A comparison between Raman spectroscopy and surface characterizations of multiwall carbon nanotubes

The distribution of graphene units with an axial symmetry gives rise to different types of carbon filaments: nanotubes, nanofilaments and classical fibers. In this work the surfaces of different multiwalled nanotubes are characterized by two complementary techniques: chemical ones based on Total Surface Area and Active Surface Area measurements, associated with a physical approach the Raman scattering spectroscopy. From analysis of Raman data we deduce the values of the in-plane coherence lengths, identified as L, the planar projection of graphene sheets, and we propose an analysis for the observed line-width behavior related to the graphitization step. From the surface chemical properties we establish a general relationship between the density of functional surface groups and the in plane coherence length L, for all types of MWNT. This analysis allows us to show the influence of both, the structural organization and the different treatments on the interfacial characteristics of these nanocarbons. (c) 2006 Elsevier Ltd. All rights reserved.