Multiple hydrogen bonding self-assembly tailored electrospun polyimide hybrid filter for efficient air pollution control.

Air pollutions are extremely serious threats to human health and the functional hybrid filter is able to remove complicated pollutants with great potential. However, the stable structure design of hybrid filter to provide efficient filtration and adsorption performance for high temperature applications still remains a challenge. In this study, electrospun polyimide (PI) based hybrid filter was fabricated via multiple hydrogen bonding self-assembly for high-temperature air purification. In particular, Octa(amino-propylsilsesquioxane) (POSS-NH2) was utilized as "bridge" for the surface activation of PI fiber, and then amino-functionalized Zeolitic Imidazolate Framework-8 (NH2-ZIF-8) nanocrystals were anchored on the fiber surface through hydrogen bonding. On account of the synergistic effect of the interception effect of fibers and the electrostatic interaction of NH2-ZIF-8 nanocrystals, the as-obtained PI-POSS@ZIF hybrid filter possessed excellent filtration performance with a high PM0.3 removal efficiency of 99.28% and a low pressure drop of 49.21 Pa at high temperature of 280 °C. Moreover, due to the massive micropore structure, rich open metal sites and functional groups of NH2-ZIF-8, the hybrid filter exhibited prominent VOCs adsorption performance with adsorption capability of 89.95 mg/g for formaldehyde.