Viscoelasticity of two-layer vesicles in solution.
The dynamic shape relaxation of the two-layer vesicle is calculated. In addition to the undulation relaxation where the two bilayers move in the same direction, the squeezing mode appears when the gap between the two bilayers is small. At a large gap, the inner vesicle relaxes much faster, whereas the slow mode is mainly due to the outer-layer relaxation. We have calculated the viscoelasticity of the dilute two-layer-vesicle suspension. It is found that for a small gap, the applied shear drives the undulation mode strongly while the slow squeezing mode is not much excited. In this limit, the complex viscosity is dominated by the fast-mode contribution. On the other hand, the slow mode is strongly driven by shear for a larger gap. We have determined the crossover gap, which depends on the interaction between the two bilayers. For a series of samples where the gap is changed systematically, it is possible to observe the two amplitude switchings.
Department of Chemistry, Center of Theoretical Physics, National Taiwan University, Taipei 106, Taiwan. cydlu@ntu.edu.tw
C-Y David
CY
Lu
Shigeyuki
S
Komura
Kazuhiko
K
Seki
D000465:Algorithms; D001703:Biophysics / Q000379:methods*; D003198:Computer Simulation; D004548:Elasticity; D008051:Lipid Bilayers / Q000737:chemistry*; D015233:Models, Statistical; D011312:Pressure; D012212:Rheology / Q000379:methods; D012996:Solutions; D013314:Stress, Mechanical; D014783:Viscosity
D008051:Lipid Bilayers; D012996:Solutions