by University of Kentucky (a) full thickness cross-section of PVDF400 and (b) PVDF-only layer cross-section. Surface of (c) PVDF layer and (d) polyester support layer. SEM images of N95 layers (e) 1, (f) 2, (g) 3, and (h) 4. In mask orientation, layer 1 is exposed to the open environment and layer 4 is exposed...
