Photoinduced anisotropic response of azobenzene chromophore functionalized multiwalled carbon nanotubes

Abstract

Azobenzene chromophore covalently functionalized multiwalled carbon nanotubes (AZO-MWCNT) were synthesized and their optical properties were investigated by ultraviolet-visible absorption and photoluminescence spectroscopy. The polarized absorption of the AZO-MWCNT film was measured by cross-polarized light along the directions parallel and perpendicular to the incident light under the irradiation of polarized ultraviolet light. Photoinduced optical anisotropy of the AZO-MWCNT film was dominated by the enhanced dipole transition of the nanotube axis parallel to the incident light and the decreased transition perpendicular to light. The unique anisotropy induced by the photo-orientation of azobenzene chromophore provides insight into the polarized optical properties of carbon nanotubes. © 2007 American Institute of Physics.