Ostwald–Freundlich equation

The Ostwald–Freundlich equation governs boundaries between two phases; specifically, it relates the surface tension of the boundary to its curvature, the ambient temperature, and the vapor pressure or chemical potential in the two phases. The Ostwald–Freundlich equation for a droplet or particle with radius R {\displaystyle R} is: p p e q = exp ⁡ ( R c r i t i c a l R ) {\displaystyle {\frac {p}{p_{\rm {eq}}}}=\exp {\left({\frac {R_{\rm {critical}}}{R}}\right)}} R c r i t i c a l = 2 ⋅ γ ⋅ V a t o m k B ⋅ T {\displaystyle R_{critical}={\frac {2\cdot \gamma \cdot V_{\rm {atom}}}{k_{\rm {B}}\cdot T}}} V a t o m {\displaystyle V_{\rm {atom}}} = atomic volume k B {\displaystyle k_{\rm {B}}} = Boltzmann constant γ {\displaystyle \gamma } = surface tension (J ⋅ {\displaystyle \cdot } m−2) p e q {\displaystyle p_{\rm {eq}}} = equilibrium partial pressure (or chemical potential or concentration) p {\displaystyle p} = partial pressure (or chemical potential or concentration) T {\displaystyle T} = absolute temperature One consequence of this relation is that small liquid droplets (i.e., particles with a high surface curvature) exhibit a higher effective vapor pressure, since the surface is larger in comparison to the volume.

Source: Wikipedia — Ostwald–Freundlich equation (CC BY-SA 4.0)