Structure dependent interaction between organic dyes and carbon nanotubes

Systematic studies on noncovalent functionalization of multiwalled carbon nanotubes (MWNTs) were assisted by a series of aromatic dye molecules with different structural characteristics. The effects of molecular structure on the affinities of different dyes to the MWNTs were evaluated. Two main factors have been found to play the key roles for the dye-MWNTs interactions, which are molecular geometry and charge. It was found that molecules with planar structures and high charge load are favored for the adsorption. This work not only demonstrates a simple and effective method to functionalize the sidewalls of carbon nanotubes but also give insight to the adsorption mechanism between the carbon nanotubes and aromatic molecules. (C) 2007 Elsevier B.V. All rights reserved.