Scaly bionic structures constructed on a polyester fabric with anti-fouling and anti-bacterial properties for highly efficient oil–water separation

Abstract

Oil–water separation has become a hot issue due to excessive amounts of oily waste as well as frequent oil leakage accidents that highly threaten biological safety. Inspired by fish scales, we designed a scaly structure on modified polyester fabric to give full play of its outstanding anti-pollution and water-capturing properties. As the substrate with micro/nanoscale structure, ZnO nanorods were assembled on a polyester fabric for further modification. Furthermore, a PEI coating was added to establish a scaly structure for superhydrophilicity. The two factors mentioned above contributed to both superhydrophilicity and anti-fouling properties for the modified polyester fabric. Further studies explored the as-prepared fabric with super-hydrophilicity and found that the underwater superoleophobicity was extremely suitable for oil–water separation with ultra-high separation efficiencies (>99.99%) under only natural gravity forces. Furthermore, the as-prepared fabric could be washed by flowing water and retained the ultra-high separation efficiency even after 10 circles. Surprisingly, the modified fabric had superb performance under high-salinity solution (10 wt% NaCl) and high temperature (40 °C, 60 °C and 80 °C) conditions. In addition, the as-prepared fabric had outstanding anti-bacterial ability, which could inhibit the growth of both Gram-negative and Gram-positive bacteria, greatly increasing the service life of the modified fabric and preventing the water from being secondly polluted. Moreover, the research provided an innovative way to develop effective oil–water separation methods and related devices.