Soriyan et al.: The Basic Hydrolysis of Malachite Green... Scientific paper The Basic Hydrolysis of Malachite Green in β-Cyclodextrin/Cetyltrimethlammonium Bromide (CTAB) Mixed System

The basic hydrolysis of malachite green (MG) was studied in the mixed systems of β-cyclodextrin (β–CD) and cetyltrimethylammonium bromide (CTAB) at 25 °C. The observed rate constant, (kobs) increases with increase in concentration of β–CD until saturation is reached while at constant β–CD concentration it varies with CTAB concentration in a sigmoid shape curve which is analogous to positive cooperativity in enzymat-ic reaction. The kinetic analysis shows that the major effect of CD on the system is the complexation of the surfactant monomers which delays the formation of micelles. The data obtained fit the pseudophase model of micellar reaction