Preparation and Characterization of CA−PEG−TiO2 Membranes: Effect of PEG and TiO2 on Morphology, Flux and Fouling Performance

Abstract

Modified cellulose acetate (CA) membranes were prepared by dissolving the polymers in a mixture of acetone (AC) and N, N dimethylacetamide (DMAc) (70:30) solvent and deionized (DI) water was used in the coagulation bath. The introduction of polyethylene glycol (PEG) additive and TiO2 nanoparticles (NPs) into the casting solution has changed the structures of the resulting membranes during the phase inversion process. Effects of PEG additive and TiO2 NPs on the preparation of the phase-inverted CA ultrafiltration membrane were investigated in terms of morphology, equilibrium water content (EWC), pure water flux (PWF), hydraulic resistance, thermal stability, water contact angle (WCA) and anti-fouling performance. Improvements in average pore size, porosity, thermal stability, and the hydrophilic nature of the CA membranes was detected after the introduction of PEG and TiO2 simultaneously to the polymer matrix. Thermo gravimetric analysis (TGA) results confirmed that the interaction between TiO2 and the degradation temperature of the CA membrane were significantly improved. The anti-fouling performance and the flux recovery potential of the membranes were investigated using the bovine serum albumin (BSA) protein. The M3 (CA-PEG-TiO2) membrane (10.5 Wt. % CA: 4 Wt. % PEG: 2 Wt. % TiO2) exhibited the highest BSA flux result and normalized flux recovery ratios (NFR) for the three fouling cycles.