Facile preparation of hydrophilic PVDF membrane via tea polyphenols modification for efficient oil-water emulsion separation

Facile preparation of hydrophilic membranes is essential for achieving efficient separation of oil-water emulsion. In this paper, a hydrophilic PVDF@TP membrane was prepared by very simple direct modification using green tea (The main extract is tea polyphenols, TP). The PVDF@TP membrane exhibits good hydrophobicity in air and underwater superoleophilicity. The oil-water separation potential of this membrane was studied using several model oil-in-water emulsions. The resulting membrane exhibitd high separation efficiency (above 99 %) and separation fluxes (955–1672 L m−2 h−1 bar−1) for various oil-in-water emulsions. Additionally, separation efficiency of PVDF@TP membrane was still above 98 % even after 10 times continuous separation, demonstrating its good antifouling ability and stability. In addition, bending, ultrasonic and stirring treatments showed that the membrane has good mechanical durability. In view of the advantages of facile preparation, economy and high-performance, the hydrophilic PVDF@TP membrane has a very broad application potential in industrial oily wastewater and oil spill treatment.