Examining the theoretical predictions, we observe that they qualitatively predict the same behavior with varying pH res . Quantitatively, we see a good agreement between theory and simulations at low pH res , because of the relatively weak electrostatic interactions in the system, and at high pH res , where the ionization degrees saturate at the maximum. For intermediate values of pH res , it is well known that the presence of both the microion-microion and bead-bead correlations play a key contribution in the determination of the ionization degree, 7 resulting in an extra energy penalty that leads to an effective lower ionization for given pH res . These correlations are present in the simulations since we consider explicit charges, but absent in the mean-field swelling model, leading to an overall smaller suppression of the ionization in the latter case.