The thermal diffusivity, thermal effusivity, and thermal conductivity are the heat transport properties responsible for the thermal management in major technological developments. Understanding and controlling the thermal properties of materials provides opportunities to radiate, insulate, store, and transform the heat efficiently. Here I review the basic principles and the development of temperature wave analysis and thermal imaging methods in thermal analysis that make use of thermally modulated stimulation to be detected by the contact and the non-contact temperature sensors in accordance with the linear response theory. The anisotropic heat transfer properties in liquid crystals, phase change materials, femtosecond-laser fabricated polymer films, and bio-materials are presented in the multi-dimensional approaches with the developed techniques. It is demonstrated that the molecular model is valid for the qualitative prediction of the effect of the molecular length on the magnitude of the thermal conductivity of liquid crystals. More recent topics on the development of the thermo-spectroscopy is presented with the thermal and the spectroscopic imaging of phase transition of n-alkane and the radical polymerization of styrene in microfluidics. Advances in such measuring techniques provide the accurate data of thermal properties to be linked to the materials informatics and the information technology that will become more important in the future industry.
Keywords:Temperature wave analysis, Thermal diffusivity, Thermal effusivity, Thermal conductivity, Infrared camera, Microscale thermography, Thermo-spectroscopy
Publication Date: 2018-01-25