Poulin Philippe, Jalili Rouhollah, Neri Wilfrid, Nallet Frédéric, Divoux Thibaut, Colin Annie, Aboutalebi Seyed Hamed, Wallace Gordon, Zakri Cécile
Centre de Recherche Paul Pascal - CNRS, University of Bordeaux, 33600 Pessac, France.
Australian Research Council Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, Australian Institute of Innovative Materials Facility, Innovation Campus, University of Wollongong, Wollongong, NSW 2522, Australia.
Proc Natl Acad Sci U S A. 2016 Oct 4;113(40):11088-11093. doi: 10.1073/pnas.1605121113. Epub 2016 Sep 19.
Graphene oxide (GO), the main precursor of graphene-based materials made by solution processing, is known to be very stiff. Indeed, it has a Young's modulus comparable to steel, on the order of 300 GPa. Despite its very high stiffness, we show here that GO is superflexible. We quantitatively measure the GO bending rigidity by characterizing the flattening of thermal undulations in response to shear forces in solution. Characterizations are performed by the combination of synchrotron X-ray diffraction at small angles and in situ rheology (rheo-SAXS) experiments using the high X-ray flux of a synchrotron source. The bending modulus is found to be 1 kT, which is about two orders of magnitude lower than the bending rigidity of neat graphene. This superflexibility compares with the fluidity of self-assembled liquid bilayers. This behavior is discussed by considering the mechanisms at play in bending and stretching deformations of atomic monolayers. The superflexibility of GO is a unique feature to develop bendable electronics after reduction, films, coatings, and fibers. This unique combination of properties of GO allows for flexibility in processing and fabrication coupled with a robustness in the fabricated structure.
氧化石墨烯（GO）是通过溶液处理制备的石墨烯基材料的主要前驱体，已知其非常坚硬。实际上，它的杨氏模量与钢相当，约为300吉帕。尽管其刚度非常高，但我们在此表明GO具有超柔韧性。我们通过表征溶液中剪切力作用下热起伏的扁平化来定量测量GO的弯曲刚度。表征是通过小角同步加速器X射线衍射与使用同步加速器源的高X射线通量的原位流变学（流变小角X射线散射）实验相结合来进行的。发现弯曲模量为1kT，这比纯石墨烯的弯曲刚度低约两个数量级。这种超柔韧性可与自组装液体双层的流动性相媲美。通过考虑原子单层弯曲和拉伸变形中起作用的机制来讨论这种行为。GO的超柔韧性是还原后开发可弯曲电子器件、薄膜、涂层和纤维的独特特性。GO这种独特的性能组合允许在加工和制造过程中具有灵活性，同时在制造结构中具有坚固性。
