Stability study of PVDF/TiO2 dual layer hollow fibre membranes under long-term UV irradiation exposure

Abstract

Photocatalytic membrane has received overwhelming attention in recent years and has been considered as one of the most promising advanced oxidation processes. In such system, the photocatalytic membranes are constantly exposed to UV irradiation and the effects of UV irradiation on the structure and long-term stability of polymer membranes are still questionable, and therefore, it deserves to be investigated. This study focuses on the stability of the TiO2/PVDF dual layer hollow fiber (DLHF) membranes against photocatalytic reactions for photocatalytic-membrane process. 3wt% of TiO2 nanoparticles loading in DLHF membranes was evaluated under 8W UVA in 30 days. The membrane stability was characterized by observing the changes in Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscope (SEM) and tensile strength analysis. The results revealed that some differences in FTIR peaks between new membranes and used membranes were found, suggesting that UV irradiation has some effect on the stability of the TiO2/PVDF membrane for 30 days exposure. The tensile strength of used membrane showed a moderate decrease with increasing UV exposure time, resulting in negative impacts on the membrane overall stability. This work is particularly importance to evaluate the sustainability of polymeric membrane, which has considered as heart of photocatalytic membrane reactor for wastewater treatment process.