Effect of ion partitioning on electrostatics of soft particles with volumetrically charged inner core coated with pH-regulated polyelectrolyte layer.

The effect of ion partitioning on the electrostatics of a soft particle with a volumetrically charged core and a pH-dependent polyelectrolyte layer (PEL) is numerically investigated. It is observed that, whenever the ion partitioning is noticeable, the soft layer can be fully charged in a broader range of pH. Besides, a higher number density of the PEL functional groups and a lower charge density of the core result in a sharper dependence of the electric potential on the electrolyte pH. Briefly, we conclude that, since the PEL charge is dependent upon the concentration of the hydroxide/hydrogen ions, for the pH-regulated soft particles, the ion partitioning effect, as a phenomenon influencing the ionic distribution, can be a determinant factor. So taking the effect of the ion partitioning into consideration is strongly recommended for a more realistic description of the electrostatics of the pH-regulated soft particles.