Dye degradation and antifouling properties of polyvinylidene fluoride/titanium oxide membrane prepared by sol-gel method

The modified polyvinylidene fluoride (PVDF) membranes were fabricated by grafting acrylic acid on the membrane and coating it with titanium dioxide sol. TiO2 sols were prepared using varying precursor volume and solution pH. The TiO2 coated membranes were tested for its photocatalytic property using Reactive Black 5 (RB5) dye and antifouling and self-cleaning properties using 1%BSA solution. FT-IR spectroscopy and contact angles confirmed the presence of polyacrylic acid (PAA) and TiO2 on the membrane surface. The performance of the membranes, evaluated via crossflow filtration experiment, significantly improved as evident in the increase in flux and permeability of modified membranes. The rate of RB5 dye color removal due to immobilized TiO2 follows a pseudo-first-order kinetics. PVDF/PAA/TiO2/pH1.25 exhibited superior photocatalytic property, removing 98.77% of the color in a span of 5 h. The resistance study showed that modified membranes have lower total filtration resistance (RT) with PVDF/PAA/TiO2/PH1.25 having the lowest. The performance of fouled membranes flux and transmembrane pressure (TMP) was recovered through UV irradiation, and the highest recovery was demonstrated by PVDF/PAA/TiO2/pH1.25.