BULK AND INTERFACIAL BEHAVIORS OF MIXED SYSTEM OF HEXADECYLPYRIDINIUM CHLORIDE AND Na^+ 2-HYDROXY BENZOATE

The irncellization behavior of hexadecylpyridinium chloride usually called cetylpyridinium chloride (CPC) in presence of sodium salicylate ( NaSal) has been investigated. The surface tension, conductance and microcalorimetric methods have been employed to determine the critical micellar concentration (CMC) of CPC and NaSal mixed in different molar proportions. The interfacial area occupied by CPC m presence of NaSal, the free energy of adsorption and the energetics of micellization have been evaluated. The enthalpy of interaction of NaSal with CPC micelle has also been estimated from microcalorimetric measurements. The shear viscosity of the CPC-NaSal combination at equimolar proportion at different surfactant concentration and temperature, and also the shear viscosity of CPC-NaSal combination at different motority ratios with a fixed surfactant concentration have been determined. The static and dynamic light scattering measurements of the CPC-NaSal system at different composition and in presence of NaC1 have been reported. Worm-like micelles of concentration dependent dimension and intermicellar repulsive interaction have been envisaged.