Wetting and spreading phenomena are ubiquitous in a variety of fields ranging from medicine and biology to environmental and engineering applications. Our research lies at the intersection of surface science and thermofluidics and investigates experimentally the transport mechanisms when surfaces interact with liquids, and how these physical phenomena at small scales influence the efficiency of the overall process. Ultimate goal is to gain insight into the interplay of wetting and transport phenomena, and design surfaces with the desired wetting and de-wetting properties.
Hexadecane (C16H34) drop impact onto a very thin film of Hyspin (AWS 10). Due to the low surface tension and high viscosity of the liquids, instabilities originated at the bottom of the crown result in a "slingshot-like" splashing morphology.
Aqueous solution of urea (32.5% w/w) drop impact onto a superheated metal surface (300oC). The rapid heat transport causes thermal atomisation as the droplet spreads on the substrate which results in a very fast upward ejection of tiny droplets.
Thermodynamics of capillary action in fibrous materials and surface-mounted metal-organic frameworks (SURMOFs)
The capillary filling of paper is a complex liquid transport process that involves strong adsorptive interactions on the molecular scale. This results in electrostatic attractions as liquid and/or its evaporated gas molecules are adhered on the fiber surfaces upon capillary contact. The result is release of heat, which can be macroscopically quantified in the form of transient temperature rise. Our research attempts to quantify such processes by coupling solid-liquid interfacial energies with acid-base neutralization reactions for a large variety of cellulosic substrates, including surface-mounted metal-organic frameworks (SURMOFs).