Masuduzzaman Md, Kim BoHung
School of Mechanical Engineering, University of Ulsan, Daehak-ro 93, Ulsan 680-749, South Korea.
ACS Omega. 2020 Oct 5;5(41):26527-26536. doi: 10.1021/acsomega.0c03241. eCollection 2020 Oct 20.
The dependence of the heat transfer of a nanoscopic liquid channel residing at the solid-liquid interface is traditionally ascribed to the temperature jump, interfacial thermal resistance, wettability, and heat flux. Other contributions stemming from the channel width dependence such as the boundary position are typically ignored. Here, we conducted nonequilibrium molecular dynamics simulations to better understand the relation between channel width and boundary positions located at the solid-liquid interface. The system under investigation is a simple liquid confined between the solid from nanochannels of different sizes (3.27-7.35 nm). In this investigation, the existence of the correlation between the boundary position and the channel width is observed, which follows an exponential function. The thermal conductivity of the boundary positions is compared with the experimental value and Green-Kubo prediction to verify the actual boundary position. Atomistic simulation reveals that the solid-liquid boundary position, which matches the experimental value of thermal conductivity, varies with the channel width because of the intermolecular force and the phonon mismatch of the solid and the liquid.
传统上，位于固液界面的纳米级液体通道的热传递依赖关系归因于温度跳跃、界面热阻、润湿性和热通量。其他源于通道宽度依赖性（如边界位置）的因素通常被忽略。在此，我们进行了非平衡分子动力学模拟，以更好地理解通道宽度与位于固液界面的边界位置之间的关系。所研究的系统是一种简单液体，被限制在不同尺寸（3.27 - 7.35纳米）的纳米通道的固体之间。在这项研究中，观察到边界位置与通道宽度之间存在相关性，其遵循指数函数。将边界位置的热导率与实验值和格林 - 库博预测值进行比较，以验证实际边界位置。原子模拟表明，与热导率实验值匹配的固液边界位置会因分子间力以及固体和液体的声子失配而随通道宽度变化。
