UV-activated superwetting ability of electrospun polysulfone/titanium dioxide membranes toward highly efficient methylene blue removal and oil/water separation

Abstract

Enhancing the hydrophilicity/underwater superoleophobicity of fibrous membranes not only boosts their anti-contaminant property during oil/water separation, but also enhances their removal ability toward water-soluble pollutants. Here, a novel kind of electrospun polysulfone/titanium dioxide (PSF/TiO2) composite membranes with UV-activated superwetting ability were fabricated by depositing spherical TiO2 nanoparticles on the surface of PSF electrospun fibers through hydrothermal reaction. After activated by UV irradiation, the PSF/TiO2 composite membranes (FPT-A-UV) exhibited amphiphilic features with water contact angle (WCA) and oil contact angle (OCA) approaching 0° in air while under-water oil contact angle (UWOCA) and under-oil water contact angle (UOWCA) exceeding 150°, respectively. The composite membranes showed high removal ability toward methylene blue (MB). Under the complex condition in purifying the emulsion containing MB, the removal ratio of MB achieved 90.8 % with water flux of 780.3 (L m−2 h−1). The FPT-A-UV composite membranes also exhibited good demulsification effects on various emulsified solutions. It is reasonable to expect that the composite membrane has satisfactory application prospects in wastewater purification, especially in harsh environments.