Counterion-controlled phase equilibria in a charge-regulated polymer solution.
| Autor: | Celora GL; Department of Mathematics, University College London, 25 Gordon Street, London WC1H 0AY, United Kingdom., Blossey R; Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France., Münch A; Mathematical Institute, University of Oxford, Andrew Wiles Building, Woodstock Road, Oxford OX2 6GG, United Kingdom., Wagner B; Weierstrass Institute, Mohrenstr. 39, 10117 Berlin, Germany. |
|---|---|
| Jazyk: | angličtina |
| Zdroj: | The Journal of chemical physics [J Chem Phys] 2023 Nov 14; Vol. 159 (18). |
| DOI: | 10.1063/5.0169610 |
| Abstrakt: | We study phase equilibria in a minimal model of charge-regulated polymer solutions. Our model consists of a single polymer species whose charge state arises from protonation-deprotonation processes in the presence of a dissolved acid, whose anions serve as screening counterions. We explicitly account for variability in the polymers' charge states. Homogeneous equilibria in this model system are characterised by the total concentration of polymers, the concentration of counter-ions and the charge distributions of polymers which can be computed with the help of analytical approximations. We use these analytical results to characterise how parameter values and solution acidity influence equilibrium charge distributions and identify for which regimes uni-modal and multi-modal charge distributions arise. We then study the interplay between charge regulation, solution acidity and phase separation. We find that charge regulation has a significant impact on polymer solubility and allows for non-linear responses to the solution acidity: Re-entrant phase behaviour is possible in response to increasing solution acidity. Moreover, we show that phase separation can yield to the coexistence of local environments characterised by different charge distributions. (© 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).) |
| Databáze: | MEDLINE |
| Externí odkaz: |
|