物理化学学报 >> 2013, Vol. 29 >> Issue (10): 2079-2086.doi: 10.3866/PKU.WHXB201305021

热分析动力学和热动力学 上一篇    下一篇

干燥方式对高氯酸铵/石墨烯复合材料的结构和热分解行为的影响

王学宝1, 李晋庆1,2, 罗运军1   

  1. 1 北京理工大学材料学院, 北京 100081;
    2 中国兵器科学研究院, 北京 100089
  • 收稿日期:2013-03-04 修回日期:2013-05-02 发布日期:2013-09-26
  • 通讯作者: 罗运军 E-mail:yjluo@bit.edu.cn
  • 基金资助:

    北京理工大学基础研究基金(20110942019)资助项目

Effect of Drying Methods on the Structure and Thermal Decomposition Behavior of Ammonium Perchlorate/Graphene Composites

WANG Xue-Bao1, LI Jin-Qing1,2, LUO Yun-Jun1   

  1. 1 School of Material Science & Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China;
    2 cademy of Ordnance Science, Beijing 100089, P. R. China
  • Received:2013-03-04 Revised:2013-05-02 Published:2013-09-26
  • Contact: LUO Yun-Jun E-mail:yjluo@bit.edu.cn
  • Supported by:

    The project was supported by the Basic Research Foundation of Beijing Institute of Technology, China (20110942019).

摘要:

通过溶胶-凝胶法制备了石墨烯水凝胶, 并将其与高氯酸铵(AP)复合, 然后分别采用自然干燥、冷冻干燥和超临界CO2干燥三种干燥方式制备了AP/石墨烯复合材料, 并通过扫描电镜(SEM)、元素分析、X射线衍射(XRD)、差示扫描量热仪(DSC)和热重-红外联用技术(TG-FTIR)研究了不同干燥方式对其结构和热分解行为的影响. 结果表明, 干燥方式对AP/石墨烯复合材料的形貌具有明显影响, 其中通过超临界CO2干燥制备的AP/石墨烯复合材料基本能保持与石墨烯气凝胶相似的外观和多孔结构. 通过自然干燥、冷冻干燥和超临界CO2干燥制备的AP/石墨烯复合材料中AP的质量分数分别为89.97%、92.41%和94.40%, 其中通过超临界CO2干燥制备的复合材料中AP的粒径尺寸为69 nm. DSC测试结果表明, 石墨烯对AP的热分解过程具有明显的促进作用, 能使AP的低温分解过程大大减弱, 高温分解峰温明显降低. 三种干燥方式相比, 通过超临界CO2干燥制备的AP/石墨烯复合材料中石墨烯的促进作用最明显. 与纯AP相比, 其高温分解峰温降低了83.7℃, 表观分解热提高到2110 J·g-1. TG-FTIR分析结果表明, AP/石墨烯复合材料的热分解过程中, AP分解产生的氧化性产物与石墨烯发生了氧化反应, 生成了CO2.

关键词: 干燥方式, 石墨烯, 高氯酸铵, 溶胶-凝胶法, 热分解

Abstract:

Graphene hydrogels were prepared by the sol-gel method, and then used to prepare ammonium perchlorate (AP)/graphene composites by the incorporation of AP. The composites were dried naturally in air, freeze-dried, or dried with supercritical CO2. Scanning electron microscopy (SEM), elemental analyses (EA), and X-ray diffraction (XRD) were used to characterize the structure of the AP/graphene composites dried using different methods. Furthermore, the thermal decomposition behavior of the AP/graphene composites was investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis/infrared spectroscopy (TG-FTIR). Drying method had an obvious influence on the morphology of the AP/graphene composites; only the AP/graphene composites dried with supercritical CO2 showed similar three-dimensional networks and porous structure to graphene aerogels. Elemental analyses revealed that the AP contents in the AP/graphene composites prepared by drying naturally, freeze-drying, and supercritical CO2 drying were 89.97%, 92.41%, and 94.40%, respectively. XRD results showed that AP was dispersed homogeneously on the nanoscale in the AP/graphene composites dried with supercritical CO2 and the average particle diameter of AP was about 69 nm. DSC and TG-FTIR analyses indicated that graphene could promote the thermal decomposition of AP, particularly for the sample dried with supercritical CO2. Independent of drying method, the low-temperature decomposition of the as-prepared AP/graphene composites was not observed and the high-temperature decomposition was accelerated. Compared to the other two drying methods, graphene in the AP/graphene composites dried with supercritical CO2 showed most obvious promoting effects. The high-temperature decomposition temperature of the AP/graphene composites dried with supercritical CO2 decreased by 83.7 ℃ compared with that of pure AP, and the total heat release reached 2110 J·g-1. Moreover, graphene also took part in the oxidation reactions with oxidizing products, which was confirmed by the generation of CO2.

Key words: Drying methods, Graphene, Ammonium perchlorate, Sol-gel method, Thermal decomposition

MSC2000: 

  • O643