取向TS-1分子筛膜的合成与结构引导机理

通过壳聚糖的引导作用, 采用水热法在氧化铝载体上原位合成了b-轴取向的钛硅分子筛(TS-1)膜. 使用XRD、SEM等手段对所合成的TS-1膜进行了表征. 通过漫反射FT-IR和接触角的测定描述了壳聚糖薄膜的表面官能团、壳聚糖薄膜表面与合成液的相互作用. SEM结果表明, 在壳聚糖的引导下可得到b-轴取向的TS-1膜, 而直接在氧化铝载体上只能得到无序的TS-1膜层. XRD的测量结果表现了典型的TS-1结构. 漫反射FT-IR和接触角的测试结果表明, 由于壳聚糖表面官能团的作用, 其表面形成过渡层, 经过成核, 晶核生长得到片状TS-1晶体颗粒, 最后获得多层b-轴取向的TS-1膜.

Fabrication and structure-directing mechanism of oriented TS-1 films

The b-oriented TS-1 films on α-Al₂O₃ substrates were synthesized by using in situ crystallization by the inducing effect of the chitosan thin film.The synthesized TS-1 films were characterized with XRD and SEM.The functional groups on the chitosan film surface and the interactions between the chitosan film and synthesis solution were described by using diffuse-reflectance FT-IR and contact angle measurements.It was shown that the b-oriented TS-1 film could be synthesized with the help of the chitosan thin film, whereas the randomly oriented TS-1 film was obtained on the α-Al₂O₃ substrate without chitosan induction.The XRD patterns of the synthesized films revealed that the crystals possessed TS-1 zeolite structure.The diffuse-reflectance FT-IR spectrum and contact angle measurements exhibited that the functional groups were abundant on the surface of the chitosan thin film, which could attract organic and inorganic compounds.Therefore, a transitional layer could be formed on the chitosan film, with nucleation and crystal growth to sheet-shaped TS-1 crystal grains, eventually leading to the formation of the multilayer b-oriented TS-1 film.