膨胀石墨的制备及反应动力学探讨

Preparation of Expanded Graphite and the Discussion of Reaction Kinetics

研究了膨胀石墨制备中KMnO4,FeCl3及混酸的用量、混酸中H2SO4与HNO3比例、反应温度等因素对石墨膨胀容积的影响;根据L25(56)和L9(34)正交实验结果筛选出了获得最大膨胀容积实验方案:各原料质量比C∶FeCl3∶KMnO4∶混酸=1.0∶0.1∶1.0∶3.0,H2SO4与HNO3的质量比为2∶1;在15℃下反应30 min,900℃下获得最大膨胀容积240 mL/g.分别对原料石墨和制得的可膨胀石墨进行X_ray衍射扫描分析,证实了插层反应的存在及插层反应的不完全性;同时对膨胀容积受各种因素的影响结果从反应动力学角度进行了讨论.

Influence of various factors on expanded volume of expandable graphite was studied including the amount of KMnO4, FeCl3, mix-acid , reaction temperature and ratio of H2SO4 to HNO3. Optimum preparation conditions were obtained according to the result of L25 （5^6） and L9 （3^4） experiment, Maximum expanded volume of 240 mL/g was obtained under the condition of 15 ℃ , reaction 30 min, C：FeCl3：KMnO4：mix-acid equal to 1.0： 0.1： 1.0：3.0, and 2：1 of H2SO4 to HNO3 （the ratio was calculated as mass ratio ）. X-ray analysis of graphite material and expandable graphite was carried out, and the results testified the creation of intercalation compound and its＇ inadequacy. Meanwhile, a kinetic discussion was carried out according to the influence of the above factors on expanded volume.