Michael S. Bradley, PhD

Infrared and Raman bands are typically described in terms of peak location and peak height. The shape of the peak-its form, width, and asymmetry-is less well understood. Bandshapes largely depend upon interactions between vibrating molecules and their environment. An understanding of this relationship may enhance spectral interpretation and can explain unexpected behaviors, in both qualitative and quantitative analyses. This paper presents basic concepts that influence line shapes and shows the complex lineshape changes in an apparently simple system of acetone and water.

Thermal decomposition provides valuable information about the chemical composition of a material. Although thermal gravimetric analysis (TGA) measures small weight losses during a heating ramp, it cannot identify the chemicals corresponding to the weight loss.