Evolutionary mechanism of b-oriented TS-1 film on porous α-Al_2O_3 supported chitosan surface in hydrothermal reactions  

作　　者：LIU XiuFeng WANG XiaoDong NA Ping JIANG HaiYang LANG Lin ZHAO HongShe ZHANG BaoQuan 

机构地区：[1]School of Chemical Engineering and Technology and State Key Laboratory of Chemical Engineering, Tianjin University, Tianjin 300072, China [2]State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012, China

出　　处：《Chinese Science Bulletin》2010年第27期3131-3137,共7页

基　　金：supported by the National Natural Science Foundation of China(20636030,20776100 and 20776108)

摘　　要：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.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.

关 键 词：水热反应 进化机制 壳聚糖 AL2O3 TS 表面 电影 多孔 

分 类 号：TQ424.25[化学工程] Q111[生物学—普通生物学]