An innovative filtration approach with triboelectric and bimodal PA6/PVDF nanofibrous air filters via the electro-blowing method

Abstract

Fibers with electrostatic capture properties and bimodal structures, combining fibers of different diameters, offer innovative filtration approaches with low-pressure drop and high efficiency. In this study, PA6 and dielectric PVDF nanofibrous mats, positioned differently in the triboelectric series, are produced via the electro-blowing technique. To identify the most effective factors influencing filter performance, four groups are prepared: unimodal single-layer filters, group X (fibers with the same diameters but different polymers for triboelectric effect), group Y (fibers with different diameters and polymers for bimodal + triboelectric effects), and group Z (fibers with only different diameters for only bimodal effect). The unimodal PVDF mats show 100% higher surface potential and the highest filtration efficiency (99.233%) among single-layered samples. Multi-layered samples perform better, with the four-layered bimodal PA6/PVDF showing the greatest efficiency improvement due to both bimodal structure and triboelectric effect. After corona charging, sample Y3's filtration efficiency increases from 99.886% to 99.997%, with minimal change in pressure drop. After one month and IPA treatment, it retains a surface potential of −0.26 kV and 99.829% efficiency. The higher surface potential of group Y confirms the triboelectric effect, while its superior performance highlights the advantages of bimodal and electret effects. Trial Registration: Not applicable, as this study does not involve a clinical trial.