Reactive Wetting Taxonomy

Abstract

AbstractContact angles and spreading rates of liquids on solids are oft characterized owing to the widespread importance of wetting. Particularly with dissimilar materials, such as liquid metals on ceramics, where wetting can be poor, additives that can induce various reactions often promote wetting, even if it preceeds the reaction. However, excessive or unwanted reaction can equally well be detrimental in other metallic or ceramic systems. Despite obvious needs, mechanisms of reactive wetting are poorly known.An effort is described to categorize sessile or spreading drop situations having a potential for some degree of reaction and ways wherein the driving force for reaction can actually couple with or parallel that for fluid flow. Several categories where reactivity enhances or retards spreading are described for which the very existence typically depends upon kinetic or nucleation limitations; this includes defining situations in which metastable interfaces have a meaningful context and unique properties. Examples use pairs of inorganic materials, for which the solid may only rarely be truly inert.