The development of techniques to probe spatial variations in chemical composition on the nanoscale continues to be an important area of research in the characterization of polymeric materials. Recent efforts have focused on the development and characterization of near-field microscopy in the mid-infrared spectral region. This technique involves coupling the high spatial resolution of near-field scanning optical microscopy with the chemical specificity of infrared absorption spectroscopy. This chapter describes the application of this technique to the chemical imaging of a polymer composite consisting of polystyrene particles dispersed in a poly (methyl methacrylate) thin film. Particular focus is placed on utilizing the measured spectral contrast to identify the nature and magnitude of the various sources of image contrast, including near-field coupling, topography induced optical contrast, scattering, and absorbance.
Citation: ACS Symposium Series
Pub Type: Journals
chemical imaging, IR microscopy, near-field optics, NSOM, polymer characterization, scanned probe microscopy, vibrational spectroscopy