|  |  |  | Zeta potential (mV) | Hydrodynamic diameter (nm) |  |  | ||||
---|---|---|---|---|---|---|---|---|---|---|---|
 | Size (ø) nm a | Average TEM Size b (nm+sd) | BET surface area (m 2 . g -1 ) | Water | PBS | DMEM F-12 | Water | PBS | DMEM F-12 | Crystalline Structure | Impurities (% basis) |
CB | 13 | 23 ± 6 | 350 | -48 | -4 | -7 | 86 and 668 | 281 | 253 | amorphous | nonc |
TiO2 | 15 | 12 ± 2 | 210 | -24 | -11 | -9 | 53 and 311 | 461 | 86 and 356 | anatase | 0.3d |