The vapour pressures of materials and the enthalpy changes associated with their sublimation and evaporation are often necessary parameters for many processes. This paper reviews the origins and development of a method for determining these properties using a conventional thermobalance and sample holders with a modified form of the Langmuir equation. Alternative approaches for data treatment are discussed, many of which promise to derive the vapour pressure of a material directly rather than by calibration with reference materials. The applications of non-linear rising temperature programs are considered and a protocol for correction of volatilisation rate to take into account the diffusion-limited transfer of material through the stagnant boundary layer above the sample is proposed.
[back] [full text (1.40 MB)]