Sciortino F, Tartaglia P, Zaccarelli E
Dipartimento di Fisica and INFM-CRS-SOFT, Università di Roma La Sapienza, P. le A. Moro 2, 00185 Roma, Italy.
J Phys Chem B. 2005 Nov 24;109(46):21942-53. doi: 10.1021/jp052683g.
We report extensive numerical simulations of a simple model for charged colloidal particles in suspension with small nonadsorbing polymers. The chosen effective one-component interaction potential is composed of a short-range attractive part complemented by a Yukawa repulsive tail. We focus on the case where the screening length is comparable to the particle radius. Under these conditions, at low temperature, particles locally cluster into quasi one-dimensional aggregates which, via a branching mechanism, form a macroscopic percolating gel structure. We discuss gel formation and contrast it with the case of longer screening lengths, for which previous studies have shown that arrest is driven by the approach to a Yukawa glass of spherical clusters. We compare our results with recent experimental work on charged colloidal suspensions (Phys. Rev. Lett. 2005, 94, 208301).
我们报告了一个关于悬浮液中带电胶体粒子与小的非吸附性聚合物的简单模型的广泛数值模拟。所选择的有效单组分相互作用势由一个短程吸引部分和一个 Yukawa 排斥尾组成。我们关注屏蔽长度与粒子半径相当的情况。在这些条件下，在低温时，粒子局部聚集成准一维聚集体，这些聚集体通过分支机制形成宏观渗流凝胶结构。我们讨论凝胶的形成，并将其与屏蔽长度更长的情况进行对比，对于后者，先前的研究表明，粒子的聚集是由接近 Yukawa 球形团簇玻璃态驱动的。我们将我们的结果与最近关于带电胶体悬浮液的实验工作（《物理评论快报》2005 年，94 卷，208301 页）进行比较。
