Slip, yield, and bands in colloidal crystals under oscillatory shear.
Slip, yield, and bands in colloidal crystals under oscillatory shear.
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振荡剪切下胶体晶体中的滑移、屈服和能带。
DOI：
10.1103/physrevlett.97.215502
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发表时间：
2006
影响因子：
8.6
通讯作者：
D. Weitz
中科院分区：
文献类型：
--
作者：
I. Cohen;B. Davidovitch;A. Schofield;M. Brenner;D. Weitz
我们使用共焦显微镜研究振荡剪切下的致密胶体晶体。在大应变下，晶体产生并且悬浮液形成剪切带。悬浮液表现出的纯谐波响应排除了通常用于描述其他类型复杂流体中剪切带的非线性流变模型的适用性。相反，我们表明基于胶体悬浮液线性响应相共存的模型解释了观察到的流动。这些结果凸显了振荡测量在区分线性和非线性局部流变学对全局非线性材料响应的贡献方面的新用途。
We study dense colloidal crystals under oscillatory shear using a confocal microscope. At large strains the crystals yield and the suspensions form shear bands. The pure harmonic response exhibited by the suspension rules out the applicability of nonlinear rheology models typically used to describe shear banding in other types of complex fluids. Instead, we show that a model based on the coexistence of linearly responding phases of the colloidal suspension accounts for the observed flows. These results highlight a new use of oscillatory measurements in distinguishing the contribution of linear and nonlinear local rheology to a globally nonlinear material response.