Temperature-resolved determination of the London dispersive surface energy and interfacial separation in solid materials

The London dispersive component of surface energy (?<inf>s</inf>^d) is a fundamental interfacial parameter governing van der Waals interactions between solid materials and surrounding molecules. Its accurate determination is essential for understanding and controlling a wide range of processes, including adhesion, wetting, catalysis, tribology, pharmaceutical formulation, nanomedicine, as well as energy and environmental technologies. Despite decades of investigation, the reliable determination of ?<inf>s</inf>^d for solid materials remains a major challenge. Conventional approaches, such as contact angle measurements and calorimetric methods, are generally limited to well-defined planar surfaces or specific material systems. In contrast, inverse gas chromatography (IGC) has emerged as a powerful and versatile technique for characterizing powders, fibers, and porous solids. In this work, a rigorous thermodynamic framework is developed based on the Hamaker constant, enabling the intrinsic determination of the dispersive surface energy ?<inf>s</inf>^d(T) of oxide materials. A key advance lies in the explicit incorporation of the temperature-dependent intermolecular separation distance D<inf>0</inf>(T), extracted from inverse gas chromatography measurements of n-alkane adsorption. Application to a series of oxides (Al<inf>2</inf>O<inf>3</inf>, SiO<inf>2</inf>, ZnO, TiO<inf>2</inf>, and MgO) reveals a consistent hierarchy of dispersive surface energies, governed primarily by electronic polarizability and surface dielectric screening. While the Hamaker constant exhibits only weak temperature dependence, the observed variation of ?<inf>s</inf>^d(T) is shown to arise predominantly from changes in interfacial configuration through D<inf>0</inf>(T). This demonstrates that thermal effects on dispersive interactions are controlled by structural fluctuations rather than intrinsic electronic properties. The proposed methodology provides a unified description linking microscopic interaction distances to macroscopic surface energetics. It establishes a robust and physically grounded approach for determining dispersive surface energies and offers new insight into the fundamental mechanisms governing adhesion and interfacial interactions in solid materials.