Figure 4.

Disjoining pressure profiles. (a–c) Asymmetric system and (d–f) symmetric system for (a,d) negative, (b,e) uncharged, and (c,f) positive surfaces. The black markers (○) are the MD simulation data points. The solid orange lines are the full, nonlinear integro-differential theory. The other dashed and dash-dot lines are applications of the approximation in eq 14, where the parameters P₀ and z₀ are fit only to the first minimum. Here, the cyan dash-dot lines correspond to the analytical expressions for κ in eqs 28 and 29, while the magenta dashed lines plotted in (d–f) correspond to the definitions in eqs 30 and 31. These equations are derived in the framework of the linear response analysis.