Evolutionary mechanism of b-oriented TS-1 film on porous a-Al2O3 supported chitosan surface in hydrothermal reactions

The acid-base titration, atomic force microscopy （AFM）, contact angle technique, energy dispersive X-ray （EDX） and electron probe microanalysis （EPMA） were performed to check the existence of the gel-layer on the chitosan surface after it was dipped in aqueous TPAOH solution as well as in TS-1 synth...

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Bibliographic Details
Published in:Chinese science bulletin 2010 (27), p.3131-3137
Main Author: LIU XiuFeng WANG XiaoDong NA Ping JIANG HaiYang LANG Lin ZHAO HongShe ZHANG BaoQuan
Format: Article
Language:English
Subjects:
Al2O3
壳聚糖
水热反应
进化机制
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Summary:The acid-base titration, atomic force microscopy （AFM）, contact angle technique, energy dispersive X-ray （EDX） and electron probe microanalysis （EPMA） were performed to check the existence of the gel-layer on the chitosan surface after it was dipped in aqueous TPAOH solution as well as in TS-1 synthesis solution. The evolution of TS-1 monolayer and multi-layered film on the chitosan surface was studied using SEM imaging at different stages during hydrothermal reactions. Experimental evidence for the formation mechanism of supported zeolite films and membranes revealed that a gel-layer enriched with TPA cations and TS-1 precursors was first formed on the chitosan surface, followed by the nucleation within the gel-layer especially on the chitosan surface. The nuclei formed on the chitosan surface were further transformed into crystalline particles and TS-1 crystal grains. The nuclei beyond the chitosan surface subsequently grew up, leading to the formation of multi-layered TS-1 film with preferential b-orientation. The result is significant for engineering the microstructure of supported zeolite films and membranes in hydrothermal reactions.
ISSN:1001-6538
1861-9541