Plant-inspired biomimetic hybrid PVDF membrane co-deposited by tea polyphenols and 3-amino-propyl-triethoxysilane for high-efficiency oil-in-water emulsion separation

Membrane pollution caused by separating oily wastewater is a big challenge for membrane separation technology. Recently, plant-/mussel-inspired interface chemistry has received more and more attention. Herein, a high antifouling poly (vinylidene fluoride) (PVDF) membrane, coated with tea polyphenols (TP, extracted from green tea) and 3-amino-propyl-triethoxysilane (APTES), was developed to purify oil-inwater emulsions. ATR-FTIR, XPS and SEM were used to demonstrate the evolution of surface biomimetic hybrid coatings. The performances of the developed membranes were investigated by pure water permeability and oil rejection for various surfactant-stabilized oil-in-water emulsions. The experimental results revealed that the membrane deposited with a mass ratio of 0.1/0.2 exhibited ultrahigh pure water permeability (14570 L center dot m-2 center dot h-1 center dot bar-1, 1 bar=0.1 MPa) and isooctane-in-water emulsion permeability (5391 L center dot m-2 center dot h-1 center dot bar-1) with high separation efficiency (>98.9%). Even treated in harsh environment (acidic, alkaline and saline) for seven days, the membrane still maintained considerable underwater oleophobic property (148 degrees-153 degrees). The fabricated plant-inspired biomimetic hybrid membranes with excellent performances light a broad application prospect in the field of oily wastewater treatment. (c) 2022 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.