A supramolecular concept for stabilization of liquid crystalline blue phases – A first step towards 3D-photonic sensors

• Applicant: Professor Michael Giese, Ph.D.
• Subject Area: Organic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 417615610

Within the past decades, liquid crystalline blue phases have attracted tremendous scientific and commercial attention. These special types of chiral mesophases bear great application potential in liquid crystal displays and soft photonics. The use of these materials, however, remains limited due to the small temperature range in which blue phases are usually observed and a comprehensive understanding of structure-property relationships is missing. The research project aims to fill this gap by employing a modular approach for the investigation of hydrogen-bonded assemblies with liquid crystalline blue phases. The utilized method provides a simple synthetic access to a plethora of new liquid crystals and at the same time allows for systematic structure-property relationship studies due to the excellent comparability of the systems. Especially, the role of non-covalent interactions in the transfer of chirality into the mesophase and the stabilization of blue phases will be focus of the present project. In addition, the influence of the architecture of the supramolecular assemblies and the fluorination pattern will be investigated (phase 1). The results of these structure-property relationship studies will create the basis for first proof-of-principal studies towards application in the field of photo-tunable photonic reflectors and photonic sensors (phase 2). Thereby, the analyte might interfere with the hydrogen-bonds of the 3-dimensional photonic structure or react with the stilbazole based side chains (e.g. addition of chlorine or ozone). In the future the materials might be tested for the construction of dye-doped liquid crystal LASERs.

• DFG Programme: Research Grants