Determination of the Micelle Concentration of Surfactants by Resonance Rayleigh Scattering Method (CAT#: STEM-ST-0004-YJL)

Introduction

Critical micelle concentration (CMC) is the concentration in which a surfactant starts to aggregate and form micelle, and it is one of the most important physical parameters of surfactants. The properties of a surfactant vary markedly when its concentration is higher or lower than its CMC, and the studies and industrial applications of a surfactant are always based on the value of its CMC. The usually called CMC actually refers to the first critical micelle concentration (FCMC) of a surfactant. Critical premicelle concentration (CPMC) can be defined as the onset of premicellar aggregate for a surfactant at the concentration far below its FCMC, which usually is lower by about two or three orders of magnitude than its FCMC. When the concentration of a surfactant is higher than its FCMC, spherical micelles can aggregate to form ellipsoidal, oblatoid or lamellar micelles and the concentration was called second critical micelle concentration (SCMC).