title: Functionalization of graphene via 1,3-dipolar cycloaddition.
abstract: Few-layer graphenes (FLG) produced by dispersion and exfoliation of graphite in N-methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azomethine ylides. The amino functional groups attached to graphene sheets were quantified by the Kaiser test. These amino groups selectively bind to gold nanorods, which were introduced as contrast markers for the identification of the graphene reactive sites. The interaction between gold nanorods and functionalized graphene was followed by UV-vis spectroscopy. The presence of the organic groups was confirmed by X-ray photoelectron spectroscopy and thermogravimetric analysis. The sheets were characterized by transmission electron microscopy, demonstrating the presence of gold nanorods distributed uniformly all over the graphene surface. This observation indicates that reaction has taken place not just at the edges but also at the internal C horizontal lineC bonds of graphene. Our results identify exfoliated graphene as a considerably more reactive structure than graphite and hence open the possibility to control the functionalization for use as a scaffold in the construction of organized composite nanomaterials.
authors.affiliation: Center of Excellence for Nanostructured Materials (CENMAT) and INSTM, Unit of Trieste, Dipartimento di Scienze Farmaceutiche, University of Trieste, Piazzale Europa 1, I-34127 Trieste, Italy.
authors.forename: Mildred
authors.initials: M
authors.lastname: Quintana
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Spyrou
authors.forename: Marek
authors.initials: M
authors.lastname: Grzelczak
authors.forename: Wesley R
authors.initials: WR
authors.lastname: Browne
authors.forename: Petra
authors.initials: P
authors.lastname: Rudolf
authors.forename: Maurizio
authors.initials: M
authors.lastname: Prato
mesh_terms: 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; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D006108:Graphite