PH值与温度感应型智能开关膜的研究

Study on pH and Thermo-Responsive Intelligent Gating Membranes

利用等离子体诱导填孔接技聚合法将聚异而基丙烯酰胺(PNIPAM)或聚丙烯酸(PAAC)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型开关膜(接枝PNIPAM)和pH值感应型开关膜(接技PAAC),研究了接枝率对膜的温度感应以及pH值感应开关特性的影响。研究结果表明,开关膜的接枝率对膜的开关特性有十分重要的影响。对于温度感应型开关膜,当接枝率等于2.81％时,可以获得最好的膜孔开关特性;而且发现在溶质扩散时,低接枝率膜与高接技率膜呈现两种完全相反的开关特性。对于pH值感应型开关膜,当接枝率为1.01％时膜孔开关特性最好。因此,为了获得预期的开关特性,必须将接枝率控制在合适的范围内。

A series of thermo-responsive gating membranes and pH-responsive gating membranes,with a wide range of grafting yields,were prepared by grafting poly(N-isopropylacrylamide)(PNIPAM)or polyacrylic acid (PAAC)onto porous polyvinylidene fluoride (PVDF) membrane with a plasma-induced pore-filling polymerization method.The effect of the grafting yield on the gating characteristics of thermo and pH-responsive gating membranes was investigated.Results showed that the grafting yield heavily affected the gating characteristics.For the thermo-responsive gating membranes,the responsiveness coefficient of the membrane pore size was the largest when the grafting yield was 2.81% .In diffusional permeation experiments, results showed that the PNIPAM-grafted membranes with high and low grafting yields took on totally opposite gating characteristics.For the pH -responsive gating membranes, the responsiveness coefficient of the membrane pore size was the largest when the grafting yield was 1.01%.In order to obtain a satisfactory gating property of the stimuli-responsive membranes, the grafting yield must be kept to a proper level.