Fig. 2From: Transparent Polyurethane Nanofiber Air Filter for High-Efficiency PM2.5 CaptureSEM images of electrospun TPU. a–f SEM images and diameter distributions with TPU concentrations of 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, and 16 wt%, respectivelyBack to article page