A multi-layer antimicrobial cellulose filter with electrostatic adsorption properties prepared by coating cellulose with chitosan and CuO

The health impacts of air pollution such as particulate matter (PM) and bioaerosols have prompted a focus on the utilization of personal protective filters. Traditional filters pose environmental concerns due to their non-biodegradable composition, while cellulose presents a promising alternative for biodegradable air filtration applications. This research involved the development of cellulose filter substrates with a customizable pore structure by adjusting the nanofiber content in cellulose filters and employing a simultaneous freeze-drying method. By integrating chitosan and CuO nanoparticles, the filters gained electrostatic adsorption capabilities, leading to a substantial enhancement in filtration efficiency, as well as imparting moisture resistance and durable antimicrobial properties to the filter. Subsequently, a three-layer cellulose filter integrated with chitosan and CuO (abbreviated as Int-Cs&CuO) was constructed based on the generalized Murray’s law to enable multi-stage PM filtration. The Int-Cs&CuO cellulose filter demonstrated filtration efficiencies of 99.2 % for non-oily PM 0.3 and 99.5 % for oily PM 0.3 , with a low pressure drop of 49.5 Pa. Under humid conditions, the filtration efficiency of the Int-Cs&CuO cellulose filter against PM 0.3 particles was minimally impacted, showcasing a decrease of only 1.3 %. Notably, the filter exhibited complete biodegradation in composted soil within approximately 2 months.