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Environmentally friendly polysilane photoresists

Description: Several novel polysilanes synthesized by the free-radical hydrosilation of oligomeric polyphenylsilane or poly(p-tert- butylphenylsilane) were examined for lithographic behavior. This recently developed route into substituted polysilanes has allowed for the rational design of a variety of polysilanes with a typical chemical properties such as alcohol and aqueous base solubility. Many of the polysilane resists made could be developed in aqueous sodium carbonate and bicarbonate solutions. These m… more
Date: December 31, 1995
Creator: Beach, J.V.; Loy, D.A.; Hsiao, Yu-Ling & Waymouth, R.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Improved Synthesis of [Si6Cl14]2-Salts as Precursors for Si6H12and other Novel Silanes

Description: The reaction of excess HSiCl{sub 3} with the aforementioned triamines led to the formation of [Si{sub 6}Cl{sub 14}]{sup 2-} containing salts in all instances. The isolated complex salts were characterized using FT-IR and elemental analysis. IR spectra of these compounds showed characteristic Si-H stretching modes around 2100cm{sup -1} due to the hexacoordinate silane cation and Si-Cl active modes near 528cm{sup -1} as a result of the cyclic dianion. Reaction yields and elemental analysis (CHN) … more
Date: August 18, 2009
Creator: Anderson, Kenneth; Dai, Xuliang; Nelson, Kendric; Schulz, Doug & Boudjouk, Philip
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Polymethylsilsesquioxanes Through Base-Catalyzed Redistribution of Oligomethylhydridosiloxanes

Description: There has been an increasing amount of interest in silsesquioxanes and polysilsesquioxanes. They have been used as models for silica surfaces and have been shown to have great potential for several industrial applications. Typical synthesis of polysilsesquioxanes involves the hydrolysis of organotricholorosilanes and/or organotrialkoxysilanes in the presence of acid or base catalysts, usually in the presence of organic solvents.
Date: April 4, 2000
Creator: Rahimian, Kamyar; Assink, Roger A. & Loy, Douglas A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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INOR-037: Encapsulation of hazardous metals with organic modified minerals

Description: The authors studies have focused on the development of new materials for the control, treatment, and long term storage of hazardous metals. The process involves the introduction of hazardous cations into the matrix of clays through aqueous ion-exchange methods. These cations are subsequently encapsulated within the clay by treating the material with a variety of organic silanes. This treatment results in the formation of organic coatings which are chemically bonded to the surface of the clay. T… more
Date: December 31, 1995
Creator: Song, Kang; Wasserman, R. & Yuchs, S.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High-purity, isotopically enriched bulk silicon

Description: The synthesis and characterization of dislocation-free, undoped, single crystals of Si enriched in all 3 stable isotopes is reported: {sup 28}Si (99.92%), {sup 29}Si (91.37%), and {sup 30}Si (89.8%). A silane-based process compatible with the relatively small amounts of isotopically enriched precursors that are practically available was used. The silane is decomposed to silicon on a graphite starter rod heated to 700-750 C in a recirculating flow reactor. A typical run produces 35 gm of polycry… more
Date: November 17, 2004
Creator: Ager, J. W., III; Beeman, J. W.; Hansen, W. L.; Haller, E. E.; Sharp, I. D.; Liao, C. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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LDRD final report on chemical functionalization of oligo(hydrido)silanes, economically attractive routes to new photoresponsive materials

Description: Metathesis-catalyzed polymerizations of primary silanes were performed to generate polysilanes suitable for functionalization with a variety of side groups. Modeling was employed to predict conformations and estimate electronic properties of candidate functionalized polysilanes. Chemical functionalization of oligo(hydrido)silanes with terminal {alpha}, {omega}-dienes under free radical conditions yielded highly crosslinked, nonporous polysilane networks. Ketone reduction with oligo(hydrido)sila… more
Date: May 1, 1997
Creator: Jamison, G. M.; Loy, D. A. & Curro, J. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Stopping the growth of particles to silica-supported mono-nuclear Ru hydride surface species by tuning silica with surface silanes

Description: Tuning silica by replacing surface silanols with silanes allows chemical grafting of Ru(COD)(COT) through a covalent Ru-Si bond, as evidenced by elemental analysis, IR spectroscopy and EXAFS. Treatment of these surface species under H2 at 300 oC yields a mononuclear Ru hydride species, without any sintering of the metal according to TEM and EXAFS analyses. This supported system displays catalytic properties different from those of supported Ru particles (2 nm), selectively hydrogenating olefins… more
Date: July 11, 2007
Creator: Berthoud, Romain; Fenet, Bernard; Lukens, Wayne; Pelzer, Katrin; Basset, Jean-Marie; Candy, Jean-Pierre et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Humidity Dependence of Adhesion for Silane Coated Microcantilevers

Description: This study examines adhesion between silane-coated micromachined surfaces that are exposed to humid conditions. Our quantitative values for interfacial adhesion energies are determined from an in-situ optical measurement of deformations in partly-adhered cantilever beams. We coated micromachined cantilevers with either ODTS (C{sub 18}H{sub 37}SiCl{sub 3}) or FDTS (C{sub 8}F{sub 17}C{sub 2}H{sub 4}SiCl{sub 3}) with the objective of creating hydrophobic surfaces whose adhesion would be independen… more
Date: November 9, 1999
Creator: DE BOER,MAARTEN P.; MAYER,THOMAS M.; CARPICK,ROBERT W.; MICHALSKE,TERRY A.; SRINIVASAN,U. & MABOUDIAN,R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Porosity in polysilsesquioxane xerogels

Description: Polysilsesquioxanes, [RSiO{sub 1.5}]{sub n} are a class of hybrid organic-inorganic materials in which silicon atoms are linked with up to three siloxane bonds to other monomer units in the polymer and the organic group is a pendent functionality. Polysilsesquioxanes are prepared by the hydrolysis and condensation of organotrialkoxysilanes (Scheme l). Organotrialkoxysilanes RSi(OR{prime}){sub 3}, have been extensively used as coupling agents for composites or surface treatments for materials. P… more
Date: May 9, 2000
Creator: Loy, Douglas A.; Schneider, Duane A.; Baugher, Brigitta M. & Rahimian, Kamyar
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Rapid prototyping of patterned functional nanostructures

Description: Living systems exhibit form and function on multiple length scales, and the prospect of imparting life-like qualities to man-made materials has inspired many recent efforts to devise hierarchical materials assembly strategies. For example, Yang et al. grew surfactant-templated mesoporous silica on hydrophobic patterns prepared by micro-contact printing {micro}CP{sup 3}. Trau et al. formed oriented mesoporous silica patterns, using a micro-molding in capillaries MIMIC technique, and Yang et al. … more
Date: February 9, 2000
Creator: Fan, Hongyou; Lu, Yunfeng; Stump, Aaron; Reed, Scott T.; Baer, Thomas A.; Schunk, P. Randall et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Liquid Silane Routes to Electronic Materials

Description: New chemistries based upon liquid cyclohexasilane (Si{sub 6}H{sub 12} or CHS) have been used as precursors to silicon-containing electronic materials. Spin-coating of CHS-based inks with subsequent UV light and/or thermal treatment yielded amorphous silicon (a-Si:H) films. While initial ink chemistries gave a-Si:H with high resistivity (i.e., > 10{sup 6} {Omega}.cm), several doping strategies are under development to address this limitation. In this contribution, the current status of soluti… more
Date: December 4, 2008
Creator: Schulz, Douglas L.; Dai, Xuliang; Nelson, Kendric J.; Pokhodnya, Konstantin; Hoey, Justin M.; Akhatov, Iskander S. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Gas-phase silicon atom densities in the chemical vapor deposition of silicon from silane

Description: Silicon atom number density profiles have been measured using laser-induced fluorescence during the chemical vapor deposition of silicon from silane. Measurements were obtained in a rotating-disk reactor as a function of silane partial pressure and the amount of hydrogen added to the carrier gas. Absolute number densities were obtained using an atomic absorption technique. Results were compared with calculated density profiles from a model of the coupled fluid flow, gas-phase and surface chemis… more
Date: December 31, 1993
Creator: Coltrin, M. E.; Breiland, W. G. & Ho, P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Thin-film silica sol-gels doped with ion responsive fluorescent lipid bilayers

Description: A metal ion sensitive, fluorescent lipid-b i layer material (5oA PSIDA/DSPC) was successfully immobilized in a silica matrix using a tetramethoxysilane (TMOS) sol-gel procedure. The sol-gel immobilization method was quantitative in the entrapment of seif-assembled Iipid-bilayers and yielded thin films for facile configuration to optical fiber piatforms. The silica matrix was compatible with the solvent sensitive lipid bilayers and provided physical stabilization as well as biological protection… more
Date: January 12, 1999
Creator: Sasaki, Darryl Y.; Shea, Lauren E. & Sinclair, Michael B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The addition of disilanes to cumulenes

Description: The syntheses of silicon-containing compounds and the studies of their rearrangements have been active research areas in the Barton research group. Previously, the addition of disilanes to acetylenes was studied in the group and an intramolecular 2S + 2A mechanism has been proposed. In this thesis, the work is focused on the addition of disilanes to cumulenes. The syntheses of the precursors are discussed and the possible mechanisms for their thermal, photochemical and catalytic rearrangements … more
Date: October 8, 1997
Creator: Chen, Y.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Polymerization of trialkoxysilanes. Effect of the organic substituent on the formation of gels

Description: Hydrolysis and condensation of trialkoxysilanes, R-Si(OR{prime}){sub 3}, generally leads to the formation of silsesquioxane oligomers and polymers. These polymers are composed of a monomer repeat unit, [R-SiO{sub 1.5}]{sub n}, with a single silicon atom attached to other repeat units in the polymer through one to three siloxane bonds. The remaining substituent is an organic group attached to the silicon through a silicon-carbon single bond. Silsesquioxanes have been the subject of intensive stu… more
Date: September 1, 1998
Creator: Loy, D.A.; Baugher, B.M. & Schneider, D.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electrospun a-Si using Liquid Silane/Polymer Inks

Description: Amorphous silicon nanowires (a-SiNWs) were prepared by electrospinning cyclohexasilane (Si{sub 6}H{sub 12}) admixed with polymethylmethacrylate (PMMA) in toluene. Raman spectroscopy characterization of these wires (d {approx} 50-2000 nm) shows 350 C treatment yields a-SiNWs. Porous a-SiNWs are obtained using a volatile polymer.
Date: December 1, 2010
Creator: Schulz, D.L.; Hoey, J.M.; Smith, J.; Lovaasen, J.; Braun, C.; Dai, X. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electrospun a-Si using Liquid Silane/Polymer Inks

Description: Amorphous silicon nanowires (a-SiNWs) were prepared by electrospinning cyclohexasilane (Si{sub 6}H{sub 12}) admixed with polymethylmethacrylate (PMMA) in toluene. Raman spectroscopy characterization of these wires (d {approx} 50-2000 nm) shows 350 C treatment yields a-SiNWs. Porous a-SiNWs are obtained using a volatile polymer.
Date: December 9, 2010
Creator: Schulz, Doug
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Metal Carbonyl-Hydrosilane Reactions and Hydrosilation Catalysis

Description: Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a siloxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Three relevant catalytic reactions are shown. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(C0){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{su… more
Date: April 14, 2001
Creator: Cutler, A. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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