Morphology and properties of a polyrotaxane based on γ-cyclodextrin and a polyfluorene copolymer

The effect of complexation of a poly[2,7-(9,9-dioctylfluorene-alt-2,7-fluorene)] copolymer into the inner cavity of γ-cyclodextrin on the morphology, the optical and the electrical properties was investigated. The fluorescence spectra of the rotaxane copolymer and of a reference, non complexed copolymer exhibit typical well resolved blue emission bands arising from the fluorene chromophore units. The complexation of the fluorene copolymer chain increases the fluorescence lifetime from 0.54 to 0.59 ns and decreases the activation energy of the electrical conduction from 2.41 to 1.49 eV. The rotaxane copolymer presents higher semiconducting properties as compared to the reference copolymer.