Androulidakis Ch, Sourlantzis D, Koukaras E N, Manikas A C, Galiotis C
Institute of Chemical Engineering Sciences, Foundation of Research and Technology-Hellas (FORTH/ICE-HT) Stadiou Street, Platani Patras 26504 Greece
Department of Chemical Engineering, University of Patras Patras 26504 Greece.
Nanoscale Adv. 2019 Nov 5;1(12):4972-4980. doi: 10.1039/c9na00323a. eCollection 2019 Dec 3.
In the present study, the stress transfer mechanism in graphene-polymer systems under tension is examined experimentally using the technique of laser Raman microscopy. We discuss in detail the effect of graphene edge geometry, lateral size and thickness which need to be taken under consideration when using graphene as a protective layer. The systems examined were composed of graphene flakes with a large length (over ∼50 microns) and a thickness of one to three layers simply deposited onto PMMA substrates which were then loaded to a tension of ∼1.60% strain. The stress transfer profiles were found to be linear while the results show that large lateral sizes of over twenty microns are needed in order to provide effective reinforcement at levels of strain higher than 1%. Moreover, the stress built up has been found to be quite sensitive to both edge shape and geometry of the loaded flakes. Finally, the transfer lengths were found to increase with the increase of graphene layers. The outcomes of the present study provide crucial insight into the issue of stress transfer from polymers to graphene nano-inclusions as a function of edge geometry, lateral size and thickness in a number of applications.
在本研究中，使用激光拉曼显微镜技术对石墨烯-聚合物系统在拉伸状态下的应力传递机制进行了实验研究。我们详细讨论了石墨烯边缘几何形状、横向尺寸和厚度的影响，在将石墨烯用作保护层时需要考虑这些因素。所研究的系统由长度较大（超过约50微米）且厚度为一到三层的石墨烯薄片组成，这些薄片简单地沉积在聚甲基丙烯酸甲酯（PMMA）基板上，然后加载到约1.60%应变的拉伸状态。发现应力传递曲线是线性的，而结果表明，为了在高于1%的应变水平下提供有效的增强作用，需要超过二十微米的大横向尺寸。此外，已发现所积累的应力对加载薄片的边缘形状和几何形状都相当敏感。最后，发现转移长度随着石墨烯层数的增加而增加。本研究的结果为在许多应用中聚合物到石墨烯纳米夹杂物的应力传递问题提供了关键见解，该问题是边缘几何形状、横向尺寸和厚度的函数。
