AFM characterization of fumed silica AEROSIL® 200 NPs. 5 μL of AEROSIL® 200 NPs suspension (10 μg/mL in water) were deposited on freshly cleaved mica then dried under vacuum. AFM imaging was recorded with a Multimode and Nanoscope V instrument (Veeco, Santa Barbara, CA, USA). The scale of false colors spectrum code ranges from 0 to maximum height (in nm) using Gwyddion software. A) AFM imaging shows average size of individual disperse disks with diameter 10 ± 5 nm and thickness 2 nm ± 0.3 nm. An agglomerate is observed in the upper right side. B) Details of AFM imaging of SiO2 NPs agglomerate in the same sample. The average size of agglomerates is 160 ± 90 nm. In the inset, a zoom of a SiO2 agglomerate, recorded with peak force phase, reveals details of individual members clustered in the agglomerate.