Modified Poisson-Boltzmann theory for polyelectrolytes in monovalent salt solutions with finite-size ions

Abstract

We present a soft-potential-enhanced Poisson-Boltzmann (SPB) theory to efficiently capture ion distributions and electrostatic potential around rodlike charged macromolecules. The SPB model is calibrated with a coarse-grained particle-based model for polyelectrolytes (PEs) in monovalent salt solutions as well as compared to a full atomistic molecular dynamics simulations with explicit solvent. We demonstrate that our modification enables the SPB theory to accurately predict monovalent ion distributions around a rodlike PE in a wide range of ion and charge distribution conditions in the weak-coupling regime. These include excess salt concentrations up to 1 M, and ion sizes ranging from small ions, such as Na or Cl, to softer and larger ions with size comparable to the PE diameter. The work provides a simple way to implement an enhancement that effectively captures the influence of ion size and species into the PB theory in the context of PEs in aqueous salt solutions.

References in corpus (4)

• Canonical sampling through velocity-rescaling
• Scaling and Universality in the Counterion-Condensation Transition at Charged Cylinders
• Ionic Size Effects on the Poisson-Boltzmann Theory
• Multivalent cation induced attraction of anionic polymers by like-charged pores

Cited by in corpus (4)

• Adsorption of polyelectrolytes in the presence of varying dielectric discontinuity between solution and substrate
• Theoretical and computational analysis of the electrophoretic polymer mobility inversion induced by charge correlations
• Interaction between two polyelectrolytes in monovalent aqueous salt solutions
• Interactions between polyelectrolytes mediated by ordering and orientation of multivalent non-spherical ions in salt solutions