Using Fourier transform near infrared (FT-NIR) spectroscopy, the characteristics and phase change mechanism of the phase change process for PMMA-SiO2@PCM microcapsules were explored.We investigated changes in the microstructure of the microcapsules as well.The results show that the melting of paraffin molecules in the microcapsules is a process wherein the －CH2 symmetric stretching vibration gradually increases and the asymmetric stretching vibration changes randomly.During the paraffin phase change process, the change in absorbance intensity is only half that of the shell materials.Additionally, NIR spectroscopy was used to analyze the core-shell structure and to monitor the phase change process for the microcapsules.The application of NIR spectroscopy to study the phase change process for microcapsule phase change materials has scientific significance and is of value to study the phase change mechanism for the determination of the most efficient phase change materials.%通过傅里叶变换近红外(FT-NIR)光谱分析技术,探索聚甲基丙烯酸甲酯-二氧化硅@相变材料(PMMA-SiO2@PCM)微胶囊相变过程的光谱学特性和相变机理,分析相变过程微胶囊的微结构变化特性.结果显示:微胶囊中,石蜡的融化过程就是-CH2对称伸缩振动逐渐增强和非对称伸缩无规则振动共存的振动变化过程.石蜡相变过程中,其近红外吸收峰强度的变化仅是壳层材料吸收峰强度变化幅度的一半.同时,近红外光谱可以用来辅助分析微胶囊的核壳结构,实现微胶囊相变过程监测.近红外光谱在微胶囊相变材料相变过程的应用对相变机理的研究及高效相变材料的选择具有重要的科学意义和应用价值.
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