Nonlinear Rheology of Bicontinuous Bilayer Systems

剪切片层/海绵共存相后的动态光散射测量表明，片层相中的连接膜显著影响了片层相的粘弹性行为。DMPG脂质体系制成的囊泡相在加热和冷却循环中的粘弹性表现出明显的滞后。这种温度依赖性可以归因于囊泡的变形性。研究发现，高变形囊泡呈现剪切增厚行为，表现为非平衡相变。我们设计了一种带有剪切室的扩散波光谱仪。我们的装置可以测量剪切引起的非平衡相的微观流变性。我们还尝试通过动态光散射来实现微观流变性的测量。不幸的是，我们发现通过DLS的微流变学还不适用于粘弹性材料，因为出现了探测粒子均方距离的波长依赖关系。

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.