分子内转子可以控制分子材料的导热率吗?
Naoyuki Karasawa1, Tetsuya Morishita1, Hisao Nakamura1
1National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
The Journal of chemical physics
|June 17, 2025
概括
分子动力学控制纳米级的热传输. 分子间运动,而不是分子内旋转,主导分子材料的导热性,指导热管理策略.
科学领域:
- 在纳米尺度科学科学.
- 材料科学是一种材料科学.
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 控制纳米级热传输对于热管理和纳米设备设计至关重要.
- 分子材料由于其灵活的结构和动态运动,提供可调节的热性能.
- 分子动力学对热传输的具体影响尚不清楚.
研究的目的:
- 研究分子内旋转和分子间动力学对分子多层分子导热性的影响.
- 为了确定哪些分子运动是最有效的纳米级的热控制.
主要方法:
- 使用理论计算来评估导热率.
- 这项研究分析了自我组装的分子多层.
- 研究了受阻和自由的分子内旋转,以及分子间 (层间) 运动.
主要成果:
- 内部分子旋转,即使在从受阻到自由状态的过渡时,也极少影响热导率.
- 分子间动力学,特别是层间运动,是确定导热性的主要因素.
- 分子间运动通过热激活驱动从弹道热传输到扩散热传输的过渡.
结论:
- 分子间动力学是控制分子材料中的热传输的主要机制.
- 内分子动力学与热导通道的相互作用很弱.
- 未来的热管理策略应侧重于操纵分子间运动.
相关概念视频
Thermal Electrocyclic Reactions: Stereochemistry
2.1K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.1K
Intermolecular vs Intramolecular Forces
89.8K
Intermolecular forces (IMF) are electrostatic attractions arising from charge-charge interactions between molecules. The strength of the intermolecular force is influenced by the distance of separation between molecules. The forces significantly affect the interactions in solids and liquids, where the molecules are close together. In gases, IMFs become important only under high-pressure conditions (due to the proximity of gas molecules). Intermolecular forces dictate the physical properties of...
89.8K
Radical Reactivity: Intramolecular vs Intermolecular
1.8K
Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak...
1.8K
Molecular and Ionic Solids
17.9K
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
17.9K
Thermal Sigmatropic Reactions: Overview
2.2K
Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
2.2K
Mechanisms of Heat Transfer
598
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
598


