Anchoring a liquid crystal molecule on a single-walled carbon nanotube

The atomic and electronic structures of the tri-fluorophenyl2 (TFP2) liquid crystal (LC) molecule anchored on a carbon nanotube (CNT) wall were investigated by using density functional calculations. The TFP2 LC molecule was anchored helically to the CNT wall to enhance pi-pi stacking by maximizing the hexagon-hexagon interactions between two species. The anchoring was further strengthened with a binding energy of nearly -2.0 eV by electrostatic energy due to a considerable amount of charge transfer from LC molecule to the CNT. These charges were distributed asymmetrically on the CNT due to the anchoring of asymmetric LC molecule, which induced a permanent dipole moment on the CNT. This plays an important role for electro-optical responses of CNTs in the LC cell. Our theoretical study can explain the recent experimental report for the various dynamical motions of CNT in the LC cell under an external electric field.