1987 Fiscal Year Final Research Report Summary
Mono- and Multicomponent Porous Oxide Glasses Prepared by the Sol-Gel Process
| Project/Area Number |
61470074
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
無機工業化学
|
|---|
| Research Institution | Okayama University |
|---|
Principal Investigator |
TAKAHASHI Katsuaki President Okayama University, 学長 (90032911)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
ODA Kiichi Faculty of Engineering, Okayama University, 工学部, 助手 (50033410)
OSAKA Akiyoshi Faculty of Engineering, Okayama University, 工学部, 助教授 (20033409)
MIURA Yoshinari Faculty of Engineering, Okayama University, 工学部, 教授 (80032952)
|
|---|
| Project Period (FY) |
1986 – 1987
|
| Keywords | Sol-Gel process / silica glass / borosilicate / solvent / catalyst / organometallic compounds / crystallization / 結晶化 |
|---|
| Research Abstract |
Mono- and multicomponent porous glasses have been prepared by the sol-gel process using organometallic compounds, and their pore characteristics have been investigated as a function of the starting material, catalyst, solvent and their mixing ratio.
1. Gel derived silica glass. Gelation time was dependent on the solvent and its concentration in the solution. Granular gels and glass were easily obtained by using HF as the catalyst. HC1-catalysis of tetraethoxysilane (Si(OEt)^4:TEOS) with 1-hexanol takes three times as long for gelation as that with ethanol as the solvent. H^3PO^4 catalysis gave a pore characteristic similar to the HC1 catalysis though more water and organics (mainly ethanol) were trapped in the gels with H^3PO^4 Gel-derived silica glass containing smaller amount of Na^2O precipitated cristobalite at about 650゜C, indicating that the heat treatment should be done at temperatures lower than 600゜C for fixing useful oxides like calcium apatite on the surface of the pores.
2. Sodium borosilicate glasses. The glass of composition 5Na^2O.15B^2O.^3.80SiO^2(wt%) has been.prepared from NaOCH^3, B(OCH^3)^3 and TEOS with HCl as the catalyst and ethanol nol as the solvent. Porosity and specific surface area increased with heat-treatment temperature and reached a maximum value at 450゜C, and decreased to null (pores collapsed). Slight phase separation was observed as well as in the melt-quenched borosilicate glass of the same composition. Cristobalite was precipitated by the treatment at 800゜C from the gel-derived borosilicate glasses. It was concluded that the sodium ions are interacted with Si atoms forming Si-ONa bonds in the gels but not with boron atoms, and that the del-derived glass has no BO^4 units and is different from the melt-quenched glass.
|
