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

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 degrees C, 60 degrees C and 80 degrees 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.