Liquid Crystallinity and Dimensions of Surfactant-Stabilized Sheets of Reduced Graphene Oxide.
Graphene oxide (GO) flakes dissolved in water can spontaneously form liquid crystals. Liquid crystallinity presents an opportunity to process graphene materials into macroscopic assemblies with long-range ordering, but most graphene electronic functionalities are lost in oxidation treatments. Reduction of GO allows recovering functionalities and makes reduced graphene oxide (RGO) of greater interest. Unfortunately, chemical reduction of GO generally results in the aggregation of the flakes, with no liquid crystallinity observed. We report in the present work liquid crystals made of RGO. The addition of surfactants in appropriate conditions is used to stabilize the RGO flakes against aggregation maintaining their ability to form water-based liquid crystals. Structural and thermodynamical studies allow the dimensions of the flakes to be deduced. It is found that the thickness and diameter of RGO flakes are close to that of neat GO flakes.
†Centre de Recherche Paul-Pascal, Université de Bordeaux - CNRS, 115 Avenue Schweitzer, 33600 Pessac, France.|‡Laboratorio de Física de la Materia Condensada, Centro de Física, Instituto Venezolano de Investigaciones Científícas, Altos de Pipe, 1204 Caracas, Venezuela.
Camilo
C
Zamora-Ledezma
†Centre de Recherche Paul-Pascal, Université de Bordeaux - CNRS, 115 Avenue Schweitzer, 33600 Pessac, France.
Nicolas
N
Puech
†Centre de Recherche Paul-Pascal, Université de Bordeaux - CNRS, 115 Avenue Schweitzer, 33600 Pessac, France.
Cécile
C
Zakri
†Centre de Recherche Paul-Pascal, Université de Bordeaux - CNRS, 115 Avenue Schweitzer, 33600 Pessac, France.
Eric
E
Grelet
§ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, New South Wales, Australia.
Simon E
SE
Moulton
§ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, New South Wales, Australia.
Gordon G
GG
Wallace
§ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, New South Wales, Australia.
Sanjeev
S
Gambhir
∥Laboratoire Charles Coulomb UMR 5221, Université Montpellier II, place Eugène Bataillon, 34095 Montpellier Cedex 5, France.
Christophe
C
Blanc
∥Laboratoire Charles Coulomb UMR 5221, Université Montpellier II, place Eugène Bataillon, 34095 Montpellier Cedex 5, France.
Eric
E
Anglaret
†Centre de Recherche Paul-Pascal, Université de Bordeaux - CNRS, 115 Avenue Schweitzer, 33600 Pessac, France.
Philippe
P
Poulin
X-ray scattering; bile salts; graphene; graphene oxide; liquid crystals; nematic; reduced graphene oxide