Slip and Flow of Hard-Sphere Colloidal Glasses
Slip and Flow of Hard-Sphere Colloidal Glasses
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DOI：
10.1103/physrevlett.101.258301
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发表时间：
2008-12-19
影响因子：
8.6
通讯作者：
Poon, W. C. K.
中科院分区：
文献类型：
--
作者：
Ballesta, P.;Besseling, R.;Poon, W. C. K.
我们研究了浓缩的硬球胶体悬浮液沿着光滑，不粘壁使用锥板流变仪和同步共聚焦显微镜的流动。在玻璃制度，全球流动表现出从赫歇尔-Bulkley行为在大剪切速率的特性宾汉滑移响应在小速率，遍历胶体流体缺席的过渡。成像揭示了“固体”的微观结构在充分的滑移和“滑移剪切”过渡的局部性质。局部和全球流动的描述由一个唯象模型，和相关的宾汉滑移参数表现出特征标度的大小和浓度的硬球。
We study the flow of concentrated hard-sphere colloidal suspensions along smooth, nonstick walls using cone-plate rheometry and simultaneous confocal microscopy. In the glass regime, the global flow shows a transition from Herschel-Bulkley behavior at large shear rate to a characteristic Bingham slip response at small rates, absent for ergodic colloidal fluids. Imaging reveals both the "solid" microstructure during full slip and the local nature of the "slip to shear" transition. Both the local and global flow are described by a phenomenological model, and the associated Bingham slip parameters exhibit characteristic scaling with size and concentration of the hard spheres.