Infrared spectroscopy as a tool to monitor the extent of intercalation and exfoliation in polymer clay nanocomposites

The scientific and commercial interest for polymer aluminium silicate clay nanocomposites has risen dramatically over the last decades, whereas the monitoring of the extent of intercalation and exfoliation using an efficient, fast and convenient method remains an issue. For this purpose, infrared spectroscopy constitutes a very promising characterization technique to fulfill this role. Few studies have already been conducted towards this direction, however no direct correlation between the intercalation/exfoliation and the SiO stretching vibrations has been reported so far. In most cases multiple peaks are used for the fitting of the spectra without any direct report on their origin. We report for the first time in the present study the distinct vibrational species that are attributed to the intercalated/exfoliated structures and are necessary for the fitting of the spectra in the SiO stretching vibration region. Moreover, we also report that the intercalation/exfoliation process gives rise to two new peaks at around 1085 and 1040 cm−1 whose relative intensities to the main SiO stretching peaks at 1070 and 1050 cm−1 provide insight on the progress of intercalation/exfoliation in polymer clay nanocomposites.