Nanocellulose implantation enriched the pore structure of aerogel for effective particulate matter removal.

Particulate matter (PM) pollution poses a serious threat to public health, disposable and degradable filter materials are expected to handle the problem in the future. Here, polyvinyl alcohol (PVA)/borax/cellulose nanofibrils (CNF) aerogels were implanted on a biodegradable corrugated paper to form composite air filters for the first time via freeze-drying the coated composite hydrogels. The low content of CNF and PVA could be cross-linked by borax to form hydrogels, which enhanced its maneuverability for surface implanting on the substrate. More importantly, the addition of CNF greatly enriched the pore structure of aerogels, which provided a structural basis for PM capture. The as-prepared composite air filters exhibited excellent filtration efficiencies of 92 % and 96 % toward PM1.0 and PM3.0, respectively. Moreover, the addition of dimethylol-5,5-dimethylhydantoin endowed the filters with an antibacterial property. This work shows a new possibility for the design of degradable and functional filter materials.