A new mechanism for dendritic pattern formation in dense systems.
A new mechanism for dendritic pattern formation in dense systems.
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DOI：
10.1038/srep28960
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发表时间：
2016-06-29
影响因子：
4.6
通讯作者：
Kurita R
中科院分区：
文献类型：
--
作者：
Oikawa N;Kurita R
图案往往是在粒子聚集时形成的：由于图案反映了不同类型物质的连通性，图案的出现影响着系统的物理和化学性质，并与其宏观功能有着密切的关系。在许多系统中都观察到放射状树突图案（RDP），例如雪晶体、聚合物晶体和生物系统。尽管大多数这些系统被认为是致密颗粒悬浮液，但致密颗粒系统中 RDP 形成的机制尚不清楚。需要注意的是，扩散限制聚集模型不适用于稠密系统中的RDP形成，而是适用于稀颗粒系统中的RDP形成。在这里，我们提出了一个简单的模型，该模型展示了致密粒子系统中 RDP 的形成。粒子间相互作用的模型势由两部分组成：排斥力和吸引力。排斥力始终施加在所有粒子上，而吸引力仅施加在圆形域内的粒子之间，该圆形域以一定速度扩展为从预选中心传播的波前。研究发现，如果触发吸引相互作用的波前速度与聚集速度定义的时间尺度处于同一数量级，则形成RDP。
Patterns are often formed when particles cluster: Since patterns reflect the connectivity of different types of material, the emergence of patterns affects the physical and chemical properties of systems and shares a close relationship to their macroscopic functions. A radial dendritic pattern (RDP) is observed in many systems such as snow crystals, polymer crystals and biological systems. Although most of these systems are considered as dense particle suspensions, the mechanism of RDP formation in dense particle systems is not yet understood. It should be noted that the diffusion limited aggregation model is not applicable to RDP formation in dense systems, but in dilute particle systems. Here, we propose a simple model that exhibits RDP formation in a dense particle system. The model potential for the inter-particle interaction is composed of two parts, a repulsive and an attractive force. The repulsive force is applied to all the particles all the time and the attractive force is exerted only among particles inside a circular domain, which expands at a certain speed as a wave front propagating from a preselected centre. It is found that an RDP is formed if the velocity of the wave front that triggers the attractive interaction is of the same order of magnitude as the time scale defined by the aggregation speed.