Date

Place

Room G (Room 306)
34. Ferroelectric LCs
August 20, 2015 (Thursday)
11:00 ~ 12:05

[34-3]
11:25 ~ 11:50
Title:[Invited] Supramolecular Liquid Crystals for Paintable Ferroelectrics
Fumito Araoka, Daigo Miyajima, Takuzo Aida (RIKEN CEMS, Japan), and Hideo Takezoe (Tokyo Inst. of Tech., Japan)
Abstract: Recently, we have discovered a novel ferroelectric liquid crystal (ferroelectric columnar LC: FCLC) phase in a self-organized supramolecular system of polar stacks of tapered-paraffinic-wedge molecules based on a phthalonitrile core structure. Unlike the conventional ferroelectrics including the crystalline inorganic solids and polymer films, supra-molecular LCs easily self-organize into large uniform ferroelectric domains in painted films or LC bulks as well as variety of forms such as nano-/micro-fibers and gels, which makes possible easy-fabrication of devices such as high-density memories, ferroelectric field-effect transistors, and organic photovoltaic cells.?Ferroelectricity in these wet-processed films was visualized with a relatively new nonlinear optical imaging technique, phase-sensitive second-harmonic generation (SHG) microscopy, enabling the mapping of the distribution of the spontaneous polarization as well as its directional sense. Besides, detailed switching behavior of the system was discussed with SHG response together with classical electric measurements. Stabilization mechanism of the spontaneous polarization and molecular dynamics of the ferroelectric switching have been investigated also with a nonlinear optical technique, infrared-visible sum-frequency generation (IV-SFG) spectroscopy which can probe resonant vibrational modes of molecular moieties packed in a non-centrosymmetric manner hereby contributing the ferroelectricity. These results are very important for further molecular design, particularly towards practical application.
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