Perils of ad hoc approximations for the activity function of chemically powered colloids
Perils of ad hoc approximations for the activity function of chemically powered colloids
复制标题
化学动力胶体活度函数的临时近似的危险
DOI：
10.1140/epje/i2017-11529-1
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
S. Dietrich
中科院分区：
文献类型：
--
作者：
M. N. Popescu;W. E. Uspal;M. Tasinkevych;S. Dietrich
摘要胶体可以通过在其表面促进周围溶液中的化学反应来实现运动。一个研究得很好的例子是自凝胶，由于溶液化学成分的空间不均匀以及溶剂分子和反应产物与胶体的明显相互作用而产生了运动性。对于这种化学活性胶体的简单模型，无限溶液中的稳态运动可以解析地以封闭形式推导出来。相比之下，对于在墙壁附近运动的这种化学活性粒子，即使对简单的模型来说，推导出控制其动力学的封闭形式和物理直观的方程也是一个严峻的挑战。因此，最近对这些现象的研究采用了数值方法和基于多极展开的近似分析方法。我们讨论和澄清关于后一种方法的某些概念方面，这是由于基本的所谓的活度函数被截断而产生的，活度函数描述了化学反应在粒子表面的分布。
AbstractColloids can achieve motility by promoting at their surfaces chemical reactions in the surrounding solution. A well-studied case is that of self-phoresis, in which motility arises due to the spatial inhomogeneities in the chemical composition of the solution and the distinct interactions of the solvent molecules and of the reaction products with the colloid. For simple models of such chemically active colloids, the steady-state motion in an unbounded solution can be derived analytically in closed form. In contrast, for such chemically active particles moving in the vicinity of walls, the derivation of closed-form and physically intuitive solutions of the equations governing their dynamics turns out to be a severe challenge even for simple models. Therefore, recent studies of these phenomena have employed numerical methods as well as approximate analytical approaches based on multipolar expansions. We discuss and clarify certain conceptual aspects concerning the latter type of approach, which arise due toad hoctruncations of the underlying so-called activity function, which describes the distribution of chemical reactions across the surface of the particle.Graphical abstract
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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
影响因子：
3.9
作者：
J. de Graaf;G. Rempfer;Christian Holm
通讯作者：
Christian Holm