Role of stringlike, supramolecular assemblies in reentrant supernematic liquid crystals.
Role of stringlike, supramolecular assemblies in reentrant supernematic liquid crystals.
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弦状超分子组装体在可重入超向列液晶中的作用
DOI：
10.1103/physreve.83.051704
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
M. Schoen
中科院分区：
文献类型：
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作者：
M. G. Mazza;M. Greschek;R. Valiullin;M. Schoen
采用等温等压蒙特卡罗和微正则分子动力学相结合的方法，利用盖-伯恩-基哈拉势研究了模型液晶在不同相中的结构与自扩散之间的关系。这些分子被限制在具有原子光滑基底表面的介观狭缝孔中。正如最近报道的那样[似乎]。G. Mazza，物理学家。PRLTAO0031-900710.1103/PhysRevLett.105.227802]，在足够高的压力和密度下，可形成重入向列相（RN）。该相具有高度的向列有序和在指向n∧方向上显著增强的自扩散率，比低密度的向列相和间断的近晶相高出约一个数量级。在这里，我们证明了在RN相中独特的输运行为可能与导致超分子、弦状构象形成的约束诱导的堆积效应有关。弦由沿n∧方向运动的几个分子组成，就像由分子“车”链组成的单个“火车”。
Using a combination of isothermal-isobaric Monte Carlo and microcanonical molecular dynamics we investigate the relation between structure and self-diffusion in various phases of a model liquid crystal using the Gay-Berne-Kihara potential. These molecules are confined to a mesoscopic slit pore with atomically smooth substrate surfaces. As reported recently [seeM. G. Mazza , Phys. Rev. Lett. 105, 227802 (2010)PRLTAO0031-900710.1103/PhysRevLett.105.227802], a reentrant nematic (RN) phase may form at sufficiently high pressures and densities. This phase is characterized by a high degree of nematic order and a substantially enhanced self-diffusivity in the direction of the director n∧ that exceeds that of the lower-density nematic and an intermittent smectic-phase by about an order of magnitude. Here we demonstrate that the unique transport behavior in the RN phase may be linked to a confinement-induced packing effect that causes the formation of supramolecular, stringlike conformations. The strings consist of several molecules traveling in the direction of n∧ as individual “trains” consisting of chains of molecular “cars.”