Thermochimica Acta, Vol.300, No.1-2, 29-41, 1997
State Variables in Calorimetric Investigations - Experimental Results and Their Theoretical Impact
Use of state variables (p, V, T) in scanning calorimetric measurements is demonstrated by results obtained for various condensed systems, such as dense liquids of various physicochemical natures, polymers, and liquid crystals. The simultaneous determination of thermal and mechanical responses of the investigated system, perturbed by a variation of an independent thermodynamic variable while the other independent variable is kept automatically constant, allows the determination of thermodynamic derivatives over wide ranges of pressure and temperature, impossible to obtain by other known techniques. It is demonstrated that through appropriate molecular models for respective thermodynamic derivatives or models on which the respective EOS are constructed, the pVT-controlled scanning calorimetry is a useful means of relating microscopic molecular properties with macroscopic observations.
Keywords:ISOBARIC HEAT-CAPACITY;400 MPA;THERMOPHYSICAL PROPERTIES;TEMPERATURE-RANGE;HIGH-PRESSURE;THERMODYNAMIC PROPERTIES;THERMAL EXPANSIVITIES;SIMPLE LIQUIDS;NORMAL-HEXANE;503 K