温度感应式开关膜的接枝率对其开关特性的影响

利用等离子体诱导填孔接枝聚合法将聚(N-异丙基丙烯酰胺)（PNIPAM）接枝聚合在聚偏氟乙烯（PVDF）微孔膜上制备了一系列具有较宽接枝率范围的温度感应式开关膜，系统地研究了接枝率对膜的温度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、温度感应开关系数和膜孔径感温变化倍数都有十分重要的影响.接枝率在小于等于2.81%时，温度感应开关系数和膜孔径感温变化倍数均随接枝率增加而增加；而对于接枝率大于等于6.38%的膜，膜开关系数和膜孔径感温变化倍数总是趋近于1，膜不具备温度感应开关特性.为了获得预期的开关性能，必须将膜的接枝率控制在适当的范围.

EFFECT OF GRAFTING YIELD ON GATING CHARACTERISTICS OF THERMO-RESPONSIVE GATING MEMBRANES

A series of thermo-responsive gating membranes, with a wide range of grafting yields, were prepared by grafting poly(N-isopropylacrylamide)(PNIPAM) onto porous polyvinylidene fluoride (PVDF) membrane substrates with a plasma-induced pore-filling polymerization method. The effect of grafting yield on gating characteristics of thermo-responsive gating membranes was investigated systematically. The results showed that the grafting yield heavily affected water flux,responsiveness coefficient and thermo-responsive gating factor of membrane pore size. When the grafting yield was smaller than 2.81%, both responsiveness coefficient and thermo-responsive gating factor of pore size increased with increasing grafting yield; however, when the grafting yield was higher than 6.38%, both responsiveness coefficient and thermo-responsive gating factor of membrane pore size were always equal to 1, i.e., no gating characteristics existed. In order to obtain a satisfactory gating property of the membrane, the grafting yield must be kept in a proper range.