Heat-Triggered Crystallization of Liquid Crystalline Macrocycles Allowing for Conductance Switching through Hysteretic Thermal Phase Transitions
Langue
EN
Article de revue
Ce document a été publié dans
Chemistry-an Asian Journal. 2019, vol. 14, n° 1, p. 141-148
Résumé en anglais
A polymesomorphic thermal phase-transition of a macrocyclic amphiphile consisting of aromatic groups and oligoethylene glycol (OEG) chains is reported. The macrocyclic amphiphile exists in a highly-ordered liquid crystal ...Lire la suite >
A polymesomorphic thermal phase-transition of a macrocyclic amphiphile consisting of aromatic groups and oligoethylene glycol (OEG) chains is reported. The macrocyclic amphiphile exists in a highly-ordered liquid crystal (LC) phase at room temperature. Upon heating, this macrocycle shows phase-transition from columnar-lamellar to nematic LC phases followed by crystallization before melting. Spectroscopic studies suggest that the thermally induced crystallization is triggered by a conformational change at the OEG chains. Interestingly, while the macrocycle returns to the columnar-lamellar phase after cooling from the isotropic liquid, it retains the crystallinity after cooling from the thermally-induced crystal. Thanks to this bistability, conductance switching was successfully demonstrated. A different macrocyclic amphiphile also shows an analogous phase-transition behavior, suggesting that this molecular design is universal for developing switchable and memorizable materials, by means of hysteretic phase-transition processes.< Réduire
Mots clés en anglais
amphiphiles
isomerization
liquid crystals
macrocycles
polymorphisms
Unités de recherche