Solution phase production of graphene with controlled thickness via density differentiation.
Graphene flakes with controlled thicknesses are isolated in solution using density gradient ultracentrifugation. These stable graphene dispersions are produced using the bile salt sodium cholate, which promotes graphite exfoliation and results in graphene-surfactant complexes having buoyant densities that vary with graphene thickness. The sorted graphene flakes are characterized using atomic force microscopy and Raman spectroscopy. Graphene dispersions produced using density differentiation offer superior performance in transparent conductors than those produced using conventional sedimentation-based centrifugation techniques.
Department of Materials Science, Northwestern University, Evanston, Illinois 60208-3108, USA.
Alexander A
AA
Green
Mark C
MC
Hersam
D005591:Chemical Fractionation / Q000379:methods*; D003460:Crystallization / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D044367:Phase Transition; D012996:Solutions / Q000737:chemistry; D013499:Surface Properties
D046911:Macromolecular Substances; D012996:Solutions; D006108:Graphite