Understanding interfacial wetting transitions with classical density functional theory

Interfaces provide valuable insights into the workings of the atomic world. In problems of wetting, where often a liquid-gas interface is in contact with a solid substrate, the width and position of the gas-liquid interface depend strongly on the range of interparticle potentials. A satisfactory description of wetting can be achieved by classical density-functional theory (DFT), a fully microscopic approach, capturing the small-scale behavior of matter, as well as the inherently non-local nature of interparticle interactions. In this talk, we apply classical DFT to investigate small-scale surface phase transitions in a wide spectrum of physical settings with emphasis on wetting on heterogeneous planar substrates. We compute wetting isotherms, locating hystereses and the jumps in adsorption, wetting temperatures and interface binding potentials (disjoining pressure). Our results may have important ramifications for the design of lab-on-a-chip devices, superhydrophobic surfaces, and controlled micro-/nanofluidics.