Thermal Analysis Instrument coupled to a Mass Spectrometer

采购由同时热分析（STA）与质谱仪（MS）耦合组成的装置，可以获得质量变化信号，并结合有关废气成分的定量信息。从这个意义上说，在高达1600°C的温度下工作并进行氧敏感测量的可能性对于以下研究尤其必要：材料性质的推导；研究合成步骤，如热解、选择性解吸、碳活化、还原或氧化；洞察在非催化和催化过程中的变化。虽然达姆施塔特工业大学的不同小组已经使用了这种技术，但目前还没有一种装置可以覆盖高达1600°C的温度范围，同时满足无氧操作和长期稳定的定量质谱测量所产生气体的特殊要求。特别是对于聚合物在1600℃高温下的热解，最小的残余氧是至关重要的。当研究表面官能团的解吸行为时，也可以得到一个扭曲的图像，特别是对于只有小程度官能团的材料。同样地，残余氧也会对惰性气体作用下离子液体长期稳定性的研究产生影响。到目前为止，热重仪固有的大死体积和由此产生的未知的长清洗时间一直是主要问题。然而，通过在设备的净化步骤中监测氧含量，确保随后的无氧操作，而不会污染质谱仪，例如被水污染。此外，使用自动样品转换器不仅是有效使用仪器和最大吞吐量所必需的，而且还允许在测量活动期间对校准物质进行自动分析。由于计划应用复杂的温度和气体程序，需要一个良好的热重和质谱分析软件耦合。

The procurement of a setup consisting of a Simultaneous Thermal Analysis (STA) coupled to a Mass Spectrometer (MS) allows the acquisition of a mass change signal in combination with quantitative information about the exhaust gas composition. In this sense, the possibility to work at temperatures up to 1600 °C and to perform oxygen-sensitive measurements is especially necessary for the following studies: Derivation of material properties; studies of synthesis steps such as pyrolysis, selective desorption, carbon activation, reduction or oxidation; insights into changes during non-catalytic and catalytic processes. Although different groups at the TU Darmstadt already use this technique, there is currently no setup that can cover the temperature range up to 1600 °C while meeting the special requirements of an oxygen-free operation and long-term stable quantitative mass spectrometry measurements of the evolved gas. Especially for the pyrolysis of polymers at temperatures up to 1600 °C, the smallest amounts of residual oxygen are critical. A distorted picture can also be obtained when investigating the desorption behavior of surface functional groups, particularly for materials exhibiting only a small degree of functionalization. Likewise, residual oxygen can falsify investigations on the long-term stability of ionic liquids under inert gas. Until now, the inherently large dead volume of the thermogravimetric apparatus and the resulting unknown long purging time has been the major problem. However, by monitoring the oxygen content during the purging step of the apparatus ensures the subsequent oxygen-free operation without the contamination of the mass spectrometer, e.g. with water. The use of an automatic sample changer is furthermore not only necessary for an efficient use of the instrument and maximum throughput, but also allows the automated analysis of calibration substances during the measurement campaign. Due to the planned application of complex temperature and gas programs, a good software coupling of thermogravimetric and mass spectrometry analysis is necessary.