Controlling and Quantifying Oxygen Functionalities on Hydrothermally and Thermally Treated Single-Wall Carbon Nanotubes

• DOI: 10.1021/jp200464d
• Publication Date: 2011-04-13T17:22:51Z
• Authors: George E. Romanos; Vlassis Likodimos; Rita R. N. Marques; Theodore A. Steri...; Sergios K. Papage...; Joaquim L. Faria; José L. Figueiredo; Adrián M. T. Silva; Polycarpos Falaras
• Keywords: Carbon fibers

The effects of hydrothermal and thermal treatments on surface oxygen functionalization single-wall carbon nanotubes (SWNTs) were quantitatively investigated by means water adsorption/desorption, temperature-programmed desorption (TPD), Raman spectroscopy, thermogravimetric analysis, nitrogen porosimetry. SWNTs hydrothermally treated under mild acidic conditions compared to highly purified reference materials heavily functionalized aggressive reflux conditions. Water adsorption/desorption TPD analysis successfully combined determine the nature, concentration, stability, strength functional groups SWNT's surface. These results correlated spectroscopy data that allowed identifying marked evolution defect-activated phonon modes SWNTs. concomitant charge transfer differentiated through distinct variation both first- second-order as a function amount acidity well chirality. In addition, analytical investigations thermally in oxidative (in air) pyrolytic (under Ar) confirmed formation amorphous depends primarily acidification process, although significant fraction remains attached SWNTs' walls rather than carboxylated carbonaceous fragments. Quenched solid density theory (QSDFT) bimodal pore size distribution revealed pronounced variations underlying microporous mesoporous structure, associated with diverse packing between SWNT bundles closer aggregation individual upon oxidation treatment. procedure can be effectively controlled quantified, optimum defined relation desired physicochemical properties structure characteristics for specific applications.