聚丙烯酸接枝型聚偏氟乙烯多孔膜的pH值感应开关特性

A series of pH-responsive gating membranes, with a wide range of grafting yields, were prepared by grafting poly (acrylic acid) (PAAC) onto porous polyvinylidene fluoride (PVDF) membrane substrates with a plasma-induced pore-filling polymerization method. The effect of grafting yields on gating characteristics of pH-responsive gating membranes was investigated systematically. The results showed that the grafting yield heavily affected water flux, pH-responsiveness coefficient and pH-responsive gating factor of membrane pore size. When the grafting yield was smaller than 1.01%, both flux responsiveness coefficient and pH-responsive gating factor of pore size increased with increasing grafting yield. When the grafting yield was in the range from 1.01% to 6.44%, both flux responsiveness coefficient and pH-responsive gating factor of pore size decreased with increasing grafting yield； however, when the grafting yield was higher than 6.44%, both flux responsiveness coefficient and pH-responsive gating factor of membrane pore size approached to 1, i.e. , little gating characteristics existed. In order to obtain a satisfactory pH-responsive gating property of the membrane, the grafting yield must be kept in a proper range.

pH-RESPONSIVE GATING CHARACTERISTICS OF PAAC-GRAFTED POROUS POLYVINYLIDENE FLUORIDE MEMBRANES

A series of pH responsive gating membranes, with a wide range of grafting yields, were prepared by grafting poly(acrylic acid) (PAAC) onto porous polyvinylidene fluoride (PVDF) membrane substrates with a plasma induced pore filling polymerization method The effect of grafting yields on gating characteristics of pH responsive gating membranes was investigated systematically.The results showed that the grafting yield heavily affected water flux, pH responsiveness coefficient and pH responsive gating factor of membrane pore size When the grafting yield was smaller than 1 01%, both flux responsiveness coefficient and pH responsive gating factor of pore size increased with increasing grafting yield.When the grafting yield was in the range from 1 01% to 6 44%, both flux responsiveness coefficient and pH responsive gating factor of pore size decreased with increasing grafting yield;however, when the grafting yield was higher than 6 44%, both flux responsiveness coefficient and pH responsive gating factor of membrane pore size approached to 1, i e , little gating characteristics existed.In order to obtain a satisfactory pH responsive gating property of the membrane, the grafting yield must be kept in a proper range.