東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

FindBook

Google Book

Amazon

博客來

Investigation of water -based silica and organically modified silicate sol -gel systems.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Investigation of water -based silica and organically modified silicate sol -gel systems./
作者:	Parkhill, Robert Lynn.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 1999,
面頁冊數:	255 p.
附註:	Source: Dissertations Abstracts International, Volume: 62-01, Section: B.
Contained By:	Dissertations Abstracts International62-01B.
標題:	Chemistry. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=9963575
ISBN:	9780599678064

Investigation of water -based silica and organically modified silicate sol -gel systems.
Parkhill, Robert Lynn.

Investigation of water -based silica and organically modified silicate sol -gel systems. - Ann Arbor : ProQuest Dissertations & Theses, 1999 - 255 p.

Source: Dissertations Abstracts International, Volume: 62-01, Section: B.

Thesis (Ph.D.)--Oklahoma State University, 1999.

This item must not be sold to any third party vendors.

Scope and method of study. The purpose of this study was to address chemical issues associated with developing a water-based sol-gel system. The studies were conducted to provide a foundation for identifying chemical and structural formations in low and high water-content synthetic processes. Both silicate and organically modified silicate (ormosil) systems were investigated with respect to water content, precursor use, curing temperature, and organic content. In each system, gels and films were characterized using 13C and 29Si Nuclear Magnetic Resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, and picnometry density measurements. Results of each study were used to identify fundamental chemical species evolution, and to help elucidate structural developments that take place in sol-gel materials derived from water-based processes. Findings and conclusions. Results from the pure silicate and organically modified silicate sol-gel systems indicated the use of variable water concentrations had profound effects on the resulting gel microstructure and chemical content. Results from the pure silica systems revealed a progressive development from linear chain to aggregate particle formation. The low water content gels were identified to have developed through the entanglement of linear chains to form dense microporous silica networks, while an increase in the water content led to increased cyclization of the polymeric siloxane chains and a progressive evolution in microstructure from branch-like to colloidal type particles. The effects of using a water-based process for the epoxide ormosil gels were identified with the stability of the epoxide functional group. Hydrolysis of the epoxide group and esterification of the diol-end group formation resulted in the development of two different types of networks. At low water concentrations, the diol group was esterified with silanol end groups resulting in the development of a carbosiloxane bond formation and a homogenous type hybrid network. At elevated water concentrations, the carbosiloxane formation was hydrolyzed resulting in non-terminated diol end groups with preferential orientation toward surface sites. Conclusions from the dissertation research have shown that the water content truly effects the final gel microstructure and chemical content.

ISBN: 9780599678064Subjects--Topical Terms:

516420
Chemistry.
Subjects--Index Terms:

Ormosil

Investigation of water -based silica and organically modified silicate sol -gel systems.
LDR:03654nmm a2200397 4500 001 2347851
005 20230509065517.5
006 m o d
007 cr#unu||||||||
008 241004s1999 ||||||||||||||||| ||eng d
020 $a 9780599678064
035 $a (MiAaPQ)AAI9963575
035 $a AAI9963575
040 $a MiAaPQ $c MiAaPQ
100 1 $a Parkhill, Robert Lynn. $3 3687150
245 1 0 $a Investigation of water -based silica and organically modified silicate sol -gel systems.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 1999
300 $a 255 p.
500 $a Source: Dissertations Abstracts International, Volume: 62-01, Section: B.
500 $a Publisher info.: Dissertation/Thesis.
500 $a Advisor: Knobbe, Edward T.
502 $a Thesis (Ph.D.)--Oklahoma State University, 1999.
506 $a This item must not be sold to any third party vendors.
506 $a This item must not be added to any third party search indexes.
520 $a Scope and method of study. The purpose of this study was to address chemical issues associated with developing a water-based sol-gel system. The studies were conducted to provide a foundation for identifying chemical and structural formations in low and high water-content synthetic processes. Both silicate and organically modified silicate (ormosil) systems were investigated with respect to water content, precursor use, curing temperature, and organic content. In each system, gels and films were characterized using 13C and 29Si Nuclear Magnetic Resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, and picnometry density measurements. Results of each study were used to identify fundamental chemical species evolution, and to help elucidate structural developments that take place in sol-gel materials derived from water-based processes. Findings and conclusions. Results from the pure silicate and organically modified silicate sol-gel systems indicated the use of variable water concentrations had profound effects on the resulting gel microstructure and chemical content. Results from the pure silica systems revealed a progressive development from linear chain to aggregate particle formation. The low water content gels were identified to have developed through the entanglement of linear chains to form dense microporous silica networks, while an increase in the water content led to increased cyclization of the polymeric siloxane chains and a progressive evolution in microstructure from branch-like to colloidal type particles. The effects of using a water-based process for the epoxide ormosil gels were identified with the stability of the epoxide functional group. Hydrolysis of the epoxide group and esterification of the diol-end group formation resulted in the development of two different types of networks. At low water concentrations, the diol group was esterified with silanol end groups resulting in the development of a carbosiloxane bond formation and a homogenous type hybrid network. At elevated water concentrations, the carbosiloxane formation was hydrolyzed resulting in non-terminated diol end groups with preferential orientation toward surface sites. Conclusions from the dissertation research have shown that the water content truly effects the final gel microstructure and chemical content.
590 $a School code: 0664.
650 4 $a Chemistry. $3 516420
650 4 $a Inorganic chemistry. $3 3173556
653 $a Ormosil
653 $a Silicate
653 $a Sol-gel
653 $a Water-based silica
690 $a 0488
690 $a 0485
710 2 $a Oklahoma State University. $3 626630
773 0 $t Dissertations Abstracts International $g 62-01B.
790 $a 0664
791 $a Ph.D.
792 $a 1999
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=9963575