The first case of interest is the swelling for varying values of pH res , for a suspension containing microgels with only acidic sites and a reservoir salt concentration of c res salt = 1mM. In Fig. , the ionization degree of the acidic sites, ζ a , is plotted versus pH res , for microgels with varying numbers of segments per chain, N . As expected, the simulations show an increase of ζ a with increasing pH res and a shift of the ionization curve towards larger pH res as compared to the ideal prediction. With increasing N at constant pH res , ζ a increases due to a growth in the mean end-to-end distance of the polymer chains forming the microgel, 6 weakening the interchain interaction and bringing the ionization slightly closer to the ideal case.