Multilamellar vesicles (“onions”) under shear quench: pathway of discontinuous size growth

Abstract

The size growth of multilamellar vesicles (MLV; “onions”) of a non-ionic surfactant system composed of 40 wt.% C10E3 in D2O was investigated by shear quench experiments, i.e. by reducing the shear rate. Structural changes were monitored by means of viscosity, rheo-small angle neutron scattering, rheo-small angle light scattering and optical microscopy. Discontinuous growth of vesicle size was observed in addition to the continuous process reported previously. In the discontinuous size growth, first lamellar domains are formed, which afterwards transform into larger MLVs. The lamellar domains coexist with the original small vesicles leading to a bimodal size distribution. The transition of the lamellar domains into new MLVs follows the same pathway as was observed for the MLV formation from aligned lamellar phases.