Influence of polymer structure inhomogeneity on oxygen quenching of phenanthrene phosphorescence in poly(methyl methacrylate)

Abstract

Abstract Decay kinetics of phenanthrene phosphorescence in atactic poly(methyl methacrylate) have been studied at 130–170 K in the presence of dissolved oxygen. The kinetics show anomalous behavior and cannot be described in terms of homogeneous diffusion of oxygen. Analysis of the dependence of the kinetics on oxygen concentration shows that such behavior is well accounted for by a polychromatic model assuming a dispersion of diffusion coefficients due to the inhomogeneity of the polymer structure. Possible errors in determining the diffusion coefficient from the phosphorescence quantum yield on the assumption of homogeneous diffusion are discussed. © 1992 John Wiley & Sons, Inc.