Imaging studies of photodegradation and self-healing in anthraquinone derivative dye-doped PMMA

We study photodegradation and self-healing of nine different anthraquinone-derivatives doped into PMMA using transmission imaging microscopy in search of structure-property relationships of the underlying mechanisms. We find that seven of the nine anthraquinone derivatives display partially reversible photodegradation, with 1,8-dihydroxyanthraquinone (Dantron/Chrysazin) having the best photostability and recovery characteristics of all dyes tested in this study. Based on these measurements we predict that a sample of 1,8-dihydroxyanthraquinone doped into PMMA with a concentration of 9 g l-1 will have a record setting irreversible inverse quantum efficiency of Bε = 4.56 × 109. Additionally, by considering the performance of the different anthraquinone derivatives and their structures, we develop three rules-of-thumb to qualitatively predict the photostability and recovery characteristics of anthraquinone derivatives. These rules-of-thumb will help guide future experiments and molecular modeling in discerning the underlying mechanisms of reversible photodegradation. Finally, we compare our results for disperse orange 11 dye-doped PMMA to the extended Correlated Chromophore Domain Model (eCCDM). While the eCCDM correctly predicts the behavior of the reversible decay component, it fails to correctly predict the behavior of the irreversible degradation component. This implies further modifications to the eCCDM are required.