Figure 3.

(a) SEM images of 16.5 $\mathsf{\mu }$m size zinc oxide microcapsules; (b) shell thickness was found about 0.6 $\mathsf{\mu }$m; and (c,d) element mapping images of the ZnO microspheres. Scale bars: (a,b) 10 $\mathsf{\mu }$m; and (c,d) 2 $\mathsf{\mu }$m.