New Methods of Thermal Analysis and Chemical Mapping on a Micro and Nano Scale by Combining Microscopy with Image Analysis

A new approach to thermal analysis is described that combines microscopy, a temperature controlled stage and image analysis. It is shown how images acquired using a hot stage microscope can be analysed by a robust algorithm that tracks how structures change as a sample is heated; we call this new method thermal analysis by structural characterisation or TASC. We present an overview of how it can be used to measure glass transitions and examples of its application to polymers and pharmaceuticals are given including an example of how it can be used to study the kinetics of devitrification. Because a discrete feature on a sample surface is analysed, TASC can be used to perform local thermal analysis or LTA. Examples of this are given including one performed on a nanoscale using atomic force microscopy. The same algorithm can be used to follow dissolution rates. It is shown how materials can be distinguished between using differences in dissolution kinetics and how this represents a new paradigm for mapping chemical composition called chemical imaging by dissolution analysis or CIDA. Future prospects and the implications for nanoscale chemical imaging are discussed.