Micellar catalysis by perfluorooctanoic acid

Rates of acidic hydrolysis of hexano-, octano-, and decanohydroxamic acids and of 4-bromophenylaceto- and phenylacetohydroxamic acids have been determined in aqueous perfluorooctanoic acid—a reactive counterion surfactant system. Typical micellar catalysis was observed for the hydrolyses of the n-alkyl hydroxamic acids but not for the arylacetohydroxamic acids. The Arrhenius activation energy for hydrolysis of octano-hydroxamic acid is smaller above the cmc of the surfactant than it is below the cmc.