Effects of Macroion Geometry and Charge Discretization in Charge Reversal

TL;DR

This study investigates how macroion shape and discrete surface charges influence charge reversal, revealing that geometry and valence interactions significantly affect overcharging efficiency, with some cases favoring discrete charges over continuous ones.

Contribution

It provides a comparative analysis of macroion charge reversal considering geometry and charge discretization, using energy minimization simulations and an analytical model.

Findings

Macroion geometry impacts overcharging behavior.

Valence combinations influence charge reversal efficiency.

Discrete surface charges can outperform continuous charges in certain cases.

Abstract

The effects of discrete macroion surface charge distribution and valences of these surface charges and counterions on charge reversal have been studied for macroions of three different geometries and compared with those of continuous surface charge distributions. The geometry of the macroion has been observed to play an important role in overcharging in these cases. The interplay of valences of discrete microions and counterions have noticeable effects on overcharging efficiency. For some valence combinations overcharging the macroion with discrete surface charge is seen to be more efficient than those with continuous charge distribution. The calculations have been performed using a previously developed energy minimization simulation technique. For comparison purposes the corresponding continuous charge distribution cases together with an analytical model derived from modified Scatchard approach (for continuous charge distribution) have been evaluated.