Preparation of dense polysulfonamide acid-resistant composite membrane with high rejection based on polyethylene substrate

• Published in: Journal of membrane science Vol. 701; p. 122778
• Main Authors: Li, Feiyang, Zhai, Yuxia, Zhao, Shengchao, Xu, Zewen, Chen, Kuo, Wei, Bingxin, Sun, Haixiang, Hou, Yingfei, Wang, Ming, Li, Peng, Niu, Q. Jason
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2024
• Subjects: Acid resistance; Dense polysulfonamide membrane; Polyethylene substrate; Positive charge; Dense polysulfonamide membrane; Polyethylene substrate; Acid resistance; Positive charge
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2024.122778

Polysulfoneamide (PSA) separation membranes show promising prospects for use in acidic wastewater treatment due to their outstanding acid stability. However, current PSA membranes have the disadvantages of low flux, poor NaCl rejection, and poor acid resistance of substrate. In this paper, a positively charged PSA membrane was successfully prepared by using polyethylene (PE) stretch membrane (usually used as a battery diaphragm) as the substrate, with polyethyleneimine (PEI) and naphthalene-1,3,6-trisulfonyl chloride (NTSC) as the monomers for interfacial polymerization. The acid-resistant membrane exhibits a dense structure with an average pore size of just 0.2844 nm. Consequently, the membrane exhibits superior rejection rates for monovalent and divalent metals (MgCl2 99.15 %, CaCl2 98.85 %, MgSO4 94.5 %, NaCl 93.27 %), while also maintaining satisfactory flux. The membrane has excellent acid resistance, and maintains its superior separation performance after being immersed in 20 wt% H2SO4 at a high temperature of 24 h. [Display omitted] •PSA acid-resistant membrane with excellent performance by using porous PE substrate.•PSA membranes show 93 % rejection for NaCl.•PSA membrane has a positively charged surface, with rejection up to 99.1 % for MgCl2.•The differences between porous PE and PSF substrates were compared.•The influence of PEI Mw on membrane performance was discussed.