Abstract
The rate of hydrolysis for triflusal was measured at varying concentrations of NaOH at four different temperatures (i.e. 25, 35, 45 and 55 degrees C). The micelles of cetyltrimethylammonium bromide (CTABr), cetyltrimethylammonium chloride (CTACl), cetyltrimethylammonium hydroxide (CTAOH) and dodecyltrimethyl-ammonium bromide (DTABr) had catalytic effect on the rate of hydrolysis. CTABr, CTACl and DTABr gave maxima like curve for the rate-[surfactant] plot while CTAOH gave plateau like curve. The anionic sodium dodecyl sulfate (SDS) did not influence the rate of alkaline hydrolysis of triflusal. The non-ionic Brij-35 inhibited the rate of the hydrolytic reaction. The catalytic effect by cationic micelles was treated by applying the pseudophase ion exchange model while the inhibitive effect by non-ionic micelles has been described by using the Poisson-Boltzmann pseudophase model. The variation in k(Psi) with the change in [surfactant] was used to determined various kinetic parameters e.g., binding constant (K-s), and micellar rate constant (k(m)). The addition of electrolytes decreased the reaction rate in CTABr and CTAOH micelles. (C) 2015 Elsevier B.V. All rights reserved.