Kumacheva Eugenia, Garstecki Piotr, Wu Hongkai, Whitesides George M
Chemistry & Chemical Biology Department, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2003 Sep 19;91(12):128301. doi: 10.1103/PhysRevLett.91.128301.
This Letter describes the generation of 2D colloidal lattices in microchannels by coupling the laminar flow of dispersions of spherical colloids and geometrical confinement. We describe a nonequilibrium, convective, mechanism leading to formation of ordered 2D structures of both closed-packed hexagonal and non-closed-packed rhombic symmetries. The number and types of possible lattices is determined by the ratio of the width of the channel to the diameter of the particle. The structures tend to return to a regular lattice after a defect is introduced; that is, for example, they tend to self-repair disorder induced by particle polydispersity, contaminants, and flow instabilities. The stability of different lattices is analyzed numerically for particles with different polydispersity.
本信函描述了通过耦合球形胶体分散体的层流与几何限制，在微通道中生成二维胶体晶格的过程。我们描述了一种非平衡对流机制，该机制导致形成具有密排六边形和非密排菱形对称的有序二维结构。可能的晶格数量和类型由通道宽度与颗粒直径的比值决定。在引入缺陷后，这些结构倾向于恢复到规则晶格；也就是说，例如，它们倾向于自我修复由颗粒多分散性、污染物和流动不稳定性引起的无序。针对具有不同多分散性的颗粒，对不同晶格的稳定性进行了数值分析。
