Liu Xu, Sun Xinying, Wang Zhenyu, Shen Xi, Wu Ying, Kim Jang-Kyo
Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong.
ACS Appl Mater Interfaces. 2015 Sep 30;7(38):21455-64. doi: 10.1021/acsami.5b06476. Epub 2015 Sep 15.
Planar interconnected graphene woven fabrics (GWFs) are prepared by template-based chemical vapor deposition and the GWFs are employed as multifunctional filler for epoxy-based composites. Apart from flexibility, transparency, lightweight, and high electrical conductivity, the GWFs have unique morphological features consisting of orthogonally interweaved, inherently percolated, hollow graphene tubes (GTs). The orthogonal GT structure means that the GWF/epoxy composites hold significant anisotropy in mechanical and fracture properties. The composites with 0.62 wt % graphene deliver a combination of excellent electrical and fracture properties: e.g., an electrical conductivity of ~0.18 S/cm; and fracture toughness of 1.67 and 1.78 MPa·m(1/2) when loaded along the 0° and 45° directions relative to the GT direction, respectively, equivalent to notable 57% and 67% rises compared to the solid epoxy. Unique fracture processes in GWF/epoxy composites are identified by in situ examinations, revealing crack tip blunting that occurs when the crack impinges GTs, especially those at 45° to the crack growth direction, as well as longitudinal tearing of hollow GTs as the two major toughening mechanisms.
通过基于模板的化学气相沉积制备平面互连石墨烯织物（GWFs），并将其用作环氧基复合材料的多功能填料。除了柔韧性、透明度、轻质和高导电性外，GWFs还具有独特的形态特征，由正交交织、固有渗透的中空石墨烯管（GTs）组成。正交的GT结构意味着GWF/环氧复合材料在机械和断裂性能方面具有显著的各向异性。含有0.62 wt%石墨烯的复合材料兼具优异的电学和断裂性能：例如，电导率约为0.18 S/cm；相对于GT方向，在0°和45°方向加载时，断裂韧性分别为1.67和1.78 MPa·m(1/2)，与纯环氧树脂相比，显著提高了57%和67%。通过原位观察确定了GWF/环氧复合材料中独特的断裂过程，揭示了裂纹撞击GTs时发生的裂纹尖端钝化，尤其是那些与裂纹扩展方向成45°的GTs，以及中空GTs的纵向撕裂是两种主要的增韧机制。
