| Abstract Scope |
Interfacial evolution in materials is commonly described in terms of Gibbs free energy. This approach is appropriate for processes governed by chemical equilibrium, but it does not explicitly account for the minimization of interfacial area under mechanical equilibrium. Here, we argue that the Helmholtz free energy is the natural thermodynamic potential for describing interfacial evolution when mechanical equilibrium is the governing condition. By using the Gibbs–Duhem relation, the driving force for interfacial mass transport is related to chemical potentials at interfaces and is directly connected to pressure differences. This formulation provides a generalized mechanical framework for interfacial evolution across diverse systems, including sessile droplets, capillary rise, equilibrium crystal shapes, grain-boundary evolution, coalescence of miscible and immiscible crystalline phases, and pore stability in multiparticle crystalline systems during sintering. |