Theory of nonuniform complex liquids

非均匀复杂液体理论

• 批准号: 3445-2008
• 负责人: Sullivan, Donald
• 金额: $ 1.78万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=520583
• 关键词: Theory; nonuniform; complex; liquids

Most of the proposed research topics are extensions of ones which I have recently studied in the theory of polymeric liquid crystals (PLC). These materials are important due to their many applications, such as to LC display devices, nanolithography, and biological structures. My recent research has examined two complementary athermal models of the polymer chains, one based on a discrete microscopic model consisting of bonded hard-sphere chains, the other employing a continuum "wormlike-chain" representation of the molecules. In both models, excluded-volume interactions between the molecules which lead to liquid-crystalline ordering are taken into account by means of the Onsager second-virial approximation. A main focus has been to study smectic liquid-crystalline phases of these models, which have a layered morphology similar to that of lipid vesicles, and to understand the interplay between the interactions and the degree of molecular flexibility in the formation of these phases. We are also interested in the effects of a confined geometry on the phase boundaries, which is relevant to systems such as DNA confined within viruses. A variant of the work on confined systems has been concerned with the behaviour of free-standing smectic films, in particular the phenomena of layer-thinning transitions. The proposed research will extend my recent studies in the following ways: (1) revision of the numerical algorithms for solving both the wormlike-chain and the hard-sphere chain models, in order to apply these to molecules with physically realistic length-to-width ratios; (2) extension of our studies of confined systems (so far limited to liquids trapped between flat parallel walls) to other geometries, such as cylinders and spheres; (3) studies of the dynamics of layer-thinning transitions for films having 1st-order isotropic-smectic phase transitions. Mixed with these topics, we will also study various fundamental aspects such as the nature of boundary conditions at a wall, inclusion of high-density effects, and "self-interactions" between polymer chains in the wormlike model.

大多数提出的研究主题是我最近在聚合液晶理论（PLC）中研究的主题。这些材料由于其许多应用而很重要，例如LC显示器，纳米光刻和生物结构。我最近的研究检查了两个聚合物链的互补含量模型，一个基于一个离散的显微镜模型，该模型由键合的硬球链组成，另一个采用连续的“蠕虫状链”表示分子。在这两个模型中，通过Onsager二项近似值考虑了导致液晶排序的分子之间的排除体积相互作用。主要的重点是研究这些模型的近晶液结晶阶段，它们具有与脂质囊泡相似的分层形态，并了解相互作用与这些相形成中分子灵活性程度之间的相互作用。我们还对限制几何形状对相位边界的影响感兴趣，这与病毒中限制的DNA等系统有关。封闭系统上的工作的一种变体一直涉及独立式薄膜的行为，尤其是透明层的过渡现象。拟议的研究将通过以下方式扩展我的最新研究：（1）修订用于求解蠕虫链和硬球链模型的数值算法，以便将这些算法应用于具有物理上现实的长度宽度比的分子； （2）扩展我们对限制系统的研究（到目前为止，仅限于在平行壁之间被困在平行壁之间的液体）到其他几何形状，例如圆柱体和球体； （3）研究具有一阶各向同性 - 摩尔相过渡的膜的层粉状过渡的动力学。与这些主题混合在一起，我们还将研究各个基本方面，例如墙壁上边界条件的性质，高密度效应的包含以及聚合物链之间的“自相互作用”。