Abstract
The effect of sodium dodecyl sulfale (SDS) concentration on the efficiency of the photooxidation of Methyl Orange sensitized by tetraphenylporphyrin (TPP) in the surfactant solution was investigated. It was found that the efficiency of the photooxidation is lower above the critical micelle concentration of SDS-TPP mixed solution (cmcmix) than below the cmc<mix>. By taking into consideration the formation of an oligomer complex between one TPP molecule and several SDS molecules below the cmc<mix>, it was possible to explain the relatively lower efficiency above the cmc<mix> in terms of the lower reactivity between singlet oxygen produced by the excited TPP and methyl orange (MO) in the less polar environment on the micellar surface.
