等离子体诱导接枝聚合法制备pH感应开关膜

利用等离子体诱导填孔接枝聚合法在聚偏氟乙烯多孔膜上接枝聚甲基丙烯酸pH感应型开关,系统研究了接枝率对膜的pH感应开关特性的影响.结果表明,开关膜的接枝率对膜的过滤通量、pH感应开关系数和膜孔径感应pH变化倍数都有重要的影响.接枝率≤5.98%时,pH感应开关系数和膜孔径感应pH变化倍数均随接枝率的增加而增加;而对于接枝率＞5.98%的膜,pH感应开关系数和膜孔径pH感应变化倍数随接枝率的增加而减少,直至膜开关系数和膜孔径pH感应变化倍数趋近于1.为了获得较好的开关性能,必须将膜的接枝率控制在适当的范围内.

pH-RESPONSIVE GATING MEMBRANES PREPARED BY PLASMA-INDUCED PORE-FILLING GRAFT POLYMERIZATION

A series of pH-responsive gating membranes with a wide range of grafting yields were prepared by grafting poly(methacrylic acid) (PMAA) onto porous polyvinylidene fluoride (PVDF) membrane substrates with a plasma-graft pore-filling polymerization method. The effect of PMAA grafting yield on the gating characteristics of pH-responsive gating membrane was investigated systematically. The results show that the grafting yield of PMAA heavily affects the water flux, the pH-responsiveness coefficient and the pH-responsive gating factor of membrane pore size. When the grafting yield is smaller than 5.98%, both the pH-responsiveness coefficient and the pH-responsive gating factor of membrane pore size increase with increasing the grafting yield; however, when the grafting yield is higher than 5.98%, both the pH-responsiveness coefficient and the pH-responsive gating factor of membrane pore size decreas with increasing grafting yield. When the grafting yield is larger than 13.38%, the pH-responsiveness coefficient is equal to 1, i.e., no gating characteristics exist any more. To get a desired pH-responsive gating property, the membranes should be designed and prepared with a proper range of grafting yield.