The Basic Hydrolysis of Malachite Green in β-Cyclodextrin/Cetyltrimethlammonium Bromide (CTAB) Mixed System

Oladega Soriyan, Olarenwaju Owoyomi and Akinola Ogunniyi

Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria
* Corresponding author: E-mail: osoriyan@oauife.edu.ng

Abstract
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, (k_obs) 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 enzymatic 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.

Keywords: Basic hydrolysis; malachite green; micellar pseudophases