THE EFFECT OF BENZYL ALCOHOL ON THE MICELLAR PROPERTIES OF CTAB IN KBr SOLUTION

The effect of benzyl alcohol on the micellar size and shape of CTAB in KBr solution has been investigated by means of viscosity, LLS (laser light scattering), and NMR measurements. The surfactant CTAB (cetyltrimethylammonium bromide) and KBr content are kept constant at 0.01 mol.L^-1 and 0.lmol.L^-1. The data from the various techniques are quantitatively in agreement. The viscosity of 0.01mol.L^-1 CTAB/ 0.01mol.L^-1 KBr micellar system has a marked maximum at benzyl alcohol content 0.6% (v/v), where the size of rod micelles are largest. The results from 1H-NMR spectra of CTAB molecules show that before the maximum viscosity, benzyl alcohol is located in the interfacial region of CTAB micelles in the presence of KBr salt. If more benzyl alcohol is added, it starts solubilizing in the palisades of the micelles.