The absorption and fluorescence changes due to the photo-oxidation of polyvinylcarbazole and its copolymers

The effects of a photo-oxidation evenly distributed over the whole volume of polyvinyl carbazole (PVCA) solutions on the spectral properties have been studied. The absorption spectra of the photo-oxidate have been found to be connected with the monomer chains present in the main chain. They were measured and also the fluorescence spectra at 4·2°K in conditions permitting to neglect the masking effect by eximer emissions. An effect of the migration of the excitation energy of the singlet has been detected on the photo-oxidation kinetics of the polymer, also on the magnitude and the kinetics of the fluorescence extinction associated with it. The passage of the singlet excitons along the PVCA macromolecules has been estimated and the quantum yield of the photochemical reaction in dioxane as well as that of the extinction of the singlet excitation by the solution oxygen. The photo-oxidation also had the same effect on the spectral properties of the PVCA copolymers.