The intercalation of molten polymer into layered silicates (nanoclays) is a critical step in the fabrication of commercial polymer nanocomposite products, so it is therefore very important to understand the process of intercalation and exfoliation, as well as to properly characterize the final state achieved. Following on our recent work demonstrating the potential of transmission infrared spectroscopy for this purpose, we show in this work how the attenuated total reflection technique can be used to study the intercalation process in real time. Although various aspects of the Si–O stretching bands near 1150–950 cm–1 are sensitive to the intercalation, the most sensitive parameter is the relative intensity of the out-of-plane band near 1077 cm–1. A method based on the second derivative of the spectrum has been developed to quantify this aspect. The application of this approach is described in detail and examples are given involving different polymers.
Kenneth C. Cole, "The Use of Attenuated Total Reflection Infrared Spectroscopy to Study the Intercalation of Molten Polymer into Layered Silicates in Real Time," Appl. Spectrosc. 63, 1343-1350 (2009)