Structure and dynamics of ionic liquid crystals

• Applicants: Professor Dr. Frank Gießelmann; Professorin Dr. Sabine Laschat; Professor Dr. Andreas Taubert
• Subject Area: Preparatory and Physical Chemistry of Polymers ; Organic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 257901426

Ionic Liquid Crystals (ILCs) combine the extraordinary properties of ionic liquids with the anisotropy of conventional thermotropic liquid crystals. Being long-range ordered liquid electrolytes, they represent an extremely promising new class of materials. Like already in the first project phase, the general goal of our project is to provide a sound basis for the molecular understanding of ionic LCs, their structures and dynamics, and to identify and evaluate application-relevant aspects of ionic LCs on this basis. In terms of the molecular understanding of ionic LCs, the first project phase provided interesting new aspects that will be pursued in the second funding period. Specifically, these are (i) the existence of surprisingly strong pre-transition effects in the isotropic phase of ionic LCs, (ii) the relevance of ion-specific effects, which may be systematized by the Hofmeister series, and (iii) the relationship between ILCs and lyotropic liquid crystals. Using new series of ILCs to be synthesized, in which monovalent anions and cations of the respective Hofmeister series are systematically varied, the investigations of the second funding phase should clarify to what extent the properties and phase behaviour of ionic LCs can be systematized and understood by more general concepts from the fields of lyotropic liquid crystals (packing parameters), interionic interactions (Hofmeister series) or pre-transition phenomena. In addition to the molecular understanding of ionic LCs, application-relevant aspects of ionic LCs will receive increased attention in the second funding phase. The investigations planned for this purpose are primarily aimed at electrochemical applications of ILCs, in particular the transport properties of H+ and Li+ ions in thermotropic and possibly lyotropic ILC phases as well as the anisotropy of ionic charge transport in ILCs. The results of these investigations should allow a first evaluation of potential applications of ILCs as thermally and electrochemically stable electrolytes in batteries and (medium temperature) fuel cells.

• DFG Programme: Research Grants