玉米醇溶蛋白导向合成b轴取向Silicalite-1担载膜

Preparation of b-axle Oriented Silicalite-1 Membrane by Zein Film as Directed Template

采用旋涂工艺在多孔氧化铝（α-Al2O3）基片上制备玉米醇溶蛋白（zein）膜,以预涂zein膜的Al2O3基材为载体,通过原位水热法合成了silicalite-1担载膜。结果表明：以zein膜为模板可有效导向合成优先b轴取向silicalite-1晶体,所制备silicalite-1膜层表面平整且连续性好。而在未涂覆zein膜的Al2O3基材上所合成的silicalite-1晶体呈随机取向,表面缺陷较大,需多次重复水热合成制备。渗透蒸发实验中选择有机溶剂含量为3%（质量分数）的乙醇/水和丙酮/水二元体系,考察料液温度在25-40℃范围内优先b轴取向silicalite-1担载膜对有机组分的筛分浓缩能力。实验表明,对乙醇和丙酮两组分的分离因子大小顺序为乙醇、丙酮,渗透通量的大小则刚好相反。

Zein film was deposited via spin coating zein ethanol aqueous solutions onto porous asymmetric α-Al2O3 tablets, and the highly b-axle oriented silicalite-1 membrane on the Al2O3 substrate pre-coated with zein film was prepared by in-situ hydrothermal synthesis method. The results show that the zein film as a direct template is conducive to the formation of highly b-axle oriented silicalite-1 crystals, and the b-axle oriented silicalite-1 membrane presents the surface flatness, uniform thickness and excellent continuity. However, the prepared silicalite-1 membrane on the Al2O3 substrate without zein film exhibits random orientation and bigger surface defects and repeats the hydrothermal procedures for several times to finish the preparation of separation layer. Based on the result of the pervaporation experiment, the highly b-axle oriented silicalite-1 membrane can effectively concentrate ethanol and acetone from 3%（mass fraction） ethanol–water and acetone–water binary feeds due to the pervaporation. The separation factor（α） of ethanol is lower than that of acetone, but the total permeate fluxe of ethanol is higher than that of acetone at 25-40 ℃.