Ion specific forces between charged self-assembled monolayers explained by modified DLVO theory

We recently investigated specific ion effects near a single charged self-assembled monolayer (SAM) in a salt solution by exploiting a modified Poisson–Boltzmann equation that accounts for both water profile and ion-surface potential profiles inferred from molecular dynamics simulations. In the present contribution we extend this work to consider two charged SAMs interacting across different salt solution. Our results demonstrate one important reason why the double layer force between charged colloidal surfaces in electrolytes could be highly ion specific.