石墨烯与柔性基底界面载荷传递的拉曼光谱实验

本文研究了CVD制备的大尺寸石墨烯与柔性PET基底在拉伸变形过程中切向界面载荷传递的问题,采用原位拉曼光谱实验给出了加载过程中石墨烯的正应变、正应力以及界面切应力的分布曲线。分析表明,石墨烯与PET基底间的载荷传递存在四个阶段,分别是初始阶段、粘附阶段、滑移阶段和界面脱粘破坏阶段。在此基础上,本文对50μm、140μm、270μm和600μm四种尺寸石墨烯试件的界面力学性能进行测量,得到了不同尺寸石墨烯试件的界面力学性能参数,并初步给出了基底变形引起的石墨烯切向界面粘接能的变化,同时分析了试件尺寸对石墨烯界面力学性能的影响。实验结果表明,石墨烯材料和柔性基底最大切应力与临界脱粘切向界面粘接能等界面强度指标受到尺寸的显著影响,尺寸越小切向界面强度越高,反之,尺寸越大则越低。

Raman Spectroscopic Experiment of Interface Load Transfer between Graphene and Flexible Substrate

In this paper,the problem of tangential interfacial load transfer between the large scale graphene prepared by Chemical Vapor Deposition (CVD) and the flexible poly(ethylene terephthalate) (PET) substrate during tensile deformation process was investigated.The distribution curves of normal strain,normal stress and interfacial shear stress of graphene in the loading process were obtained by in-situ Raman spectroscopy experiment.Experimental results show that the process of load transfer between graphene and PET substrate can be divided into four stages:initial stage,adhesion stage,slide stage,and debonding failure stage,respectively.According to these results,the interface mechanical properties of four sizes of graphene specimens,i.e.50μm,140μtm,270μm and 600μm,were respectively measured.The change of bonding energy of graphene interface caused by substrate deformation was also preliminary given.The influence of specimen size on mechanical properties of graphene interface was also analyzed.Experimental results show that the interfacial strength index,such as maximum shear stress and critical debonding tangential interface adhesion energy,between graphene material and flexible substrate are significantly affected by size.The smaller the size is,the higher the tangential interface strength,otherwise,the larger the size is,the lower the strength.