Mechanistic Aspects of the Oxygen Quenching of the Solid-Matrix Phosphorescence of Perdeuterated Phenanthrene on Partially Hydrophobic Paper

Abstract

The effects of oxygen over a wide concentration range on the solid-matrix phosphorescence (SMP) of perdeuterated phenanthrene (D₁₀) adsorbed on partially hydrophobic paper (1PS) were investigated. The SMP lifetime results of D₁₀ adsorbed on Whatman 1PS paper and Whatman No. 1 paper were considered, and the SMP intensities and SMP lifetimes of D₁₀ on 1PS paper were compared. The SMP quenching model employed showed that diffusional quenching was not very extensive for D₁₀ adsorbed on both types of paper. In addition, a large fraction of the D₁₀ phosphor molecules did not undergo diffusional quenching in either paper. The changes in the SMP intensities for D₁₀ adsorbed on 1PS paper were much greater than the corresponding SMP lifetime changes, which indicated that static quenching by oxygen was very effective for D₁₀ on 1PS paper. Also, the SMP intensity data indicated that a relatively large fraction of the D₁₀ molecules were not quenched statically. The quenching data were interpreted and compared with equations that permitted both linear and nonlinear models to be employed.