PVA/TEOS/GA杂化膜的制备及溶胀吸附性能

采用溶胶-凝胶法(sol-gel)制备了PVA/TEOS/GA有机/无机杂化膜,比较杂化膜在3种不同温度下在乙醇/水全浓度范围的溶胀性能,分析无机相和交联剂对PVA膜溶胀性能的影响.比较不同溶胶-凝胶反应条件及不同热处理条件对膜溶胀度和溶解选择性的影响.用FTIR和XRD对杂化膜结构进行分析表征.结果表明PVA与无机相(TEOS)发生溶胶-凝胶反应生成氢键和共价键Si-O-Si,形成交联有机聚合物/无机杂化体系,使杂化膜的结晶度减少,控制了膜的溶胀,提高膜的溶解选择性能,但膜的溶胀减少会使通量有所下降.加入GA后,使PVA杂化膜溶胀度和溶解选择性都有所提高,表明PVA杂化有利于控制膜在乙醇/水溶液中的溶胀,从而提高膜的分离性能.

Preparation of PVA/TEOS/GA Hybrid Membrane and Its Swelling Behavior

PVA/TEOS/GA hybrid membranes were prepared by sol-gel method.The swelling characteristics of the hybrid membranes in ethanol aqueous solutions over various concentrations were studied at three different temperatures.The effect of the addition of inorganic phase tetraethoxysilane(TEOS) and the crosslinking agent glutaraldehyde(GA) on the membranes swelling was tested.It showed that PVA/TEOS membrane presented the best swelling behavior with the addition of inorganic phase TEOS(15 wt%) to PVA.With the addition of GA to PVA/TEOS,the PVA/TEOS/GA sol could be easy to form cast film by the test of forming cast film,and the degree of hybrid membrane swelling increased.When the concentration of GA exceeded 8%(mass),PVA/TEOS/GA sol became gel and can't form membrane.The influence of the sol-gel reaction,annealing and dryness conditions on the sorptiondesorption behavior of the membranes was analyzed.The hybrid membranes were characterized by FTIR and XRD methods.The results indicated that hydrogen bond and covalence bond were formed between PVA and TEOS through the sol-gel reaction.Thus the membrane crystallinity was decreased and the membrane swelling was effectively limited.In the end,the membrane adsorption selectivity was increased.With the addition of GA,the swelling and adsorption selectivity for the hybrid membrane both increase.