Thermal properties of graphite intercalation compounds with acids
Thermal properties of graphite intercalation compounds with acids
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DOI：
10.1016/j.jpcs.2003.10.013
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发表时间：
2004-03
影响因子：
4
通讯作者：
N. V. Maksimova;N. E. Sorokina;O. Shornikova;V. Avdeev
中科院分区：
文献类型：
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作者：
N. V. Maksimova;N. E. Sorokina;O. Shornikova;V. Avdeev
本文采用热重-差示扫描量热法（Netzsch）对硝酸（HNO_3）和硝酸-R（R= CH_3COOH，H_3 PO_4）二元石墨层间化合物（GIC）的第一至第五阶段进行了系统的热分析。GIC的热处理导致酸的完全脱嵌和样品的显著膨胀。GICs-HNO_3-R共插层复合材料的热性能和热膨胀系数取决于插层剂的性质。在110-150 °C下的内峰对应于在具有HNO 3的二元第二至第五级GIC的DSC曲线中观察到的硝酸损失。GIC与HNO_3-CH_3COOH三元体系的DSC曲线较GIC与HNO_3三元体系的DSC曲线有一个宽的内峰，其特征是GIC与HNO_3三元体系的DSC曲线的分解温度比GIC与HNO_3三元体系的高。因此，乙酸使硝酸石墨基质稳定。在第二和第三阶段HNO_3-H_3PO_4共插层GIC的DSC曲线中，观察到HNO_3（110-180 ℃）和H_3PO_4（450-800 ℃）脱嵌引起的两种内效应。随着GICs级数的增加，热分解热（ΔH）和失重率减小。ΔH = 0.40- 14.8kJ/g ~（-1）。
This work is devoted to systematic thermal analysis of first to fifth stages of binary graphite intercalation compounds (GIC) with HNO3and ternary GICs with HNO3–R (R=CH3COOH, H3PO4) by simultaneous TG–DSC thermoanalyses (Netzsch). Thermolysis of GIC leads to the full deintercalation of acid and significant expansion of samples. The thermal properties of co-intercalated GICs-HNO3-R and the thermal expanding coefficient of GIC depend on the nature of the intercalate. The endopeak at 110–150 °C corresponds to the loss of nitric acid was observed in DSC- curve of binary second to fifth stages of GICs with HNO3. A wide endopeak which is characterized by the increasing of decomposition temperature in comparison with GIC-HNO3was observed in DSC—curve of ternary GIC with HNO3–CH3COOH. Thus, acetic acid stabilizes the graphite nitrate matrix. Two endoeffects due to the deintercalation of HNO3(110–180 °C) and H3PO4(450–800 °C) were observed in the DSC-curves of co-intercalated GICs with HNO3–H3PO4of second and third stages. The value of decomposition heat (ΔH) and weight loss decrease with the increasing of the stage number of GICs. The values of ΔH are equal to 0.40–14.8 kJ/g-at C.