The structure design of poly (tetrafluoroethylene-co-perfluoropropylvinylether) (PFA) hollow fiber membrane with high-temperature and chemical resistance for oil purification

Background: Presently, membrane separation technology has been attracting increasing attention in the research and development of waste oil treatment due to its outstanding performance. Oil purification reduces not only the pollution, but also certain economic losses, as well as to alleviate the current situation of resource scarcity. Methods: The poly (p-phenylene terephthalamide) (PPTA) braided tube reinforced (PBR) PFA hollow fiber membranes (HFMs) with high-temperature and chemical resistance were successfully prepared by dipping coating and thermal sintering technique with no harmful diluent and additives (green preparation). Significant findings: The morphologies, permeability of PBR-PFA HFMs were investigated by scanning electron microscopy, three-dimensional optical profilometer and filtration experiments, etc. The results indicated that the increased PFA content led to a dense pore structure and enhanced surface roughness. Besides, the increased sintering temperature brought about porous surface with a narrow pore size distribution and tiny average pore size. The membrane exhibited a high-temperature resistance under 60-150 degrees C operating conditions. Furthermore, it showed excellent chemical resistance after immersing in strong acid and alkali solution. Finally, the membrane's separation efficiency for two-phase oil-water could be up to 98.5 % and the retention rate for waste oil could be 97.6 % above, respectively.