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.

Graphene and derivatives – Synthesis techniques, properties and their energy applications

“…The conjugated polymers and aromatic compounds can be used to stabilise the rGO resulted from reduction reaction and can be used in the production of composite materials. The conjugated and aromatic polymers used are sulfonated polyaniline [77], conjugated polyelectrolyte [78], porphyrin [79] and cellulose derivatives [80]. The summary of advantages and disadvantages of various synthesis techniques is given in Table 1.…”

Graphene-based hybrid materials and their applications in energy storage and conversion

“…-, hydrophobic, electrostatic and chemisorption interaction. Many kinds of stabilizer have so far been employed, such as polyelectrolyte [8], pyrene derivative [9] and amphiphilic polymers [10]. Meanwhile, the oxygen containing groups, which could react with many groups, such as amido, hydroxyl, and isocyanato groups, provide a wide variety of reactions for covalent modification of graphene [11,12].…”

Recent advances in optical limiting properties of fluorinated graphene oxides

“…For example, cross-linking polyallylamine with GO results in improved stiffness and strength 16 . Grafting a polymer to GO can improve dispersibility of the material in liquid media 17,18 . Chitosangrafted GO exhibits excellent biocompatibility 19 .…”