Silk-crosslinked polyester fibrous air filters with electrostatic interfacial mediation for high- efficiency and low-resistance air purification

Similar to most air filtration strategies, fibrous filters have the trade-off between efficiency and air flow. An electrostatic-assisted electret filter may help improve filtration efficiency while maintaining air flow. In this work, we present a silk-nanofiber-modified polyethylene terephthalate (SNF@PET) fiber filter with an improved compression strength and modulus by 1.9 and 1.6 times respectively, at 2 wt % SNF content, increasing the structural stability of the filter to support a higher air flow. The filtration efficiencies of the SNF@PET fiber membrane for PM 0.3-0.5 and PM 0.5-1 are up to 99.7% and 99.6%, respectively, with a corresponding pressure drop of 3.3 Pa at 0.1 m s −1 air velocity. The SNF@PET fiber filter showed a slight decrease in filtration efficiency to 98.3% for PM 0.3-0.5 and a small increase of pressure drop to 3.7 Pa (from 3.3 Pa) after 400 h.