School of Physics and CRANN, Trinity College Dublin, Dublin 2, Ireland.
Small. 2010 Apr 9;6(7):864-71. doi: 10.1002/smll.200902066.
A method is demonstrated to prepare graphene dispersions at high concentrations, up to 1.2 mg mL(-1), with yields of up to 4 wt% monolayers. This process relies on low-power sonication for long times, up to 460 h. Transmission electron microscopy shows the sonication to reduce the flake size, with flake dimensions scaling as t(-1/2). However, the mean flake length remains above 1 microm for all sonication times studied. Raman spectroscopy shows defects are introduced by the sonication process. However, detailed analysis suggests that predominantly edge, rather than basal-plane, defects are introduced. These dispersions are used to prepare high-quality free-standing graphene films. The dispersions can be heavily diluted by water without sedimentation or aggregation. This method facilitates graphene processing for a range of applications.
本文展示了一种制备高浓度石墨烯分散体的方法，浓度高达 1.2mg/mL，单层产率高达 4wt%。该方法依赖于低功率超声处理长时间，最长可达 460 小时。透射电子显微镜显示超声处理可以减小薄片尺寸，薄片尺寸与 t(-1/2)成正比。然而，在所有研究的超声时间内，平均薄片长度仍高于 1 微米。拉曼光谱显示超声处理过程中会引入缺陷。然而，详细分析表明，主要引入的是边缘缺陷，而不是基面缺陷。这些分散体用于制备高质量的自支撑石墨烯薄膜。分散体可以用水大量稀释而不会沉降或聚集。该方法为一系列应用提供了便利的石墨烯处理方法。
