Flexible Polyelectrolytes with Monovalent Salt

TL;DR

This paper introduces a model for flexible polyelectrolytes in good solvents with monovalent salt, describing their conformational changes with temperature and validating results against simulations.

Contribution

It provides a new theoretical model capturing temperature-dependent conformations of polyelectrolytes with validation against simulation data.

Findings

Polyelectrolyte transitions from extended to stretched to collapsed states with decreasing temperature.

The model's predictions align well with simulation results.

Conformational behavior characterized by the end-to-end distance scaling exponent b3.

Abstract

We present a model for describing flexible polyelectrolytes in a good solvent a nd in the presence of monovalent salt . The molecule composed by $N$ monomers is characterized by the end to end distanc e $R_e=b (Z-1)^\gamma$ and the number of associated counterions $n$. At high tem peratures the polyelectrolyte behaves as a neutral polymer ($\gamma=0.588$). Dec reasing the temperature, the macromolecule changes from this extended configurat ion($\gamma=0.588$) to a stretched form ($\gamma\approx 1$). At even lower temp eratures, above the Manning condensation threshold, the polyelectrolyte collapse s ($\gamma\approx 0.3$). Our results show good agreement with simulations.