A Study of the Adsorption properties of Single-Walled Carbon Nanotubes treated with Nitric Acid

ANDRÉS A. GARCÍA BLANCO, JHONNY VILLARROEL ROCHA, MARCELO NAZZARRO, GIORGIO ZGRABLICH AND KARIM SAPAG; JOHN MÚNERA

Adsorption Science and Technology

Multi Science

Lugar: Brentwood ; Año: 2011

0263-6174

The changes observed in the properties of Single Walled Carbon Nanotubes after the treatment with nitric acid are reported. The oxidized nanotube samples were characterized morphologically by Scanning Electron Microscopy and structurally by Raman Spectroscopy, Thermogravimetric Analysis, Infrared spectroscopy, and X-ray Photoelectronic Spectroscopy. Gas adsorption was used to study the changes in the surface properties of the samples (including the changes in their porosity), as well as the changes in the adsorbate-adsorbent interactions, which occurred as a result of the acid treatment. The adsorption studies were conducted using N2 at 77 K and CO2 at different temperatures between 263 and 289 K at sub-atmospheric pressures from which the isosteric heat was calculated, obtaining a higher adsorbate-adsorbent interaction for the oxidized materials. A correlation was found connecting the morphological and structural evolution with the adsorption properties of CO2, a probe gas which appears to be very suitable to characterize the microporosity of these kinds of materials.