Interplay of distinct modes of charge regulation on poly-acid ionization and conformation
Soft Condensed Matter
2025-08-25 v2 Statistical Mechanics
Abstract
We adapt the Edwards-Muthukumar theoretical framework for a single polymer chain to investigate the interplay between proton binding and counterion condensation for poly-acids. We find that changes to pH enable non-monotonic transitions between anti- and conventional polyelectrolyte behaviors. In the former, the net charge and the overall dimensions increase with increasing salt concentration, while the converse is true for conventional polyelectrolytes. The polymeric nature and local solvent polarization drive significant pKa shifts when compared to the values of reference monoacids. These pKa shifts are enhanced in semi-flexible chains.
Cite
@article{arxiv.2508.07055,
title = {Interplay of distinct modes of charge regulation on poly-acid ionization and conformation},
author = {Souradeep Ghosh and Aritra Chowdhury and Dylan T. Tomares and Benjamin Schuler and Arindam Kundagrami and Rohit V. Pappu},
journal= {arXiv preprint arXiv:2508.07055},
year = {2025}
}