Fabrication of cellulose acetate–zirconia hybrid membranes for ultrafiltration applications: Performance, structure and fouling analysis

Abstract

Organic–inorganic hybrid membranes were fabricated by solution casting using different ratios of cellulose acetate (CA) and zirconia (ZrO 2) in N,N′-dimethylformamide (DMF). The addition of ZrO 2 microparticles in the CA matrix was varied from 0 to 7 wt.%. The developed membranes were characterized for ultrafiltration (UF) performance, mechanical stability, morphology and fouling-resistant ability. It is found that the pure water flux increases from 15.6 to 46.7 lm −2 h −1 while the tensile strength decreases from 2 to 1.4 N/mm 2 with addition of zirconia from 0 to 7 wt.% to pure CA, respectively. Morphological studies indicate that the CA:ZrO 2 hybrid membranes possess asymmetric structure with ultra scale pores. From the pore statistics analysis, it was seen that the CA:ZrO 2 (6:4 ratio) hybrid membranes have an average pore radius of 47.52 Å compared to 26.88 Å of pure CA membrane. It was found that the hybrid CA:ZrO 2 membranes exhibit higher permeate flux for the separation of different molecular weight proteins compared to pure CA membrane. It has been demonstrated that the fouling-resistant ability and the recycling property of CA:ZrO 2 hybrid membranes are enhanced due to the high flux recovery ratio with the addition of ZrO 2 in the casting solution.