“充填型”复合膜脱除水中微量有机氯化物的研究

Preparation of Composite Membrane by Plasma-graft Polymerization and its Pervaporation Properties for Removing Chlorinated Organics from Water

利用等离子体照射引发接枝聚合方式制备了具有“充填型”结构的复合膜,在渗透汽化膜分离过程中研究了其从水中脱除微量有机氯化物的分离性能。该复合膜由两种材料组成;耐溶剂性能优良的高密度聚乙烯多孔基膜和接枝聚合后充填于基膜微孔中的聚丙烯酸甲酯,后者形成渗透汽化过程的分离选择性。使用FT-IR光谱图证实基膜接枝后表面存在羰基,表明形成接枝聚合的复合膜。在室温下进行渗透汽化实验,能够有效脱除水中微量的二氯甲烷、三氯甲烷和三氯乙烯,其中脱除二氯甲烷的渗透汽化分离因子超过2000,渗透通量达到120g.(m2?h)?1。

A filling-type membrane was prepared by the plasma-graft polymerization technique and its separation performance was demonstrated by pervaporation for removing chlorinated organic from water. This membrane is composed of two materials: the solvent resistant porous substrate and the filling polymer, which fills the pores of the substrate and plays the role of separation medium. The high-density polyethylene (HDPE) was used as porous substrate and the methyl acrylate as grafting monomer. Comparison of the carbonyl group FT-IR spectra in grafted membrane with that in the substrate demonstrated the formation of filling-type composite membrane. Pervaporation separation of dichloromethane, chloroform and 1,1,2-trichloroethylene (TCE) from water with this membranes was carried out at ambient temperature. The results show that the filling-type membrane has good separation properties for removing chlorinated organics from water, and the separation factor for dichloromethane in water is over 2000 and flux over 120 g&middot(m2&middoth)-1.