室温离子液体[bmim][BF_4]和水混合物的计算机模拟研究

Computer Simulation Study of the Mixtures of Room Temperature Ionic Liquid [bmim][BF_4] and Water

针对室温离子液体[bmim][BF4]和水的混合物,用分子动力学模拟研究了溶液的微观组成与浓度的关系.模拟结果表明:该混合物中各组分间的径向分布函数随[bmim][BF4]摩尔分数的增加呈有规律的变化;在此基础上计算了溶液的局部组成以及组分间的缔合因子,进一步考察了各组分间的相互作用情况;另外基于Kirkwood-Buff理论估算了混合物的偏摩尔体积、等温压缩因子以及活度系数对浓度的偏导数,对于理解离子液体与水之间的交互作用具有一定的参考意义.

The mixtures of [bmim] [BF4] ＋water are studied by molecular dynamics simulation. The radial distribution function （RDF）, local composition, as well as Kirkwood-Buff integration between different components are obtained. The simulation results show that the RDFs change regularly with the concentrations. The interaction manner between the different components can be understood more clearly through the association factor. In addition, the partial molar properties and the derivatives of activity coefficients were estimated by Kirkwood-Buff theory, which can provide valuable information of the mixture.