Fabrication and performance evaluation of polycarbonate/polyvinyl alcohol–titanium dioxide thin‐film nanocomposite membranes for water treatment

Abstract In recent years, there has been growing interest in using polymer nanocomposite membranes as a more advanced method for removing pollutants from water and treating wastewater for various purposes. In this study, thin‐film nanocomposite (TFN) membranes of polycarbonate/polyvinyl alcohol–titanium dioxide thin‐film (PC/PVA–TiO 2 ) were fabricated by dip‐coating a PC substrate in a PVA/TiO 2 solution. Various methods, including attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) spectroscopy, field emission scanning electron microscopy (FE‐SEM), atomic force microscopy (AFM), and water contact angle were utilized to assess the structural characteristics of the produced membranes. The PC/PVA thin‐film composite (TFC) and PC/PVA–TiO 2 TFN membranes were then examined in a submerged membrane system to evaluate their effectiveness in filtering humic acid (HA) under various vacuum transmembrane pressure (0.3 and 0.6 bar) condition. The FTIR‐ATR results confirmed the formation of the active layer of PVA/TiO 2 nanoparticles (NPs). It was observed that adding 1 wt.% of TiO 2 NPs to the active layer of PVA/TiO 2 significantly enhanced the water contact angle from 77.5° for PC support to 55.3° for PC/PVA–TiO 2 (0.1) TFN membranes. Furthermore, the FE‐SEM results confirmed the formation of an active layer of PVA/TiO 2 with a thickness of 237.87 nm. The pure water flux increased from 101.64 L/m 2 h for the PC/PVA TFC membrane to 144.02 L/m 2 h and 199.09 L/m 2 h for the PC/PVA–TiO 2 (0.05) and PC/PVA–TiO 2 (0.1) TFN membranes, respectively. Also, the results revealed that at lower transmembrane pressure, all membranes showed higher value in HA removal as compared to when higher transmembrane pressure was used.