The study of the vapor pressure and the enthalpy of vaporization of ionic liquids

离子液体蒸气压和汽化焓的研究

• 批准号: 29180562
• 负责人: Professor Dr. Sergey Verevkin
• 金额: --
• 依托单位: Lehrstuhl für Allgemeine Physikalische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/29180562?language=en
• 关键词: study; vapor; pressure; enthalpy; vaporization

A reliable knowledge of the vapor pressure of RTILs is of considerable interest for many reasons. Such data would be import for testing theoretical calculations of vapor pressures and heats of vaporization based on MD technique or other techniques. Several attempts have been made in the literature to estimate vapor pressures of RTILs in a more or less semiempirical way. We have developed a concept, which offers a direct way to measure the vapor pressure of RTILs using an extended version of the ¿transpiration technique¿, which has successfully been applied for determining vapor pressures of substances of very low valatility in our laboratory. In addition high precision measurements of the heats of combustion of different RTILs will be carried out using a ¿rotating bomb¿ calorimeter available in our group. This leads immediately to the heats of formation of RTILs in the liquid state. Heats of formation in the gaseous state will be obtained by high level quantum mechanical calculations, which have reached today a quality ensuring the required accuracy of a few percent for heats of formation in the gaseous state. The difference of the heats of formation in the gaseous and the liquid state is the heat of vaporization. Values obtained by this method will be compared with experimental values derived from the temperature dependence of the measured vapor pressure providing a sensitive but indispensable consistency test of both ways to obtain heats of vaporization. Theoretical calculations described will be performed in cooperation with the group of Theoretical Chemistry in Rostock (Prof. Ludwig) where the highest possible computer capacities guarantee the required reliably.

一个可靠的知识RTIL的蒸气压是相当感兴趣的原因有很多。这些数据对于检验基于分子动力学技术或其它技术的蒸汽压和汽化热的理论计算具有重要意义。在文献中已经进行了几次尝试，以或多或少的半经验方式估计RTIL的蒸气压。我们已经开发了一种概念，它提供了一种直接的方法来测量RTIL的蒸汽压使用的扩展版本的蒸发技术，它已成功地应用于确定在我们的实验室非常低valatility的物质的蒸汽压。此外，将使用我们小组现有的旋转弹式量热计对不同RTIL的燃烧热进行高精度测量。这直接导致液态RTIL的生成热。气态的生成热将通过高水平的量子力学计算来获得，其今天已经达到确保气态的生成热的百分之几的所需精度的质量。气态和液态的生成热之差就是汽化热。通过这种方法获得的值将与实验值进行比较，从测量的蒸汽压的温度依赖性提供了一个敏感的，但不可或缺的一致性测试的两种方式来获得汽化热。所述理论计算将与罗斯托克的理论化学组（路德维希教授）合作进行，其中最高可能的计算机容量保证所需的可靠性。