a Nabipour Chakoli - Nuclear Safety and Radiological Protection Research Department, NSTRI, Tehran, Iran, P.O.Box:۱۴۳۹۵-۸۳۶, School of Chemical Engineering and Technology, State key
m Amirian Chayjan - Teachers University, Shahrak Ghods, Niayesh Blv, Tehran, Ferdosi Center, Baghestan, Karaj, Iran,
j.m he - School of Chemical Engineering and Technology, State key laboratory of urban water resource and environment, Harbin Institute of Technology, Harbin ۱۵۰۰۰۱, China,
y.d huang - School of Chemical Engineering and Technology, State key laboratory of urban water resource and environment, Harbin Institute of Technology, Harbin ۱۵۰۰۰۱, China,

Carboxylation is a procedure used in materials science to oxidize the surface of materials. Several researchers use this technique to improve Mutiwalled carbon nanotubes (MWCNTs) for interaction and dispersion in Matrix materials. The present article evaluates the effect of chemical carboxylation of CNTs. Sulfuric acid and nitric acids were used on the functionalization. Experimental results obtained by XPS spectroscopy indicated the maintenance of the structure of CNTs after all oxidations. The presence of other structures was proved by thermogravimetry decomposition and the addition of functional groups was confirmed by transform Fourier infrared spectroscopy. From these experimental results, we conclude that all methodologies used showed a percentage of adsorption of functional groups on the CNTs. Also, the SEM micrographs show that the MWCNTs were shortening during carboxylation.

MWCNTs, Carboxylation, Oxidation, Functionalization