Spectroscopic studies of the mechanism of reversible photodegradation of 1-substituted aminoanthraquinone-doped polymers

TL;DR

This study investigates the reversible photodegradation mechanism of aminoanthraquinone dyes in polymers using spectroscopic methods and computational modeling, revealing interactions between dyes and degraded polymers that lead to reversible or irreversible damage.

Contribution

It combines experimental spectroscopy with density functional theory to elucidate the reversible photodegradation process in dye-doped polymers, providing new insights into the underlying mechanisms.

Findings

Both dye and polymer undergo reversible photodegradation.

Photodegradation involves interactions between dyes and thermally-degraded polymers.

Metastable products can recover or further degrade irreversibly.

Abstract

The mechanism of reversible photodegradation of 1-substituted aminoanthraquinones doped into poly(methyl methacrylate) and polystyrene is investigated. Time-dependent density functional theory is employed to predict the transition energies and corresponding oscillator strengths of the proposed reversibly- and irreversibly-damaged dye species. Ultraviolet-visible and Fourier transform infrared (FTIR) spectroscopy are used to characterize which species are present. FTIR spectroscopy indicates that both dye and polymer undergo reversible photodegradation when irradiated with a visible laser. These findings suggest that photodegradation of 1-substituted aminoanthraquinones doped in polymers originates from interactions between dyes and photoinduced thermally-degraded polymers, and the metastable product may recover or further degrade irreversibly.