不同实验条件对DSC峰形的影响以及相变温度的确定

The Influences of Experimental Conditions on the Shape of DSC Curve and the Determination of Phase-Change Temperature

本文通过深入分析实际的DSC过程,阐述了DSC曲线上各个特征点以及这些点所对应的物理意义。在理论上分析了各种不同的实验条件对DSC曲线形状的影响,指出了目前在DSC分析中所用的确定试样熔点的方法以及用高纯金属在DSC相变曲线上熔融峰前沿的斜率修正试样相变温度所存在的问题,指出DSC相变曲线刚开始偏离基线的那点所相应试样盒的温度即为试样的熔点,本文还提出了通过提高试样、试样盒以及试样支座之间的热导率,来提高DSC分析方法的灵敏度和分辨率。

The real process of differential scanning calorimetry(DSC) is deeply analysed and the phy-sical meaning of each eigenpoint in the DSC curve is explained in detail. The influences ofexperimental conditions on the shape of DSC curve are theoretically studied and showed thatboth methods used in DSC to determine the phase-change temperature of samples and used thegradient of DSC molten curve of a highly purified metal to correct the phase-change tempera-ture are doubtful. The proposal is advanced that the phase-change temperature of samples iscorresponding to the first point deviating from the baseline of DSC curve and some improve-ments must be done to increase the sensitivity and resolution of the DSC experiment such asincreasing the heat conductivity of sample, its vessel, etc.