Solvent-free functionalization of fullerene C60 and pristine multi-walled carbon nanotubes with aromatic amines

• Published in: Applied surface science Vol. 328; pp. 45 - 62
• Main Authors: Ramírez-Calera, Itzel J., Meza-Laguna, Victor, Gromovoy, Taras Yu, Chávez-Uribe, Ma. Isabel, Basiuk, Vladimir A., Basiuk, Elena V.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.02.2015
• Subjects: Amines; Buckminsterfullerene; Dispersions; Fullerene C60; Fullerenes; Functionalization; Ionization; Multi wall carbon nanotubes; Multi-walled carbon nanotubes; Nanostructure; Pristine; Solvent-free; Spinning; Thermogravimetric analysis; Amines; Pristine; Functionalization; Multi-walled carbon nanotubes; Solvent-free; Fullerene C60
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2014.11.188

•Pristine multi-walled carbon nanotubes were functionalized with aromatic amines.•The amines add onto nanotube defects, likewise they add onto fullerene C60.•The addition takes place at elevated temperature and without organic solvents.•Functionalized nanotubes were characterized by a number of instrumental techniques. We employed a direct one-step solvent-free covalent functionalization of solid fullerene C60 and pristine multi-walled carbon nanotubes (MWCNTs) with aromatic amines 1-aminopyrene (AP), 2-aminofluorene (AF) and 1,5-diaminonaphthalene (DAN). The reactions were carried out under moderate vacuum, in a wide temperature range of 180–250°C, during relatively short time of about 2h. To confirm successful amine attachment, a large number of analytical techniques were used (depending on the nanomaterial functionalized) such as Fourier transform infrared, Raman, X-ray photoelectron, 13C cross-polarization magic angle spinning NMR spectroscopy, thermogravimetric analysis, laser-desorption ionization time-of-flight mass spectrometry, temperature-programmed desorption with mass spectrometric detection, as well as scanning and transmission electron microscopy. The nucleophilic addition of the aromatic amines to C60 molecule was studied theoretically by using density functional theory (PBE GGA functional with Grimme dispersion correction in conjunction with the DNP basis set). In the case of crystalline C60, the solvent-free technique has a limited applicability due to poor diffusion of vaporous aromatic amines into the bulk. Nevertheless, the approach proposed allows for a facile preparation of aromatic amine-functionalized pristine MWCNTs without contamination with other chemical reagents, detergents and solvents, which is especially important for a vast variety of nanotube applications spanning from nanoelectronics to nanomedicine.