摘要
以1-乙基-3-甲基咪唑醋酸盐([EMIM][OAC])为基准,通过分别在阴阳离子上修饰胺基(—NH2)、羟基(—OH)、腈基(—CN)、卤素(Br、F)等,虚拟设计了15种阳离子和21种阴离子组成的离子液体(IL)。采用基于COSMO-RS模型的COSMOtherm X软件计算了所设计的离子液体对乙腈-水混合物恒压汽液相平衡的影响,探索了修饰基团的种类、离子液体结构对乙腈相对挥发度的影响规律。研究发现,在阳离子碳链上修饰—NH2,阴离子(醋酸根和丙酸根)羰基的邻碳上进行单一的—OH修饰能促进乙腈与水的分离,且阳离子修饰的—NH2数越多,促进分离的效果越明显,其他嫁接方式未取得好的分离效果。虚拟设计的两种阳离子(1-胺乙基-3-甲基咪唑、2,2,2-三胺乙基-3-甲基咪唑)与3种阴离子(羟基乙酸、2-羟基丙酸、2-羟基-3-胺基丙酸)组合的离子液体分离效果明显比[EMIM][OAC]好。
Based on 1-ethyl-3-methylimidazolium acetate（[EMIM][OAC]）, ionic liquids composed by 15 cations and 21 anions were designed by modifying [OAC] and [EMIM] with different groups, including amine（—NH2）, hydroxy（—OH）, nitrile（—CN）, halogen（Br, F） and so on. The effect of the designed ionic liquids on the vapor-liquid phase equilibrium of acetonitrile and water mixtures was predicted by COSMOtherm X based on COSMO-RS model. The influence of group type and IL structure on relative volatility of acetonitrile was also investigated. The results showed that the ILs carrying —NH2 in cation or carrying —OH in anion can promote the separation of acetonitrile from water and the separation effect becomes more obvious with increasing number of — NH2 group. The ionic liquids composed by 2 cations（1-（2-aminoethyl）-3-methylimidazolium, 2,2,2-triaminoethyl-3-methylimidazolium） and 3 anions（hydroxyacetic acid, 2-hydroxypropanoic acid, 2-hydro-3-aminopropanoic acid） had better performance in separation water from acetonitrile than [EMIM][OAC].
出处
《化工学报》
EI
CAS
CSCD
北大核心
2016年第2期425-434,共10页
CIESC Journal
基金
国家重点基础研究发展计划项目(2015CB251401)
国家自然科学基金项目(21136004,21276073)
中央高校基本科研业务费资助项目(222201313001)
