聚乙烯基咪唑/陶瓷复合膜的渗透汽化性能  

Pervaporation Performance of the Poly(1-vinylimidazole)-grafted Ceramic Composite Membrane

作　　者：曹绪芝[1] 平郑骅[1] 

机构地区：[1]复旦大学高分子科学系教育部聚合物分子工程重点实验室,上海200433

出　　处：《化学学报》2008年第7期803-809,共7页Acta Chimica Sinica

基　　金：国家973基础研究(No.2003CB615702);国家自然科学基金(No.20374014)资助项目

摘　　要：通过自由基接枝聚合反应在硅烷化处理的沉积有SiO2活性层的无机陶瓷微孔膜上接枝乙烯基咪唑(VI),经质子化后,制备出一种聚电解质亲水性有机-无机复合膜.用FT-IR表征了接枝PVI前后化学组成的变化;用TGA测定了单体在二氧化硅粉末上的接枝率;用SEM观察了接枝反应前后膜表面形态的变化;并系统研究了操作条件对膜的渗透汽化分离性能的影响.结果表明,这种膜用于醇/水(甲醇、乙醇和异丙醇)、乙酸/水和丙酮/水溶液的分离都有很好的选择性和渗透性.在所测试的浓度和温度范围内,水在透过液中的含量都高于99%.尤其引人注意的是该膜用于甲醇水溶液分离时有很好的选择性和比其他醇水溶液更高的渗透性.膜的渗透性随操作温度的变化表现异常,结合SEM的结果可以推断有机单体主要是在无机膜的孔内接枝形成活性分离层.A hydrophilic polymeric/ceramic polyelectrolyte composite pervaporation membrane was prepared by free-radical graft polymerization of poly（1-vinylimidazole） onto the microporous ceramic membrane and protonation. The mineral support was pre-coated with active silica and pretreated by silane coupling agent to introduce vinyl end groups for the grafting. By means of FT-IR and TGA the chemical composition and grafting yield on the powder silica gel were measured. The membrane morphology was observed with SEM. The effect of operation conditions on the pervaporation performance of the membrane was also studied. The results showed that the composite membrane was very permeable and selective to water for the dehydration of the alcohol （methanol, ethanol or 2-propanol）, acetone and acetic acid. The water content in permeate was higher than 99% at studied feed concentration and temperature. It is noticeable to find the similar selectivity and higher permeation flux of this membrane in separation of methanol/water mixture than other alcohol/water mixtures. According to the abnormal variation of membrane permeation with operation temperature and SEM image it suggests that the grafting took place inside the pores of the ceramic supports.

关 键 词：渗透汽化 聚合物/陶瓷复合膜 聚乙烯基咪唑 阳离子聚电解质 

分 类 号：TQ028.8[化学工程]