In-situ growth of CuBTC and PFOTES modification to fabricate superhydrophobic PVDF membranes for membrane absorption of CO2

Climate change is one of the major challenges facing the world, and reducing carbon dioxide (CO 2 ) emissions is a crucial means of addressing global warming. Membrane CO 2 absorption technology integrates membrane technology with chemical absorption techniques, offering advantages such as flexible operation, low cost, low energy consumption, and ease of scale-up. The membrane contactor serves to separate the gas and liquid phases. When the membrane pores become wetted, the mass transfer resistance of CO 2 across the membrane increases rapidly. Therefore, improving the anti-wetting properties of the membrane material is fundamental to enhancing its CO 2 absorption capacity. Research findings indicate that through surface roughness analysis, contact angle measurements, and immersion testing, the composite PVDF membrane fabricated via in-situ growth of CuBTC and PFOTES modification exhibited superhydrophobic properties with a maximum contact angle of 156.77°. After 60 h of continuous operation, the CO 2 mass transfer rate of the composite membrane only decreased by 5.6 %, which is significantly lower than the 27.7 % decrease of the pristine PVDF membrane, demonstrating superior operational stability and anti-wetting properties. Meanwhile, under the optimal condition of 15 modification cycles, the CO 2 removal efficiency and mass transfer rate of the composite membrane were higher than those of the pristine membrane, achieving improved mass transfer performance.