Robust Superhydrophobic Polytetrafluoroethylene Nanofibrous Coating Fabricated by Self-Assembly and Its Application for Oil/Water Separation

A novel and facile method is developed to fabricate polytetrafluoroethylene (PTFE) nanofibrous coating on both flat surface and curved micro metal fibers via self-assembly technique. The process starts from PTFE nanoparticles as building blocks and utilizes electrostatic interaction as self-assembly driving force followed by molecular rearrangement through thermal aging treatment. The formation process of nanofibers from nanoparticles was experimentally investigated and its mechanism was discussed in detail. As-prepared PTFE nanofibrous coating presented ultrathin morphology with high uniformity and outstanding chemical stability. Porous metal fiber sintered felt (PMFSF) coated with nanofibers exhibited superhydrophobic and superoleophilic properties and could separate various oil/water mixtures with high efficiency and good reusability. The coated PMFSF also presented excellent anticorrosion. Overall, the self-assembling fabrication method presented in this paper is simple, cost-efficient, productive, and very applicable for large-area treatment and industrialization.