Haffner B, Khidas Y, Pitois O
Université Paris Est, Laboratoire Navier, UMR 8205 CNRS -École des Ponts ParisTech - IFSTTAR cité Descartes, 2 allée Kepler, 77420 Champs-sur-Marne, France.
Soft Matter. 2014 May 14;10(18):3277-83. doi: 10.1039/c4sm00049h. Epub 2014 Mar 14.
The drainage of particulate foams is studied under conditions where the particles are not trapped individually by constrictions of the interstitial pore space. The drainage velocity decreases continuously as the particle volume fraction φ(p) increases. The suspensions jam--and therefore drainage stops--for values φ*(p) which reveal a strong effect of the particle size. In accounting for the particular geometry of the foam, we show that φ*(p) accounts for unusual confinement effects when the particles pack into the foam network. We model quantitatively the overall behavior of the suspension--from flow to jamming--by taking into account explicitly the divergence of its effective viscosity at φ*(p). Beyond the scope of drainage, the reported jamming transition is expected to have a deep significance for all aspects related to particulate foams, from aging to mechanical properties.
在颗粒不会因间隙孔隙空间的收缩而单独被困住的条件下，对颗粒泡沫的排水进行了研究。随着颗粒体积分数φ(p)的增加，排水速度持续降低。对于φ*(p)值，悬浮液会发生堵塞，从而排水停止，φ*(p)值显示出颗粒大小的强烈影响。考虑到泡沫的特殊几何形状，我们表明当颗粒填充到泡沫网络中时，φ*(p)体现了异常的限制效应。通过明确考虑其有效粘度在φ*(p)处的发散，我们对悬浮液从流动到堵塞的整体行为进行了定量建模。除了排水的范围之外，所报道的堵塞转变预计对与颗粒泡沫相关的所有方面都具有深远意义，从老化到机械性能。
