Mechanical buckling induced periodic kinking/stripe microstructures in mechanically peeled graphite flakes from HOPG

• Published in: Acta mechanica Sinica Vol. 31; no. 4; pp. 494 - 499
• Main Authors: Ren, Manrui, Liu, Ze, Zheng, Quan-shui, Liu, Jefferson Zhe
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society of Theoretical and Applied Mechanics; Institute of Mechanics, Chinese Academy of Sciences 01.08.2015
• Subjects: Classical and Continuum Physics; Computational Intelligence; Engineering; Engineering Fluid Dynamics; HOPG; Research Paper; Theoretical and Applied Mechanics; 周期性; 实验测量; 屈曲; 扭曲; 机械剥离法; 条纹结构; 石墨薄片; Mechanical exfoliation; Mechanical buckling; Periodic microstructures; Kinking; HOPG
• ISSN: 0567-7718; 1614-3116
• DOI: 10.1007/s10409-015-0417-6

Mechanical exfoliation is a widely used method to isolate high quality graphene layers from bulk graphite. In our recent experiments, some ordered microstructures, consisting of a periodic alternation of kinks and stripes, were observed in thin graphite flakes that were mechanically peeled from highly oriented pyrolytic graphite. In this paper, a theoretical model is presented to attribute the formation of such ordered structures to the alternation of two mechanical processes during the exfoliation： （1） peeling of a graphite flake and （2） mechanical buckling of the flake being sub- jected to bending. In this model, the width of the stripes L is determined by thickness h of the flakes, surface energy Y, and critical buckling strain ecr. Using some appropriate values of y and ecr that are within the ranges determined by other inde- pendent experiments and simulations, the predicted relations between the stripe width and the flake thickness agree reason- ably well with our experimental measurements. Conversely, measuring the L-h relations of the periodic microstructures in thin graphite flakes could help determine the critical mechan- ical buckling strain εcr and the interface energy γ.