在固体和液体状态下D-葡萄糖单水合物的热脱水
Kazuki Kato1, Masami Hara1, Nobuyoshi Koga1
1Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan. nkoga@hiroshima-u.ac.jp.
Physical chemistry chemical physics : PCCP
|June 13, 2023
概括
在热脱水过程中D-葡萄糖单水合物 (DG-MH) 的化显著改变了反应途径. 控制条件显示了不同的固态,液态和混合相动力学DG-MH脱水.
科学领域:
- 化学动力学 化学动力学
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 碳水化合物的热脱水对于理解它们的稳定性和反应性至关重要.
- D-葡萄糖单 (DG-MH) 在加热时经历复杂的转化,受其点的影响.
- 以前的研究往往忽视了相变对脱水动力学的影响.
研究的目的:
- 阐明D-葡萄糖单一水合物 (DG-MH) 热脱水的物理几何反应路径和动力学.
- 为了研究反应中途融如何影响脱水过程.
- 在各种反应条件和模式下系统地分析脱水动力学.
主要方法:
- 使用热分析技术 (热重力测量) 来追踪DG-MH的热脱水情况.
- 实验是在受控的异热和非异热条件下进行的,加热速度各不相同 (β).
- 系统地研究了反应大气 (干燥N2,水蒸气压) 和样品状态 (固体,液体) 的影响.
主要成果:
- 在低加热速率 (<1K分钟-1) 的固态脱水显示了诱导周期和西格形质量损失,类似于自催化动力学.
- 在更高的加热速率 (≥2 K min-1) 下,发生了DG-MH化,形成了核心外结构,导致复杂的多阶段脱水.
- 在液态 (用水蒸气) 中在点附近启动的脱水导致晶体无水化物流的质量损失.
结论:
- 化DG-MH是一个关键因素,它极大地改变了其热脱水路径和动力学.
- 反应条件,包括加热速度和大气,决定脱水是否以固体,液体或混合相进行.
- 详细的动力分析提供了关于DG-MH热分解的基本机制的见解.
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