Preparation of the sandwiched PS-SiO2-PVAc-SiO2 electrospinning fiber membrane with super-hydrophobic and self-cleaning and its performance in oil-water emulsion separation

Oil-water emulsion separation could improve the efficiency of oil resources and reduce environmental pollution. The efficiency of oil-water separation was directly affected by the surface hydrophobicity of the membrane and its reliability and reusability. Therefore, the construction of a reliable and reusable super-hydrophobic surface was very important. In this research, the EFM with sandwich structure of PS-SiO 2 -PVAc-SiO 2 was easily fabricated by a three times liquid phase induction process and heat treatment. The PS-SiO 2 -PVAc-SiO 2 EFM was first formed by a triple liquid phase induction process, then the EFM was heat-treated, the PVAc, which is a heat-sensitive material, resulting in SiO 2 nanoparticles being welded onto PS fibers. The rolling contact angle experiment at an inclination of 8° proved that the PS-SiO 2 -PVAc-SiO 2 EFM has super-hydrophobic properties. Meanwhile, the PS-SiO 2 -PVAc-SiO 2 EFM showed excellent stability and reliability of super-hydrophobic properties after the EFM was washed or taped. In addition, the PS-SiO 2 -PVAc-SiO 2 EFM had self-cleaning function and fine oil-water separation property. The oil-water separation efficiency was over 99.50 % and the flow rate was 68 L/m 2 h. After 5 times of oil-water separation, the flux and separation efficiency did not decrease significantly, which proved that the PS-SiO 2 -PVAc-SiO 2 EFM could be reusable.