Wetting behaviors influence many aspects of life and industry from consumer product goods to oil recovery to cosmetics. While the traditional solid-liquid-vapor (SLV) system has been studied for many years now, wetting transitions in the solid-liquid-liquid (SLL) system has remained relatively unexplored. The purpose of this work is to bring light to the wetting transition of the solid-liquid-liquid system and to understand the replacement rates of initially hydrocarbon-filled microscopic cavities with water and the factors affecting these rates. Factors studied were viscosity, density, diffusion related properties, and surface related properties in both hydrocarbon-saturated and hydrocarbon-non-saturated conditions. Cylindrical microscopic cavities were etched in a silicon wafer, filled with various organic solvents dyed with fluorophores, then submerged in water. Through fluorescence microscopy techniques, the transition or replacement rates of the initially hydrocarbon-filled cavities with water in both hydrocarbon-saturated and hydrocarbon-absent water conditions are observed. Among the factors we investigated, namely viscosity, density, surface chemistry, and diffusive flux (composed of solubility and diffusivity), diffuse flux dominated replacement rates in hydrocarbon-absent water conditions. By using hydrocarbon-saturated water, diffusive flux was minimized, allowing for deeper investigation of other factors. In the hydrocarbon-saturated scenario, replacement rates are largely affected by initial fluid motion, specific cavity geometry, and cavity penetration mechanisms. Image analysis reveals the geometry of the oils in the cavities and shows how the transition from hydrocarbon-fully-filled to hydrocarbon-partially-filled states occurs in the SLL system.



College and Department

Ira A. Fulton College of Engineering and Technology; Chemical Engineering



Date Submitted


Document Type



wetting transition, cavity replacement, contact angle, surface tension, interfacial tension, surface behavior