Tank treading and unbinding of deformable vesicles in shear flow: Determination of the lift force
Tank treading and unbinding of deformable vesicles in shear flow: Determination of the lift force
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DOI：
10.1103/physrevlett.88.068103
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发表时间：
2002-02-11
影响因子：
8.6
通讯作者：
Viallat, A
中科院分区：
文献类型：
--
作者：
Abkarian, M;Lartigue, C;Viallat, A
用光学显微镜定量研究了近壁线性剪切流中松弛囊泡的变形和踩槽运动。有界小泡的速度服从为刚性球体建立的高盛定律。随着剪切速率(伽马)对点的增加，小泡的渐进性倾斜和解离的转变被证明是明显的。这些观测揭示了粘性升力F-L的存在，它取决于流体的粘度ETa、囊泡的半径R、与衬底的距离h以及约化体积v的单调递减函数f(1-v)，其方式如下：F-L=ETa(γ)/点(R-3/h)f(1-v)。这一关系对于靠近和远离底物的囊泡都有效。
Deformation and tank-treading motion of flaccid vesicles in a linear shear flow close to a wall are quantitatively studied by light microscopy. Velocities of bounded vesicles obey Goldman's law established for rigid spheres. A progressive tilt and a transition of unbinding of vesicles are evidenced upon increasing the shear rate, (gamma)over dot. These observations disclose the existence of a viscous lift force, F-l, depending on the viscosity eta of the fluid, the radius R of the vesicle, its distance h from the substrate, and a monotonous decreasing function f (1 - v) of the reduced volume v, in the following manner: F-l = eta(gamma)over dot (R-3/h)f(1 - v). This relation is valid for vesicles both close to and farther from the substrate.