Fabrication of polyphenylene sulfide nanofibrous membrane via sacrificial templated-electrospinning for fast gravity-driven water-in-oil emulsion separation

Polyphenylene sulfide (PPS) has excellent hydrophobicity and stability, making it an ideal material for preparing water-in-oil separation membranes. PPS membranes are mainly fabricated via thermally induced phase separation which requires a certain amount of solvent. The electrospinning technique is relatively simple and requires little solvent, and it has become a research hotspot in recent years. This study proposes a new strategy for preparing a PPS membrane for water-in-oil emulsion separation in harsh environments. Here, we prepared PPS composite nanofiber membranes via electrospinning and sintering technology. The membrane was formed using polyvinyl alcohol (PVA) as the sacrificial template and polyacrylonitrile as the supporting substrate. By studying the effects of the PPS/PVA mass ratio and sintering temperature on the PPS composite nanofiber membrane structure and performance, the optimum PPS membrane was selected for subsequent water-in-oil emulsion separation. The results show that the water contact angle of the PPS membrane was above 150°; the maximum pure oil flux was 1707 L/ (m2 h) for the surfactant-stabilized water-in-oil emulsion separation under gravity; and the separation efficiency was around 99%. Moreover, the membrane maintained good chemical resistance after immersion in an organic mixed or acid-base solutions for 5 days.