Effect of Grafting Yields on the Gating Characteristics of Thermo-Responsive Gating Membranes

摘要

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 the grafting yield on the gating characteristics of thermo-responsive gating membranes was investigated systematically. The results showed that the grafting yield heavily affected all of the water flux, the responsiveness coefficient and the thermo-responsive gating factor of membrane pore size. When the grafting yield was smaller than 2.81%, the responsiveness coefficient and the thermo-responsive gating factor of pore size both increased with increasing the grafting yield; however, when the grafting yield was higher than 6.38%, both the responsiveness coefficient and the thermo-responsive gating factor of membrane pore size always tended to 1, that is, no gating characteristics existed. In order to obtain a satisfactory gating property of the membrane, the grafting yield must be kept to a proper level.