Thermal analysis and differential thermal analysis offers a novel means of studying the desorption of acids such as stearic
acid from clay surfaces. Both adsorption and chemisorption can be distinguished through the differences in the temperature
of mass losses. Increased adsorption is achievable by adsorbing onto a surfactant adsorbed montmorillonite. Stearic acid sublimes
at 179 °C but when adsorbed upon montmorillonite sublimes at 207 and 248 °C. These mass loss steps are ascribed to the desorption
of the stearic acid on the external surfaces of the organoclays and from the de-chemisorption from the surfactant held in
the interlayer of the montmorillonite.