THE PHOTOSENSITIZED FORMATION AND REACTION OF SINGLET OXYGEN, O₂*(1Δ), IN AQUEOUS MICELLAR SYSTEMS

Abstract

Abstract— Oxygenated aqueous solutions of methylene blue containing dispersions of sodium dodecyl sulphate micelles with solubilised diphenyl isobenzofuran were irradiated with red light and the rate of loss of furan was followed over several min. The results are consistent with a mechanism in which singlet oxygen is produced by energy transfer from methylene blue triplet in the aqueous phase, and then diffuses to and penetrates the interior of the micelles where it reacts with the furan. The competition between this process and the natural decay of the excited oxygen has been examined and a β‐value of 9.7 times 10 ‐5 M determined which is comparable to that for the same reaction in homogeneous solvents. A model of the system is proposed and its kinetic features discussed.