fig4
Figure 4. SEM images of SiO2 aerogel microspheres and PIA@SiO2 aerogel microspheres: SiO2 aerogel microspheres (A and B), PIA@SiO2 5-10 (C and D), PIA@SiO2 10-10 (E), PIA@SiO2 15-10 (F), PIA@SiO2 10-15 (G), PIA@SiO2 10-25 (H) and PIA@SiO2 10-30 (I).
