Competition between aggregation and hydrolysis in the reaction of arylperfluorooctanoates in micellar solutions.

MARIANA ADELA FERNÁNDEZ; RITA HOYOS DE ROSSI

LANGMUIR

American Chemical Society

Lugar: Washington; Año: 2006 vol. 22 p. 6523 - 6523

0743-7463

font face="Times,Times New Roman"> The rate of hydrolysis of phenyl and p-nitrophenyl perfluorooctanoate (2a and 2b) was measured in water and in the presence of different surfactants cationic (DTACl, DTABr, CTABr), anionic (SDS and perfluorooctanoate, PFO) and neutral (Brij-35) surfactants. In water solution, the formation of phenol from 2a and p-nitrophenol from 2b takes place through two kinetic processes, both of which are much slower than the expected rate of hydrolysis for the monomeric compounds in water. The two kinetic processes are attributed to a coupling of the rates of hydrolysis and aggregation of the substrates. In the presence of charged surfactants at concentrations below the respective critical micelar concentration (cmc), two relaxation times are also observed. These are of the same order of magnitude as for the substrates alone in the case of SDS, but faster for the cationic surfactants. AT some concentration above the cmc, al