Super-hydrophobic F-TiO2@PP membranes with nano-scale “coral”-like synapses for waste oil recovery

•F-TiO2@PP membrane with coral synapses is formed by in-situ cross-linking polymerization.•F-TiO2@PP membrane shows outstanding oil-collecting capacity with ultra-high oil fluxes.•Water rejection efficiency of 99.7% is reached by gravity-driven filtration.•F-TiO2@PP membrane also has high separation performance for seawater and oil. Super-hydrophobic F-TiO2@PP membranes were developed from polypropylene (PP) non-woven fabric by in situ cross-linking polymerization of trifluorofluorooctyl methacrylate (FOMA) and sol–gel-derived titanium dioxide with vinyltriethoxysilane (VTES). Due to the formation of super-hydrophobic “coral”-like synapses on the filamentous surfaces of PP non-woven fabric, F-TiO2@PP membranes showed extremely high water contact angles up to 157° and capability of rapidly absorbing oil drops. The F-TiO2@PP membranes were also able to expel water from water-in-oil emulsions with robustly high oil permeate fluxes (up to 11,000 L m−2h−1 under gravity), water removing efficiency (up to 99.7%), re-usability and long-term stability even at the presence of surfactant and salts. Such superior performance could lead to potential applications in rapid collection and efficient purification of recovered oily organic components from waste liquids or accidental oil discharges in marine or continental situations.