甲醇对1-丁基-3-甲基咪唑四氟硼酸离子液体结构与性质影响的模拟研究

采用分子动力学模拟方法研究了298.15 K、0.1 MPa下摩尔分数为0.1-0.9 的甲醇对1-丁基-3-甲基咪唑四氟硼酸盐([BMIM][BF₄])结构与性质的影响. 获得了体系的密度、径向分布函数、配位数、自扩散系数、粘度和电导率, 模拟得到的密度值与实验值符合较好. 结果显示: 体系各组分之间的径向分布函数随甲醇摩尔分数的增加呈规律性变化; 体系内阴阳离子的自扩散系数随着甲醇摩尔分数的增加不断增大; 甲醇的加入削弱了阴阳离子之间的相互作用, 体系粘度随着甲醇摩尔分数的增加逐渐减小, 电导率不断增大. 分析空间分布函数得到体系中各组分的三维空间分布情况.

Simulation Study of the Effect ofMethanol on the Structure and Properties of 1-Butyl-3-methylimidazolium Tetrafluoroborate Ionic Liquid

The microstructure and properties of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] [BF₄])/methanol mixtures with different amount-of-substance fractions for methanol (0.1-0.9) were studied by molecular dynamics (MD) simulations at 298.15 K and 0.1 MPa. The densities, radial distribution functions, coordination numbers, self-diffusion coefficients, viscosities, and conductivities of the systems were obtained. The simulated densities agreed with experimental values. As the methanol amount-ofsubstance fraction increased, the radial distribution functions of different components in the mixture showed regular changes, the interaction between the anion and cation and the viscosity decreased, and the conductivity and the self-diffusion coefficients increased. The spatial distribution functions obtained from the MD simulations were visualized to depict the microscopic structures of different components in the system.