Hierarchical electrospun nanofibers treated by solvent vapor annealing as air filtration mat for high-efficiency PM2.5 capture

Recently, air pollution has become more serious and started to have a dramatic effect on the health of humans in many large cities. Generally, outdoor personal protection, such as commercial masks, cannot effectively prevent the inhalation of many pollutants. Particulate matter (PM) pollutants are a particularly serious threat to human health. Here we introduce a new efficient air filtration mat that can be used for outdoor protection. The new efficient air filter's nanocomposite materials were successfully fabricated from poly(epsilon-caprolactone)/polyethylene oxide (PCL/PEO) using an electrospinning technique and solvent vapor annealing (SVA). SVA treatment endows the wrinkled fiber surface and enhances the PM2.5 capture capacity of protective masks. This nanowrinkled air filtration mat can effectively filter PM2.5 with a removal efficiency of 80.01% under seriously polluted conditions (PM2.5 particle concentration above 225 mgm(-3)). Our field test in Qinhuangdao indicated that the air filtration mat had a high PM2.5 removal efficiency under thick haze. Compared to commercial masks, the fabricated SVA-treated PCL/PEO air filter mat demonstrated a simpler and ecofriendly preparation process with excellent degradation characteristics, showing wide potential applications with a high filtration efficiency.