LETTER TO THE EDITOR: Fluid particle dynamics simulation of charged colloidal suspensions
LETTER TO THE EDITOR: Fluid particle dynamics simulation of charged colloidal suspensions
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致编辑的信：带电胶体悬浮液的流体颗粒动力学模拟
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
Hajime Tanaka
中科院分区：
文献类型：
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作者：
H. Kodama;Kimiya Takeshita;Takeaki Araki;Hajime Tanaka
基于流体粒子动力学方法（Tanaka和Araki 2000 Phys. Rev . Lett.）85 1338），以便适当地结合电流体动力学相互作用。流体粒子近似允许我们处理带电胶体悬浮体的三个相关元素的运动之间的动态耦合，即，胶体颗粒、离子云和液体，以物理上自然的方式。我们的方法的有效性证明了带电胶体的电泳沉积的问题。我们的模拟结果清楚地表明，电渗流导致“有效的”长距离吸引力的带电粒子之间的相同的符号，如先前所建议的实验和理论。含有胶体的液体悬浮液在软物质物理学、表面化学、生物学和工业中具有根本的重要性[1-3]。在胶体悬浮液中，电荷在稳定分散体和电操纵悬浮颗粒方面起着关键作用。众所周知，它们影响胶体悬浮液的各种动力学现象，如沉降、流变学和电泳。当人们试图从理论上或数值上研究带电胶体悬浮体的动力学时，最困难的问题来自于三个关键元素（胶体粒子、离子和液体分子）之间的复杂动力学耦合。这些元素通过静电和流体动力相互作用彼此强烈相互作用。由于这些静态和动态的相互作用都是长程性质，我们必须不可避免地处理一个非常复杂的动态多体问题。由于这些困难，迄今为止既没有理论研究也没有数值研究，考虑到胶体悬浮液的这三个关键要素的运动之间的完全静态和动态耦合，尽管科学上已经证明了这一点。
An ew method of simulation of the dynamics of charged colloidal suspensions is formulated that is based on the fluid particle dynamics method (Tanaka and Araki 2000 Phys. Rev .L ett. 85 1338) so as to incorporate the electrohydrodynamic interactions properly. The fluid particle approximation allows us to treat dynamic coupling among motions of the three relevant elements of charged colloidal suspensions, i.e., colloidal particles, ion clouds, and liquid, in a physically natura lm anner. The validity of our method is demonstrated for a problem of the electrophoretic deposition of charged colloids. Our simulation results clearly indicate that the electro-osmotic flow causes ‘effective’ long-range attractions between charged particles of the same sign, as previously suggested by experiments and theories. Liquid suspensions containing colloids are of fundamental importance in soft matter physics, surface chemistry, biology, and industry [1–3]. In colloidal suspensions, charges play key roles in stabilizing the dispersions and also in electrically manipulating suspended particles. It is also widely known that they affect various kinetic phenomena of colloidal suspensions, such as sedimentation, rheology, and electrophoresis. When one tries to study the dynamics of charged colloidal suspensions either theoretically or numerically, the most difficult problem arises from the complex dynamic coupling among motions of the three key elements; that is ,c olloidal particles, ions, and liquid molecules. These elements are strongly interacting with each other via both electrostatic and hydrodynamic interactions. Since these static and dynamic interactions are both of long-range nature, we must inevitably deal with a very complex dynamic many-body problem. Because of these difficulties, there have so far been neither theoretical nor numerical studies that take into account the full static and dynamic coupling among the motions of these three key elements of colloidal suspensions, despite the scientific