Ab‐initio modeling of carbon nanotubes functionalized with pyrrolidine

Abstract

Recently it was found non‐oxidative unzipping of functionalized multiwall carbon nanotubes (CNT) in solvent‐free reaction. In order to relate the effect of functionalization to the unzipping process we have modelled, using ab‐initio methods, various small diameter single wall CNT functionalized with pyrrolidine. Using a density functional theory code we have studied the electronic and vibrational properties of these structures where the pyrrolidine on the external wall is either at longitudinal or transversal position. The hydrogenation of the nanotube along an axial unzipping direction is also simulated in order to evaluate its effect on the opening of hexagonal carbon structure as suggested in other works. We have found that only the longitudinal position of pyrrolidine along with hydrogenation induces the spontaneous opening of the CNT. This unzipping effect increases with the decreasing of CNT diameter. We also found important differences for the calculated local vibrational modes between longitudinal and transversal positions of pyrrolidine. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)