Synthesis of Photocatalytic Ultrafiltration Membranes From MMT/TiO2‐Copolymer Nanocomposite for Removal and Degradation of Organic Pollutants From Water

ABSTRACT Photocatalytic membranes can simultaneously remove and degrade organic pollutants in water. Nano TiO 2 and sodium montmorillonite (NaMMT) nanoclay were incorporated into poly (acrylonitrile‐co‐N‐vinyl‐2‐pyrrolidone) copolymers during their synthesis via emulsion polymerization. A number of photocatalytic nanocomposites were prepared by altering the molar ratios of acrylonitrile and N‐vinyl‐2‐pyrrolidone and the weight % of TiO 2 and clay. These nanocomposites were converted into ultrafiltration membranes by the phase inversion technique. The membrane polymers were characterized. The contact angles, mechanical characteristics, molecular weight cut‐off (MWCO), antifouling characteristics, and pore size distribution were used to analyze the resulting membranes. The membranes were utilized for the removal of cationic methylene blue dye from water in the presence of anionic sodium dodecylsulfonate (SDS) emulsifier by micellar‐enhanced ultrafiltration (MEUF). The membrane fabricated with acrylonitrile:N‐vinyl‐2‐pyrrolidone molar ratio of 10:1, 1% TiO 2 , 1% NaMMT, and an evaporation time/gelation temperature of 90 s/30°C showed a flux/rejection of 88.1 L/m 2 h/98% for 50 mg/L methylene blue in the presence of 10 mM SDS at an operating pressure of 0.1 MPa. The same membrane showed 95.5% degradation after 150 min exposure to sunlight with a first‐order rate constant of 0.0046 min −1 .