A Hexanol-Induced Sphere-to-Flexible Cylinder Transition in Aqueous Alkyl Polyglucoside Solutions

Abstract

Sugar surfactants have recently attracted considerable interest. Here we report a systematic light and neutron scattering investigation of aqueous solutions of the alkyl polyglucoside C8/10G1.5. The system exhibits a transition from globular to giant wormlike micelles upon the addition of hexanol. We can finely tune the extent of micellar growth and in particular reach conditions where solutions of relatively short cylinders exist, which dramatically grow into giant wormlike micelles upon the addition of small amounts of hexanol. While considerable progress has been made in the understanding of interaction effects in solutions of spheres or large polymer-like objects, limited information exists for short flexible cylinders. An important reason for this is the lack of good model systems. Here we now demonstrate that the APG system provides us with an ideal set of data for an analysis of micellar growth and interactions in solutions with cylindrical particles of moderate axial ratios. We apply theoretical expressions for the static structure factor derived from Monte Carlo computer simulations of semiflexible polymers with excluded volume interactions, which allow us to self-consistently incorporate micellar interactions and growth in a quantitative analysis of the light and neutron scattering data.