【作者】 吴晓萍；

【导师】 汪文川； 刘志平；

【作者基本信息】 北京化工大学 ， 化学工程， 2005， 博士

【摘要】 室温离子液体是由有机阳离子和无机或有机阴离子构成的、在室温或室温附近呈液态的一类有机盐。与传统的有机溶剂相比，离子液体具有液态温度范围宽；蒸汽压低，不易挥发；对大量的无机和有机物质都表现出良好的溶解能力，且具有溶剂和催化剂的双重功效；可设计性强等优点。由于离子液体的这些特殊性质和表现，使得近年来有关离子液体的研究备受关注。 本工作中，首先应用本组开发的基于咪唑类离子液体的全原子力场模型（AA）（J.Phys.Chem.B,2004,108,12978-12989）对[bmim][BF₄]（1）+乙腈（2）的混合物进行了分子动力学模拟。预测的密度和实验值吻合非常好，偏差小于2％；超额摩尔体积为负值，且在[bmim][BF₄]摩尔分率为0.3时出现最小值，这与实验观察到的现象相吻合。根据模拟得到的各组分的自扩散系数估算了混合物的扩散系数，并根据Stokes-Einstein关联式估算了混合物的粘度，结果与实验测定的粘度数据吻合。另外，本文详细考察了该混合物体系的微观结构，组分间径向分布函数及空间分布均表明，在[bmim][BF₄]摩尔分率为0.3时混合物的微观结构存在一定的特殊性，与宏观现象相一致。模型总体上合理地反映了该混合物体系的特性。 由于离子液体体系完全由带电粒子构成，静电能的计算需耗费大量机时，同时也为了增强模型的预测能力，在接下来的工作中对该力场进行了简化，开发了联合原子力场（UA）模型。对咪唑基阳离子烷更多还原

【Abstract】 Room temperature ionic liquids （RTILs） are a class of organic salts that remain liquid at or near room temperature, usually composed of organic cations and organic or inorganic anions. Compared with traditional organic solvents, RTILs have tremendous advantages, such as negligible vapor pressure, good solvation ability for organic or inorganic materials, and having the function of both solvent and catalyst. Furthermore, through different combinations of cations and anions, there is a tremendous variety of "designer" solvents. Their status as "green" or "designer" solvents explains the large amount of studies concerning their possible industrial use as reaction or extraction media.To test the force field of RTILs proposed by our group （J. Phys. Chem. B, 2004, 108, 12978-12989）, thermodynamic properties of the mixture of [bmim][BF₄] （1） + acetonitrile （2） were investigated by molecular dynamics simulations. The calculated densities are in good agreement with the experimental data, with absolute relative deviations （ARD） less than 2%. The excess molar volumes are negative over the whole concentration range and present a minimum at [bmim][BF₄] mole fraction of 0.3, which coincides with the phenomenon from experiment. The Self-diffusion coefficients of the mixture were estimated by using those of three components. Furthermore, the viscosities of the mixture were estimated by更多还原