The boiling temperature of ionic liquids--An experimental approach
讲座名称：
The boiling temperature of ionic liquids--An experimental approach
讲座时间：
2016-08-09
讲座人：
Christoph Schick
形式：
校区：
兴庆校区
实践学分：
讲座内容：
应能动学院王晓坡副教授邀请，国际期刊《Thermochimica Acta》主编、德国罗斯托克大学Christoph Schick教授于2016年8月8日-11日来访交流。期间将做一次公开学术讲座。
报告题目：The boiling temperature of ionic liquids--An experimental approach
报告时间：2016年8月9日上午9:30-11:00
报告地点：东三楼圆桌会议室
报告摘要：
The very low vapor pressure of ionic liquids is challenging to measure. At elevated temperatures the liquids might start to decompose, at relatively low temperatures the vapor pressure becomes extremely low to be measured by conventional methods. We developed a highly sensitive method for mass loss determination at temperatures starting from 350 K up to 800 K. The technique is based on fast scanning (10 000 K s-1) and an alternating current (AC) calorimeter equipped with a chip sensor, that consists of a free-standing SiNx-membrane (thickness < 1 µm) and a measuring area with lateral dimensions of the order of 1 mm. A small droplet (diameter ca. 300 µm) of an ionic liquid is vaporized isothermally from the chip sensor in a vacuum-chamber. The surface-to-volume-ratio of such a droplet is large and the relative mass loss due to evaporation is therefore easy to be monitored by the changing heat capacity (J K-1) of the remaining liquid. The vapor pressure is determined from the measured mass loss rates using the Langmuir equation. The method was successfully tested with determination of vapor pressures and the vaporization enthalpy of the archetypical ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm][NTf2]). The created in this way data set in the extremely broad temperature range 358 K to 780 K has allowed estimation of the boiling temperature of [EMIm][NTf2]. The value (1120 ± 50) K should be considered as the first reliable boiling point of this ionic liquid obtained from experimental vapor pressures measured in the most possible close proximity to the normal boiling temperature.
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