Catalytic performance of polyvinylidene fluoride (PVDF) supported TiO2 additive at microwave conditions

Abstract

TiO2 is a widely used additive material to improve the properties of filtration membranes. Asfar as its contribution to filtration performance, TiO2 acts as a catalytic agent. In this study, the catalyticactivity of TiO2 added PVDF flat sheets (membranes) prepared by the phase inversion method, and wetested them on the oxidation of benzyl alcohol at microwave irradiation. We investigated the structure,thermal behaviors, and morphology of samples by FTIR, TG-DTA, and SEM analysis, respectively. Contactangle measurements determined the hydrophilicity, and we observed the interaction between TiO2 andPVDF chain. TiO2-added PVDF membranes had improved filtration and rejection performance. 32.4% BSArejection was obtained with composites while it was 7.5% for the pristine membrane. We obtained93.86% conversion and 56% selectivity with composites in a microwave-assisted batch reactor. Thedecomposition of the polymer increased with a 6% additive due to the catalytic effect of TiO2 then, and itdecreased with further loading. We obtained detailed evidence by activation energies (Ea) ofdecomposition calculated by Kissinger’s method. The microwave-assisted catalytic effect of TiO2 inside thepolymeric matrix promise to obtain fast, high yielded, and disposable membrane materials for catalyticreactors to in-situ production of fine chemicals.