Graphene oxide modification with graft polymers via nitroxide mediated radical polymerization

• Published in: Polymer (Guilford) Vol. 55; no. 10; pp. 2347 - 2355
• Main Authors: García-Valdez, Omar, Ledezma-Rodríguez, Raquel, Saldívar-Guerra, Enrique, Yate, Luis, Moya, Sergio, Ziolo, Ronald F.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 13.05.2014; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Grafting-from polymerization; Graphene–polymer nanocomposites; Nitroxide mediated polymerization; Organic polymers; Physicochemistry of polymers; Polymers with particular structures; Preparation, kinetics, thermodynamics, mechanism and catalysts; Graphene–polymer nanocomposites; Grafting-from polymerization; Nitroxide mediated polymerization; Surface reaction; Living polymer; Experimental study; Free radical polymerization; Graphene-polymer nanocomposites; Morphology; Preparation; Piperidine derivatives; Styrene polymer; Isoprene polymer; Nanostructured materials; Graft polymers
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2014.03.042

We demonstrate a method to modify the surface of graphene oxide (GO) by grafting polymer chains using nitroxide mediated radical polymerization (NMRP). Surface modification by NMRP was achieved using GO functionalized with 2,2,6,6-tetramethyl-piperidine 1-oxyl (TEMPO, T) to produce graphene oxide-TEMPO (GO-T). GO prepared from graphite by the Hummer's method was facilely functionalized in one step with T. Graft polymerization reactions of styrene and isoprene were carried out using nitroxide chemistry to control the polymerization and the ‘grafting from the surface’ polymerization technique. GO-T acts as a multifunctional macroalkoxyamine initiating and controlling the polymerization in the presence of monomer. The grafting reactions were performed by dispersing GO-T in dimethylformamide and heating at 130 °C in the presence of monomer to form graphene oxide-g-polystyrene-TEMPO (GO-g-PS-T) and graphene oxide-g-polyisoprene-TEMPO (GO-g-PI-T). FT-IR, Raman, XPS, XRD, TGA and TEM data are consistent with the attachment of the TEMPO group to the GO surface and with polystyrene and polyisoprene being grafted onto the GO surface. The amount of PS and PI grafted to GO-T was estimated from TGA data to be approximately 34% for a 7 h reaction time and 68% for a 144 h reaction time, respectively. [Display omitted]