Dehydration kinetics of D-glucose monohydrate studied using THz time-domain spectroscopy

We report the first use of THz time-domain spectroscopy (THz-TDS) to probe the dehydration process of a polycrystalline hydrate. Anhydrous and monohydrated D-glucose exhibit different THz absorption features, presumably due to their different intermolecular vibrational modes. The absorption peaks of anhydrous D-glucose were used to quantify the dehydration. The dehydration kinetics was found to obey the contracting area equation of the solid-state reaction. The dehydration rate constants at different temperatures were obtained and the activation energy was extracted from the Arrhenius plot. Our investigation demonstrates that THz-TDS is an effective new tool to characterize the dehydration kinetics of polycrystalline hydrates.