Symmetrical charge-charge interactions in ionic solutions: implications for biological interactions

TL;DR

This paper demonstrates that symmetrical charge interactions in ionic solutions can significantly enhance electrostatic repulsion, implying a potential role in biological processes despite electrolyte screening effects.

Contribution

It reveals that symmetry in charge systems increases electrostatic repulsion in ionic solutions, challenging previous assumptions about screening limitations in biological interactions.

Findings

Electrostatic repulsion is increased by symmetry compared to bare charges.

The increased repulsion depends on charge magnitude and separation.

Steady state is reached at distances beyond the Debye length.

Abstract

As is well known in electrolyte theory, electrostatic fields are attenuated by the presence of mobile charges in the solution. This seems to limit the possibility of an electrostatic repulsion model of biological interactions such as cell division. Here, a system of two charges in an ionic solution is considered. It is found that in the context of the symmetries of the system, the electrostatic repulsion between the two is considerably increased as compared to the electrostatic repulsion between two bare charges in a dielectric. This increase in repulsion, directly resulting from interactions between the symmetrical parts of the system, was found to be dependent on the magnitude of the charges and the separation between them. It was also found that this increases reaches a steady state for separation greater than a solvent determined length scale related to the Debye length. These findings strongly suggest that electrostatic interactions can play a crucial part in the physical forces that are involved in biological interactions.