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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, all the surfactants, except for PFO, showed a clean pseudo-first-order behavior attributed to the hydrolysis of the substrate incorporated into the micellar phase. In cationic micelles, the rates for 2a are slower and those for 2b are faster than the value expected for the monomer in water. The difference in behavior is attributed to the location of the substrates in the micellar phase and to the charge distribution in the transition state of the reactions. It is shown that the reactions in the micelar phase are catalyzed by the buffer PO4H2-/PO4H2- . The reactions in SDS micelles are faster than those in water but slower than the estimated value for the monomer in water. The rate of the reactions in the presence of non ionic surfactant has values in between those in cationic and anionic surfactant, that is, the rates are kcationic >knon ionic > kanionic. The behavior of 2a and 2b in water and in micellar solutions indicates that the substrates form aggregates in water at a rate that competes with the rate of hydrolysis.