Effect of n-Alkylamines on Micellization of Aqueous Sodium Dodecyl Sulphate Solutions through Ultrasonic Measurements

Acoustical studies are undertaken in 0.025 m aqueous solution of SDS with the addition of n-alkyl amines (ethylamine, diethyl amine and triethyl amine) at various concentrations ranging from 0.01 to 0.05 molar at 303 K. From the measured values of velocity, density, viscosity and observed absorption (α/f 2 ) obs, various other parameters such as compressibility, free length, free volume, relative association, Rao's constant, classical absorption (α/f 2 )cl, excess absorption (α/f 2 )ex, volume viscosity and relaxation time are calculated and reported. The results indicate that the addition of amines to the surfactant activates the micellar growth and leads to solubilization of shorter chain amines.