Fracture of Jammed Colloidal Suspensions.
Fracture of Jammed Colloidal Suspensions.
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DOI：
10.1038/srep14175
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发表时间：
2015-09-16
影响因子：
4.6
通讯作者：
Smith MI
中科院分区：
文献类型：
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作者：
Smith MI
随着剪切速率的增加，浓缩的胶体悬浮液的粘度急剧上升，导致堵塞和造粒。有人提出，这些影响是由于颗粒间摩擦，因为润滑力被克服。这表明浓缩胶体悬浮液的堵塞应该表现出一些与宏观颗粒系统相同的现象，其中摩擦导致两种不同类型的堵塞状态。在这里，我们表明，瞬态流变测量可以用来探测浓缩胶体悬浮液中的造粒过程。我们的研究结果支持的想法，摩擦接触之间产生堵塞的颗粒。堵塞行为显示出由临界应变率分离的两个定性不同的区域，其具有定性不同类型的断裂/破碎行为。在较低的应变率制度，它被发现，振动可以用来控制堵塞和造粒，导致在一个可流动的流体。
Concentrated colloidal suspensions display dramatic rises in viscosity, leading to jamming and granulation, with increasing shear rate. It has been proposed that these effects result from inter particle friction, as lubrication forces are overcome. This suggests the jamming of concentrated colloidal suspensions should exhibit some shared phenomenology with macroscopic granular systems where friction leads to two different types of jammed state. Here we show that transient rheological measurements can be used to probe the processes of granulation in concentrated colloidal suspensions. Our results support the idea that frictional contacts are created between jammed particles. The jamming behaviour displays two qualitatively different regimes separated by a critical strain rate with qualitatively different types of fracture/break up behaviour. In the lower strain rate regime, it is found that vibrations can be used to control jamming and granulation, resulting in a flowable fluid.