Dynamic wetting phenomena in lattice models for nematic fluids/liquid crystals nearswitchable substrate potentials

使用理论方法和伴随的模拟，我们将研究可切换衬底附近的液晶。特别感兴趣的是不同润湿状态之间的润湿跃迁和开关的方法。作为一个模型系统，我们考虑具有短程吸引的晶格棒。我们已经发展并将进一步改进这些模型的经典密度泛函，并建立了合适的动态密度泛函理论。我们将计算向列相有序(直立或平卧)和近晶(可能有分层转变)薄膜的湿相图。特别令人感兴趣的是近晶层的形成动力学和不同取向的向列相润湿态之间的切换动力学。在这些过程中，几乎没有涉及到质量传输，因此我们预计类似于布朗动力学的晶格动力学可以很好地描述这些过程。我们将进行宏正则和动力学蒙特卡罗类型的补充模拟来衡量和验证理论结果。通过与实验小组的合作，对近晶层化和向列相润湿状态之间的转换的时间依赖性的结果进行了检验。

Using theoretical methods and accompanying simulations, we will investigate liquid crystals near switchable substrates. Of particular interest is the approach to wetting transitions and switches between different wetting states.As a model system, we consider lattice rods with short–range attractions. We have developed and will further improve classical density functionals for these models as well as formulate a suitable dynamic density functional theory.Wetting phase diagrams will be computed for nematically ordered (upright or lying–down) and smectic (with possible layering transitions) films. Of particular interest will be the dynamics of smectic layer formation and the switching dynamics between nematic wetting states of different orientation. In these processes, there is little mass transport involved and thus we expect that a lattice dynamics akin to Brownian dynamics can describe these well.Complementary simulations of grand canonical and kinetic Monte Carlo type will be performed to gauge and validate the theoretical results. Through collaborations with experimental groups the results on time–dependence of smectic layering and of the switching between nematic wetting states shall be tested.