- Photolysis of 2-chlorophenol dissolved in surfactant solutions
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The photochemical degradation and dechlorination of 2-chlorophenol (2CP) dissolved in surfactant solutions was studied. The initial degradation and dechlorination of 2CP followed apparent first-order kinetics. The quantum yields of 2CP degradation and dechlorination were enhanced in the presence of nonionic surfactant Brij 35 and anionic surfactant sodium dodecyl sulfate. A larger enhancement was observed at surfactant concentrations greater than the critical micelle concentration and was attributed to partitioning of 2CP into the micelles. Furthermore, the study of 2CP photolysis in hexane, methanol and dimethoxyethane suggested that the surfactant can serve as a hydrogen atom source in promoting 2CP degradation.The photochemical degradation and dechlorination of 2-chlorophenol (2CP)(0.1 g/L) dissolved in surfactant solutions has been studied. The initial degradation and dechlorination of 2CP followed apparent first-order kinetics in nearly all the test solutions. The quantum yields of 2CP degradation and dechlorination were enhanced in the presence of nonionic surfactant Brij 35 and anionic surfactant sodium dodecyl sulfate (SDS). A larger enhancement was observed at surfactant concentrations greater than the critical micelle concentration (cmc) and was attributed to partitioning of 2CP into the micelles. Furthermore, the study of 2CP photolysis in hexane, methanol, and dimethoxyethane suggested that the surfactant can serve as a hydrogen atom source in promoting 2CP degradation. Two 2CP phototransformation pathways in surfactant solutions were identified. The electronically excited anionic form of 2CP led to cyclopentadienecarboxylic acid formation through a ring contraction via the Wolff rearrangement Electronic excitation of the undissociated form of 2CP led to the formation of catechol via a nucleophilic displacement of chloride in the presence of water. Phenol also observed as a photoproduct in non-nucleophilic solvents that can act as hydrogen atom donors. Phenol was also demonstrated to sensitize the 2CP transformation to phenol in micellar media.
- Shi, Zhou,Sigman, Michael E.,Ghosh, Mriganka M.,Dabestani, Reza
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p. 3581 - 3587
(2007/10/03)
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