Biomimetic modified polypropylene membranes based on tea polyphenols for efficient oil/water separation

In recent years, the fabrication of efficient, green, and anti-pollution membrane materials has attracted extensive attention in the field of oil/water separation. Herein, a facile co-deposition strategy based on the reaction between tea polyphenols (TP) and γ-aminopropyltriethoxysilane (APTES) was proposed. Hierarchical nanoparticles were successfully constructed on the surface of polypropylene (PP) melt-blown nonwoven via a mild process, which endowed it with superhydrophilicity and underwater superoleophobicity. The as-prepared membranes could realize the efficient separation of oil/water mixtures, whether for vegetable oil/water mixtures or mineral oil/water mixtures. All separation efficiencies were above 99.1% and the optimal permeation flux was as high as 113,000 L m−2 h−1. The recyclability and recoverability of the coated membranes were further evaluated by conducting "30 + clean + 30" cyclic experiments. Additionally, the modified membranes also exhibited superior underwater oil resistance, low oil adhesion, and self-cleaning capacity. Good corrosion resistance allowed them to be used in acidic and mildly alkaline environments, and the treated membranes could keep stable underwater superoleophobicity though placed in ultrasonic water for 60 min. Therefore, the modified PP membranes with high efficiency, energy saving, environmental protection, and anti-pollution could be applied in the treatment of oily wastewater.