Experimental tests of a new correlated chromophore domain model of self-healing in a dye-doped polymer

Abstract

Temperature-dependent photodegradation and recovery studies of Dipserse Orange 11 (DO11) dye dissolved in poly(methyl methacrylate) and polystyrene polymer hosts are used as a test of a new model that builds on the recently proposed correlated chromophore domain model. [Ramini and Kuzyk, J. Chem. Phys., 2012, 137, 054705.] Our model posits that dye molecules form domains or aggregates. The nature of aggregation or how it mediates self-healing is not yet well understood. In this paper we present evidence that supports the hypothesis that the dye molecules undergo a change to a state with higher dipole moment whether it be a tautomer or a TICT state and hydrogen bond with the amines and keto-oxygens of the polymer. Groupings of such molecules in a polymer chain form what we call a domain, and interactions between molecules in a domain make them more robust to photodegradation and mediate self-healing. All of the data is found to be consistent with our new model in the time–temperature–intensity–concentration domain.