title: "Green" functionalization of pristine multi-walled carbon nanotubes with long-chain aliphatic amines.
abstract: Short pristine multi-walled carbon nanotubes (MWNTs) were functionalized with a series of long-chain (including polymeric) aliphatic amines, namely octadecylamine (ODA), 1,8-diaminooctane (DO), polyethylene glycol diamine (PEGDA) and polyethylenimine (PEI), via two "green" approaches: (1) gas-phase functionalization (for volatile ODA and DO) and (2) direct heating in the melt (for polymeric PEGDA and PEI). Both of them consist in one-step reaction between MWNTs and amine without the use of organic solvents. The nanostructures obtained were characterized by using infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. It was observed that both solvent-free methods were efficient in the nanotube functionalization, and the nanostructures of variable solubility and morphology were obtained depending on the amines attached. ODA, PEGDA and PEI-functionalized MWNTs were found to be soluble in propanol, meanwhile the MWNTs-PEGDA and MWNTs-PEI were soluble in water as well. The attachment of 1,8-diaminooctane onto MWNTs resulted in cross-linked stable nanostructure.
authors.affiliation: Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México (UNAM), Circuito Exterior C.U., 04510 México, DF, Mexico.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Basiuk
authors.forename: Omar
authors.initials: O
authors.lastname: Ochoa-Olmos
authors.forename: Flavio F
authors.initials: FF
authors.lastname: Contreras-Torres
authors.forename: Víctor
authors.initials: V
authors.lastname: Meza-Laguna
authors.forename: Edgar
authors.initials: E
authors.lastname: Alvarez-Zauco
authors.forename: Iván
authors.initials: I
authors.lastname: Puente-Lee
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Basiuk
mesh_terms: D000588:Amines / Q000737:chemistry*; D003959:Diamines; D055772:Green Chemistry Technology / Q000379:methods*; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry
chemical_list: D000588:Amines; D003959:Diamines; D037742:Nanotubes, Carbon; D011092:Polyethylene Glycols; C008697:octamethylenediamine; D011094:Polyethyleneimine; C009317:stearylamine