Improved oil/water emulsion separation performance of PVC/CPVC blend ultrafiltration membranes by fluorination treatment

The introduction of perfluoroalkyl groups played an important role in enhanced antifouling ability in oil/water emulsion membrane separation. Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) blend membranes were used to prepare the novel fluorinated membranes. Amination treatment of PVC/CPVC blend membranes was first carried out through chemical grafting with ethylenediamine (EDA). Fluorination treatment was then achieved through chemical reaction between the redundant amino group of EDA and the carboxyl group of pentadecafluorooctanoica acid. The component of the fluorinated membrane surfaces was measured by X-ray photoelectron spectroscopy. The structure change was observed by scanning electron microscope. The fluorinated membranes were fully wetted by water in short time according to water contact angle measurement. The fluorinated membranes had higher permeate fluxes and higher flux recovery than PVC/CPVC blend membranes in oil/water emulsion membrane separation.