The long-range component ∆ƒlong is the one that monotonically increases with approaching the solid surface, which was assumed to be described by a double-exponential function 𝑎𝑒 ,.! + 𝑐𝑒 ,/! + ℎ (𝑎, 𝑏, 𝑐, 𝑑, ℎ: arbitrary constants, 𝑧: relative distance from the solid surface). By fitting the ∆ƒ-z curve with this function form, the ∆ƒlong-z curve was obtained as the double-exponential curve with the fitted coefficients a, b, c, d, and h. The double-exponential functional format was used because it approximated the ∆ƒ-z curve well and provided only negligible residuals other than the periodic ∆ƒ oscillations. This function has also been empirically used for approximating the force-distance curve obtained by static-mode AFM . Therefore, the residual ∆ƒ-∆ƒlong practically contains only the oscillation derived by the layering interfacial structures, which was taken as a short-range oscillatory component ∆ƒshort.