论文标题
无定形甘露酸的超冷液体和玻璃状态的分子松弛：介电光谱，量热法和理论方法
Molecular relaxations in supercooled liquid and glassy states of amorphous gambogic acid: dielectric spectroscopy, calorimetry and theoretical approach
论文作者
论文摘要
使用理论和实验研究了超冷和玻璃状甘露酸的弛豫动力学和热力学特性。我们测量了三个多晶型物（α-，β-和伽马形式）中松弛时间的温度依赖性。为了深入了解放松过程，我们提出了一种理论方法，以定量理解这三个放松的性质。 α-释放捕获了分子的合作运动，而β过程主要由其最近邻居形成的笼子中的单个分子的局部动力学控制。基于理论和实验数据之间的定量一致性，我们的计算清楚地表明，β过程是结构弛豫和分子内运动的先驱，负责伽马释放。此外，该方法被利用以研究加热过程对α弛豫的影响。我们发现，加热速率随TG和1000/TG的对数变化。这些变化在质量上与许多先前的研究一致。
The relaxation dynamics and thermodynamic properties of supercooled and glassy gambogic acid are investigated using both theory and experiment. We measure the temperature dependence of the relaxation times in three polymorphs (alpha-, beta-, and gamma-form). To gain insight into the relaxation processes, we propose a theoretical approach to quantitatively understand nature of these three relaxations. The alpha-relaxation captures cooperative motions of molecules while the beta-process is mainly governed by local dynamics of a single molecule within the cage formed by its nearest neighbors. Based on quantitative agreement between theory and experimental data, our calculations clearly indicate that the beta-process is a precursor of the structural relaxation and intramolecular motions are responsible for the gamma-relaxation. Moreover, the approach is exploited to study effects of the heating process on alpha relaxation. We find that the heating rate varies logarithmically with Tg and 1000/Tg. These variations are qualitatively consistent with many prior studies.
