Study of association thermodynamics between crystal violet and sodium bis(2-ethylhexyl)sulfosuccinate and kinetics of basic fading of crystal violet in microemulsions

The thermodynamics of the association between 4,4',4"-tris(dimethylamino)triphenylmethyl chloride (crystal violet or CV) and sodium bis(2-ethylhexyl)sulfosuccinate (aerosol OT or AOT) in water/AOT/n-decane microemulsion and the kinetics of the basic hydrolysis of CV in a water-in-oil microemulsion were investigated by UV-vis spectroscopic measurements. An association model of CV and AOT was used to analyze the experimental data to obtain the association constants at various temperatures. By taking the association into account, the "actual" rate constants and the activation energies of the basic hydrolysis of CV in the media of water/AOT/oil were obtained. The difference in thermodynamics and kinetics between the two media of water/AOT/n-decane and water/AOT/isooctane is discussed. (C) 2008 Wiley Periodicals, Inc.