Heat‐Triggered Crystallization of Liquid Crystalline Macrocycles Allowing for Conductance Switching through Hysteretic Thermal Phase Transitions |
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Authors: | Takahiro Muraoka Tatsuya Shima Takashi Kajitani Norihisa Hoshino Estelle Morvan Axelle Grlard Erick J Dufourc Takanori Fukushima Tomoyuki Akutagawa Kota Nabeya Kazushi Kinbara |
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Institution: | Takahiro Muraoka,Tatsuya Shima,Takashi Kajitani,Norihisa Hoshino,Estelle Morvan,Axelle Grélard,Erick J. Dufourc,Takanori Fukushima,Tomoyuki Akutagawa,Kota Nabeya,Kazushi Kinbara |
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Abstract: | 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. |
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Keywords: | amphiphiles isomerization liquid crystals macrocycles polymorphisms |
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