Ionic Liquid Crystals Confined in Nanoporous Solids: Self-Assembly, Molecular Mobility and Electro-Optical Functionalities

限制在纳米多孔固体中的离子液晶：自组装、分子迁移率和电光功能

• 批准号: 430146019
• 负责人: Professor Dr. Patrick Huber
• 金额: --
• 依托单位: Institut für Organische Chemie (IOC)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/430146019?language=en
• 关键词: Ionic; Liquid; Crystals; Confined; Nanoporous

Ionic liquid crystals (ILC) bridge the gap between conventional liquid crystalline and ionic matter. Discotic columnar phases along with very high 1-D ion mobility in columnar phases have been found and studied with regard to potential functionalities. These functionalities depend strongly on the type of orientation and translation order. In principle, these orders can be optimized by embedding ILCs in nanostructured solid templates. However, very sparse knowledge is available about the effect of nanoconfinement on ILCs, even though it provides entirely novel self-assembly paths and thus electro-optical functionalities. Here we propose the exploration of the phase behavior of ionic liquid crystals in nanoporous solids and to relate it to the corresponding bulk phenomenology. It shall be scrutinized how the behavior changes as a function of pore-size and pore-surface chemistry, in particular with regard to hydrophilic and hydrophobic pore walls. To this end synchrotron-based X-ray diffraction, dielectric spectroscopy, calorimetry on ILCs confined in monolithic nanoporous silica, silicon and alumina membranes shall be performed. This will allow detailed insights in the structure and dynamics of the confined mesogens. The project particularly profits from the complementary expertise of the research groups involved, i.e. microscopic translational and orientational order (Huber), thermodynamics and molecular dynamics (Schoenhals) and tailored synthesis of ILCs (Laschat). Moreover, the functionalities with regard to optical anisotropy, optical activity, dielectric properties and electrical conductivity will be systematically explored and the mesogen interactions tailored with respect to mesophase formation and mesogen-pore wall interaction in order to optimize these functionalities. Specifically, we intend to explore ILCs forming discotic hexagonal phases with high charge carrier mobilities along the columnar axis. In addition, interactions of chiral ILCs with the pores will be studied regarding confinement-induced formation of chiral mesophases, absent in the bulk state. It is expected that by proper pore surface-grafting and pore-size selection optical and electrical functionalities can be tuned. The study is aimed at a fundamental understanding of the physical chemistry of confined ILCs, but also at the functionalities of the resulting hybrid materials, consisting of soft functional ILC fillings in monolithic solids providing mechanical stability.The successful realization of the project requires an intense cooperation between the three research groups because the chemical molecular structure (synthesis) determines the supermolecular structures and the molecular dynamics as well as the interaction with the confining walls in nanoporous solids. Besides the expected synergistic benefit on the scientific results the PhD students will significantly profit in their scientific education and from the cooperative spirit of this research project.

离子型液晶（ILC）弥补了传统液晶与离子型液晶之间的差距。已经发现并研究了在柱状相中具有非常高的1-D离子迁移率的离散柱状相沿着的潜在功能。这些功能在很大程度上取决于方向和翻译顺序的类型。原则上，可以通过将ILC嵌入纳米结构固体模板中来优化这些顺序。然而，非常稀疏的知识是可用的纳米约束的影响ILC，即使它提供了全新的自组装路径，从而电光功能。在这里，我们提出了探索的相行为的离子液体晶体在纳米多孔固体，并将其与相应的散装现象。应仔细检查性能如何随孔径和孔表面化学变化而变化，特别是关于亲水性和疏水性孔壁。为此，将对限制在单片纳米多孔二氧化硅、硅和氧化铝膜中的ILC进行基于同步加速器的X射线衍射、介电光谱、量热法。这将允许在结构和动力学的限制介晶的详细见解。该项目特别受益于所涉研究小组的互补专业知识，即微观平移和取向顺序（Huber），热力学和分子动力学（Schoenhals）以及ILC的定制合成（Laschat）。此外，光学各向异性，光学活性，介电性能和电导率方面的功能将被系统地探索和介晶相互作用定制相对于中间相的形成和介晶孔壁的相互作用，以优化这些功能。具体而言，我们打算探索ILC形成的dispersed六方相与高电荷载流子迁移率沿沿着的柱状轴。此外，手性离子液体与孔隙的相互作用将研究限制诱导形成的手性中间相，在本体状态下不存在。预计通过适当的孔表面接枝和孔径选择，可以调节光学和电学功能。这项研究的目的是从根本上了解限制离子液体的物理化学，但也在所得的杂化材料的功能，该项目的成功实现需要三个研究小组之间的密切合作，因为化学分子结构（合成）决定了纳米多孔固体中的超分子结构和分子动力学以及与限制壁的相互作用。除了对科学成果的预期协同效益外，博士生还将在他们的科学教育和本研究项目的合作精神中获益匪浅。