Synthesis and characterization of silver nanoparticle incorporated copolymer composite membrane for polymer enhanced ultrafiltration of hexavalent chromium ions from water

Abstract Removal of highly toxic chromium ions from water is of utmost necessity. The objective of the present work was to prepare a low‐cost ultrafiltration (UF) membrane for removal of Cr (VI) from water. UF membranes were prepared by phase inversion from the copolymers of acrylonitrile (AN) and partially neutralized acrylic acid (AA)/sodium acrylate (NaAA). Three such copolymers, CP15, CP10, and CP5 were prepared by emulsion polymerization with feed AN: AA/ NaAA molar ratios of 15:1, 10:1 and 5:1, respectively. Silver nanoparticles (AgNP) were incorporated in‐situ during the polymerization by chemical reduction of silver nitrate with ascorbic acid. CP5 and AgNP filled CP5AgNP UF membranes were prepared by varying the polymer concentration in dope solution ( C p ), evaporation time ( t eva ) and gelation temperatures ( T gel ). Various characterizations confirmed the structure, morphology, presence of AgNP, flux decline and antifouling properties of the membranes. For polymer enhanced ultrafiltration (PEUF), CP5 and CP5AgNP membranes prepared with C p /t eva /T gel of 13 wt%/90s/30°C with a molecular weight cut off (MWCO) of 7.4 kDa and 5.7 kDa, respectively, showed a pressure normalized flux/rejection of 184.64Lm −2 h −1 bar −1 /88.8% and 177.77Lm −2 h −1 bar −1 /91%, respectively from a feed containing 100 mg/L of Cr (VI) in the presence of 0.5 wt% PVA.