Yoon Heng-Ju, Lee Jae Young, Yoon Tae-Ho
School of Materials Science and Engineering, Gwangju Institute of Science and Engineering (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, South Korea.
Nanoscale Res Lett. 2018 Jun 20;13(1):186. doi: 10.1186/s11671-018-2598-y.
A millstone (MS) was introduced in the production of large-size few-layer-graphene oxide (FLGO) via true shear exfoliation in order to minimize fragmentation. The MS was constructed with two glass plates, where the top plate was designed to rotate against the stationary bottom plate, thereby generating true shear force. Mildly oxidized graphite (MOG) was used for MS exfoliation in order to obtain both good property and high yield. The rpm of rotation (10, 20, 30, 40, and 50), solution concentration (0.5, 1, and 2 mg/ml), and number of exfoliation (1, 2, and 3) were optimized by measuring the UV-vis absorption, and the effect of oxidation time (30, 60, and 90 min) was studied under the given optimum conditions. Next, the FLGO was isolated by centrifugation and characterized by TEM and AFM. The FLGO obtained was as large as ~ 10 μm in size, which was slightly smaller than the pristine graphite, suggesting a possibility of slight fragmentation. But it was still much larger than the FLGO obtained via sonication (< 1 μm), demonstrating successful MS exfoliation.
为了使碎片化程度最小化，在通过真正的剪切剥离法生产大尺寸少层氧化石墨烯（FLGO）的过程中引入了磨盘（MS）。该磨盘由两块玻璃板构成，其中顶板设计为相对于固定的底板旋转，从而产生真正的剪切力。为了同时获得良好的性能和高产量，使用轻度氧化石墨（MOG）进行磨盘剥离。通过测量紫外可见吸收对旋转转速（10、20、30、40和50）、溶液浓度（0.5、1和2mg/ml）以及剥离次数（1、2和3）进行了优化，并在给定的最佳条件下研究了氧化时间（30、60和90分钟）的影响。接下来，通过离心分离出FLGO，并通过透射电子显微镜（TEM）和原子力显微镜（AFM）对其进行表征。所获得的FLGO尺寸大至约10μm，略小于原始石墨，这表明存在轻微碎片化的可能性。但它仍比通过超声处理获得的FLGO（<1μm）大得多，证明磨盘剥离法是成功的。
