Preparation of PVA@PEI@BAC@CNC composite nanofibrous film with high efficiency filtration for PM2.5

It is still a challenge to prepare a water- and polymer-based electrospun air filter film with high efficiency filtration, low pressure drop, and good mechanical properties. To address this issue, polyvinyl alcohol (PVA) was employed as the main material, mixing polyethyleneimine (PEI), bamboo-based activated carbon (BAC) and cellulose nanocrystal (CNC) to construct the air filter film by electrostatic electrospinning. In this system, the negatively charged BAC and CNC are fixed in the system through bonding with the positively charged PEI, showing a double adsorption effect. One is the mechanical filtration of the porous network structure constructed by PVA@PEI electrospun nanofibers, and the other is the electrostatic adsorption of PM2.5 on the surface of BAC and CNC. It is significant that the resulting composite air filter displays a high filtration efficiency of 95.86%, a pressure drop of only 59 Pa, and good thermal stability. Moreover, the introduced methyltrimethoxysilane (MTMS) endows it with good water-resistance. Given these excellent performances, this system can provide theoretical and technical references for the development of water- and polymer-based electrospun air filter film.