膜科学与技术

聚砜基复合正渗透膜的结构设计与性能表征

作者：凡祖伟，柯超，周建强，张如意，徐愿坚，张卫东

单位： 1. 北京新源国能科技集团股份有限公司研究院，北京 100044； 2. 北京化工大学化学工程学院，北京 100029

关键词：聚酯筛网；聚砜；聚酰胺；复合正渗透膜；脱水

出版年,卷(期):页码： 2018,38(2):66-72

摘要：

本文采用连续制膜技术制备聚酯（PET）筛网增强型聚砜（PSF）基膜，并通过两次刮涂的方法获取单皮层基膜；然后通过在基膜表面界面聚合制备复合正渗透（FO）膜。PET筛网的引入使基膜内部大孔贯通性变差，孔隙率和纯水通量降低；另一方面，却大大增强了基膜强度，并使其更具韧性。基膜引入PET筛网，所得复合膜正渗透过程中的内浓差极化程度有所增大；由于单皮层基膜底面较为疏松且PET筛网局部裸露出来形成界面大孔，故所得复合膜传质阻力降低，以2 mol/L的NaCl溶液为汲取液，其正渗透水通量比双皮层基膜复合膜高50%左右。本文提出一种提高正渗透膜性能的新型方法，即通过结构设计获取单皮层的基膜，不仅能够提高复合膜水通量，还能减少膜脱水现象的发生。

Polyester (PET) mesh reinforced polysulfone (PSF) substrate membrane was fabricated via continuous preparation technology, and the single-skinned substrate membrane was achieved by two-step coating method; then composite forward osmosis (FO) membrane was prepared through interfacial polymerization on the top surface of the substrate membrane. The substrate membranes with PET mesh had decreased macrovoid connectivity, porosity and pure water flux; on the other hand, they possessed greatly improved strength and tenacity. After introducing PET mesh into the substrate membrane, the composite membranes had increased degree of internal concentration polarization during FO process; the composite membrane with single-skinned substrate had lower mass transfer resistance due to the looser bottom surface and interfacial macrovoid induced by partly exposed PET mesh, whose FO water flux was about 50% higher than the double-skinned with 2 mol/L NaCl solution as the draw solution. This study proposed a novel method to improve the FO membrane performance, and the fabrication of single-skinned substrate through structural design not only improved the water flux of the composite membrane but also reduced the occurrence of dehydration.

第一作者简介：凡祖伟（1988—），男，安徽阜阳人，博士（后），工程师，从事聚合物膜材料、水环境污染控制技术等研发工作，E-mail：fanzwgoon@163.com

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