聚哌嗪酰胺/聚砜纳滤复合膜结构的研究

Structure of polypiperazine amide/polysulfone nanofiltration thin film composites

以哌嗪水溶液和均苯三甲酰氯正己烷溶液,通过油水两相界面聚合在聚砜超滤膜表面形成功能层,制备了超薄聚哌嗪酰胺/聚砜纳滤复合膜,利用衰减全反射傅立叶变换红外技术和X光电子能谱研究了超薄复合膜(TFC)表面化学结构,利用扫描电子显微镜和原子力显微镜观察了膜的形态结构.结果表明,在最初很短聚合时间(<30s)内基膜表面形成一层聚酰胺脱盐功能层.新生功能层不能阻隔两相界面聚合,使得功能层不断增厚趋于稳定.基膜表层对复合膜通量影响很大,基膜表层越薄,所得TFC通量越大;TFC表面粗糙度与其性能关系密切,适宜的粗糙度可以使其获得高通量和高脱盐率.

A polypiperazine amide/polysuffone thin film composite（TFC） is prepared by interracial polymerization（IP） using trimesoyl chloride hexane solution as the oil phase and piperazine aqueous solution as the water phase on porous polysuffone substrate. The surface chemical structure of the TFCs is studied by attenuated total reflec- tion-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The morphology of the TFCs is observed by scanning electronic microscope and atomic force microscope. The results show that a polyamide barrier layer is formed on the substrate within a very short IP time （〈30 s）. The thickness of the barrier layer gradually increases to a plateau with IP because the nascent barrier layer can not hold the monomers in the two phases. The effect of the dense top layer of the substrate on the flux of TFC is important. The thinner the dense top layer, the greater the flux of TFCs. An optimal roughness of TFC surface will enable it to reach a high flux and a high desalination.