CO2促使离子液体与极性物质相分离的机理研究

项目名称： CO2促使离子液体与极性物质相分离的机理研究

项目编号： No.20806066

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 邢华斌

作者单位： 浙江大学

项目金额： 18万元

中文摘要： 离子液体-极性物质-CO2三元体系随CO2浓度升高可发生液-液或液-固相分离，可用于离子液体和极性物质的分离。本项目测定了常规离子液体、氨基离子液体和磺酸离子液体与极性物质、CO2三元体系的相平衡，研究表明CO2具有较强的促使离子液体与极性物质相分离的能力；采用溶剂显色探针法研究离子液体-极性物质二元体系的微观物性，发现二元体系中离子液体可优先溶解探针分子，显示离子液体可与酸性物质发生特异性作用。采用分子动力学模拟研究了三元体系相互作用和微观结果，研究表明极性物质甲醇、CO2与离子液体主要作用位点均为阴离子，特别的是CO2可与阴离子形成很强的酸碱相互作用，因此CO2作为竞争性组分，当溶于离子液体-极性物质中时，它破坏了离子液体-极性物质之间的相互作用，削弱了阴离子的溶剂化层，形成新的离子液体-CO2相互作用，将极性物质置换出来发生相分离，可称为"竞争/置换机理"。发表标注资助SCI收录论文7篇（J.Supercritic.Fluids 3篇，Ind.Eng.Chem.Res.1篇），返回审稿意见1篇（J. Phys. Chem. B），拟投稿2篇。项目负责人入选浙江省新世纪151人才。

中文关键词： 离子液体;相平衡;二氧化碳;抗溶剂法;分子模拟

英文摘要： Ionic liquids (IL), when used for replacing classical organic solvents, offer a new and environmentally benign approach toward modern chemical processes. One of potential challenge in using ionic liquids for practical chemical processes is the separation of IL and polar compound. Recent studies show that IL-polar compound mixture can be separated by using carbon dioxide as an antisolvent to induce phase split. In this project, the phase equilibrium of ternary system composed of ILs, polar compound and CO2were measured, and the microscopic physical properties of binary system of ILs-polar compounds were studied in which ILs refer to traditional ILs, amino-functionalized ILs and sulfuric acid ILs. The results showed that ILs can preferentially solvate probe molecules in binary system which indicated that CO2 could formed specific interaction with ILs. Molecular dynamic simulation study of ternary system were carried to study the interaction among three compounds in a microscopic scale. The research showed that the major interaction site between methanol and ILs or CO2 and ILs is anion, especially CO2 had a strong acid-base interaction with anion. As a result, CO2 can act as a competitive component when dissolving into the binary system consisted of ILs and polar compounds. It broke the interaction between ILs and polar compounds, and impaired the solvation layer of anions, giving rise to new IL- CO2 interaction and phase separation with substitution of polar compounds, and the whole process can be called "competitive/ substitutional mechanism". For now, seven papers with fund labeled have been accepted by SCI (J. Supercritic. Fluids 3, Ind. Eng. Chem. Res. 1).

英文关键词： ionic liquid; carbon dioxide; phase equilibrium;anti-solvent;simulation