Agarwal Amit K, Yethiraj Anand
Department of Physics and Physical Oceanography, Memorial University, St. John's, Newfoundland and Labrador, A1B 3X7, Canada.
Phys Rev Lett. 2009 May 15;102(19):198301. doi: 10.1103/PhysRevLett.102.198301. Epub 2009 May 11.
We study the low volume fraction and electric field phase behavior of a Brownian colloidal suspension. On the application of a uniform ac field, we find a novel phase where chains of particles aggregate to form a well defined cellular network, consisting of particle-free "voids" surrounded by a percolating network of particle-rich walls. This cellular structure is stable to very long times, indicative of an equilibrium thermodynamic phase. The cell-cell spacing is not sensitive to the concentration of the sample but scales with sample thickness. Any self-consistent mechanism for the existence of this void phase must consist of long-ranged repulsions and shorter-ranged attractions.
我们研究了布朗胶体悬浮液的低体积分数和电场相行为。在施加均匀交流电场时，我们发现了一种新的相，其中粒子链聚集形成一个定义明确的蜂窝状网络，该网络由无粒子的“空隙”组成，周围是富含粒子的壁的渗流网络。这种蜂窝状结构在很长时间内都是稳定的，这表明它是一个平衡热力学相。细胞间距对样品浓度不敏感，但与样品厚度成比例。这种空隙相存在的任何自洽机制都必须包括长程排斥和短程吸引。
