Supercritical Phase Inversion to Produce Photocatalytic Active PVDF-coHFP_TiO(2) Composites for the Degradation of Sudan Blue II Dye

TiO(2)-loaded poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-coHFP) membranes were produced by supercritical CO(2)-assisted phase inversion. Three different TiO(2) loadings were tested: 10, 20, and 30 wt% with respect to the polymer. Increasing the TiO(2) amount from 10 wt% to 20 wt% in the starting solution, the transition from leafy-like to leafy-cellular morphology was observed in the section of the membrane. When 30 wt% TiO(2) was used, the entire membrane section showed agglomerates of TiO(2) nanoparticles. These polymeric membranes were tested to remove Sudan Blue II (SB) dye from aqueous solutions. The adsorption/photocatalytic processes revealed that membrane morphology and TiO(2) cluster size were the parameters that mainly affected the dye removal efficiency. Moreover, after five cycles of exposure of these membranes to UV light, SB removal was higher than 85%.