高铁酸盐氧化法制备膨胀石墨的可行性研究

Feasibility Study on the Preparation of Expanded Graphite by Ferrate Oxidation

以天然鳞片石墨为原料,浓硫酸和高铁酸钾为插层剂和氧化剂,可使硫酸分子进到石墨层间,是一种绿色且快速制备膨胀石墨的方法。结果表明:该方法制备得到的可膨胀石墨在微波辐射下的膨胀性能明显优于常规加热方式,当石墨(g)、高铁酸钾(g)、浓硫酸(m L)用量之比1∶0.25∶20,反应时间30 min,微波辐射时间20 s时,最大膨胀体积为140 m L·g-1;对石墨膨胀前后的红外光谱、X光射线衍射(XRD)和扫描电镜(SEM)分析,发现高铁酸盐能够有效的削弱石墨层间的范德华力,使硫酸分子进入到层间,但并不能使石墨发生显著地氧化,制得的膨胀石墨具有丰富的网状结构呈现"蠕虫"状结构特征,表面结构和原料基本一致。

The expanded graphite could be prepared rapidly by making the sulfuric acid molecule into the graphite layer with natural flake graphite as raw material, concentrated sulfuric acid and potassium ferrate as intercalation agent and oxidizing agent. The results show that the expansion property of the prepared expandable graphite under microwave irradiation is better than that of the conventional heating method, and the biggest volume expansion was 140 mL·g^-1 when the mass ration is graphite, K2FeO4 and the volume of sulfuric acid consumption 1 ： 0.25 ： 20, the response time of 30 min, the microwave radiation time of 20 s; the Infrared spectra and XRD and SEM characterization were carried out. Then found that the ferrate weaken the graphite layer force effectively make the sulfate molecule into the interlayer , but the graphite can not be oxidized significantly, and the prepared expanded graphite has obvious ＂worm＂ like structure, and the layer is opened to form a rich network structure, and the surface structure and the material are basically consistent.