Factors Controlling the Size of Graphene Oxide Sheets Produced via the Graphite Oxide Route
Factors Controlling the Size of Graphene Oxide Sheets Produced via the Graphite Oxide Route
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DOI：
10.1021/nn200666r
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发表时间：
2011-05-01
期刊：
影响因子：
17.1
通讯作者：
Aksay, Ilhan A.
中科院分区：
文献类型：
--
作者：
Pan, Shuyang;Aksay, Ilhan A.
我们研究了氧化途径和机械能输入对氧化石墨衍生的氧化石墨烯片尺寸的影响。石墨从（0002）平面的交叉平面氧化导致最上面的氧化石墨烯层的周期性破裂，将其横向尺寸限制为小于30 μ m。我们使用与氧化石墨烯片在羟基和环氧树脂位点处的波动相关联的弹性应变能、裂纹形成能和石墨烯层之间的相互作用能之间的能量平衡来确定裂纹的单元尺寸。由于在交叉平面方向上的有效裂纹扩展速率比边缘到中心的氧化速率小一个数量级，因此取决于石墨颗粒的纵横比，产生大于由周期性裂纹单元尺寸限定的那些的氧化石墨烯单片。我们还表明，外部能量输入流体运动或超声处理产生的流体动力学阻力，通过在片中的张应力积累，进一步降低了氧化石墨烯片的尺寸。
We have studied the effect of the oxidation path and the mechanical energy input on the size of graphene oxide sheets derived from graphite oxide. The cross-planar oxidation of graphite from the (0002) plane results in periodic cracking of the uppermost graphene oxide layer, limiting its lateral dimension to less than 30 mu m. We use an energy balance between the elastic strain energy associated with the undulation of graphene oxide sheets at the hydroxyl and epoxy sites, the crack formation energy, and the interaction energy between graphene layers to determine the cell size of the cracks. As the effective crack propagation rate in the cross-planar direction is an order of magnitude smaller than the edge-to-center oxidation rate, graphene oxide single sheets larger than those defined by the periodic cracking cell size are produced depending on the aspect ratio of the graphite particles. We also demonstrate that external energy input from hydrodynamic drag created by fluid motion or sonication, further reduces the size of the graphene oxide sheets through tensile stress buildup in the sheets.