通过3D科布-安德森玻璃中局部平均自由体积的增强结构动力学相关性
Yifan Yang1,2, Yuyuan Lu1,3, Lijia An1,2
1State Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
The journal of physical chemistry. B
|November 29, 2025
概括
局部平均的自由体积,而不是单颗粒的自由体积,更好地预测玻璃形成液体的减速. 自由体积中的异质性种子放松事件,对于理解玻璃过渡至关重要.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
- 计算物理 计算物理
背景情况:
- 了解玻璃形成液体的动态减速是一个关键的挑战.
- 讨论了自由体积在结构松中的作用.
研究的目的:
- 调查自由体积和动态异质性的不同指标之间的关系.
- 为了确定控制玻璃过渡的结构因素.
主要方法:
- 采用了3D科布-安德森二元列纳德-斯模型的分子动力学模拟.
- 分析了局部平均的自由体积 (V2) 和单粒子自由体积 (V0).
- 量化相关性与空间丰富,概率密度转移和局部放松时间.
主要成果:
- 局部平均的自由体积 (V2) 与动态异质性和放松的相关性比V0.0更强.
- 不同类型的自由体积与增强的粒子流动性和配置自由度有关.
- 具有大,异构的自由体积 (τ长) 的粒子的寿命与结构放松时间 (τa) 相匹配.
- 冷却导致"活跃区域"的丧失,这些区域抑制运动,并驱动tα的超阿雷尼乌斯增长.
结论:
- 提出了一个统一的自由体积框架,强调局部空间相关性和异构性.
- 自由体积中的异位性被确定为启动放松事件的关键因素.
- 这些发现提供了对玻璃形成液体中观察到的超级Arrhenius减速的见解.
相关概念视频
Structures of Solids
17.4K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
17.4K
Crystal Field Theory - Octahedral Complexes
30.5K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
30.5K
Network Covalent Solids
16.0K
Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
16.0K
Molecular Geometry and Dipole Moments
17.9K
The VSEPR theory can be used to determine the electron pair geometries and molecular structures as follows:
17.9K
Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation
38.7K
Thus far, the ideal gas law, PV = nRT, has been applied to a variety of different types of problems, ranging from reaction stoichiometry and empirical and molecular formula problems to determining the density and molar mass of a gas. However, the behavior of a gas is often non-ideal, meaning that the observed relationships between its pressure, volume, and temperature are not accurately described by the gas laws.
38.7K
Fluid Mosaic Model
15.5K
Scientists identified the plasma membrane in the 1890s and its principal chemical components (lipids and proteins) by 1915. The model for plasma membrane structure, proposed in 1935 by Hugh Davson and James Danielli, was the first model to be widely accepted in the scientific community. The model was based on the plasma membrane's "railroad track" appearance in early electron micrographs. Davson and Danielli theorized that the plasma membrane's structure resembled a sandwich...
15.5K


