual stresses in functionally graded materials  

Microsoft Academic Search

A physically based computational micromechanics model is developed to study random and discrete microstructures in functionally graded materials (FGMs). The influences of discrete microstructure on residual stress distributions at grain size level are examined with respect to material gradient and FGM volume percentage (within a ceramic-FGM-metal three-layer structure). Both thermoelastic and thermoplastic deformation are considered, and the plastic behavior of

Ming Dao; Pei Gu; Akhilesh Maewal; R. J. Asaro

1997-01-01

321

Some basic fracture mechanics concepts in functionally graded materials  

Microsoft Academic Search

In this paper, the crack-tip fields in a general nonhomogeneous material are summarized. The fracture toughness and R-curve of functionally graded materials (FGMs) are studied based on the crack-bridging concept and a rule of mixtures. It is shown that the fracture toughness is significantly increased when a crack grows from the ceramic-rich region into the metal-rich region in an alumina-nickel

Z.-H. Jin; R. C. Batra

1996-01-01

322

Functional soft materials from metallopolymers and metallosupramolecular polymers  

Microsoft Academic Search

Synthetic polymers containing metal centres are emerging as an interesting and broad class of easily processable materials with properties and functions that complement those of state-of-the-art organic macromolecular materials. A diverse range of different metal centres can be harnessed to tune macromolecular properties, from transition- and main-group metals to lanthanides. Moreover, the linkages that bind the metal centres can vary

George R. Whittell; Martin D. Hager; Ulrich S. Schubert; Ian Manners

2011-01-01

323

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

324

Analytical Model for Thermal Elastoplastic Stresses of Functionally Graded Materials  

SciTech Connect

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

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

2008-02-15

325

PREFACE: 4th International Symposium on Functional Materials (ISFM2011)  

NASA Astrophysics Data System (ADS)

The 4th International Symposium on Functional Materials (ISFM2011) was held in Sendai, Japan, on 2-6 August 2011. This Special Issue of Journal of Physics: Conference Series (JPCS) consists of partial manuscripts which were presented at ISFM2011. Advanced materials have experienced a dramatic increase in demand for research, development and applications. The aim of the International Symposium on Functional Materials (ISFM) was to provide an overview of the present status with historical background and to foresee future trends in the field of functional materials. The 4th symposium, ISFM 2011, covered a wide variety of topics within state-of-the-art advanced materials science and technology, and focused especially on four major categories including: Environmental Materials, Electronic Materials, Energy Materials and Biomedical Materials. As you know, a massive earthquake and the Tsunami that followed occurred near the Tohoku region on 11 March 2011. After the earthquake, although there were many difficulties in continuing to organize the symposium, we received warm encouragement from many researchers and societies, especially from the members of the International Advisory Committee and Organizing Committee, so that ISFM2011 could be held on schedule. We are honored that ISFM2011 was the first formal international academic conference held in the Tohoku area of Japan after the 11 March earthquake. About 140 participants from 14 countries took part in the ISFM2011 symposium, which included five plenary talks by world-leading scientists, 32 invited talks, and many oral and poster presentations. We are delighted to see that many researchers are interested in the synthesis and the properties as well as the applications of functional materials. Many fruitful and exciting research achievements were presented in the symposium. We believe that this symposium provided a good chance for scientists to communicate and exchange opinions with each other. We would also like to express our sincere appreciation to all the members of the International Advisory Committee, the Organizing Committee, and all the authors and participants. It is expected that the published output of this special issue will be accepted as an original and valuable contribution to the literature in the functional materials field. Guest Editors Dr Shu Yin Tohoku University, Japan Dr Tohru Sekino Tohoku University, Japan Professor Shun-ichiro Tanaka, IMRAM, Tohoku University, Japan Professor Tsugio Sato IMRAM, Tohoku University, Japan Professor Li Lu National University of Singapore, Singapore Professor Dongfeng Xue Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, China Conference photograph Group photograph of the participants of ISFM2011 held in Sendai, 4 August 2011

Yin, Shu; Sekino, Tohru; Tanaka, Shun-ichiro; Sato, Tsugio; Lu, Li; Xue, Dongfeng

2012-01-01

326

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

327

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

328

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

329

Multi-phase functionally graded materials for thermal barrier systems  

SciTech Connect

Jet engine and gas turbine hot section components can be protected from the 1,350--1,650 C combustion gases by thermal barrier coatings (TBCs). Metallic candidates for functionally graded material (FGM) coatings have been evaluated for potential use in bonding zirconia to a single crystal superalloy. Properties for four materials were studied for the low-expansion layer adjacent to the ceramic. Ingots were produced for these materials, and oxidation, expansion and modulus were determined. A finite element model was used to study effects of varying the FGM layers. Elastic modulus dominated stress generation, and a 20--25% reduction in thermal stress generated within the zirconia layer may be possible.

Jackson, M.R.; Ritter, A.M.; Gigliotti, M.F.; Kaya, A.C.; Gallo, J.P. [General Electric CRD, Schenectady, NY (United States)

1996-12-31

330

Thermal Characterization of Functionally Graded Materials: Design of Optimum Experiments  

NASA Technical Reports Server (NTRS)

This paper is a study of optimal experiment design applied to the measure of thermal properties in functionally graded materials. As a first step, a material with linearly-varying thermal properties is analyzed, and several different tran- sient experimental designs are discussed. An optimality criterion, based on sen- sitivity coefficients, is used to identify the best experimental design. Simulated experimental results are analyzed to verify that the identified best experiment design has the smallest errors in the estimated parameters. This procedure is general and can be applied to design of experiments for a variety of materials.

Cole, Kevin D.

2003-01-01

331

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

332

Hybrid organic-inorganic optoelectronic subsystems on a chip  

Microsoft Academic Search

We report on hybrid organic-inorganic optoelectronic sysbsystems that integrate passive and active optical functions. The integration approaches involve various levels of hybridization, from splicing of pigtailed elements, to chip-to-chip attachment, to hybrid on-chip integration involving grafting and flip-chip mounting, and finally to true heteroepitaxy. The materials integrated include polymer, silica, silicon, silicon oxynitride, lithium niobate, indium phosphide, gallium arsenide, yttrium

Louay Eldada; Junichiro Fujita; Antonije Radojevic; Reinald Gerhardt; Tomoyuki Izuhara

2005-01-01

333

Thermal residual stresses in a functionally graded material system  

Microsoft Academic Search

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

K. S. Ravichandran

1995-01-01

334

Thermal fracture behavior of metal\\/ceramic functionally graded materials  

Microsoft Academic Search

Thermal fracture behavior of metal\\/ceramic functionally graded materials (FGMs) was evaluated by a well controlled burner heating method using a H2\\/O2 combustion flame, which simulated real environment.Partially stabilized zirconia (PSZ)\\/IN100 FGMs having finely mixed microstructures and PSZ\\/Inco718 FGMs having rather coarse microstructures were prepared by a slurry dipping and HIP sintering process. Also, three types of functionally graded thermal barrier

A Kawasaki; R Watanabe

2002-01-01

335

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

PubMed

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

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

2009-08-26

336

Organic\\/inorganic nanocomposites, methods of making, and uses as a permeable reactive barrier  

Microsoft Academic Search

Nanocomposite materials having a composition including an inorganic constituent, a preformed organic polymer constituent, and a metal ion sequestration constituent are disclosed. The nanocomposites are characterized by being single phase, substantially homogeneous materials wherein the preformed polymer constituent and the inorganic constituent form an interpenetrating network with each other. The inorganic constituent may be an inorganic oxide, such as silicon

Mason K. Harrup; Frederick F. Stewart

2007-01-01

337

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

338

Stochastic multiscale models for fracture analysis of functionally graded materials  

E-print Network

A functionally graded material (FGM) is an engineered composite medium in which the composition of constituent. An FGM derived from an optimized compositional variation and microstructure rather than traditional]. However, the extent to which an FGM can be tailored to produce target mechanical performance depends

Rahman, Sharif

339

Love wave propagation in functionally graded piezoelectric material layer  

E-print Network

functionally graded material (FGM) was proposed to solve problems in the thermal- protection systems of aerospace structures in 1980s. Since then, FGM has attracted interest of investigators from many engineering disciplines. Today, FGM can be used not only in thermal-protection systems but also in elec- tronic and many

Wang, Ji

340

Synthesis of functionally graded materials via electrophoretic deposition and sintering  

Microsoft Academic Search

In this research, both the experiments and the modeling aspects of the net-shape fabrication of Functionally Graded Materials (FGM) by Electrophoretic Deposition (EPD) and consecutive sintering have been investigated. In order to obtain FGMs with desired final shape and properties, the issues regarding the shape evolution during sintering, the optimization of initial properties and composition profiles, and the fabrication of

Xuan Wang

2006-01-01

341

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

342

A photometric function for diffuse reflection by particulate materials  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

343

Exploring Electro-active Functionality of Transparent Oxide Materials  

NASA Astrophysics Data System (ADS)

Ceramics, one of the earliest materials used by humans, have been used since the Stone Age and are also one of the core materials supporting modern society. In this article, I will review the features of transparent oxides, the main components of ceramics, and the progress of research on their electro-active functionalities from the viewpoint of material design. Specifically, the emergence of the functionality of the cement component 12CaO.7Al2O3, the application of transparent oxide semiconductors to thin-film transistors for flat panel displays, and the design of wide-gap p-type semiconductors are introduced along with the progress in their research. In addition, oxide semiconductors are comprehensively discussed on the basis of the band lineup.

Hosono, Hideo

2013-09-01

344

Functional materials from cellulose-derived liquid-crystal templates.  

PubMed

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

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

2015-03-01

345

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

346

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

347

Organic--Inorganic Layer Compounds: Physical Properties and Chemical Reactions  

Microsoft Academic Search

In contrast with intercalation compounds, which can exist both with and without organic molecules between the planes of inorganic material, `molecular composite' compounds have organic groups covalently or ionically bound to inorganic layers. In such crystals the aim is to combine magnetic or optical properties characteristic of the inorganic solid state, like magnetism and luminescence, with properties found in the

P. Day

1985-01-01

348

Hollow-structured mesoporous materials: chemical synthesis, functionalization and applications.  

PubMed

Hollow-structured mesoporous materials (HMMs), as a kind of mesoporous material with unique morphology, have been of great interest in the past decade because of the subtle combination of the hollow architecture with the mesoporous nanostructure. Benefitting from the merits of low density, large void space, large specific surface area, and, especially, the good biocompatibility, HMMs present promising application prospects in various fields, such as adsorption and storage, confined catalysis when catalytically active species are incorporated in the core and/or shell, controlled drug release, targeted drug delivery, and simultaneous diagnosis and therapy of cancers when the surface and/or core of the HMMs are functionalized with functional ligands and/or nanoparticles, and so on. In this review, recent progress in the design, synthesis, functionalization, and applications of hollow mesoporous materials are discussed. Two main synthetic strategies, soft-templating and hard-templating routes, are broadly sorted and described in detail. Progress in the main application aspects of HMMs, such as adsorption and storage, catalysis, and biomedicine, are also discussed in detail in this article, in terms of the unique features of the combined large void space in the core and the mesoporous network in the shell. Functionalization of the core and pore/outer surfaces with functional organic groups and/or nanoparticles, and their performance, are summarized in this article. Finally, an outlook of their prospects and challenges in terms of their controlled synthesis and scaled application is presented. PMID:24687906

Li, Yongsheng; Shi, Jianlin

2014-05-28

349

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

350

Synthesis, crystal structure, vibrational spectroscopy, optical properties and theoretical studies of a new organic-inorganic hybrid material: [((CH3)2NH2)+]6·[(BiBr6)3-]2  

NASA Astrophysics Data System (ADS)

A new organic-inorganic hybrid material, [((CH3)2NH2)+]6·[(BiBr6)3-]2, has been synthesized and characterized by X-ray diffraction, FT-IR, Raman spectroscopy and UV-Visible absorption. The studied compound crystallizes in the triclinic system, space group P1bar with the following parameters: a=8.4749(6)(Å), b=17.1392(12)(Å), c=17.1392(12)(Å), ? = 117.339(0)°, ? = 99.487(0)°, ? = 99.487(0)° and Z = 2. The crystal lattice is composed of a two discrete (BiBr6)3- anions surrounded by six ((CH3)2NH2)+ cations. Complex hydrogen bonding interactions between (BiBr6)3- and organic cations from a three-dimensional network. Theoretical calculations were performed using density functional theory (DFT) for studying the molecular structure, vibrational spectra and optical properties of the investigated molecule in the ground state. The full geometry optimization of designed system is performed using DFT method at B3LYP/LanL2DZ level of theory using the Gaussian03. The optimized geometrical parameters obtained by DFT calculations are in good agreement with single crystal XRD data. The vibrational spectral data obtained from FT-IR and Raman spectra are assigned based on the results of the theoretical calculations. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) results complements with the experimental findings. The simulated spectra satisfactorily coincide with the experimental UV-Visible spectrum. The results show good consistent with the experiment and confirm the contribution of metal orbital to the HOMO-LUMO boundary.

Ben Ahmed, A.; Feki, H.; Abid, Y.

2014-12-01

351

Synthesis, crystal structure, vibrational spectroscopy, optical properties and theoretical studies of a new organic-inorganic hybrid material: [((CH3)2NH2)(+)]6·[(BiBr6)(3-)]2.  

PubMed

A new organic-inorganic hybrid material, [((CH3)2NH2)(+)]6·[(BiBr6)(3-)]2, has been synthesized and characterized by X-ray diffraction, FT-IR, Raman spectroscopy and UV-Visible absorption. The studied compound crystallizes in the triclinic system, space group P1¯ with the following parameters: a=8.4749(6)(?), b=17.1392(12)(?), c=17.1392(12)(?), ?=117.339(0)°, ?=99.487(0)°, ?=99.487(0)° and Z=2. The crystal lattice is composed of a two discrete (BiBr6)(3-) anions surrounded by six ((CH3)2NH2)(+) cations. Complex hydrogen bonding interactions between (BiBr6)(3-) and organic cations from a three-dimensional network. Theoretical calculations were performed using density functional theory (DFT) for studying the molecular structure, vibrational spectra and optical properties of the investigated molecule in the ground state. The full geometry optimization of designed system is performed using DFT method at B3LYP/LanL2DZ level of theory using the Gaussian03. The optimized geometrical parameters obtained by DFT calculations are in good agreement with single crystal XRD data. The vibrational spectral data obtained from FT-IR and Raman spectra are assigned based on the results of the theoretical calculations. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) results complements with the experimental findings. The simulated spectra satisfactorily coincide with the experimental UV-Visible spectrum. The results show good consistent with the experiment and confirm the contribution of metal orbital to the HOMO-LUMO boundary. PMID:24967541

Ben Ahmed, A; Feki, H; Abid, Y

2014-12-10

352

Incorporating microorganisms into polymer layers provides bioinspired functional living materials  

PubMed Central

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

353

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

354

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.

355

Nearly Perfect Triplet-Triplet Energy Transfer from Wannier Excitons to Naphthalene in Organic-Inorganic Hybrid Quantum-Well Materials  

NASA Astrophysics Data System (ADS)

We report the observation of extremely efficient energy transfer (greater than 99%) in an organic-inorganic hybrid quantum-well structure consisting of perovskite-type lead bromide well layers and naphthalene-linked ammonium barrier layers. Time-resolved photoluminescence measurements confirm that the transfer is triplet-triplet Dexter-type energy transfer from Wannier excitons in the inorganic well to the triplet state of naphthalene molecules in the organic barrier. Using measurements in the 10 300 K temperature range, we also investigated the temperature dependence of the energy transfer.

Ema, K.; Inomata, M.; Kato, Y.; Kunugita, H.; Era, M.

2008-06-01

356

Application of localized reactivity index in combination with periodic DFT calculation to rationalize the swelling mechanism of clay type inorganic material  

Microsoft Academic Search

Clays are layered alumino-silicates. Clays swell and expand in aqueous solution. This property governs the usage of these\\u000a materials in synthesis of nano-composites and is a source of many of its catalytic applications. We used both localized and\\u000a periodic calculations within the realm of density functional theory (DFT) on a series of monovalent (Li+, Na+, K+, Rb+, Cs+), and divalent

Abhijit Chatterjee; Accelrys K K

2005-01-01

357

Green's function approach to unsteady thermal stresses in an infinite hollow cylinder of functionally graded material  

Microsoft Academic Search

Summary A Green's function approach based on the laminate theory is adopted for solving the two-dimensional unsteady temperature field (r, z) and the associated thermal stresses in an infinite hollow circular cylinder made of a functionally graded material (FGM) with radial-directionally dependent properties. The unsteady heat conduction equation is formulated as an eigenvalue problem by making use of the eigenfunction

K.-S. Kim; N. Noda

2002-01-01

358

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

359

Molecular Modeling of Heme Proteins Using MOE: Bio-Inorganic and Structure-Function Activity for Undergraduates  

ERIC Educational Resources Information Center

A biochemical molecular modeling project on heme proteins suitable for an introductory Biochemistry I class has been designed with a 2-fold objective: i) to reinforce the correlation between protein three-dimensional structure and function through a discovery oriented project, and ii) to introduce students to the fields of bioinorganic and…

Ray, Gigi B.; Cook, J. Whitney

2005-01-01

360

A model for designing functionally gradient material joints  

SciTech Connect

An analytical, thin-plate layer model was developed to assist research and development engineers in the design of functionally gradient material (FGM) joints consisting of discrete steps between end elements of dissimilar materials. Such joints have long been produced by diffusion bonding using intermediates or multiple interlayers; welding, brazing or soldering using multiple transition pieces; and glass-to-glass or glass-to-metal bonding using multiple layers to produce matched seals. More recently, FGM joints produced by self-propagating high-temperature synthesis (SHS) are attracting the attention of researchers. The model calculates temperature distributions and associated thermally induced stresses, assuming elastic behavior, for any number of layers of any thickness or composition, accounting for critically important thermophysical properties in each layer as functions of temperature. It is useful for assuring that cured-in fabrication stresses from thermal expansion mismatches will not prevent quality joint production. The model`s utility is demonstrated with general design cases.

Messler, R.W. Jr.; Jou, M.; Orling, T.T. [Rensselaer Polytechnic Inst., Troy, NY (United States)

1995-05-01

361

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

362

Stress waves in functionally gradient materials and its use for material characterization  

Microsoft Academic Search

A method is presented to investigate elastic waves in functionally gradient material (FGM) plates excited by plane pressure wavelets. The FGM plate was first divided into linearly inhomogeneous elements (LIEs). A general solution for the equation of motion governing the LIE was derived. The general solution was then used together with the boundary and continuity conditions to obtain the displacement

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

1999-01-01

363

Insensitive nitrogen-rich materials incorporating the nitroguanidyl functionality.  

PubMed

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

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

2014-01-01

364

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

365

Processing and characterization of functionally gradient ceramic materials  

NASA Astrophysics Data System (ADS)

Tape casting of ceramic materials offers the flexibility of gradually altering the electronic or structural properties of two dissimilar systems in order to improve their compatibility. This research outlines the processing and fabrication of two systems of functionally gradient materials. The systems are both electronic ceramic composites consisting of Ba1-xSrxTiO3 (BSTO) and alumina or a second oxide additive. These composites would be used in phased array antenna systems, therefore, the electronic properties of the material have specific requirements in the microwave frequency regions. The composition of the tapes are varied to provide a graded dielectric constant, which gradually increases from that of air (dielectric constant equals 1) to that of the ceramic (dielectric constant equals 1500). This allows maximum penetration of incident microwave radiation as well as minimum energy dissipation and insertion loss into the entire phase shifting device.

O'Day, Michelina E.; Sengupta, Louise C.; Ngo, E.; Stowell, S.; Lancto, R.

1994-05-01

366

Functional Materials Based on Self-Assembly of Polymeric Supramolecules  

Microsoft Academic Search

Self-assembly of polymeric supramolecules is a powerful tool for producing functional materials that combine several properties and may respond to external conditions. We illustrate the concept using a comb-shaped architecture. Examples include the hexagonal self-organization of conjugated conducting polymers and the polarized luminance in solid-state films of rodlike polymers obtained by removing the hydrogen-bonded side chains from the aligned thermotropic

Olli Ikkala; Gerrit ten Brinke

2002-01-01

367

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

NASA Technical Reports Server (NTRS)

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.

1993-01-01

368

Chromonic liquid crystals: properties and applications as functional materials.  

PubMed

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

Tam-Chang, Suk-Wah; Huang, Liming

2008-05-01

369

Bidirectional reflectance distribution function measurements and analysis of retroreflective materials.  

PubMed

We compare the performance of various analytical retroreflecting bidirectional reflectance distribution function (BRDF) models to assess how they reproduce accurately measured data of retroreflecting materials. We introduce a new parametrization, the back vector parametrization, to analyze retroreflecting data, and we show that this parametrization better preserves the isotropy of data. Furthermore, we update existing BRDF models to improve the representation of retroreflective data. PMID:25606744

Belcour, Laurent; Pacanowski, Romain; Delahaie, Marion; Laville-Geay, Aude; Eupherte, Laure

2014-12-01

370

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

371

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

372

Organic and inorganic–organic thin film structures by molecular layer deposition: A review  

PubMed Central

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

Sundberg, Pia

2014-01-01

373

Interfacial Properties and Design of Functional Energy Materials  

SciTech Connect

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

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

2014-01-01

374

Apparatus for depositing a low work function material  

DOEpatents

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

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

2006-10-10

375

Preparation, characterization and properties of amino-functionalized montmorillonite and composite layer-by-layer assembly with inorganic nanosheets  

NASA Astrophysics Data System (ADS)

An amino-functionalized montmorillonite (APTMS-MMT) was prepared by the grafting of 3-aminopropyltrimethoxysilane (APTMS) on the surface of MMT via the ultrasonic synthesis process and characterized by a variety of techniques: FT-IR, thermogravimetic analysis (TGA), particles size analysis and ?-potential measurement. The results showed the size and size distribution of APTMS-MMT particles were decreased, and the ?-potential of particles was increased obviously via the ultrasonic synthesis process. The particles of 30% APTMS-MMT US (MMT modified with 30 wt% APTMS with ultrasonic synthesis process) had a z-average diameter of about 500 nm and a polydispersity index of 0.2. The resultant 30% APTMS-MMT US was dispersed uniformly and stably in water. The poly(acrylic acid) (PAA)/APTMS-MMT multilayer films were grown through layer-by-layer (LBL) deposition of PAA and APTMS-MMT. SEM results indicated that the ultrasonic synthesis of APTMS-MMT increased dispersability of clay sheets at high loadings. The thermal stability and mechanical properties of PAA/APTMS-MMT composites were investigated by TGA and tensile test respectively. The results showed the ultrasonic synthesis of APTMS-MMT enhanced the thermal stability and mechanical properties of PAA/APTMS-MMT composites significantly. PAA/30% APTMS-MMT US composite displayed 3 times higher strength and 6 times higher Young's modulus when compared with pure PAA polymer.

Huang, Guo-bo; Ge, Chang-hua; He, Bing-jing

2011-06-01

376

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

377

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

378

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

379

Inorganic polymers for environmental protection applications  

NASA Astrophysics Data System (ADS)

Aluminosilicate inorganic polymers have been proposed as low-energy cements since, unlike Portland cement, their production does not require high temperatures or generate large quantities of greenhouse gases. Other environmental protection applications for inorganic polymers are to encapsulate hazardous mining or radioactive wastes for safe long-term storage and as fireproof components for buildings and vehicles. However, newly developed methods for synthesising these materials have opened up the possibility of other novel environmental protection applications. These include porous cladding material for passive cooling of buildings, cost-effective exchange materials for removing heavy metals from wastewater, bacteriocidal materials for purifying polluted drinking water and materials for photodegrading hazardous organic environmental pollutants. The nature and synthesis of inorganic polymers for these environmental applications will be discussed here.

MacKenzie, K. J. D.

2011-10-01

380

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

Microsoft Academic Search

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

Bradley A. Foreman

1996-01-01

381

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

382

Material properties and structure-function relationships in the menisci.  

PubMed

The menisci serve several important biomechanical functions in the knee. They distribute stresses over a broad area of articular cartilage, absorb shocks during dynamic loading, and probably assist in joint lubrication. These functions enhance the ability of articular cartilage to provide a smooth, near-frictionless articulation and to distribute loads evenly to the underlying bone of the femur and tibia. In addition, the menisci provide stability to the injured knee when the cruciate ligaments or other primary stabilizers are deficient. The ability to perform these mechanical functions is based on the intrinsic material properties of the menisci as well as their gross anatomic structure and attachments. The material properties of the menisci are determined by their biochemical composition and, perhaps more important, by the organization and interactions of the major tissue constituents: water, proteoglycan, and collagen. Interactions among the important constituents of the fibrocartilage matrix cause meniscal tissue to behave as a fiber-reinforced, porous, permeable composite material similar to articular cartilage, in which frictional drag caused by fluid flow governs its response to dynamic loading. The menisci are one-half as stiff in compression and dissipate more energy under dynamic loading than articular cartilage. Energy dissipation, or shock absorption, by the menisci is the result of high frictional drag caused by low permeability of the matrix, which is about one-sixth as permeable as articular cartilage. The dynamic shear modulus of meniscal tissue is only one-fourth to one-sixth as great as that of articular cartilage. The coarse, circumferential Type I collagen fiber bundles of the meniscus give the tissue great tensile stiffness (range, 100-300 megapascals) and strength. The highly oriented collagen ultrastructure of the menisci makes the tissue anisotropic in tension, compression, and shear and appears to dominate its behavior under all loading conditions. PMID:2406069

Fithian, D C; Kelly, M A; Mow, V C

1990-03-01

383

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

384

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

385

Simple hydrazone building blocks for complicated functional materials.  

PubMed

CONSPECTUS: The ability to selectively and effectively control various molecular processes via specific stimuli is a hallmark of the complexity of biological systems. The development of synthetic structures that can mimic such processes, even on the fundamental level, is one of the main goals of supramolecular chemistry. Having this in mind, there has been a foray of research in the past two decades aimed at developing molecular architectures, whose properties can be modulated using external inputs. In most cases, reversible conformational, configurational, or translational motions, as well as bond formation or cleavage reactions have been used in such modulations, which are usually initiated using inputs including, irradiation, metalation, or changes in pH. This research activity has led to the development of a diverse array of impressive adaptive systems that have been used in showcasing the potential of molecular switches and machines. That being said, there are still numerous obstacles to be tackled in the field, ranging from difficulties in getting molecular switches to communicate and work together to complications in integrating and interfacing them with surfaces and bulk materials. Addressing these challenges will necessitate the development of creative new approaches in the field, the improvement of the currently available materials, and the discovery of new molecular switches. This Account will describe how our quest to design new molecular switches has led us to the development of structurally simple systems that can be used for complicated functions. Our focus on the modular and tunable hydrazone functional group was instigated by the desire to simplify the structure and design of molecular switches in order to circumvent multistep synthesis. We hypothesized that by avoiding this synthetic bottleneck, which is one of the factors that hinder fast progress in the field, we can expedite the development and deployment of our adaptive materials. It should be noted though that designing structurally simple switches cannot be an end goal by itself! Therefore, we showed that our molecules can be used in applications that are beyond a simple molecular switching event (i.e., the control of the photophysical properties of liquid crystals and multistep switching cascades). While focusing on these switches, we discovered that the hydrazones can be easily transformed, using straightforward one-step reactions, into visible light activated azo switches, and two different families of fluorophores that can be used in sensing applications. These findings demonstrate that our approach of developing simple systems for sophisticated functions is not limited to the field of molecular switches and machines but can also encompass other adaptive materials. PMID:24766362

Tatum, Luke A; Su, Xin; Aprahamian, Ivan

2014-07-15

386

A micromechanical study of residual stresses in functionally graded materials  

SciTech Connect

A physically based computational micromechanics model is developed to study random and discrete microstructures in functionally graded materials (FGMs). The influences of discrete microstructure on residual stress distributions at grain size level are examined with respect to material gradient and FGM volume percentage (within a ceramic-FGM-metal three-layer structure). Both thermoelastic and thermoplastic deformation are considered, and the plastic behavior of metal grains is modeled at the single crystal level using crystal plasticity theory. The results are compared with those obtained using a continuous model which does not consider the microstructural randomness and discreteness. In an averaged sense both the micromechanics model and the continuous model give practically the same macroscopic stresses; whereas the discrete micromechanics model predicts fairly high residual stress concentrations at the grain size level (i.e., higher than 700 MPa in 5--6 vol% FGM grains) with only a 300 C temperature drop in a Ni-Al{sub 2}O{sub 3} FGM system. Statistical analysis shows that the residual stress concentrations are insensitive to material gradient and FGM volume percentage. The need to consider microstructural details in FGM microstructures is evident. The results obtained provide some insights for improving the reliability of FGMs against fracture and delamination.

Dao, M.; Gu, P.; Maewal, A.; Asaro, R.J. [Univ. of California, San Diego, La Jolla, CA (United States). Dept. of Applied Mechanics and Engineering Sciences

1997-08-01

387

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...

388

Mn-based antiperovskite functional materials: Review of research  

NASA Astrophysics Data System (ADS)

Our recent research on the Mn-based antiperovskite functional materials AXMn3 (A: metal or semiconducting elements; X: C or N) is outlined. Antiperovskite carbides (e.g., AlCMn3) show large magnetocaloric effect comparable to those of typical magnetic refrigerant materials. Enhanced giant magnetoresistance up to 70% at 50 kOe (1 Oe = 79.5775 Am-1) over a wide temperature span was obtained in Ga1-xZnxCMn3 and GaCMn3-xNix. In Cu0.3Sn0.5NMn3.2, negative thermal expansion (NTE) was achieved in a wide temperature region covering room temperature (? = -6.8 ppm/K, 150 K-400 K). Neutron pair distribution function analysis suggests the Cu/Sn-Mn bond fluctuation is the driving force for the NTE in Cu1-xSnxNMn3. In CuN1-xCxMn3 and CuNMn3-yCoy, the temperature coefficient of resistivity (TCR) decreases monotonically from positive to negative as Co or C content increases. TCR is extremely low when the composition approaches the critical points. For example, TCR is ~ 1.29 ppm/K between 240 K and 320 K in CuN0.95C0.05Mn3, which is one twentieth of that in the typical low-TCR materials (~ 25 ppm/K). By studying the critical scaling behavior and X deficiency effect, some clues of localized-electron magnetism have been found against the background of electronic itinerant magnetism.

Tong, Peng; Wang, Bo-Sen; Sun, Yu-Ping

2013-06-01

389

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

390

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

391

Self-Assembly of biologically inspired complex functional materials.  

SciTech Connect

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

Brinker, C. Jeffrey

2004-08-01

392

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

393

Centrifugally-assisted combustion synthesis of functionally-graded materials  

SciTech Connect

Functionally graded materials (FGM`s) have been prepared by a variety of techniques, including combustion synthesis, and the use of a centrifugal force in this method of synthesis has been demonstrated previously. However, in the earlier work, a centrifugal force was applied to investigate the changes in the dynamics of self-propagating combustion waves or to deposit coatings on the inside surfaces of pipes. The use of a centrifugal force to investigate the formation of FGM`s has not been reported previously and is the focus of this communication. In this work, the authors have chosen thermite reactions to investigate the feasibility of FGM formation by centrifugally-assisted combustion synthesis.

Lai, W.; Munir, Z.A.; McCoy, B.J.; Risbud, S.H. [Univ. of California, Davis, CA (United States)] [Univ. of California, Davis, CA (United States)

1997-02-01

394

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

395

Basis function sampling: a new paradigm for material property computation.  

PubMed

Wang-Landau sampling, and the associated class of flat histogram simulation methods have been remarkably helpful for calculations of the free energy in a wide variety of physical systems. Practically, convergence of these calculations to a target free energy surface is hampered by reliance on parameters which are unknown a priori. Here, we derive and implement a method built upon orthogonal functions which is fast, parameter-free, and (importantly) geometrically robust. The method is shown to be highly effective in achieving convergence. An important feature of this method is its ability to attain arbitrary levels of description for the free energy. It is thus ideally suited to in silico measurement of elastic moduli and other material properties related to free energy perturbations. We demonstrate the utility of such applications by applying our method to calculate the Frank elastic constants of the Lebwohl-Lasher model of liquid crystals. PMID:25415892

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

2014-11-01

396

Synthesis of functionally graded materials via electrophoretic deposition and sintering  

NASA Astrophysics Data System (ADS)

In this research, both the experiments and the modeling aspects of the net-shape fabrication of Functionally Graded Materials (FGM) by Electrophoretic Deposition (EPD) and consecutive sintering have been investigated. In order to obtain FGMs with desired final shape and properties, the issues regarding the shape evolution during sintering, the optimization of initial properties and composition profiles, and the fabrication of green components by EPD have been analyzed. In order to fabricate FGMs by the proposed technological sequence (EPD with the following sintering), the initial shape has to be optimized prior to sintering. In this research, the formulations to simulate sintering of an FGM were developed based on the continuum theory of sintering. A finite element sintering-modeling subroutine has been created and linked to the commercial finite element package ABAQUS. The shape changes of FGM disks during sintering were simulated. In order to obtain the desired final shape after sintering, an inverse modeling methodology was developed to optimize the initial shape. In order to fabricate the optimized initial shape of a green FGM specimen determined by the inverse continuum modeling of sintering, EPD of a number of FGMs was investigated. The FGM green specimens made of Al2O 3 and ZrO2 with the initial shape predicted by the inverse modeling, were deposited using self-designed equipments. The acetone-based suspension with n-butylamine as a particle-charging additive was used. The comparison of the shape between the sintered and the green FGM indicated that the developed experimental-theoretical methodology provided a reliable solution for near net shaping of complex 3-D FGM components. Other applications of EPD, such as in electronic packaging materials and zeolites, were also investigated. In order to fabricate functionally graded materials based on aligned porous structures, unidirectional freezing followed by freeze-drying and sintering has been investigated. The aligned porous preforms were sintered and then impregnated by brushing gold. After annealing at 600°C, the gold wires which have the diameters ranging from several hundreds of nanometers to several micrometers have been found in the ceramic preforms.

Wang, Xuan

397

Photofunctional host-guest hybrid materials and thin films of lanthanide complexes covalently linked to functionalized zeolite A.  

PubMed

Eight host-guest assemblies of zeolite A (ZA) and their thin films have been synthesized. The assembly of zeolite A was prepared by first embedding lanthanide complexes (Eu(TTA)n or Tb(TAA)n) into the cages of zeolite A and then grafting lanthanide complexes (Eu(L) or Tb(L), L = bipy or phen) onto the surface of functionalized zeolite A via 3-(methacryloyloxy)propyltrimethoxysilane (?-MPS). The obtained organic-inorganic hybrid materials were investigated by means of XRD, FT-IR, SEM and luminescence spectroscopy. Firstly, the dependence of the crystal stability of zeolite A as the host of lanthanide complexes on the level of ion exchange was studied by XRD. The results indicated the degradation and partial collapse of zeolite A framework occurred upon doping with high amounts of lanthanide complexes into its channels. The integrity of zeolite A's framework was well maintained after fabrication through careful control of the ion-exchange extent. Secondly, the thin films of zeolite A assemblies obtained this way have the properties of homogeneous dense packing and a high degree of coverage of the crystals on the ITO glass, as shown in SEM images. Thirdly, the luminescence behavior of all the materials were investigated in detail. Among them, four white light-emitting materials from a three-component system that comprises a blue-emitting zeolite A matrix, a red-emitting europium complex and a green-emitting terbium complex were obtained. PMID:24336874

Hao, Ji-Na; Yan, Bing

2014-02-21

398

Synthesis, crystal structure and optical properties of a novel organic-inorganic hybrid materials (C 9H 14N) 2PbCl 4  

NASA Astrophysics Data System (ADS)

A novel organic-inorganic hybrid compound (C 9H 14N) 2PbCl 4 was grown via a solution-cooling process by employing the organic cation-2,4,6-trimethylaniline to control the hybrid compound and the structure was determined by single-crystal X-ray diffraction to be monoclinic, P2(1)/c with a = 24.350(0) Å, b = 25.167(0) Å, c = 7.694(0) Å, ? = 95.77(9)°, and Z = 8. The compound adopted an unprecedented structure, which was built with the staircase-like 1-D chains of PbCl 4 octahedra sandwiched with the square pyramids of PbCl 5. Raman and infrared spectra were used to gain more information of the title compound. The hybrid compound showed the photoluminescence emission at 424 nm.

Liu, Yao; Yang, Peipei; Meng, Jian

2011-05-01

399

Fabrication, Characterization and Modeling of Functionally Graded Materials  

NASA Astrophysics Data System (ADS)

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

Lee, Po-Hua

400

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.

401

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

NASA Astrophysics Data System (ADS)

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

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

2015-03-01

402

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

403

Dislocation punching from interfaces in functionally-graded materials  

SciTech Connect

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

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

1997-06-01