ABSTRACT
Powders and fibers, or more generically, solids in a high degree of subdivision, exist in an enormous variety of chemistries and morphologies, and are used in a virtually limitless number of applications. In multicomponent capillary systems, internal diffusional equilibrium generally produces different component concentrations in the two bulk phase portions, and a composition in the interfacial zone different from that of either of the bulk phases. The formalism developed thus far for describing multicomponent interfacial systems assumes internal thermal and mechanical equilibrium, and in particular equilibrium spatial distribution of the components. Thermodynamics provides the framework for the description of the properties and behavior of interfacial systems, including powders and fibers. The model of the immiscible interfacial system, in which it is assumed that the fluid and solid phase portions of the system are completely immiscible, is especially useful in describing these types of systems.
