This project, in chemical thermodynamics, part of the experimental Physical Chemistry Program, is aimed at developing experimental expertise to measure the phase diagram and thermodynamic properties of titanium tetrachloride and vanadium oxychloride in supercritical fluids. It is expected that the measurement techniques and theoretical models developed will be useful for understanding supercritical fluid extraction processes. The phase diagram and thermodynamic properties will be measured using the techniques of flow calorimetry. The data will be interpreted to yield phase diagrams. A theoretical model of the processes involved will be developed using statistical mechanics and molecular dynamics techniques. Interpretation of the data based on specific molecular interactions will be used to understand and explain the calorimetric results. This research is cofunded by the Experimental Physical Chemistry Program and the Interfacial, Transport, and Thermodynamics Processes Program.