Xu Jianqing, Bedrov Dmitry, Smith Grant D, Glaser Matthew A
Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2009 Jan;79(1 Pt 1):011704. doi: 10.1103/PhysRevE.79.011704. Epub 2009 Jan 14.
Molecular dynamics simulations of spherical nanoparticles (NPs) in a nematogenic matrix of soft spherocylinders (SSCs) with equal NP diameter and SSC length were performed. The NPs were found to be dispersed in the isotropic SSC matrix. At higher pressure, the NP-SSC mixture demixed into a NP-poor nematic phase and a NP-rich isotropic phase over most of the composition range investigated. However, at low NP concentrations a single-phase nematic with dispersed NPs was observed, while at very high NP concentration no nematic phase was observed. When the NP-SSC interactions were changed to promote homeotropic anchoring, the matrix-induced interaction between NPs in the isotropic SSC matrix exhibited strong intermediate-range repulsion that was expected to result in even greater dispersion of NPs. However, many-body effects appear to dominate NP-NP interactions in the isotropic SSC matrix with homeotropic anchoring even at the lowest NP concentration investigated, resulting in suppression of the intermediate range repulsion leading to aggregation of the NPs.
对具有相等纳米颗粒（NP）直径和软球柱体（SSC）长度的向列型基质中的球形纳米颗粒进行了分子动力学模拟。发现纳米颗粒分散在各向同性的SSC基质中。在较高压力下，在所研究的大部分组成范围内，NP - SSC混合物分离成贫NP的向列相和富NP的各向同性相。然而，在低NP浓度下，观察到具有分散NP的单相向列相，而在非常高的NP浓度下未观察到向列相。当改变NP - SSC相互作用以促进垂直锚定时，各向同性SSC基质中NP之间的基质诱导相互作用表现出强烈的中程排斥力，预计这将导致NP的更大分散。然而，即使在研究的最低NP浓度下，多体效应似乎在具有垂直锚定的各向同性SSC基质中主导NP - NP相互作用，导致中程排斥力受到抑制，从而导致NP聚集。
