LUMINOL CHEMILUMINESCENCE IN MICELLAR MEDIA

The light reaction of luminol with sodium hypochlorite is reported in cetyltrimethylammonium chloride (CTAC) micelles. The chemiluminescence and chemiexcitation yields in this medium are reported, together with the chemical yields and the fluorescence quantum yield of 3-aminophthalate, the primary emitter. The CTAC molecules cause both chemical and photophysical quenching; however, the chemiexcitation yields are higher than in homogeneous aqueous media due to the less polar microenvironment of the micellar Stern region. Based on the chemiluminescence decay curves, the apparent pseudo-first-order rate constants are reported and the dependence on the surfactant concentration is shown to be in accordance with the pseudophase kinetic model. Employing this model the ion exchange constant between OCl- and Cl-, the micellar rate constant and the luminol-CTAC binding constant are also reported.