Micro-thermal analysis: techniques and applications

The terms micro-thermal analysis and micro-structure ol)ic analysis are use d to include any form of localized characterization or analysis combined wi th microscopy that uses a near-field thermal probe to exploit the benefits of using thermal excitation. Individual regions of a solid sample are selec ted by means of surface or sub-surface imaging (atomic force microscopy and /or scanning thermal microscopy), so as to add spatial discrimination to fo ur well-established methods of chemical fingerprinting, namely thermomechan ometry, calorimetry, spectroscopy and analytical pyrolysis. We begin by des cribing the state of the art of scanning microscopy that uses resistive the rmal probes, followed by an account of the various techniques of micro-ther mal analysis. Modern materials technology is increasingly concerned with the control of m aterials at the mesoscale. The ability to add an extra dimension of, say, c hemical composition information to high-resolution microscopy, or microscop ic information to spectroscopy, plays an increasingly useful part in applie d research. Micro-thermal analysis is now being used commercially to visual ize the spatial distribution of phases, components and contaminants in poly mers, pharmaceuticals, foods, biological materials and electronic materials . This: review outlines various applications that have been described in th e literature to date, the topics ranging from multi-layer packaging materia ls and interphase regions in composites, to the use of the technique as a m eans of surface treatment.