N. N. Smirnova, S. S. Sologubov, A. V. Markin, S. A. Milenin, E. A. Tatarinova, A. M. Muzafarov
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引用次数: 0
Abstract
The temperature dependence of the heat capacity of the sixth generation carbosilane dendrimer with terminal trimethylsilylsiloxane groups was determined by high-precision adiabatic vacuum calorimetry in the temperature range 6–318 K and differential scanning calorimetry in the range 300–600 K. Anomalous changes in the heat capacity were discovered in the range T = 179–200 K due to devitrification of the dendrimer and in the range 380–450 K due to the nanoscale effect characteristic of dendrimers of high generations. The thermal stability of the compound was studied by thermogravimetric analysis, and the temperature of the start of thermal destruction was found to be 600 K. The experimental data obtained were used to calculate the standard thermodynamic functions of the dendrimer for the range from T → 0 to 600 K for various physical states, as well as the standard entropy of its formation in the devitrified state at T = 298.15 K.
摘要 通过高精度绝热真空量热法和差示扫描量热法，分别测定了带有末端三甲基硅氧烷基团的第六代碳硅烷树枝形分子在 6-318 K 和 300-600 K 温度范围内的热容量随温度的变化情况，发现在 T = 179-200 K 和 380-450 K 温度范围内，由于树枝形分子的蜕变和高世代树枝形分子特有的纳米效应，热容量发生了异常变化。通过热重分析研究了该化合物的热稳定性，发现开始热破坏的温度为 600 K。获得的实验数据被用来计算树枝状聚合物在各种物理状态下从 T → 0 到 600 K 范围内的标准热力学函数，以及在 T = 298.15 K 时形成蜕变状态的标准熵。
期刊介绍：
Russian Journal of Physical Chemistry A. Focus on Chemistry (Zhurnal Fizicheskoi Khimii), founded in 1930, offers a comprehensive review of theoretical and experimental research from the Russian Academy of Sciences, leading research and academic centers from Russia and from all over the world.
Articles are devoted to chemical thermodynamics and thermochemistry, biophysical chemistry, photochemistry and magnetochemistry, materials structure, quantum chemistry, physical chemistry of nanomaterials and solutions, surface phenomena and adsorption, and methods and techniques of physicochemical studies.
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