Optical Rheometry of Dense Suspensions

二色性和二色性指的是真实的的变化， 各向异性折射率的虚部与方向 媒体 这项研究将测量双折射和二向色性， 高浓度悬浮液，以获得有关 当这种悬浮液经受 剪切或电场。 将特别强调 测量作为光的波长的函数，因为 二向色性对颗粒尺寸与波的比值的强依赖性 长度提供了探测不同结构的可能性， 在各向异性介质中的长度尺度。 特别地，这可以允许 由颗粒组成的悬浮液中的结构表征 不同大小的。 这项研究应该导致一个更有用的工具， 在加工条件下浓缩悬浮液。 应用 包括陶瓷铸造和电流变液。

Birefringence and dichroism refer to variations in the real and imaginary parts of the refractive index with direction for anisotropic media. This research will measure birefringence and dichroism for highly concentrated suspensions in order to gain information on the microstructures than can form when such suspensions are subjected to shear or electric fields. Special emphasis will be placed on measurements as a function of the wave length of light because the strong dependence of dichroism on the ratio of particle size to wave length offers the possibility of probing structures of different length scales in an anisotropic medium. In particular, this may allow characterization of structures in suspensions comprised of particles of different sizes. The research should lead to a more useful tool for characterizing concentrated suspensions under processing conditions. Applications include ceramics casting and electrorheological fluids.