Luminescence and Absorption Spectra of Poly(4-vinylpyridine) Thin Films and Their Surface Modification

One of popular nitrogen-containing aromatic moieties, pyridine, and its derivatives had been studied by many investigators, as these molecules show many interesting features on their photophysical and photochemical properties. In previous studies, we reported the luminescence change of a pyridine-containing polymer, poly(4-vinylpyridine) with the surface quaternization of its thin films. The emission wavelength of the films were red-shifted over 100 nm. In this study, we examined the dependence of luminescence wavelength on the film thickness of poly(4-vinylpyridine), emission decay curves and molecular orbital calculations. The emission and excitation spectra were affected with the film thickness. The nature of the luminescence was discussed.