内凝固浴流速对聚醚酰亚胺中空纤维膜结构与性能的影响

Effects of Bore Fluid Flow Rate on the Morphologies and Properties of PEI Hollow Fibre Membrane

以N,N 二甲基乙酰胺为溶剂,水为内、外凝固浴,制备聚醚酰亚胺中空纤维膜,研究了内凝固浴流速对膜的形态结构、分离性能以及力学性能的影响。实验结果表明:随着内凝固浴流速的提高,纤维外径略有下降、内径有较大程度的提高、壁厚减小,其它结构无明显变化。与此相对应,膜的力学性能有一定程度的下降,而水通量有很大程度的提高,截留率变化不大。当内凝固浴流速/纺丝液流速大于 0.4 时,纤维内壁表面产生较大的轴向应力,把处于相分离早期的分子链或分相微区拉开,产生了微孔。

Polyetherimide (PEI) hollow fiber membranes were prepared with phase inversion method. It is found that, with the increase of bore fluid flow rate, the mechanical properties decrease gradually, the pure water permeation flux increase obviously while the retention keeps almost constant for the membranes. All these results could be ascribed to the structure changes, which were observed by scanning electron microscopy.