Photothermal methods for the measurement of thermal properties of thin polymer films

The absorption of radiation in a sample gives rise to local heating. With a suitable modulated or pulsed source of radiation, a spatially well defined instantaneous heat source can be readily implemented. Radiation induced thermal transients are, therefore, the ideal heat sources for studies of thermal processes in thin films. Application of this method for measurements of thermal diffusivity and temperature dependent properties of thin polymer films are discussed. Imaging of inhomogeneities and depth profiling are another important area of application for these techniques. A number of applications emphasizing the various photoacoustic and photothermal techniques, their advantages and drawbacks are covered in detail. Copyright © 1991 Society of Plastics Engineers