Graduate Student Oral Session (I) (English)
[O7-2]
우수논문발표상 응모자Electric-Field-Assisted Self-Healable Alignment and π–π-Stabilized Mesophases in Azobenzene-containing LC BCPs
발표자김준수 (연세대학교)
연구책임자류두열 (연세대학교)
Abstract
Azobenzene-containing amorphous–liquid crystalline block copolymers, polydimethylsiloxane-b-poly((4(phenyldiazenyl)phenoxy)hexyl acrylate) (PDMS-b-PPHA): fixed chemical composition, PPHA volume fraction varied to tune light-enabled behavior and mesophases. UV irradiation triggers trans–cis isomerization, yielding photodielectric/photoplastic responses: dielectric constant increases and the Tg of the PPHA block is reduced. Under an in-plane electric field, the matrix forms monodomains of aligned cylindrical microdomains; damage repairs microscale scratches, and visible light returns to a higher-Tg state. In addition, strong segregation and side-chain LC-driven π–π stacking of trans-azobenzene yield unconventional mesophases (A15, columnar rectangular, columnar hexagonal, and lamellar), including a Colr–Colh transition and highly asymmetric lamellae owing to conformational asymmetry.