超声波辅助二元溶剂剥离制备石墨烯

Preparation of Graphene by Ultrasonic-assisted Exfoliation of Graphite in Binary Solvents

探索了N,N-二甲基甲酰胺和正丁醇、N,N-二甲基甲酰胺和乙醇两种二元体系剥离制备石墨烯的效果,得到了最佳剥离配比,提高了石墨烯分散液的浓度以及稳定性,并引入氢键的相关知识解释了该现象,指出了Hansen溶解度理论并不适合本研究所选的二元体系。通过原子力显微镜、透射电子显微镜、拉曼光谱等对样品的形貌和结构进行了表征,并通过石墨烯分散液的吸光度回归得到了其吸光度系数。经6 000r/min高速离心分离后,所得石墨烯分散液大部分为单层。

This paper reports two binary-solvent systems, i. e. dimethylformamide/n-butylalcohol system and dimethyl- formamide/ethanol system that facilitate higher concentration and improved stability of graphene dispersion. Hydrogen bond was in troduced to explain the exfoliation mechanism and stabilizing mechanism, At the same time, it was found that Hansen solubility theo- ry was not suitable for the chosen binary solvent systems. Furthermore, the topography and nanostructure of graphene were charac terized by atomic force microscopy （AFM）, transmission electron microscopy （TEM） and Raman spectroscopy. The absorbance coefficient of graphene dispersion was obtained by UV-Vis spectra. Finally, a graphene dispersion that predominantly containing single layer graphene was obtained after 6 000 r/min centrifugation.