title: Superflexibility of graphene oxide.
abstract: 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.
authors.affiliation: Centre de Recherche Paul Pascal - CNRS, University of Bordeaux, 33600 Pessac, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Poulin
authors.affiliation: 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.
authors.forename: Rouhollah
authors.initials: R
authors.lastname: Jalili
authors.affiliation: Centre de Recherche Paul Pascal - CNRS, University of Bordeaux, 33600 Pessac, France.
authors.forename: Wilfrid
authors.initials: W
authors.lastname: Neri
authors.affiliation: Centre de Recherche Paul Pascal - CNRS, University of Bordeaux, 33600 Pessac, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Nallet
authors.affiliation: Centre de Recherche Paul Pascal - CNRS, University of Bordeaux, 33600 Pessac, France.
authors.forename: Thibaut
authors.identifier: 0000-0002-6777-5084
authors.initials: T
authors.lastname: Divoux
authors.affiliation: Centre de Recherche Paul Pascal - CNRS, University of Bordeaux, 33600 Pessac, France.
authors.forename: Annie
authors.initials: A
authors.lastname: Colin
authors.affiliation: Condensed Matter National Laboratory, Institute for Research in Fundamental Sciences, 19395-5531, Tehran, Iran.
authors.forename: Seyed Hamed
authors.identifier: 0000-0002-3711-332X
authors.initials: SH
authors.lastname: Aboutalebi
authors.affiliation: 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.
authors.forename: Gordon
authors.initials: G
authors.lastname: Wallace
authors.affiliation: Centre de Recherche Paul Pascal - CNRS, University of Bordeaux, 33600 Pessac, France; zakri@crpp-bordeaux.cnrs.fr.
authors.forename: Cécile
authors.initials: C
authors.lastname: Zakri
keywords: bending rigidity; graphene oxide; rheo-SAXS