Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2V4.
J Agric Food Chem. 2011 Dec 14;59(23):12605-9. doi: 10.1021/jf202682d. Epub 2011 Nov 4.
Liquid crystals, observed as maltese crosses under cross-polarized light, form in D-(+)-glucose immediately upon melting, at ∼416 K, and become an isotropic liquid at ∼500 K. Differential scanning calorimetry (DSC) results show two overlapping endothermic peaks corresponding to the formation and disappearance of the liquid crystals. Thermogravimetric analysis (TGA) confirmed that D-(+)-glucose undergoes thermal decomposition upon melting. Cooling and reheating isotropic samples previously heated to 500 K do not lead to the reappearance of the liquid crystals. The formation of liquid crystals is irreversible. Further study is required to determine which components among the decomposition intermediates or products of D-(+)-glucose are responsible for the formation of liquid crystals and whether they have process or product applications.
在偏光显微镜下观察到的呈马耳他十字状的液晶，在 D-(+)-葡萄糖熔融时即刻形成，温度约为 416 K，在约 500 K 时变成各向同性液体。差示扫描量热法（DSC）结果表明，两个重叠的吸热峰对应于液晶的形成和消失。热重分析（TGA）证实 D-(+)-葡萄糖在熔融时发生热分解。先前加热到 500 K 的各向同性样品冷却和再加热不会导致液晶再次出现。液晶的形成是不可逆的。需要进一步研究以确定 D-(+)-葡萄糖的分解中间产物或产物中的哪些成分负责形成液晶，以及它们是否具有工艺或产品应用。
