Micro-thermal analysis is a form of analytical microscopy that affords the ability to perform calorimetric and thermomechanical measurements in a localised way so as to characterise the nature and distribution of thermal transitions in a specimen. Scanning probe microscope technology is used to move an ultraminiature heater/thermometer sensor across the specimen's surface so as to obtain images representing the sample's topography and apparent thermal conductivity. Other imaging modes are possible which can be used to generate image contrast on the basis of thermal expansivity or to obtain 3-dimensional tomographic mapping of buried structures. Various methods of image analysis may be used, for example, to de-couple the influence of changes in contact area between the sensor and surface on the heat flux from the sensor to the specimen. These images can then be used as a guide to position the sensor over areas of interest and record its vertical displacement and thermal flux whilst it is heated in contact with the sample. These measurements represent the micro-analogues of thermomechanical analysis and differential scanning calorimetry and can be used to establish the temperatures of thermal transitions of a region less than 5 Ilm square. Chemical analysis of the specimen may be carried out by using the same sensor to pyrolyse a small area of the specimen. Gaseous decomposition products from the surface are then characterised either by trapping these materials on a suitable sorbent and subsequent analysis by thermal desorption gas chromatography-mass spectrometry or by direct injection into the ion source of a mass spectrometer via a heated capillary transfer line. The development of this technique is described and illustrated by means of its applications to areas of materials science and pharmacy.
This thesis is closed access as it contains published papers. A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.