Synthesis of functional hydrophilic polyethersulfone-based electrospun nanofibrous membranes for water treatment

Abstract

The current study presents the synthesis and characterization of new ultrafiltration (UF) electrospun nanofibrous membranes (ENMs) combined with hydrophilic polyvinylpyrrolidone (PVP) for particular use in water purification. Three approaches were used to enhance the physicochemical properties of the typical ENMs. In the first strategy, n-methyl-pyrrolidinone (NMP) was mixed with dimethylformamide (DMF) during dope solution preparation wherein the mixed solvent could play a role in enhancing inter-fiber junctions. In the next strategy, PVP was added to the ENMs to enhance their water production. The final treatment was utilizing hot pressing on the resultant electrospun mat to strengthen its structure. Compared to pristine ENMs, the tensile strength and the elongation-at-break of the hot pressed ENMs were improved by 4.12 % and 9.09 %, respectively. However, the introduction of PVP into the ENMs was found to be significant in decreasing water contact angle by 50.8 % (from 123.27° to 60.66°), revealing a significant improvement in the membrane hydrophilicity. The ENMs also exhibited excellent water productivity of over 2996 L/m2h under gravitational force. It was observed that the hot pressed ENMs have smaller pore diameter (77.47 nm) in comparison to the pristine ENMs (97.15 nm). The enhanced mechanical and hydrophilic characteristics of the prepared ENMs showed high applicability to water treatment.