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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Structure/property behavior of inorganic/organic sol-gel derived hybrid materials

Brennan, Anthony Bartholomew 16 September 2005 (has links)
A novel class of inorganic/ organic hybrid materials referred to as CERAMERs have been successfully prepared by a sol-gel process using a polymeric acid catalyst, poly(styrene sulfonic acid), to form a network from tetraethylorthosilicate (TEOS) and triethoxysilane end capped oligomers of poly( tetramethylene oxide) (PTMO). The structure-property relationships were determined for these hybrid networks from their dynamic mechanical behavior, mechanical properties, and SAXS behavior. Thermal gravimetric data coupled with FfIR analysis were used to obtain a qualitative measure of the extent of conversion of the metal alkoxides as a function of acid catalyst. Another new class of CERAMERs was successfully developed by the sol-gel processing of three different metal alkoxides in conjuction with the triethoxy silane end capped PTMO oligomers. The first novel hybrid is based upon complexes of aluminum tri-n-butoxide with ethyl acetoacetonate or titanium tetra-iso-propoxide with ethyl acetoacetate reacted with the triethoxysilane end capped PTMO. The hybrid networks were optically clear and could be easily formed as relatively large monoliths. A novel method of preparation of stable sols without the use of ethyl acetoacetate, developed by Dr. Bing Wang in this laboratory, led to more stable CERAMERS of titanium tetra-iso-propoxide (TiOPr) reacted with the functionalized P'TMO as well as a fourth inorganic/organic hybrid material based upon zirconium tetra-n-propoxide and PTMO. Indeed, the mechanical properties of the TiOPr/P'TMO CERAMERs and ZrOPr/P'TMO CERAMERs were significantly enhanced over the TEOS/PTMO CERAMERs in terms of both Young's modulus and stress at break. The structure-property relationships of these materials were adequately described by the morphological model originally developed for the CERAMERs based upon TEOS/PTMO. / Ph. D.

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