分子动力学模拟橡胶

精品文档---下载后可任意编辑两种算法得到的二甲醚在橡胶中的扩散系数在数量级上保持一致，除去个别点外，两者的相对误差在一定稳定范围内。Green-Kubo 法计算需要积分，较为繁琐，误差较大，用 Green-Kubo 法求得二甲醚在 343k 温度下的氟橡胶中的模拟扩散系数最大，可推测此温度下在所有讨论的橡胶中氟橡胶的耐二甲醚的能力最差。基于本文讨论得到的数据，进行综合分析后认为本文所讨论的橡胶中丙烯腈含量为 20%的氢化丁腈橡胶的耐二甲醚性能最好。关键词： 二甲醚，分子动力学，橡胶，扩散系数ABSTRACTWith the rapid development of computer performance and computing technology,the use of computers and the movement of material microstructure numerical simulation have been developing rapidly, and the development of statistical summation of numerical calculation method based on this: Molecular Dynamics.In the article,use Materials Studio of Accelrys Companyto simulation DME diffusion behavior in the different rubber, and obtain thediffusion coefficient of DME in 6 types of rubber that has different temperature by using Einstein and Green-kubo algorithms, and compare the two algorithms.Create model based on the COMPASS force field .In order to simulate the system close to the real system, build a model of three-dimensional periodic boundary conditions, and select the lowest energy, the most stable system with periodic boundary as the initialconfiguration. Then the simulation system for energy optimization and pre-equilibrium, molecular dynamics simulations with NVTensemble in order to get DME diffusion processes and trajectories in the rubber,finally, calculate DME diffusion coefficient in the rubber withtwo algorithms. After analyzing the data of this study, found that the DME diffusion coefficients in the rubber were obtained by the two algorithms consistent in magnitude, except from a few points, the relative ...