Solid state vitrification of crystalline αα and ββ-D-glucose by mechanical milling

The structural and thermodynamic changes in the organic molecular crystals of αα-D-glucose and ββ-D-glucose upon high energy ball milling at room temperature and −15 ∘C have been studied. The investigations have been performed by X-ray diffraction, differential scanning calorimetry and Raman spectroscopy. The results show the possibility to reach the glassy amorphous state of both forms of glucose, if mechanical milling is performed far enough below the glass transition temperature of the corresponding liquid (Tg≈38∘C). This route to the glassy state is found to be free of mutarotation whatever the starting glucose variety, while this mutarotation is unavoidable using the usual thermal quench of the liquid.