Fig. 2. DIC microscopy (a1–a4), fluorescence microscopy (b1–b4), TEM (c1–c4) and AFM (d1–d4) images of HA capsules (HA₁, HA₂, HA₃ and HA₄) after 1 to 4 CAP_ATRP steps, respectively. SiO₂ particles (2.4 μm in diameter) were used as templates. Scale bars are 3 μm for DIC and fluorescence microscopy images, and 1 μm for TEM and AFM images.