Preparation and membrane performance of poly(ethylene-co-vinyl alcohol) hollow fiber membrane via thermally induced phase separation
Preparation and membrane performance of poly(ethylene-co-vinyl alcohol) hollow fiber membrane via thermally induced phase separation
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DOI：
10.1016/j.polymer.2003.08.033
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发表时间：
2003-11-01
期刊：
影响因子：
4.6
通讯作者：
Kubota, N
中科院分区：
文献类型：
--
作者：
Shang, MX;Matsuyama, H;Kubota, N
采用热诱导相分离（TIPS）法制备了具有超滤性能的聚乙烯-乙烯醇（EVOH）中空纤维膜。为了防止稀释剂蒸发和中空纤维内表面形成较大的孔，采用稀释剂甘油作为孔液制作中空纤维的管腔。所制得的中空纤维膜呈现出皮肤层靠近外表面、皮肤层下方气孔较大、靠近内表面气孔较小的不对称结构。外表面附近较大孔隙的形成是由于水的渗透促进了孔隙的生长。对影响膜结构和性能的主要因素如EVOH中乙烯含量、冷却水浴温度和吸水速度等进行了广泛的研究。提高水浴温度和吸水速度，降低电导率，可以提高透水性。为了理解透水性和溶质吸附性的实验结果，必须同时考虑外表面孔隙的大小和孔隙之间的连通性。(C) 2003 Elsevier Ltd.版权所有。
Polyethylene-co-vinyl alcohol) (EVOH) hollow fiber membranes with ultrafiltration performance were prepared from EVOH/glycerol systems via thermally induced phase separation (TIPS). The diluent glycerol was used as bore liquid to make a lumen of the hollow fiber for the purpose of prevention of the diluent evaporation and the larger pores formation at the inner surface of the hollow fiber. The obtained hollow fiber membranes showed asymmetric structures with skin layer near the outer surface, the larger pores just below the skin layer and the smaller pores near the inner surface. The formation of the larger pores near the outer surface was due to the enhanced pore growth by the water penetration. Some primary factors affecting the structure and performance of the membranes such as ethylene content (EC) in EVOH, cooling water bath temperature and take-up speed were studied extensively. The water permeability can be improved by increasing the water bath temperature and the take-up speed and by decreasing the EC. Both the pore size at the outer surface and the connectivity between the pores have to be considered together to understand the experimental result of the water permeability and the solute rejection. (C) 2003 Elsevier Ltd. All rights reserved.