Nonlinear Rheology of Bicontinuous Bilayer Systems

对层状/海绵共存相剪切后的动态光散射测量表明，层状相中的连接膜对层状相的粘弹性行为有显著影响，DMPG脂质体系制成的囊泡相的粘弹性在加热和冷却循环中表现出明显的滞后性。这种温度依赖性可以归因于囊泡的可变形性。我们设计了一个带有剪切池的扩散波光谱仪，并对该仪器的性能进行了测试。我们的装置可以测量剪切引起的非平衡相的微观流变学。我们还尝试通过动态光散射实现微观流变学的测量。不幸的是，我们发现，通过DLS的微观流变学还不适用于粘弹性材料，因为探针颗粒的均方距离的波长依赖性的外观。

Dynamic light scattering measurement after shearing the lamellar/sponge coexisting phase reveals that the connected membranes in the lamellar phase significantly influence the viscoelastic behavior of the lamellar phase.Viscoelasticity of vesicle phase made of DMPG lipid systems shows a significant hysteresis in heating and cooling cycle. This temperature dependence can be attributed to the deformability of vesicles. It is found that the highly deformable vesicle shows the shear-thickening behavior, which indicates non-equilibrium phase transition.We designed a diffusive wave spectroscopy apparatus equipped with shear cell. Our apparatus allows measuring the microrheology of non-equilibrium phase induced by shear. We also tried to achieve the microrheology measurement via the dynamic light scattering. Unfortunately, we found that the mircrorheology via the DLS is not yet applicable for the viscoelastic materials because of the appearance of the wavelength dependence of the mean square distance of the probe particle.