Effect of Shear Rates on the MLV Formation and MLV Stability Region in the C12E5/D2O System: Rheology and Rheo-NMR and Rheo-SANS Experiments

At high temperatures, pentaethylene glycol monododecyl ether (C12E5) in D2O forms a swollen lamellar phase. This letter reports the shear induced multilamellar vesicle (MLV) formation in a sample that contains 40 wt % C12E5 dissolved in D2O at 55 degrees C. This transition has been investigated by time-resolved rheo-nuclear magnetic resonance, rheo small angle neutron scattering, and rheometry. The typical transient viscosity behavior of MLV formation has been discovered at 1 s(-1). For the first time, it has been found that MLVs are not stable over time when subjected to high shear rates. Our results show that the MLV stability is confined in a narrow region in the range 1-10 s(-1) shear rates. This is not observed for other CnEm surfactants.