Fig. 1
The first row from the top: schematics of the geometry of the investigated particles. a “Small” spherical CaCO3 particles, b “small” ellipsoidal CaCO3 particles, c cuboidal CaCO3 particles, d “big” ellipsoidal CaCO3 particles, and e control “big” spherical SiO2 particles. All particles have symmetry in the x–y plane. d 1 describes the extension of the particles along the axis of symmetry, and d 2 the extension perpendicular to this axis. The second row from the top: fluorescence microscopy images of the different particles used in the uptake study as recorded in solution for (a) through (e). The scale bars in all images correspond to 20 µm. The third row from the top: SEM images of the different particles used in the uptake study for (a) through (e). The scale bars in all images correspond to 2 μm. The fourth row from the top: TEM images of the different particles used in the uptake study for (a) through (e). The scale bars in all images correspond to 1 μm.