以聚乙烯醇(PVA)为原料,在PVA水溶液中添加不同类型的金属盐,制备不同金属盐改性的PVA渗透汽化膜,讨论了金属盐对膜溶胀度、机械性能和渗透汽化能力的影响.实验结果表明,加入金属盐(除镁盐)后,改性膜的溶胀度降低,膜的稳定性提高;添加金属盐均能提高膜分离乙酸乙酯溶液的渗透汽化通量.通过改性膜综合性能的比较,LiCl改性膜性能更为优异.随着LiCl含量的增加,膜通量增大.当LiCl添加量为0.1mol时,渗透通量J=110g/(m^2·h),分离因子α=1 700;添加0.3mol LiCl时,J=536g/(m^2·h),α=1 000.
Using PVA as raw material,polyvinyl alcohol(PVA)membranes modified by metal salts were prepared by adding metal salts into PVA solutions.The effects of metal salts on the swelling degree,mechanical properties and pervaporation performance of the membranes were studied.The results revealed that the swelling degree of modified membranes decreased and the stability enhanced after adding metal salts except magnesium salts.And in separating the solution of ethyl acetate the fluxes of membranes were increased after adding metal salts.Considering the comprehensive performance of modified membranes,membranes modified by lithium chloride were more excellent.The flux increased with the increase of LiCl content,when LiCl content was 0.1mol,the flux J=110g/(m^2·h),the separation factorα=1 700;LiCl content was 0.3mol,J=536g/(m^2·h),α=1 000.