差示扫描量热法测定液体样品比热容的影响因素

Factors Affecting Specific Heat Capacity Measurement of Liquid Samples by Differential Scanning Calorimetry

  • 摘要: 液体样品的比热容在差示扫描量热法(DSC)测试中会存在一定的不稳定性,为了准确测定液体样品的比热容,并获得可靠的热物性参数,需要深入探究测试过程中的影响因素. 采用DSC,以去离子水为测试样品,考察了坩埚类型、装样方式、升温速率以及样品量对比热容测试结果的影响. 结果表明,采用concavus铝坩埚、倒盖、密闭的装样方式,样品量为25 μL,升温速率为10 ℃/min时,测得去离子水的比热容准确性和精密度更高,因此可将该条件作为测量与水的状态和性质类似的液体样品比热容的最佳试验条件.

     

    Abstract: The specific heat capacity of liquid samples exhibits variability during dfferential scanning calorimetry (DSC). In order to accurately determine the specific heat capacity of liquid samples and obtain accurate thermophysical parameters, it is necessary to deeply explore the influencing factors in the test process. The DSC was adopted, with deionized water as the sample, to investigate the effects of crucible types, sample loading methods, heating rates and sample volume on the specific heat capacity test results. The results showed that when the sample loading method of concavus aluminum crucible, inverted lid and sealed was adopted, the sample volume was 25 μL and the heating rate was 10 ℃/min. The specific heat capacity of deionized water measured had a higher accuracy and precision. Therefore, the condition was regarded as the optimal experimental condition for measuring the specific heat capacity of liquid samples with a state and properties similar to water.

     

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