A first-principle mechanism for particulate aggregation and self-assembly in stratified fluids
A first-principle mechanism for particulate aggregation and self-assembly in stratified fluids
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DOI：
10.1038/s41467-019-13643-y
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发表时间：
2019-12-20
影响因子：
16.6
通讯作者：
McLaughlin, Richard M.
中科院分区：
文献类型：
--
作者：
Camassa, Roberto;Harris, Daniel M.;McLaughlin, Richard M.
自然界中一个极其广泛和重要的现象类别涉及流体系统中物质在重力作用下的沉降和聚集。在这里，我们观察和数学模型的一个意想不到的基本机制，悬浮在分层的颗粒可以自组装，形成大的聚集体没有粘附。这种现象是通过一个复杂的相互作用，涉及溶质扩散，不可渗透的边界，和聚集体的几何形状，产生环形流。我们表明，这些流动产生吸引力的水平力粒子之间在相同的高度。我们观察到，许多粒子表现出集体运动，揭示了一个系统，该系统似乎解决了拼图般的难题，并组织成一个大规模的圆盘状形状，随着集体圆盘半径的增加，有效力也随之增加。控制实验隔离的个人动态，这是定量预测的模拟。数值力计算与两个领域被用来建立多体模拟捕捉观察到的功能的自组装。
An extremely broad and important class of phenomena in nature involves the settling and aggregation of matter under gravitation in fluid systems. Here, we observe and model mathematically an unexpected fundamental mechanism by which particles suspended within stratification may self-assemble and form large aggregates without adhesion. This phenomenon arises through a complex interplay involving solute diffusion, impermeable boundaries, and aggregate geometry, which produces toroidal flows. We show that these flows yield attractive horizontal forces between particles at the same heights. We observe that many particles demonstrate a collective motion revealing a system which appears to solve jigsaw-like puzzles on its way to organizing into a large-scale disc-like shape, with the effective force increasing as the collective disc radius grows. Control experiments isolate the individual dynamics, which are quantitatively predicted by simulations. Numerical force calculations with two spheres are used to build many-body simulations which capture observed features of self-assembly.