N-异丙基丙烯酰胺接枝聚乙烯微孔膜的结构形态和动电现象

用等离子体接枝法，在聚乙烯（PE）微孔膜上，接枝了具有温敏性的聚N－异丙基丙烯酰胺（PNIPAAm)。X射线电子能谱（XPS）、红外光谱（FT－IR）测试表明，PNIPAAm接枝链同时存在于N－异丙基丙烯酰胺接枝聚乙烯（NIPAAm-g-PE)温敏性接枝膜的微孔外表面及膜孔内部，接枝链在低临界溶解温度（LCST）32℃上下具有不同的形态结构。透过实验表明，接枝膜的水通量在LCST附近发生了5倍以上的急剧变化。流动电位研究表明，温度低于LCST时，接枝膜微孔表面zeta电位和电荷密度为较小的负值；温度高于LCST时，zeta电位和电荷密度仍为负值，但其绝对值急剧增加，并且随温度的升高继续增加。

Configuration and electrokinetic phenomena of N-isopropylacrylamide grafted polyethylene microporous membranes

Temperature-sensitive poly(N-isopropylacrylamide)was grafted onto the polyethylene microporous membrane by plasma-induced graft polymerization technique.The results of XPS analysis and FT-IR analysis indicate that the grafted chains exist both on the outside surface and on the pore walls of the grafted membrane.The XPS result also confirms that the grafted chains have different configuration below and above the low critical solution temperature(LCST).The permeation experiment shows that the permeate flux of the grafted membrane varies sharply with narrow temperature change in close vicinity to the LCST.Streaming potential method was used to characterize the electrical property of the grafted membrane.The results show that the grafted membrane possesses the negative charges.The zeta potential and charge density of the grafted membrane change dramatically around the LCST and their absolute values increase with the growth of temperature.