首页|壁面作用对受限单层水结构和热导率的影响

壁面作用对受限单层水结构和热导率的影响

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受限于亚纳米通道中的单层水结构和热导率会因壁面作用而表现出与体相流体的显著差异.本文采用分子动力学方法并结合Green-Kubo公式研究了壁面作用对亚纳米通道受限单层水结构和热导率的影响规律.模拟结果表明,在不同壁面作用强度通道中,单层水热导率随水分子面密度增加都表现出了近乎相同的变化趋势,即先平缓增加、再快速上升、最后逐渐下降的趋势,但其峰值热导率及对应的面密度差异很大.分析发现,出现这一结果的原因是由于弱壁面作用通道对水分子的空间约束能力差,促使了高密度单层水形成褶皱结构,进而会削弱声子在水平方向的传递,从而导致较低热导率;相反,强壁面作用通道对水分子空间约束能力强,能使高密度单层水形成平坦结构,这种结构有利于声子传递,进而可产生更高热导率.不过,壁面作用对低密度单层水的结构和热导率的影响都较为微弱.总之,本研究发现了壁面作用对单层水结构和热导率的影响规律,揭示了单层水结构与热导率之间相互联系的物理机制,对丰富纳米受限流体热输运理论有重要价值和意义.
Effect of wall interaction on the structure and thermal conductivity of confined monolayer water
The structure and thermal conductivity of monolayer water in a subnanometer channel considerably differ from that of bulk water because of wall interaction.In this paper,molecular dynamics simulation using the Green-Kubo formula is used to study the effect of wall interaction on the water structure and thermal conductivity of confined monolayer water.Results reveal that the trend of thermal conductivity of monolayer water with increasing area density in the channels of different wall interactions is similar,i.e.,a slow increase at first,then a rapid rise,and finally a gradual decline.However,the peak thermal conductivity and corresponding area density considerably vary.This is attributed to the poor spatial constraint ability of the channels with weak wall interactions,which promotes the formation of wrinkle structures in high-density monolayer water,weakening the phonons dispersed in the horizontal direction and leading to low thermal conductivity.In contrast,channels with strong wall interactions have a strong constraint on water molecules and make the high-density monolayer water form a flat structure,which is beneficial for phonon dispersal,resulting in high thermal conductivity.However,the effect of wall interaction on the structure and thermal conductivity of low-density monolayer water remains weak.In summary,this study investigates the effect of wall interaction on the structure and thermal conductivity of monolayer water and reveals the corresponding physical mechanism,which is essential for enriching the thermal transport theory of nanoconfined fluids.

monolayer waterthermal conductivitysubnanometer channelthermal transportnanoconfined fluid

赵志翔、孙楠、靳永辉、黄翔

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西安工程大学,城市规划与市政工程学院,西安 710600

单层水 热导率 亚纳米通道 热输运 纳米受限流体

国家自然科学基金深圳市科技计划

52206223KCXFZ20201221173409026

2024

中国科学(物理学 力学 天文学)
中国科学院

中国科学(物理学 力学 天文学)

CSTPCD北大核心
影响因子:0.644
ISSN:1674-7275
年,卷(期):2024.54(2)
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