超薄致密选择性分离层聚醚砜中空纤维膜制备及其气体性能

以聚醚砜为膜材料，N-甲基吡咯烷酮（NMP）为溶剂，乙醇（Ethanol）为非溶剂，NMP-Water为芯液，PES：NMP：Ethanol 35：57：8为铸膜液，采用干／湿相转化法制备了超薄致密选择性分离层PES中空纤维膜，讨论了芯液组成、芯液流量、硅橡胶种类、芯和凝胶槽温度对PES-A中空纤维膜结构、气体性能和机械性能的影响．实验结果表明，适宜的纺丝条件如下：凝胶槽温度17℃，芯液组成NMP：Water86：14，芯液流量0．15mL／min．在适宜的纺丝条件下，比较了PES-A和PES-B2种聚醚砜膜材料的O2／N2气体分离性能，PES-B中空纤维膜的O2／N2选择性为6．23，其O2渗透通量为9．65GPU．此外，在凝胶槽温度9～24℃范围内，PES-B中空纤维膜的O2／N2选择性为5．28～6．23，O2渗透通量为9．65-10．3GPU，并且其超薄致密选择性分离层为427-456A．因此，PES-B中空纤维膜更适合应用于气体分离．

O2/N2 SEPARATION PERFORMANCE OF PES HOLLOW FIBER MEMBRANES WITH AN ULTRATHIN DENSE-SELECTIVE LAYER

Using polyethersulfones as membrane materials, N-methyl-2-prirodidone （NMP） as a solvent, ethanol as a nonsolvent, NMP-water as the bore solution, the dope solution of PES ： NMP ： Ethanol 35 ： 57 ： 8 in wt% was obtained and PES hollow fiber membranes with an ultrathin dense-selective layer for O2/N2 separation were prepared by dry/wet phase separation method. Effects of bore fluid composition, bore fluid rate and silicone rubbers on the morphologies, gas performances and mechanical properties of PES hollow fiber membranes were discussed. On the basis of the experimental results, the suitable spinning conditions were as follows： coagulation bath temperature 17℃, bore fluid composition NMP ： water =86 ： 14 in wt% and bore fluid rate 0. 15 mL/min. Based on the comparison of O2/N2 separation performances of PES membrane materials under the suitable spinning conditions, the O2/N2 selectivity and the permeation flux of PES hollow fiber membrane were 6.23 and 9. 65 GPU, respectively. Besides, the mechanical properties of PES-B fibers were better than those of PES-A fibers while PES-B ultrathin dense-selective layers were 427--456 A. Therefore, PES-B hollow fiber membranes are more suitable for the industrial gas annlication.