论文标题
由具有不同壳厚度的核心壳颗粒形成图案的三角形晶格模型
Triangular lattice models for pattern formation by core-shell particles with different shell thicknesses
论文作者
论文摘要
为了确定壳厚度和结构的效果，引入和研究了界面处的硬核软壳颗粒的三角形晶格模型。在模型I中，我们考虑了由交联聚合链壳覆盖的硬核的颗粒。在Model II中，这种内壳被一个柔软的外壳覆盖。在这两种模型中，硬芯都可以占据三角形晶格的位点，并且假定壳重叠后的邻居排斥。毛细作用力分别由模型I或II中的第二个或第五个邻居吸引力表示。对具有固定化学势$μ$或固定占用位点C的固定化学势的基态进行了详尽的研究。对于t> 0，$μ（C）$等温线，可压缩性和特定热量由Monte Carlo模拟计算。在模型II中，除了在模型I中发现的4个阶段外，还出现了6种有序的周期模式。但是，这些其他阶段仅在相位共存线上是稳定的，即在$（μ，t）$图的零度量区域中，否则看起来像模型I的图。计算出不同接口的表面张力，发现界面的有利方向对应于两个模型中其最平稳的形状。
Triangular lattice models for pattern formation by hard-core soft-shell particles at interfaces are introduced and studied in order to determine the effect of the shell thickness and structure. In model I, we consider particles with hard-cores covered by shells of cross-linked polymeric chains. In model II, such inner shell is covered by a much softer outer shell. In both models, the hard cores can occupy sites of the triangular lattice, and nearest-neighbor repulsion following from overlapping shells is assumed. The capillary force is represented by the second- or the fifth neighbor attraction in model I or II, respectively. Ground states with fixed chemical potential $μ$ or with fixed fraction of occupied sites c are thoroughly studied. For T > 0, the $μ(c)$ isotherms, compressibility and specific heat are calculated by Monte Carlo simulations. In model II, 6 ordered periodic patterns occur in addition to 4 phases found in model I. These additional phases, however, are stable only at the phase coexistence lines, i.e. in regions of zero measure at the $(μ,T)$ diagram which otherwise looks like the diagram of model I. In the canonical ensemble, these 6 phases and interfaces between them appear in model II for large intervals of c, and the number of possible patterns is much larger than in model I. We calculated surface tensions for different interfaces and found that the favorable orientation of the interface corresponds to its smoothest shape in both models.
