Carbon based Nanofillers Embedded Fouling Resistant Polyvinyl Chloride Nanocomposite Membranes for Oil-water Separation

Abstract

Herein, we discussed the development of polyvinyl chloride (PVC) based nanocomposite ultrafiltration (UF) membrane by embedment of nanofillers such as carbon black (CB), graphitized carbon black (GCB) or mesoporous carbon, multiwalled carbon-nanotube (MWCNT), carboxylated multiwalled carbon-nanotube (CMWCNT) with increased permeate flux and fouling resistance. Ultrafiltration membranes were prepared using casting solution of PVC in N, N-dimethylacetamide (DMAc) solvent with polyethylene glycol with average MW 600Da (PEG-600) as additives with and without nanofillers. Membranes prepared were characterized in terms of pure water permeability, separation of single uncharged solutes like polyethylene oxide (PEO), water contact angle and tensile strength. Membranes were tested with synthetic oily waste water (1000 ppm oil-water emulsion) followed by pure water flux recovery after cleaning by flow reversal flushing using deionized water. The product flux was observed to increase by ~35.5%, ~11.4% & ~44.4% in PVC-GCB, PVC-MWCNT and PVC-CMWCNT membranes respectively than the pure PVC membranes. The flux recovery on cleaning of fouled membranes is ~56% in pure PVC membrane, whereas it is ~72%, ~74% & ~80% for PVC-GCB, PVC-MWCNT and PVC-CMWCNT membranes respectively. Incorporation of the carbon based nanofillers in pure polymer matrixes not only enhances the water permeability with marginal decrease of the separation performances but also it increases mechanical strength and the fouling resistance of the membranes. The carbon fillers-based PVC nanocomposite membranes are found promising candidates for cleaning oily wastewater.