Caprion D
Royal Meteorological Institute of Belgium, Brussels, Belgium.
Eur Phys J E Soft Matter. 2009 Mar;28(3):305-13. doi: 10.1140/epje/i2008-10412-6. Epub 2009 Feb 3.
We report Monte Carlo simulations of a model discotic molecule embedded in cylindrical pores. We consider a planar anchoring of the molecules on the surface for two different cylinder radii: R() = 5 and R() = 10 , in units of the molecular diameter. For both radii, we note that the system is progressively structured in concentric shells when decreasing the temperature. With the small radius, we observe continuous transitions from an isotropic to a nematic phase and then to a crystal one. The radius of the pores is sufficiently small to force the crystal to grow along their main axis. However some orientational discrepancies are observed: some samples present a zigzag configuration. With the big radius, the situation is more complex and it is likely that different scenarios are available. The crystals can be built along the main axis of the cylinders, as for the small radius, but also in any other direction. Thus we observe samples with different orientational domains. In the case of crystals oriented along the nanopore axis, we note that only the first 5 shells close to the wall are sensitive to it.
我们报告了嵌入圆柱形孔中的盘状分子模型的蒙特卡罗模拟。我们考虑了分子在表面的平面锚定，针对两种不同的圆柱半径：以分子直径为单位，(R^) = 5 和 (R^) = 10。对于这两种半径，我们注意到当降低温度时，系统在同心壳层中逐渐形成结构。对于小半径情况，我们观察到从各向同性相到向列相再到晶相的连续转变。孔的半径足够小，迫使晶体沿其主轴生长。然而，观察到一些取向差异：一些样品呈现锯齿形构型。对于大半径情况，情况更为复杂，可能存在不同的情形。晶体可以像小半径情况那样沿圆柱的主轴生长，也可以沿任何其他方向生长。因此，我们观察到具有不同取向域的样品。在晶体沿纳米孔轴取向的情况下，我们注意到只有靠近壁的前 5 个壳层对此敏感。
