Figure 6.
(a) Schematic diagram of electrospinning to prepare F-SiO2/PU nanofiber membrane [34]; (b) experimental demonstration of waterproof and moisture permeability of fiber membrane (It refers to water drops for the red circle.) [34]; (c) dmax and porosity of PVDF fibrous membranes obtained from different solution concentrations [69]; (d) illustration of the preparation of composite PVDF/PU fibrous membranes with multilevel porous structure; (e) porosity; (f) waterproof breathable performance and permeability of PVDF/PU membranes; and (g) multilevel porous structured polyvinylidene fluoride/polyurethane fibrous membranes for ultra-high waterproof and breathable applications [69].