Atomistic Insights into the Anisotropic and Low Thermal Conductivity in Neopentyl Glycol Crystals: A Molecular Dynamics Study

doi:10.1021/acs.jpcc.1c04035

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	Atomistic Insights into the Anisotropic and Low Thermal Conductivity in Neopentyl Glycol Crystals: A Molecular Dynamics Study
	Wang, Simin 2; Sun, Liang 2; Li, Bing 1; Dai, Liang 2
刊名	JOURNAL OF PHYSICAL CHEMISTRY C
	2021-07-29
卷号	125 期号:29 页码:15853-15862
ISSN号	1932-7447
DOI	10.1021/acs.jpcc.1c04035
通讯作者	Dai, Liang(liangdai@cityu.edu.hk)
英文摘要	Neopentyl glycol (NPG) is a promising next-generation environment-friendly refrigerant, because NPG can release huge latent heat during a solid-phase transition from a plastic crystal phase to a true crystal phase. However, NPG has a very low thermal conductivity, which restricts its applications. In this paper, we investigated the mechanisms of thermal transport of an NPG crystal by performing atomistic molecular dynamics (MD) simulations. Our simulation results obtained the thermal conductivities of 0.50, 0.32, and 0.33 W m(-1) K-1 at 298.15 K along the a, b, and c* directions, respectively, which agree with the experimental results ranging from 0.15 to 0.42 W m(-1) K-1. The anisotropy of the thermal conductivity along the three directions is caused by the hydrogen-bond network in NPG. We reveal the reasons for the low thermal conductivity: the large gap between the low-frequency region and the high-frequency region in the phonon spectrum and the ultrashort phonon mean free path (MFP). The effective MFPs are only 1.28, 5.47, and 2.22 nm along the a, b, and c* directions, respectively. In addition, we find that the thermal conductivity is insensitive to the temperature from 218.15 to 298.15 K, probably because the ultrashort MFP is insensitive to the temperature. Furthermore, we find that vacancy defects affect the thermal conductivity in an intriguing manner. When the defect concentrations are 2 and 4%, the thermal conductivities along the b* and c* directions increase abnormally with the increase in temperature, which is related to the reorientation of hydroxyl groups upon the change in temperature. Overall, this work reveals the molecular mechanism of the thermal transport of NPG, which should provide valuable insights in enhancing the thermal conductivity of NPG for the application as an environment-friendly refrigerant.
资助项目	National Natural Science Foundation of China[21973080] ; National Natural Science Foundation of China[11804346] ; City University of Hong Kong[9610420] ; Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology
WOS研究方向	Chemistry ; Science & Technology - Other Topics ; Materials Science
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000680445800009
资助机构	National Natural Science Foundation of China ; City University of Hong Kong ; Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/159756]
专题	金属研究所_中国科学院金属研究所
通讯作者	Dai, Liang
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab SYNL Mat Sci, Shenyang 110016, Peoples R China 2.City Univ Hong Kong, Dept Phys, Kowloon, Hong Kong 999077, Peoples R China
推荐引用方式 GB/T 7714	Wang, Simin,Sun, Liang,Li, Bing,et al. Atomistic Insights into the Anisotropic and Low Thermal Conductivity in Neopentyl Glycol Crystals: A Molecular Dynamics Study[J]. JOURNAL OF PHYSICAL CHEMISTRY C,2021,125(29):15853-15862.
APA	Wang, Simin,Sun, Liang,Li, Bing,&Dai, Liang.(2021).Atomistic Insights into the Anisotropic and Low Thermal Conductivity in Neopentyl Glycol Crystals: A Molecular Dynamics Study.JOURNAL OF PHYSICAL CHEMISTRY C,125(29),15853-15862.
MLA	Wang, Simin,et al."Atomistic Insights into the Anisotropic and Low Thermal Conductivity in Neopentyl Glycol Crystals: A Molecular Dynamics Study".JOURNAL OF PHYSICAL CHEMISTRY C 125.29(2021):15853-15862.