2026-04-13T05:46:27Zhttps://recercat.cat/oai/request

oai:recercat.cat:10459.1/583992025-11-25T20:13:54Zcom_2072_3622col_2072_479130

00925njm 22002777a 4500 dc Madurga, Sergio author Garcés, Josep Lluís author Companys Ferran, Encarnació author Rey-Castro, Carlos author Salvador, José author Galceran i Nogués, Josep author Vilaseca i Font, Eudald author Puy Llorens, Jaume author Mas i Pujadas, Francesc author 2009 The influence of ion size and surface charge model in titrations of ionizable polyelectrolytes is studied by means of the Semi Grand Canonical Monte Carlo simulation method in the context of the primitive model. Three models describing a discrete distribution of charged functional groups on the polyelectrolyte and different values for the radius of the background electrolyte spanning from ionic to hydrated radii values were analyzed. The polyelectrolyte titrations were simulated by calculating the degree of ionization versus pH curves at two ionic strengths. The results allow us to quantify the impact of the sizes of the background salt ions and surface functional groups of the polyelectrolyte on the dissociation degree. This influence is explained in terms of the effectiveness of the screening of the charged surface sites. Finally, by comparison with the Non-Linear Poisson–Boltzmann model, the influence of ionic correlations and finite size of the solution ions is assessed. The authors gratefully acknowledge support of this research by the Spanish Ministry of Science and Technology (Projects UNBA05-33-001, CTM2006-13583 and CTQ2006-14385) and from the ‘‘Comissionat d’Universitats i Recerca de la Generalitat de Catalunya’’. Macromolecular complexation Polyelectrolytic effect Specific binding Monte Carlo simulation Ion binding to polyelectrolytes: Monte Carlo simulations versus classical mean field theories