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Solventless sol-gel chemistry through ring-opening polymerization of bridged disilaoxacyclopentanes

Description: Disilaoxacyclopentanes have proven to be excellent precursors to sol-gel type materials. These materials have shown promise as precursors for encapsulation and microelectronics applications. The polymers are highly crosslinked and are structurally similar to traditional sol-gels, but unlike typical sol-gels they are prepared without the use of solvents and water, they have low VOC's and show little shrinkage during processing.
Date: April 4, 2000
Creator: Rahimian, Kamyar & Loy, Douglas A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Solventless sol-gel chemistry through ring-opening polymerization of bridged disilaoxacyclopentanes

Description: Ring-opening polymerization (ROP) of disilaoxacyclopentanes has proven to be an excellent approach to sol-gel type hybrid organic-inorganic materials. These materials have shown promise as precursors for encapsulation and microelectronics applications. The polymers are highly crosslinked and are structurally similar to traditional sol-gels, but unlike typical sol-gels they are prepared by an organic base or Bronsted acid (formic or triflic acid), without the use of solvents and water, they have… more
Date: May 1, 2000
Creator: Rahimian, Kamyar & Loy, Douglas A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Sol-gel chemistry by ring-opening polymerization

Description: Sol-gel processing of materials is plagued by shrinkage during polymerization of the alkoxide monomers and processing (aging and drying) of the resulting gels. The authors have developed a new class of hybrid organic-inorganic materials based on the solventless ring-opening polymerization (ROP) of monomers bearing the 2,2,5,5-tetramethyl-2,5-disilaoxacyclopentyl group, which permits them to drastically reduce shrinkage in sol-gel processed materials. Because the monomers are polymerized through… more
Date: February 7, 2000
Creator: Rahimian, Kamyar & Loy, Douglas A.
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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Soluble, High Molecular Weight Polysilsesquioxanes with Carboxylate Functionalities

Description: Trialkoxysilyl-containing monomers of the type (RO){sub 3}Si(CH{sub 2}){sub 3}C(O)OtBu (R = Me, Et) were prepared by hydrosilation of the corresponding vinylic tert-butyl esters CH{sub 3}CHCH{sub 2}C(O)OtBu. Acid- or base-catalyzed polymerization of the monomers leads to very high molecular weight polymers with relatively narrow polydispersities. The polymerization results in complete condensation of the alkoxy groups while the tert-butyl ester functionality remains fully intact. Partial or ful… more
Date: July 14, 2000
Creator: Rahimian, Kamyar; Loy, Douglas A. & Wheeler, David 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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Polysilsesquioxanes Through Base-Catalyzed Redistribution of Oligohydridosiloxanes

Description: Organopolysilsesquioxanes have recently gained much interest as materials for low-K dielectrics, ceramic precursors and photoresists. Typical sol-gel synthesis of polysilsesquioxanes involves the hydrolysis of organotricholorosilanes and/or organotrialkoxysilanes in the presence of acid or base catalysts and organic solvents. However, under sol-gel conditions most organotrialkoxysilanes do not afford silsesquioxane gels. This limits the range of organic functionalities that can be introduced in… more
Date: May 1, 2000
Creator: Rahimian, Kamyar; Assink, Roger A.; Lang, David P. & Loy, Douglas A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Substituent effects on the sol-gel chemistry of organotrialkoxysilanes

Description: Silsesquioxanes have been the subject of intensive study in the past and are becoming important again as a vehicle for introducing organic functionalities into hybrid organic-inorganic materials through sol-gel processing. Depending on the application, the target hybrid material may be required to be a highly cross-linked, insoluble gel or a soluble polymer that can be cast as a thin film or coating. The former has applications such as catalyst supports and separations media; the latter is an e… more
Date: May 9, 2000
Creator: LOY, DOUGLAS A.; BAUGHER, BRIGITTA M.; BAUGHER, COLLEEN R.; SCHNEIDER, DUANE A. & RAHIMIAN, KAMYAR
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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All-Ceramic Thin Film Battery

Description: We have undertaken the synthesis of a thin film ''All Ceramic Battery'' (ACB) using solution route processes. Based on the literature and experimental results, we selected SnO{sub 2}, LiCoO{sub 2}, and LiLaTiO{sub 3} (LLT) as the anode, cathode, and electrolyte, respectively. Strain induced by lattice mismatch between the cathode and bottom electrode, as estimated by computational calculations, indicate that thin film orientations for batteries when thicknesses are as low as 500 {angstrom} are … more
Date: November 1, 2002
Creator: Boyle, Timothy J.; Ingersoll, David; Cygan, Randall T.; Rodriguez, Mark A.; Rahimian, Kamyar & Voight, James A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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