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对天然鳞片石墨及椰壳活性炭进行液相氧化的初步研究
Preliminary Research on the Liquid Phase Oxidation of Natural Graphite Flakes and Activated Carbon
【摘要】 以天然鳞片石墨和椰壳活性炭为原料,在Hummers法基础上制备了氧化石墨和氧化活性炭,研究了液相天然鳞片石墨和椰壳活性炭氧化前后的结构与性能的变化.结果表明:液相氧化过程中存在表面氧化和层间氧化两种氧化反应机制,石墨质材料既有表面氧化也有层间氧化,而炭质材料则以表面氧化为主.表面氧化的结果使氧化石墨和氧化活性炭中均含有大量极性基团,这些基团的存在使它们表现出较强的极性和一定的化学活性.层间氧化使氧化石墨的层间距由原石墨的0.3354nm增加到0.8981nm,石墨片层之间的基团及H2O分子的存在是层间距增大的主要原因.在稀的碱性溶液中,氧化石墨层离后为针状或扁球状纳米颗粒,颗粒之间存在一定的团聚,而氧化活性炭为球状纳米颗粒,团聚后呈直链状.
【Abstract】 Based on the Hummers method, graphite oxide and oxidation activated carbon were prepared from graphite and activated carbon. The differences in the structure and property of graphite and activated carbon before and after the liquid-phase oxidation were analyzed. The analysis showed that there were surface oxidation and internal oxidation for natural graphite flakes, but there was only surface oxidation for activated carbon of coconut shells. Surface oxidation took place because the natural graphite flakes and activated carbon possessed many polarity groups, which gave them strong polar and chemical activity. Internal oxidation increased the distance between the layers of graphite flakes from 0.335 4 nm to 0.898 1 nm, which was induced by the polarity groups and H2O between the layers of graphite flakes. In alkaline solution, graphite oxide delaminated into needle-like and spherical nano-particles, some of which coalesced. The oxidation activated carbon was in the form of spherical nano-particles, which coalesced into chain structure.
【Key words】 liquid-phase; oxidation; nature graphite flakes; activated carbon;
- 【文献出处】 湖南大学学报(自然科学版) ,Journal of Hunan University (Natural Science) , 编辑部邮箱 ,2004年05期
- 【分类号】TB321
- 【被引频次】15
- 【下载频次】330