A Study on Synthesis of Silicates by High-Pressure Hydrothermal Method using Organic Template Reagents

Research Project

Project/Area Number	02650551
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	無機工業化学・無機材料工学
Research Institution	Osaka University
Principal Investigator	MACHIDA Ken-ichi Osaka University, Applied Chemistry, Associate Professor, 工学部, 助教授 (00157223)
Co-Investigator(Kenkyū-buntansha)	KODAIRA Kohei Hokkaido University, Applied Chemistry, Professor, 工学部, 教授 (60002002) ADACHI Gin-ya Osaka University, Applied Chemistry, Professor, 工学部, 教授 (60029080)
Project Period (FY)	1990 – 1991
Project Status	Completed (Fiscal Year 1991)
Budget Amount *help	¥1,900,000 (Direct Cost: ¥1,900,000) Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
Keywords	Silicates / Zeolites / Hydrothermal Method / Organic Template Reagent / Rare Earth Complexes / Luminescence Property / 希土類元素
Research Abstract	This study was carried out on the influences of pressure conditions and organic ions on the morphology of the silicates prepared by high-pressure hydrothermal method. Also, the physicochemical environmental characteristics of the micropores of zeolites were investigated by using the rare earth ion with excellent luminescence properties as a probe. (1) Influence of the organic template ions on the morphology of resulting zeolites A series of unsymmetrical tetraalkyl ammonium salts with the composition formula of R_3R'N^+X^- (R=R') were synthesized and were used to prepare the pentasil-type ZSM-5 zeolite. The composition and morphology of the zeolites obtained by using them were considerably different from those of ZSM-5 zeolite. This indicates that the unsymmetrical ammonium salts possess a possibility for the formation of new zeolites. (2) Physicochemical environment of the micropores of zeolites The zeolites ion-exchanged with Eu^<3+> ions showed a red emission bands based on the f-f transition, and this luminescence properties were modified by introductions of organic ligands such as 2, 2' -bipyridene, 2, 6-pyridinecarboxylic acid, and acetylacetone. Particularly, the luminescence intensity was considerably increased. The symmetry around the Eu^<3+> ion in zeolites was discussed on the basis of the luminescence patterns.