Branched Worm-like Micelles and Their Networks

Abstract

Branched worm-like micelles were found in aqueous solutions of alkylamine oxide and alkyl ethoxylate sulfate mixtures by cryo-transmission electron microscopy (cryo-TEM). These branched micelles formed interconnected micellar networks at high solution pH or salt concentrations. The networks are similar to the bilayer structures in the bicontinuous L3 phase reported in the literature, where an infinite multiconnected fluid membrane forms a bicontinuous structure. The rheological properties of these branched worm-like micelles and their networks were also studied. The branched micelle solutions exhibited weak viscoelasticity and an apparent yield stress value. However, no real yield stress value was observed. When a dense micellar network formed, the solution exhibited well-defined Maxwell behavior.