The Solidification Front Technique: Its Scope and Use to Determine Interfacial Tensions

Abstract

Experiments with particle engulfment and rejection by an advancing solidification front have shown that these phenomena are governed by the interfacial tensions operative in these systems. The results have been used to develop a technique for determining interfacial tensions, particle wettability and contact angles from the observation of particle pushing by a freezing front. An outline of this technique is presented. To test its internal consistency, particle-vapor surface tension values for polymer particles were determined and checked by independent means. Solid-vapor surface tensions and liquid-vapor surface tension of organic matrix materials were also determined, using this technique. The results presented demonstrate the potential of the solidification front technique for determining otherwise difficult to obtain quantities such as the particle-vapor surface tension of small particles or the solid-vapor surface tension of the matrix material.