Preparation and properties of super-hydrophobic TiO2&POTS@PP microfiltration membrane for oil/water separation

Abstract In this work, a membrane with super-hydrophobic (WCA = 169°±1°) and super-oleophilic (OCA≈0°) (SHBOI) was fabricated by multi-layer deposition. The functional groups, including the hydroxyl groups (–OH) on the surface of TiO2 nanoparticles and the –CF3 groups of the 1H,1H,2H,2H-perflluorooctyltrirthoxysilane (POTS) were introduced successfully onto the PP membrane surface. The composition, microstructure, and wettability of the modified membrane were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and contact angle goniometer, respectively. The surface stability, the separation efficiency of the water-in-oil emulsion and the flux of the modified membrane was also investigated. The modified membrane displayed good surface stability in the acid environment (WCA > 120° over 32 h). Meanwhile, the modified membrane can be applied in water-in-oil emulsion separation with rejection greater than 80% solely using gravity.