Removal of Particulate Matters by Using Zeolitic Imidazolate Framework-8s (ZIF-8s) Coated onto Cotton: Effect of the Pore Size of ZIF-8s on Removal

Removal of particulate matter (PM) like PM2.5 and PM10 from air was carried out with cotton coated with metal-organic frameworks (MOFs) having various pore sizes to understand the effect of the pore size of MOFs (here, ZIF-8s) on the performances in PM elimination. Both removal efficiency and quality factor, based on the unit surface area of ZIF-8s, in the filtration of PMs with ZIF-8/cotton did not rely considerably on the pore size of ZIF-8s. More importantly, small pores (even less than 0.5 nm) of conventional MOFs like ZIF-8 are more than enough in the elimination of large PMs like PM10 with a size of microns probably because small active sites (such as polar functional groups) on PMs can interact with porous materials having polarity. Additionally, electrostatic interactions between PMs and porous materials could be confirmed as a plausible mechanism for PM removal with ZIF-8/cotton.