Chen Yaqing, Dai Zhaohe, Weng Chuanxin, Wang Guorui, Liu Xuelu, Cong Xin, Tan Pingheng, Liu Luqi, Zhang Zhong
CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology Beijing 100190 People's Republic of China
University of Chinese Academy of Science Beijing 100049 People's Republic of China.
RSC Adv. 2018 Oct 25;8(63):36257-36263. doi: 10.1039/c8ra07974a. eCollection 2018 Oct 22.
Due to their extraordinary mechanical properties, nanocarbon materials ( carbon nanotube and graphene) are attracting great interests in the field of nanocomposites. One unique feature in nanocarbon-based nanocomposites is their intrinsically rich interface, allowing them to adapt the microstructures in response to external loading and, in turn, to stiffen themselves. This mechanical behavior, called responsive stiffening, was usually observed in biological materials such as bones and muscles. The mechanically responsive behaviors of nanocarbon-based materials are particularly exciting because the nanocarbon-enabled huge interface area offers opportunities to tune such stiffening performance while this interface advantage is not fully exploited yet. Here, we demonstrate stiffening behaviors in graphene oxide (GO)-based film materials in response to dynamic oscillations. Through a facile method of polymer content alteration and alkali treatment, the microstructure and interlayer interaction of GO films are modified, along with the resulted responsively stiffening performance. Based on polarized Raman spectra characterizations, we attribute the stiffening mechanism to the microstructural evolution of GO films during dynamic tension as well as the polymer chains alignment. Finally, we highlight the significantly improved static mechanical properties of GO film after a simple stiffening process. Our results not only aid in the development of biomimetic, adaptive materials, but provide a mechanical way for the design of high-performance nanocarbon-based nanocomposites.
由于其非凡的机械性能，纳米碳材料（碳纳米管和石墨烯）在纳米复合材料领域引起了极大的关注。基于纳米碳的纳米复合材料的一个独特特征是其固有的丰富界面，这使它们能够根据外部载荷调整微观结构，进而增强自身强度。这种机械行为，称为响应增强，通常在生物材料如骨骼和肌肉中观察到。基于纳米碳的材料的机械响应行为特别令人兴奋，因为纳米碳带来的巨大界面面积为调整这种增强性能提供了机会，而这种界面优势尚未得到充分利用。在这里，我们展示了氧化石墨烯（GO）基薄膜材料在动态振荡下的增强行为。通过一种简便的聚合物含量改变和碱处理方法，GO薄膜的微观结构和层间相互作用得到了改变，同时产生了响应增强性能。基于偏振拉曼光谱表征，我们将增强机制归因于动态拉伸过程中GO薄膜的微观结构演变以及聚合物链的排列。最后，我们强调了经过简单增强过程后GO薄膜静态机械性能的显著改善。我们的结果不仅有助于仿生、自适应材料的开发，还为高性能纳米碳基纳米复合材料的设计提供了一种机械方法。
