Employing singlet-singlet energy transfer for boosting the reactivity of Type I photoinitiators in radical photopolymerization.
Fiche publication
Date publication
septembre 2024
Journal
Angewandte Chemie (International ed. in English)
Auteurs
Membres identifiés du Cancéropôle Est :
Pr ALLONAS Xavier
Tous les auteurs :
Allonas X, Niederst L, Morone M, van den Branden S
Lien Pubmed
Résumé
A remarkable and unexpected increase in the photopolymerization efficiency of an acrylic resin by a bisacylphosphine oxide photoinitiator was observed when an optical brightener was present in the medium. High values for the maximal rates of photopolymerization were obtained by RT-FTIR at 365 nm under a very low irradiance of 1 mW/cm2. Fluorescence studies revealed that the quenching process was attributed to singlet-singlet energy transfer between the first singlet excited state of the optical brightener and the ground state photoinitiator. This mechanism acts as an additional pathway for the excitation of the photoinitiator, thereby increasing the total amount of initiating radicals. Using the Förster resonance energy transfer model, we calculated the relative efficiency of the photosensitization process compared to the direct excitation efficiency of the photoinitiator. The results demonstrate that the photosensitization process can be predicted, paving the way for further improvements in photoinitiating systems.
Mots clés
Fluorescence quenching, Förster energy transfer, Radical photopolymerization, Singlet-singlet photosensitization, Type I photoinitiators
Référence
Angew Chem Int Ed Engl. 2024 09 17;:e202412625