Impact of added salt on the characteristics of electric double layer composed of charged nanoparticles

We consider a mixture of large spherical nanoparticles with the charge distributed over the surface and point-like ions embedded in an aqueous solution between two similarly-charged surfaces. The finite size of nanoparticles is included via a lattice gas entropy. The electrostatic energy takes into account exact charge distribution on the nanoparticles surface. For this system the Euler-Lagrange equations are derived and solved numerically. The results show a big impact of nanoparticle's size on the concentration profiles and characteristics of electric double layer. The theoretical model predicts an attractive interaction between like charged surfaces for large enough nanoparticles with large enough charge and the addition of point-like salt ions decreases the range of attraction.

Automated summary

In this study, a mixture of point-like ions and large spherical nanoparticles with distributed charges on their surfaces is investigated. The finite size of nanoparticles is taken into account using a lattice gas entropy model, while the exact charge distribution is considered for the electrostatic energy. The Euler-Lagrange equations are solved numerically, revealing the significant influence of nanoparticle size on concentration profiles and electric double layer characteristics. The theoretical model predicts attraction between similarly-charged surfaces for sufficiently large nanoparticles with significant charge, with the range of attraction decreasing with the addition of point-like salt ions.