Scanning Transitiometry

摘要

Scanning transitiometry is a relatively new technique which is based on inducing a thermodynamic change by scanning at a low rate one of the independent thermodynamic variables (p, V or T) and keeping automatically constant the other independent variable. From the output signals recorded simultaneously (rate of heat exchange and the variations of the mechanical variable, volume or pressure) a respective pair of thermodynamic derivatives is obtained simultaneously as a function of the scanned variable. The actual instruments operate over the temperature range from 200 to 550 K and over the pressure range up to 400 MPa. Typical examples of applications of the technique in investigation of phase transitions in organic substances and liquid crystals under various conditions are presented. Possible future applications in solving various problems in biotechnology and in physics and physical chemistry education are emphasized.