Counterion-controlled phase equilibria in a charge-regulated polymer solution

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 accoun...

Full description

Bibliographic Details
Main Authors: Celora, GL, Blossey, R, Münch, A, Wagner, B
Format: Journal article
Language:English
Published: AIP Publishing 2023
_version_ 1797111569154310144
author Celora, GL
Blossey, R
Münch, A
Wagner, B
author_facet Celora, GL
Blossey, R
Münch, A
Wagner, B
author_sort Celora, GL
collection OXFORD
description 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.
first_indexed 2024-03-07T08:12:12Z
format Journal article
id oxford-uuid:23651244-f7e1-43e3-b583-fc80229bf1c8
institution University of Oxford
language English
last_indexed 2024-03-07T08:12:12Z
publishDate 2023
publisher AIP Publishing
record_format dspace
spelling oxford-uuid:23651244-f7e1-43e3-b583-fc80229bf1c82023-12-05T09:35:27ZCounterion-controlled phase equilibria in a charge-regulated polymer solutionJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:23651244-f7e1-43e3-b583-fc80229bf1c8EnglishSymplectic ElementsAIP Publishing2023Celora, GLBlossey, RMünch, AWagner, BWe 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.
spellingShingle Celora, GL
Blossey, R
Münch, A
Wagner, B
Counterion-controlled phase equilibria in a charge-regulated polymer solution
title Counterion-controlled phase equilibria in a charge-regulated polymer solution
title_full Counterion-controlled phase equilibria in a charge-regulated polymer solution
title_fullStr Counterion-controlled phase equilibria in a charge-regulated polymer solution
title_full_unstemmed Counterion-controlled phase equilibria in a charge-regulated polymer solution
title_short Counterion-controlled phase equilibria in a charge-regulated polymer solution
title_sort counterion controlled phase equilibria in a charge regulated polymer solution
work_keys_str_mv AT celoragl counterioncontrolledphaseequilibriainachargeregulatedpolymersolution
AT blosseyr counterioncontrolledphaseequilibriainachargeregulatedpolymersolution
AT muncha counterioncontrolledphaseequilibriainachargeregulatedpolymersolution
AT wagnerb counterioncontrolledphaseequilibriainachargeregulatedpolymersolution