摘要
为研究石墨烯形成的纳米级有限空间对石蜡相变行为的影响,以正十八烷代表石蜡,采用分子动力学模拟方法研究了厚度为5.1 nm的石墨烯夹层对正十八烷相变行为的约束效应。模拟结果表明,石墨烯夹层可抑制正十八烷分子的热运动,使其更难融化,更易凝固,与纯正十八烷体系相比,该尺度的石墨烯夹层使正十八烷的凝固温度和融化温度分别提高了51.39 K和19.33 K,凝固潜热和融化潜热较理论值分别降低了7.41%和8.10%;在石墨烯和正十八烷的相互作用下,石墨烯作为二维平面可为正十八烷结晶提供模板,使其优先在石墨烯界面形成结晶层,随着温度降低,从石墨烯界面向外逐渐定向结晶,并迫使正十八烷形成与石墨烯界面平行的结晶层。
In order to study the effect of the nanoconfinement space formed by graphene on the phase transformation behavior of paraffin,the molecular dynamics(MD)simulation method was used to investigate the confinement effect of 5.1 nm thickness of graphene interlayer on the phase transformation behavior of n-octadecane.The simulation results show that the graphene interlayer can inhibit the thermal motion of n-octadecane molecules,making it more dificult to melt and easier to solidify.Compared with the pure n-octadecane system,the graphene interlayer of this scale increases the solidification temperature and melting temperature of n-octadecane by 51.39 K and 19.33 K,respectively.The solidification latent heat and melting latent heat were decreased by 7.41%and 8.10%respectively compared with the theoretical value.Under the interaction between graphene and n-octadecane,graphene as a two-dimensional plane can provide a template for n-octadecane crystallization,so that it preferentially forms a crystalline layer at the graphene interface.With the decrease of temperature,n-octadecane molecules gradually oriented crystallize outwards from the graphene interface and the graphene interlayer can force the n-octadecane to form a crystalline layer parallel to it.
作者
常志娟
郎旭锋
刘梦瑶
吴学红
吕财
刘勇
CHANG Zhijuan;LANG Xufeng;LIU Mengyao;WU Xuehong;LU Cai;LIU Yong(Zhengzhou University of Light Industry,Zhengzhou 450000,China;Key Laboratory of Cold Chain Food Processing and Safety Control(Zhengzhou University of Light Industry),Ministry of Education,Zhengzhou 450000,China)
出处
《工程热物理学报》
北大核心
2025年第6期2021-2028,共8页
Journal of Engineering Thermophysics
基金
国家自然科学基金(No.51476149)
河南省中原科技创新领军人才(No.234200510011)
河南省重点研发计划(No.241111320900)
郑州市协同创新专项(校重大重点项目培育)(No.2021ZDPY0107)。
关键词
有机相变材料
正十八烷
石墨烯
扩散系数
分子动力学模拟
organic phase change material
n-octadecane
graphene
diffusivity coefficient
molecular dynamics simulation
