A chlorine-tolerant nanofiltration membrane prepared by the mixed diamine monomers of PIP and BHTTM

• Published in: Journal of membrane science Vol. 498; pp. 374 - 384
• Main Authors: Tang, Yong-Jian, Xu, Zhen-Liang, Xue, Shuang-Mei, Wei, Yong-Min, Yang, Hu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-01-2016
• Subjects: Chlorine-tolerant; Interfacial polymerization; Mixed diamine monomers; Nanofiltration; Polysulfone UF membrane; Polysulfone UF membrane; Interfacial polymerization; Nanofiltration; Mixed diamine monomers; Chlorine-tolerant
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2015.10.028

Using Polysulfone (PSF) ultrafiltration (UF) membrane as porous support, a chlorine-tolerant nanofiltration (NF) membrane was prepared by interfacial polymerization of piperazine (PIP) and 2,2'-bis(1-hydroxyl-1-trifluoromethyl-2,2,2-triflutoethyl)-4,4'-methylenedianiline (BHTTM) mixture with trimesoyl chloride (TMC). The XPS, SEM, AFM and contact angle methods were employed to characterize the physicochemical properties and morphology of the prepared NF membranes. The effects of preparation conditions such as reaction time, monomers mixing ratio and oxidation treatment on NF membrane performance were investigated. The salt rejection of the NF membrane met the order of Na2SO4>MgSO4>NaCl, indicating the membrane possessed a negative surface charge. The results showed the NF membrane prepared under the optimum conditions exhibited pure water flux (PWF) with 79.1 (L/m2h) and Na2SO4 rejection of 99.5% under 0.6MPa. The optimized post oxidation condition was treated by 3000ppm NaClO solution for 1h. The best NF membrane had a molecular weight cut-off (MWCO) less than 300Da, corresponding to the pore size of 1nm, which was calculated from the rejection of carbohydrates. The robustness of the NF membrane was proven by showing satisfactory stability in the long time running.
•A chlorine-tolerant NF membrane was prepared by PIP and BHTTM.•Effect of BHTTM/PIP mixing ratio on NF membrane performance was studied thoroughly.•The NF membrane shows high salt rejection, high flux and high chlorine resistance.