Observing and predicting the preferential functionalization of metallic or semiconducting single-walled carbon nanotubes

Abstract

The functionalization of single-walled carbon nanotubes was performed with four organic molecules. A careful study involving thermo-gravimetric analysis and Raman spectroscopy allowed us to quantify the grafting rate of each molecule, and to evidence a preferential grafting of metallic or semiconducting tube depending on the molecule under consideration. In order to understand the origin of this selectivity, we performed DFT calculations of the electronic structure of the molecules, and compared it to the electron density of states of carbon nanotubes. This approach allowed us to propose a paradigm for explaining the grafting affinity of organic molecules towards metallic or semiconducting nanotubes, and for estimating the grafting efficiency. It could further be used in order to predict the selectivity of any molecule containing a double or triple carbon bond towards metallic or semiconducting carbon nanotubes.