Reduction of Shear Viscosity in Phospholipid Vesicle Dispersions by Self-organized Ripple Structures of Vesicle Surfaces

Possible influence of the nanoscale rippled structure at a lipid vesicle surface on macroscopic physical properties of their dispersions was investigated. The macroscopic shear viscosity of highly concentrated lipid vesicle dispersions dramatically decreased under the conditions in which the ripple pattern was formed on surfaces. The decrease in the shear viscosity is suggested to originate in the prevention of aggregation of vesicles by mismatch of static rippled structures at vesicle surfaces.