氧化程度对微细鳞片可膨胀石墨结构及膨胀性的影响

Effect of Oxidation Degree on Structure and Expansion Performance of Expandable Fine Graphite

以平均粒径为19.71μm的天然微细鳞片石墨为原料,通过化学氧化法制备了具有不同氧化程度的可膨胀石墨,采用XRD、FTIR、Raman、SEM等对可膨胀石墨的结构与膨胀性进行了表征。结果表明:当氧化程度较低时制得的微细鳞片可膨胀石墨由石墨、石墨层间化合物和氧化石墨三相组成;随着氧化程度的增加,氧化石墨相含量与可膨胀石墨结构无序程度逐渐增高,石墨层间化合物相含量先增加后减少,石墨相含量则逐渐降低;氧化促使HSO4-或SO42-插入石墨层间,插入层间的HSO4-或SO42-量是决定可膨胀石墨膨胀容积的关键因素,制备的微细鳞片膨胀石墨的膨胀容积可达65.9mL·g-1。

The natural fine graphite with an average particle size of 19.71 μm was used to prepare expandable graphite with different oxidation degrees by chemical oxidation method, the structural and expansion properties were characterized by XRD, FTIR, Raman, and SEM. The results show that the prepared expandable graphite is consisted of graphite phase, graphite intercalation compound phase and graphite oxide phase. With the increase of the oxidation degree, the content of graphite intercalation compound phase increases firstly and then decreases,the content of graphite oxide and the structural disorder degree increases, while the content of graphite phase decreases. The content of H2SO4 inserted in the graphite layer is the key factor in determining the expansion performance of the expandable fine graphite. The expansion volume of the expanded graphite is 65.9 m L·g^-1.