Structure and dynamics of nematic phases with strong smectic fluctuations formed by bent-core mesogens

具有非圆柱形介晶的Meschases表现出非常复杂的结构，在某些相中，具有非常快的电光响应，例如，由弯曲介晶的空间相互作用驱动的增强的极性和近晶涨落，导致形成对外场具有强烈敏感性的簇相。这种高响应性材料具有广阔的应用前景。介晶的形状也可以通过外部刺激如光致异构分子中的光来控制。这个建议是基于我们在马格德堡的小组和马丁路德大学有机化学系的广泛合作。Türkerske和M. Alaasar）。该提案的主要目的是研究光可调纳米结构对液晶在体积和受限几何形状下的微观和宏观性质的影响。我们打算研究复杂的液晶系统，如光开关介晶形成的液晶，扭曲弯曲的液晶相，与螺旋纳米结构，和新发现的极性液晶相，中心问题是如何的中间相的纳米结构和光刺激影响的体积和表面性质的液晶，它如何影响基于这些材料的胶体的行为。我们将研究液态晶体在块状、液滴和细丝中的行为。 拟议的研究将分五个阶段进行，从本体特性的表征开始，并将重点转移到纯光开关化合物和仅具有光开关表面的系统中的光驱动锚定跃迁的研究。我们将利用所获得的知识来理解LC基质中固体夹杂物的行为。胶体粒子的平移和旋转运动将被研究在铁电相、扭弯铁电相和铁电相。在最后阶段，我们将探讨具有光致液晶基元的液晶细丝的动力学。本研究的结果将阐明光驱动的介晶形状变化，结构形成和新的液晶系统的性能之间的相互作用的机制。

Mesophases with mesogens of non-cylindrical shapes exhibit remarkable complex structures and, in some phases, a very fast electro-optical response.Enhanced polar and smectic fluctuations, driven by steric interactions of bent mesogens, for instance, result in the formation of cluster phases with strong susceptibility to external fields. Such highly responsive materials have broad perspectives for applications. The shape of the mesogens can also be controlled by external stimuli such as light in photoisomerisable molecules. This proposal is based on the extensive collaboration between our group in Magdeburg and the Department of Organic Chemistry at Martin Luther University Halle (C. Tschierske and M. Alaasar). The proposal's primary aim is to investigate the effects of the photo-tuneable nanostructures on liquid crystals' micro and macroscopical properties in bulk and restricted geometry. We propose to study complex liquid crystalline systems such as photoswitchable mesogens forming nematic, twist-bend nematic phase, bent-core smectic phases with the heliconical nanostructure, and the newly discovered polar nematic phase.The central questions are how the nanostructure of the mesophase and photo-stimulation affect the bulk and surface properties of liquid crystals, how it affects the behaviour of colloids based on such materials. We will study the behaviour of liquid crystals in bulk, in droplets and filaments as well. The proposed research will be conducted in five stages, starting with the characterisation of the bulk properties and shifting the focus to the studies of light-driven anchoring transitions in pure photoswitchable compounds and systems with photoswitchable surfaces only. We will employ the acquired knowledge for understanding the behaviour of the solid inclusions in an LC matrix. The translational and rotational motions of colloidal particles will be investigated in the nematic, twist-bend nematic and ferroelectric nematic phases. At the final stage, we will explore the dynamics of liquid crystal filaments with photoismerisable mesogens. The output of this research will elucidate the mechanisms underlying the interplay between the light-driven mesogenic shape changes, structure formation and the properties of the novel liquid crystalline systems.