Mixed Micellization of Polyoxyethylene (20) Oleyl Ether with Cetylpyridinium Chloride at the Air–Water Interface

Abstract

AbstractAdsorption and micellization behaviour of binary surfactant mixtures containing a nonionic surfactant, polyoxyethylene (20) oleyl ether (C18‐1E20), and a cationic surfactant, cetylpyridinium chloride (CPC), was studied at the air–water interface using the Wilhelmy plate method. A pseudo‐phase separation model was used to analyse mixed micellization. A Margules equation with one constant (interaction parameter, β) was fitted to the nonideal behaviour of the mixed surfactant system. This system shows synergism (β = −6.0) for micellization. The dynamic behaviour and foamability of binary mixtures at the same bulk concentration and at different mole fractions were also studied using drop volume and horizontal impinging jet methods, respectively. It was found that with an increase in the mole fraction of C18‐1E20, the foamability of a mixture increases and t* value decreases.