691967.fig.003a
(a) 684 nm
691967.fig.003b
(b) 420 nm
691967.fig.003c
(c) 362 nm
691967.fig.003d
(d) 215 nm
691967.fig.003e
(e) 140 nm
691967.fig.003f
(f) 58 nm
Figure 3: SEM micrographs and size distribution of SiO2 nanoparticles.