Electrospun Nanofiber Filtration Membrane

Electrospun filtration membranes use PAN (Mw 150,000, 8–12 wt% in DMF), PVDF (12–18 wt% in DMAc), or PA6 (15–20 wt% in formic acid) deposited onto nonwoven support (spunbond PET, 20–50 g/m²) at 15–25 kV, 15–20 cm distance, producing 100–400 nm diameter fibers at 3–10 g/m² basis weight. PM2.5 filtration efficiency exceeds 99.5% (NIOSH 42 CFR 84) at pressure drop of 50–150 Pa, versus 300–500 Pa for meltblown HEPA. Moisture-resistant fluorinated nanofibers (PVDF) maintain efficiency in 95% RH conditions. Antistatic treatment with carbon black (0.5–1.0 wt%) prevents electret charge dissipation during service. Electrospun HEPA filter medium adds $0.50–2.00/m² premium over conventional meltblown at equivalent filtration efficiency.