title: Conjugated-polyelectrolyte-functionalized reduced graphene oxide with excellent solubility and stability in polar solvents.
abstract: Conjugated-polyelectrolyte (CPE)-functionalized reduced graphene oxide (rGO) sheets are synthesized for the first time by taking advantage of a specially designed CPE, PFVSO(3), with a planar backbone and charged sulfonate and oligo(ethylene glycol) side chains to assist the hydrazine-mediated reduction of graphene oxide (GO) in aqueous solution. The resulting CPE-functionalized rGO (PFVSO(3)-rGO) shows excellent solubility and stability in a variety of polar solvents, including water, ethanol, methanol, dimethyl sulfoxide, and dimethyl formamide. The morphology of PFVSO(3)-rGO is studied by atomic force microscopy, X-ray diffraction, and transmission electron microscopy, which reveal a sandwich-like nanostructure. Within this nanostructure, the backbones of PFVSO(3) stack onto the basal plane of rGO sheets via strong pi-pi interactions, while the charged hydrophilic side chains of PFVSO(3) prevent the rGO sheets from aggregating via electrostatic and steric repulsions, thus leading to the solubility and stability of PFVSO(3)-rGO in polar solvents. Optoelectronic studies show that the presence of PFVSO(3) within rGO induces photoinduced charge transfer and p-doping of rGO. As a result, the electrical conductivity of PFVSO(3)-rGO is not only much better than that of GO, but also than that of the unmodified rGO.
authors.affiliation: School of Materials Science and Engineering Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Qi
authors.forename: Kan-Yi
authors.initials: KY
authors.lastname: Pu
authors.forename: Xiaozhu
authors.initials: X
authors.lastname: Zhou
authors.forename: Hai
authors.initials: H
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Freddy
authors.initials: F
authors.lastname: Boey
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
mesh_terms: D004553:Electric Conductivity; D004573:Electrolytes / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D010087:Oxides / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004573:Electrolytes; D010087:Oxides; D012997:Solvents; D006108:Graphite