Principles and applications of cyclodextrin liquid crystals

Cyclodextrin-based liquid crystals and their emerging applications are described in this tutorial review, which covers reports from the last decade with a focus on recent developments. Although cyclodextrins are among the best studied macrocyclic host molecules and liquid crystals have found widespread technological application, the integration of cyclodextrins in liquid crystals as versatile supramolecular materials has been barely explored. However, in the last few years promising innovations in molecular design as well as proof-of-concept applications such as ion-conductive and proton-conductive liquid crystals, nanoparticle additives for liquid crystal display technology, polyrotaxane-based liquid crystals and liquid crystal-based sensors have been reported. We discuss various examples of cyclodextrin-based liquid crystals that demonstrate the significant potential of these unique soft materials for future research and interdisciplinary applications. Cyclodextrin-based liquid crystals combine the versatile properties of macrocyclic host molecules and liquid-crystalline mesophases.