Molecular Dynamics Simulation on the Interaction between Palygorskite Coating and Linear Chain Alkane Base Lubricant
Molecular Dynamics Simulation on the Interaction between Palygorskite Coating and Linear Chain Alkane Base Lubricant
复制标题
DOI：
10.3390/coatings11030286
复制
发表时间：
2021-03
期刊：
影响因子：
3.4
通讯作者：
J. Zhang;Lv Yang;Yue Wang;Huaichao Wu;Jiabin Cai;Shusheng Xu
中科院分区：
文献类型：
--
作者：
J. Zhang;Lv Yang;Yue Wang;Huaichao Wu;Jiabin Cai;Shusheng Xu
采用分子动力学方法研究了凹凸棒石涂层与代表基础油的直链烷烃(十二烷C12、十四烷C14、十六烷C16和十八烷C18)之间的相互作用。通过在凹凸棒石涂层表面放置烷烃分子来建立模拟模型。对这些体系进行了退火和几何优化，以获得相应的稳定构型，然后分析了分子动力学过程中发生的结构变化。用界面相互作用能、均方位移和自扩散系数表征了基础润滑剂分子与凹凸棒石涂层之间的相互作用。结果表明，烷烃在平衡后表现出自排布能力。界面相互作用具有吸引力，静电能是结合能的主要组成部分。直链烷烃的链长对界面作用强度和分子扩散行为有显著影响。此外，C12分子的自扩散系数值高于C14、C16和C18分子。因此，在凹凸棒石涂层表面形成有序稳定的润滑膜是最佳的选择。这项工作为涂层和润滑剂的结构和组成优化提供了新的见解，将指导这些体系的实验开发，使其走向实际应用。
Molecular dynamics (MD) simulations were conducted to investigate the interactions between a palygorskite coating and linear chain alkanes (dodecane C12, tetradecane C14, hexadecane C16, and octadecane C18), representing base oils in this study. The simulation models were built by placing the alkane molecules on the surface of the palygorskite coating. These systems were annealed and geometrically optimized to obtain the corresponding stable configurations, followed by the analysis of the structural changes occurring during the MD process. The interfacial interaction energies, mean square displacements, and self-diffusion coefficients of the systems were evaluated to characterize the interactions between base lubricant molecules and palygorskite coating. It was found that the alkanes exhibited self-arrangement ability after equilibrium. The interfacial interaction was attractive, and the electrostatic energy was the main component of the binding energy. The chain length of the linear alkanes had a significant impact on the intensity of the interfacial interactions and the molecular diffusion behavior. Moreover, the C12 molecule exhibited higher self-diffusion coefficient values than C14, C16 and C18. Therefore, it could be the best candidate to form an orderliness and stable lubricant film on the surface of the palygorskite coating. The present work provides new insight into the optimization of the structure and composition of coatings and lubricants, which will guide the experimental development of these systems for practical applications.