Slip and flow in pastes of soft particles: Direct observation and rheology
Slip and flow in pastes of soft particles: Direct observation and rheology
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DOI：
10.1122/1.1795171
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发表时间：
2004-11-01
影响因子：
3.3
通讯作者：
Cloitre, M
中科院分区：
文献类型：
--
作者：
Meeker, SP;Bonnecaze, RT;Cloitre, M
微凝胶膏和浓缩乳液显示出在低应力下剪切时，光滑表面附近的一个通用的滑动行为。滑移的大小取决于所施加的应力。在屈服应力以上，滑移与整体流动相比可以忽略不计。在屈服应力之上，滑移变得显著，总变形由整体流动和滑移的组合产生。在屈服应力和屈服应力以下，整体流动可以忽略不计，表观运动完全是由于壁面滑移。通过直接成像的膏体的变形和流变测量，我们表明，滑的特点是通用的缩放性能，这取决于溶剂粘度，体积剪切模量，和颗粒尺寸。基于弹性流体动力润滑的模型之间的挤压颗粒和剪切表面定量解释这些属性。(C)2004流变学学会。
Microgel pastes and concentrated emulsions are shown to exhibit a generic slip behavior at low stresses when sheared near smooth surfaces. The magnitude of slip depends on the applied stress. Well above the yield stress, slip is negligible compared to the bulk flow. Just above the yield stress, slip becomes significant and the total deformation results from a combination of bulk flow and slip. At and below the yield stress, the bulk flow is negligible and the apparent motion is entirely due to wall slip. By directly imaging the deformation of pastes and from rheological measurements, we show that slip is characterized by universal scaling properties, which depend on solvent viscosity, bulk shear modulus, and particle size. A model based on elastohydrodynamic lubrication between the squeezed particles and the shearing surface explains these properties quantitatively. (C) 2004 The Society of Rheology.