Effective squirmer models for self-phoretic chemically active spherical colloids
Effective squirmer models for self-phoretic chemically active spherical colloids
复制标题
自泳化学活性球形胶体的有效蠕动模型
DOI：
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Siegfried Dietrich
中科院分区：
文献类型：
--
作者：
Mihail N. Popescu;Mihail N. Popescu;W. Uspal;W. Uspal;Zahra Eskandari;Zahra Eskandari;M. Tasinkevych;Siegfried Dietrich;Siegfried Dietrich
牛顿流体中化学活性胶体的自运动的各个方面可以通过其化学活性的简单模型加上其表面的泳滑流体动力学边界条件来捕获。对于许多实验研究中使用的简单形状的颗粒（例如球体）来说，它们在无界流体中以非常低的雷诺数移动，这种化学活性颗粒的模型有效地映射到经过充分研究的所谓流体动力学蠕动器（S. Michelin 和 E. Lauga, J. Fluid Mech. 747, 572 (2014)）。因此，“推/拉/中立”蠕动者的直观吸引人的类比自然而然地出现了。在自扩散电泳的框架内，我们说明了上述映射和无界流体中相应的流动，以选择多种活动函数（即，颗粒表面化学反应的空间分布和类型）。我们使用两个活性粒子的中心碰撞作为一个简单的范例案例，以证明在存在其他粒子或边界的情况下，即使在远场中，化学活性胶体的行为也可能与从无界流体中映射获得的相应“有效蠕动”所表现出的行为有本质上的不同。这强调了理解化学活性颗粒几何限制下的集体行为和动力学必然需要明确解释流体动力学相互作用对颗粒活性产生的化学物质分布的依赖性。
Various aspects of self-motility of chemically active colloids in Newtonian fluids can be captured by simple models for their chemical activity plus a phoretic-slip hydrodynamic boundary condition on their surface. For particles of simple shapes (e.g., spheres) --as employed in many experimental studies-- which move at very low Reynolds numbers in an unbounded fluid, such models of chemically active particles effectively map onto the well studied so-called hydrodynamic squirmers (S. Michelin and E. Lauga, J. Fluid Mech. 747, 572 (2014)). Accordingly, intuitively appealing analogies of “pusher/puller/neutral” squirmers arise naturally. Within the framework of self-diffusiophoresis we illustrate the above-mentioned mapping and the corresponding flows in an unbounded fluid for a number of choices of the activity function (i.e., the spatial distribution and the type of chemical reactions across the surface of the particle). We use the central collision of two active particles as a simple, paradigmatic case for demonstrating that in the presence of other particles or boundaries the behavior of chemically active colloids may be qualitatively different, even in the far field, from the one exhibited by the corresponding “effective squirmer”, obtained from the mapping in an unbounded fluid. This emphasizes that understanding the collective behavior and the dynamics under geometrical confinement of chemically active particles necessarily requires to explicitly account for the dependence of the hydrodynamic interactions on the distribution of chemical species resulting from the activity of the particles.
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影响因子：
3.4
作者：
W. Uspal;W. Uspal;M. N. Popescu;M. N. Popescu;S. Dietrich;S. Dietrich;M. Tasinkevych;M. Tasinkevych
通讯作者：
W. Uspal;W. Uspal;M. N. Popescu;M. N. Popescu;S. Dietrich;S. Dietrich;M. Tasinkevych;M. Tasinkevych
DOI：
10.1088/0953-8984/28/25/253001
发表时间：
2016-01
期刊：
Journal of Physics: Condensed Matter
影响因子：
--
作者：
A. Zöttl;H. Stark
通讯作者：
A. Zöttl;H. Stark
影响因子：
1.8
作者：
Ebbens, S.;Gregory, D. A.;Golestanian, R.
通讯作者：
Golestanian, R.
影响因子：
16.6
作者：
B. ten Hagen;F. Kümmel;R. Wittkowski;D. Takagi;H. Löwen;C. Bechinger
通讯作者：
B. ten Hagen;F. Kümmel;R. Wittkowski;D. Takagi;H. Löwen;C. Bechinger
DOI：
10.1140/epjst/e2016-60058-2
发表时间：
2016-11
期刊：
The European Physical Journal Special Topics
影响因子：
--
作者：
M. N. Popescu;W. Uspal;S. Dietrich
通讯作者：
M. N. Popescu;W. Uspal;S. Dietrich