基于COSMO-SAC模型的离子液体萃取剂的选择

COSMO-SAC模型是计算无限稀释活度因子的一种有效方法,只需知道分子结构,即可进行有机物或离子液体的无限稀释活度因子计算。COSMO-SAC模型中最耗时的计算步骤是产生σ-图谱(σ-profile)的量子化学计算。利用Materials Studio软件中的DMol3模块,建立了包含32种离子液体阴离子和191种离子液体阳离子的σ-图谱数据库。利用σ-图谱数据库和COSMO-SAC模型,针对离子液体液液萃取过程,提出了离子液体萃取剂的计算机辅助分子设计方法。以乙醇-乙酸乙酯体系为研究对象,选择了适宜的离子液体萃取剂,采用乙醇-乙酸乙酯-离子液体三元体系的液液平衡文献数据进行了验证。

Selection of ionic liquid solvent for liquid-liquid extraction based on COSMO-SAC model

The COSMO-SAC model is an effective method for calculation of infinite dilution activity coefficients (IDACs), and IDACs of organic solutes or ionic liquids (ILs) can be calculated if the structures of the molecules are known.The most time consuming step in COSMO-SAC model is the generation of σ-profile via quantum mechanics.A σ-profile database including 32 anions and 191 cations were established by DMol3 in Materials Studio.A computer aided molecular design method based on COSMO-SAC and the σ-profile database was proposed to select ionic liquid solvents for the liquid-liquid extraction process.The mixture of ethanol-ethyl acetate was used to test the ionic liquid solvent selection method.Effective ionic liquid solvents were selected via such a method and some of them were verified by liquid-liquid equilibrium data of ternary system of ethanol-ethyl acetate-ionic liquid in literature, which indicated that the selection method of ionic liquid solvents was effective.