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

TL;DR

This study tests the correlated chromophore domain model by examining temperature-dependent photodegradation and recovery of DO11 dye in polymers, providing evidence for domain formation and its role in self-healing.

Contribution

It offers qualitative evidence supporting the model that dye molecules form domains with enhanced stability and self-healing capabilities in polymer hosts.

Findings

Dye molecules change to a tautomer state with higher dipole moment.

Molecules form domains that are more resistant to photodegradation.

Interactions within domains facilitate self-healing.

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 the recently proposed correlated chromophore domain model.[1] This 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 qualitative evidence that supports the hypothesis that the dye molecules undergo a change to a tautomer state with higher dipole moment 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.