Laboratoire des Matériaux Mésoscopiques et Nanométriques, U.M.R. C.N.R.S. 7070, Université Pierre et Marie Curie (Paris VI), BP. 52, 4, place Jussieu, 75230 Paris Cedex 05, France.
J Chem Phys. 2011 Sep 28;135(12):124502. doi: 10.1063/1.3638048.
Mesostructures formed by dipolar particles confined between two parallel walls and subjected to an external field are studied by Monte Carlo simulations. The main focus of the work is the structural behavior of the Stockmayer fluid in the low density regime. The dependence of cluster thickness and ordering is estimated as a function of density and wall separation, the two most influential parameters, for large dipole moments and high field strengths. The great sensitivity of the structure to details of the short-range part of the interactions is pointed out. In particular, the attractive part of the Lennard-Jones potential is shown to play a major role in driving chain aggregation. The effect of confinement, evaluated by comparison with results for a bulk system, is most pronounced for a short range hard sphere potential. No evidence is found for a novel "gel-like" phase recently uncovered in low density dipolar colloidal suspensions [A. K. Agarwal and A. Yethiraj, Phys. Rev. Lett. 102, 198301 (2009)].
介观结构由两个平行壁之间的偶极粒子形成，并受到外部场的作用，通过蒙特卡罗模拟进行研究。这项工作的主要重点是在低密度状态下 Stockmayer 流体的结构行为。作为密度和壁分离的函数，估计了团簇厚度和有序性的依赖性，这两个最具影响力的参数，适用于大偶极矩和高场强。结构对相互作用的短程部分细节的高度敏感性被指出。特别是，Lennard-Jones 势的吸引力部分在驱动链聚集方面起着重要作用。通过与体相系统的结果进行比较来评估限制的影响，对于短程硬球势最为明显。没有发现最近在低密度偶极胶体悬浮液中发现的新型“凝胶状”相的证据[ A. K. Agarwal 和 A. Yethiraj，Phys. Rev. Lett. 102, 198301 (2009)]。
