非溶剂添加剂对聚醚砜超滤膜结构的影响

以聚醚砜 (PES)铸膜液体系及超滤膜为研究对象 ,研究了 2种无机添加剂氯化锂和磷酸对铸膜液性质和超滤膜结构的影响 .结果表明 ,磷酸或氯化锂的加入对皮层形态和断面结构都有明显影响 .在膜形成过程中 ,皮层的形成对水与DMAc之间的扩散造成阻力 .氯化锂和磷酸的存在 ,在一定程度上抑制了聚醚砜超滤膜亚层中大空腔的形成 ,有利于尺寸较小的指状孔的形成

The effect of nonsolvent additives on structure of polyethersulfone ultrafiltration membranes

The polyethersulfone (PES) casting solution and its prepared ultrafiltration membranes were investigated. The effect of two inorganic additives, lithium chloride and phosphoric acid, on properties of the casting solution and the membrane structures was studied. The results showed that the addition of lithium chloride and phosphoric acid had a significant effect on the morphology of the surface and the structure of cross section of the membranes. The formed toplayer restricted the interdiffusion between water and DMAc during the membrane-forming process. To some extent, the existence of lithium chloride and phosphoric acid suppressed the formation of macrovoids while it favored the formation of the small-size fingerlike pore.