Interactions and Molecular Weights of Simple Micelles and Mixed Micelles in Taurocholate and Taurocholate−Lecithin Solutions

Abstract

A quasielastic light-scattering (QLS) technique was employed to investigate simple micelles and mixed micelles formed in taurocholate (TC) and TC−lecithin (L) solutions. When the size and polydispersity of simple TC micelles were nearly unchanged with total TC concentrations, the simple TC micelles were suggested to be all of a single size. According to the relationship between the total TC concentration and the TC monomer concentration, a monomer−micelle model predicted the aggregation number (n) and the critical micellar concentration (cmc) of simple TC micelles to be 5 and 10 mM. Based on Flory's theory, the scattered intensity, the TC monomer concentration, the molecular weights of simple TC micelles, and mixed TC−L micelles were estimated to be 2138 Da and 35 840 Da. Moreover, the interaction coefficients of simple TC micelles and mixed TC−L micelles were found to be 1.30 × 10-5 dL mol g-2 and 5.09 × 10-6 dL mol g-2. According to Flory's equation, the estimated interaction coefficients and the concen...