小分子酸与高分子酸在油中扩散行为的分子动力学模拟  

Molecular Dynamics Simulation on Diffusion Behaviors of Small Molecule Acids and Polymer Acids in Oils

作　　者：李亚莎[1] 刘志鹏 花旭[1] 代亚平[1] 沈星如 LI Yasha;LIU Zhipeng;HUA Xu;DAI Yaping;SHEN Xingru(College of Electrical Engineering ＆ New Energy,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学电气与新能源学院,湖北宜昌443002

出　　处：《绝缘材料》2018年第9期70-75,共6页Insulating Materials

基　　金：国家自然科学基金资助项目(51577105)

摘　　要：为深入了解小分子酸和高分子酸在油中的扩散行为,利用分子动力学方法分别对甲酸和环烷酸在不同含水量油中的扩散行为进行了模拟研究。根据均方位移计算了两种酸在不同含水量油中的扩散系数,通过径向分布函数观察了两种酸的不同官能团与水分子形成氢键的情况,并且分析了不同酸油模型的动能变化。结果表明:环烷酸的扩散系数明显小于甲酸,且其下降趋势较甲酸平缓;两种酸中羰基氧原子比羟基氧原子更易与水分子形成氢键;酸油模型中水和酸含量越高,形成的氢键数目越多,所具有的动能越大,分子间相互撞击所释放的能量更强,更容易破坏油分子结构的稳定性。In order to further study the diffusion behaviors of small molecule acids and polymeric acids in oils, the diffusion behaviors of formic acid and naphthenic acid in oils with different water contents were simulated by molecular dynamics method. The diffusion coefficients of two kinds of acid in oils with different water contents were calculated according to the mean square displacement, the hydrogen bond formation situation between different functional groups of two acids and water molecules were observed according to the radial distribution function, and the kinetic energy variation of different acid-oil models was analyzed. The results show that the diffusion coefficient of naphthenic acid is obviously less than that of formic acid, and its decrease trend is more gently. The oxygen atoms in carbonyl group are easier to form hydrogen bonds with water molecules than that in hydroxyl groups in two kinds of acid.The higher the water and acid contents in the acid oil model, the greater the number of hydrogen bonds formed, the greater the kinetic energy, and the energy released by intermolecular collision is stronger,which is more likely to damage the stability of oil molecule structure.

关 键 词：变压器油 分子动力学 扩散系数 氢键 

分 类 号：TM214[一般工业技术—材料科学与工程]