Construction of ultra-stable polypropylene membrane by in-situ growth of nano-metal-organic frameworks for air filtration

Air pollution, especially solid particulate pollution, seriously endangers people's physical and mental health. As a result, the performance and stability of air filtration membranes are increasingly required. In this work, the nanosized (sizes 100 nm) polypropylene@zeolitic imidazolate framework-8 (PP@ZIF-8) membranes and polypropylene@copper(II) benzene-1,3,5-tricarboxylate (PP@Cu-BTC) membranes were designed in an in-situ growth method. These membranes can achieve efficient and stable filtration of PM2.5 particles in a practical environment. The PM1.0 quality factor and filtration efficiency of PP@Cu-BTC increased by 49.28% and 58.04%, respectively, compared to the PP membrane. In addition, more than 87% of metal-organic frameworks (MOFs) particles are still fixed on the fiber after ultrasonic treatment with ultrasonic power of 600 W for 30 min. Moreover, the membranes are recyclable and have excellent water resistance ( 74.5% against PM1.0 after five washing cycles) and outstanding long-term storage performance (>94.9% against PM1.0 after storage for one month). This PP@MOFs membrane provides another idea for building stable and efficient air filtration membranes.