Antiacne Effects of PVA/ZnO Composite Nanofibers Crosslinked by Citric Acid for Facial Sheet Masks

Figure 3

HR-TEM images of (a) ZnO nanoparticles and PVA/ZnO nanofibers with different relative concentrations of ZnO NPs: (b) 0%, (c) 1%, (d) 4%, and (e) 7%.

(a)

(b)

(c)

(d)

(e)