Timur A. Mukhametzyanov , Airat A. Notfullin , Alisa A. Fatkhutdinova , Christoph Schick
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引用次数: 0
Abstract
Organic compounds can be used as temperature calibrants in fast scanning calorimetry. Their advantages include ease of surface cleaning of the calorimetric chip and good thermal contact with the chip surface. Among several compounds tested, benzoic acid was identified as a convenient and reliable calibrant for temperatures below approximately 130 °C. However, organic calibrants often exhibit unusual heating rate dependencies of the onset temperatures of melting. This phenomenon can be semi-quantitatively explained by considering different heat flows within the sensor. Notably, the thermal resistance between the heater and thermopile, often overlooked, introduces an additional time constant that can sometimes result in a negative apparent thermal lag. In addition, the onset temperatures are influenced by factors such as sample position, thickness, surface wetting, and spreading. These factors limit the accuracy of transition temperature determinations to approximately ±1 K below 130 °C and ±5 K up to 220 °C.
有机化合物可用作快速扫描量热仪的温度校准器。有机化合物的优点包括易于清洁量热芯片的表面以及与芯片表面良好的热接触。在测试的几种化合物中，苯甲酸被认为是温度低于约 130 °C 时方便可靠的校准物。然而，有机定标物在开始熔化的温度上往往表现出不寻常的加热速率依赖性。考虑到传感器内的不同热流，这种现象可以得到半定量的解释。值得注意的是，加热器和热电堆之间的热阻经常被忽视，它会带来一个额外的时间常数，有时会导致负的表观热滞后。此外，起始温度还受到样品位置、厚度、表面润湿和扩散等因素的影响。这些因素将过渡温度测定的精确度限制在 130 °C 以下约 ±1 K 和 220 °C 以下 ±5 K。
期刊介绍：
Thermochimica Acta publishes original research contributions covering all aspects of thermoanalytical and calorimetric methods and their application to experimental chemistry, physics, biology and engineering. The journal aims to span the whole range from fundamental research to practical application.
The journal focuses on the research that advances physical and analytical science of thermal phenomena. Therefore, the manuscripts are expected to provide important insights into the thermal phenomena studied or to propose significant improvements of analytical or computational techniques employed in thermal studies. Manuscripts that report the results of routine thermal measurements are not suitable for publication in Thermochimica Acta.
The journal particularly welcomes papers from newly emerging areas as well as from the traditional strength areas:
- New and improved instrumentation and methods
- Thermal properties and behavior of materials
- Kinetics of thermally stimulated processes
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