Korean Journal of Chemical Engineering, Vol.40, No.5, 1141-1150, May, 2023
Thin film composite on sulfonated PVDF electrospun and its performance in nanofiltration
Thin-film composite membranes (TFC) have attracted great attention in the field of seawater and wastewater treatment. A novel nanofiltration membrane was fabricated via interfacial polymerization of meta phenylene diamine (MPD) and 1,3,5-benzene tricarbonyl chloride (TMC) on the surface of a recently developed nanofibrous mat from sulfonated PVDF (S-PVDF). Chlorosulfonic acid was used to sulfonate PVDF powder, and new peaks on 1HNMR and FT-IR techniques confirmed the preparation of S-PVDF. Using solutions of NaCl, CaCl2, MgSO4, and Na2SO4, a filtration trial was performed with dead-end filtration equipment. The results demonstrated that sulfonation of PVDF decreased the water contact angle from 137.1 for intact PVDF to 85.5 for S-PVDF/PVDF (50/50). In addition, it reduced the mean diameter of nanofibers from 300 to under 130 nm and, consequently, smaller pores with a mean size of around 90 nm were formed. The membrane containing 10% S-PVDF had the highest steady pure water flux by 25.5 L/m2h and exhibited higher rejection of bivalent and univalent salt ions (>97% bivalent and >88% univalent) with the sensible flow. The electrospun nanofibrous S-PVDF/PVDF proved to be a usable supporting material with a higher hydrophilic character that makes electrospun mats an interesting option for liquid treatment.