Cutting-Edge Synchrotron Techniques for Polymer Structure and Property Analysis
발표 구분
초청강연
제목
Stimuli-Responsive Helical Columnar Liquid Crystals: From Ferroelectric Switching to Polymorphic E-field-chromism
발표자
조병기 (단국대학교)
연구책임자
조병기 (단국대학교)
공동저자
조병기 (단국대학교)
초록
내용
We present C3-symmetric star-shaped and C2-symmetric pyrene-cored hexacatenar liquid crystals consisting of triazole moieties, exhibiting hydrogen-bonded helical architectures with axial polarization. In the star-shaped system, GIWAXS analysis and helix simulations reveal a 51 helical column with an azimuthal rotation angle of 72°. This assembly enables RT-operable ferroelectric switching, offering potential for high-density ferroelectric random-access memory (FeRAM). Furthermore, in the hexacatenar system, we demonstrate an unprecedented RT-reversible polymorphic transformation between a metastable 81 helical columnar phase and a thermodynamically stable crystalline phase. This system exhibits mechanochromism, where mechanical pressure converts the blue-emissive crystalline phase into the green-emissive helical LC phase. Notably, this metastable polymorph can be reverted to the crystalline state via an AC E-field, a phenomenon termed “E-field-chromism.”