分子玻璃成型器中的正常至超冷液体过渡:一种隐藏的结构转变,由形态互换驱动
Andrzej Nowok1,2, Joanna Grelska3, Mateusz Dulski4
1Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Stanisława Wyspiańskiego 27, 50-370 Wrocław, Poland.
The journal of physical chemistry. B
|May 10, 2024
概括
研究人员研究了一种形成玻璃的宏循环皇冠乙,MeBzSO,在333 K确定了Arrhenius交叉. 这种转变与形状变化有关,影响分子动力学和结构,促进玻璃化.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 玻璃成型系统在阿雷尼乌斯交叉点附近的分子动力学和运输特性出现了显著的变化.
- 了解这些转变对于描述超冷液体的行为至关重要.
研究的目的:
- 为了研究玻璃形成的宏循环冠状 thiaether MeBzSO 在其玻璃过渡温度以上的动态过程和结构转变.
- 确定和描述阿雷尼乌斯交叉及其与正常到超冷液体过渡的关系.
主要方法:
- 宽带介电光谱学 (BDS) 是一种
- 在X射线中,X射线的衍射效果是不同的.
- 福里埃变换红外光谱法 (FTIR) 光谱法
- 分子动力学 (MD) 模拟
- 密度函数理论 (DFT) 的计算.
主要成果:
- 确定了两个交叉温度:T_B在309 K和T_A在333 K,其中T_A被确定为阿雷尼乌斯交叉.
- 阿雷尼乌斯交叉与结构放松时间的温度依赖性变化有关,从激活式到超级阿雷尼乌斯.
- 观察到近邻分子的双重局部组织,由MeBzSO的构造变化驱动,有利于超冷状态下最低能量的构造,并促进玻璃化.
结论:
- 在MeBzSO中,Arrhenius过渡主要是由形状变化驱动的,与现有理论相比,这是一个新的发现.
- 这些形状动态显著影响了短距离的分子间秩序,并对玻璃化过程作出了贡献.
- 这项研究强调了玻璃成型材料中分子构造,动力学和结构之间的复杂相互作用.
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