A review on surface modification strategies of nanofibers for fine particle filtration

Air filtration is one of the most effective solutions for reducing exposure to particles that threaten human health. Various methods of nanofibers surface modification lead to optimizing the filter structure, and improved filter performance while balancing filtration efficiency and pressure drop. This research examines the conventional methods of nanofiber surface modification and the advantages and disadvantages of each. In the present study, it was determined 70% of the studies are related to the use of self-charging materials. Two studies (4.8%) involved the use of aerogels and another two studies (4.8%) employed physical and chemical methods including plasma and hydrolysis. Additionally, 21.4% of studies used different methods to produce composites, incorporating materials such as nanoparticles, functional protein groups, metal-organic-framework (MOF), and microbeads. The findings showed that each of the surface modification methods improves the filters by creating different properties, such as reducing the diameter of the fibers, increasing the surface area, creating roughness on the surface of the fibers, increasing the surface charge, etc. In addition, in some studies, other properties such as biodegradability and mechanical strength have been added to the filter. In general, using different methods of nanofiber surface modification improves filters and increases their efficiency in trapping particles in the air.