Here, we notice that the acid-site density profile vanishes outside of the microgel, while inside the microgel it increases with r, which indicates that more acid sites are deprotonated towards the microgel periphery. This behavior is a consequence of the local dependency of the considered law of mass action in Eqs. ( ) and ( ), which results in spatially varying ionization profiles. The effect is qualitatively similar to the ionization behavior of weak polyelectrolyte chains, which are also ionized more at the chain ends. Moreover, in Fig. , we show the H + density profile, which provides information about the local pH across the cell. Complementary to the acidic case, the case with only basic sites is depicted in Fig. of the SI, where we observe again a good agreement between the linear approximation and the fully nonlinear case. Radial distance is normalized with respect to the microgel size a. In all panels, empty points correspond to nonlinear case, while solid lines to the linear approximation. System parameters: a = 50 nm, λ B = 0.71 nm, ϕ = 0.01, c res salt = 0.1 mM, Z max,a = 100, pK a = 4 and pH res = 5.