Modification of PSf/SPSf Blended Porous Support for Improving the Reverse Osmosis Performance of Aromatic Polyamide Thin Film Composite Membranes

• Published in: Polymers Vol. 10; no. 6; p. 686
• Main Authors: Liu, Li-Fen, Gu, Xing-Ling, Xie, Xin, Li, Rui-Han, Yu, Chun-Yang, Song, Xiao-Xiao, Gao, Cong-Jie
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 20.06.2018; MDPI
• Subjects: Aramid fibers; blending porous support; Contact angle; doping content of SPSf; Membrane separation; Membranes; Morphology; Permeability; Physical properties; Polyamide resins; polyamide TFC membrane; Polymerization; Polymers; Polysulfone resins; pore nature; Pore size; Porosity; Reverse osmosis; reverse osmosis performance; Separation; Solvents; sulfonated polysulfone; Thin films; Ultrafiltration; China; doping content of SPSf; polyamide TFC membrane; sulfonated polysulfone; blending porous support; pore nature; reverse osmosis performance
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym10060686

In this study, modification of polysulfone (PSf)/sulfonated polysulfone (SPSf) blended porous ultrafiltration (UF) support membranes was proposed to improve the reverse osmosis (RO) performance of aromatic polyamide thin film composite (TFC) membranes. The synergistic effects of solvent, polymer concentration, and SPSf doping content in the casting solution were investigated systematically on the properties of both porous supports and RO membranes. SEM and AFM were combined to characterize the physical properties of the membranes, including surface pore natures (porosity, mean pore radius), surface morphology, and section structure. A contact angle meter was used to analyze the membrane surface hydrophilicity. Permeate experiments were carried out to evaluate the separation performances of the membranes. The results showed that the PSf/SPSf blended porous support modified with 6 wt % SPSf in the presence of DMF and 14 wt % PSf had higher porosity, bigger pore diameter, and a rougher and more hydrophilic surface, which was more beneficial for fabrication of a polyamide TFC membrane with favorable reverse osmosis performance. This modified PSf/SPSf support endowed the RO membrane with a more hydrophilic surface, higher water flux (about 1.2 times), as well as a slight increase in salt rejection than the nascent PSf support. In a word, this work provides a new facile method to improve the separation performance of polyamide TFC RO membranes via the modification of conventional PSf porous support with SPSf.