title: Comparative study of the covalent diazotization of graphene and carbon nanotubes using thermogravimetric and spectroscopic techniques.
abstract: The direct diazotization of the sp(2) carbon network of graphene and multi-walled carbon nanotubes (MWNTs) is one of the many methods employed to introduce functional groups into these nanostructures. Herein, a methodical study on solvent-free diazotization with ethynylaniline in the presence of isoamyl nitrite is reported. Thermogravimetric analysis and UV-visible, infrared and Raman spectroscopies are used to precisely determine the degree of modification, confirm the presence of physisorption and describe the mechanism of elimination of the modifying groups. The results suggest that the same synthetic protocol in both cases leads to a certain degree of covalent modification, whilst a proportion of the modifying groups remains adsorbed to the carbon nanostructure. A higher level of global modification was observed for MWNTs. It was found that the elimination mechanism of the covalently-linked modifiers is identical for both nanostructures and involves two steps; acetylenic-aromatic bond rupture in the modifier followed by modifier-carbon nanostructure cleavage.
authors.affiliation: Departamento de Física de Polímeros, Elastómeros y Aplicaciones Energéticas, Instituto de Ciencia y Tecnología de Polímeros, CSIC. c/ Juan de la Cierva 3, 28006 Madrid, Spain. horacio@ictp.csic.es.
authors.forename: Marta
authors.initials: M
authors.lastname: Castelaín
authors.forename: Peter S
authors.initials: PS
authors.lastname: Shuttleworth
authors.forename: Carlos
authors.initials: C
authors.lastname: Marco
authors.forename: Gary
authors.initials: G
authors.lastname: Ellis
authors.forename: Horacio J
authors.initials: HJ
authors.lastname: Salavagione
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives / Q000737:chemistry; D000814:Aniline Compounds / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013696:Temperature
chemical_list: C483919:2-ethynylaniline; D000814:Aniline Compounds; D037742:Nanotubes, Carbon; D006108:Graphite; D000114:Acetylene