Non-monotonic behavior of weak-polyelectrolytes adsorption on a cationic surface: a Monte Carlo simulation study
In this work, the weak polyelectrolyte (PE) adsorption on a strong cationic surface is studied with constant pH Monte Carlo simulations using a coarse-grained model. When a large number of PE chains is added to the system, the PE adsorbed amount vs pH curve exhibits a nonmonotonic behavior, with the...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Universitat de Lleida (UdL) |
| Repositorio: | Repositori Obert UdL |
| OAI Identifier: | oai:repositori.udl.cat:10459.1/73266 |
| Acceso en línea: | https://doi.org/10.1016/j.polymer.2020.123170 http://hdl.handle.net/10459.1/73266 |
| Access Level: | acceso abierto |
| Palabra clave: | Weak polyelectrolytes Adsorption Charge reversion Charge surface Constant pH simulation Monte Carlo |
| Sumario: | In this work, the weak polyelectrolyte (PE) adsorption on a strong cationic surface is studied with constant pH Monte Carlo simulations using a coarse-grained model. When a large number of PE chains is added to the system, the PE adsorbed amount vs pH curve exhibits a nonmonotonic behavior, with the appearance of a maximum close to the intrinsic p -value of the PE titratable groups. The apparent p -value of the PE chains shows a non-trivial tendency depending on the pH-value and the surface coverage degree. In increasing the pH-value, the small anions that accompany the cationic surface are replaced by PE chains and small cations. For pH > ~ p + 1, an evident charge reversion of surface is observed. These results are explained analyzing the interplay between the attractive and repulsion electrostatic interactions between the different components of the system (inter- and intra-charged monomers of PE chains, the strong cationic surface and small ions) and their effects on the PE chain ionization. |
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