POS2-1131
Multi-Responsive Behaviors and Configurational Mesophases of Amorphous–Liquid Crystalline Block Copolymers Containing Azobenzene Units
Topic
S2. High-End Characterization/Polymer Physics/Properties
When and Where
Sep 29, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Hae Jung SON
Boseok KANG
Presenter(s)
SUHYEON BAEK (Yonsei University)
Co-Author(s)
Abstract
Various self-assembled morphologies can be observed amorphous–liquid crystalline (LC) polydimethylsiloxane-b-poly((4-(phenyldiazenyl)phenoxy)hexyl acrylate) (PDMS-b-PPHA) block copolymers, governed by conformational asymmetry and reversible photoisomerization of side-chain azobenzene units. A trans-to-cis isomerization upon UV irradiation, triggers photoplastic and photodielectric responses, significantly enhancing the dielectric constant of the PPHA matrix while reducing its glass transition temperature (Tg). In cylinder-forming structures, these behaviors enable macroscopic alignment along an in-plane electric field, while facilitating the self-healing of 300 nm-wide surface scratches at 40 °C. Concurrently, the configurational anisotropy of planar trans-isomers, driven by strong π-π stacking, stabilizes highly unconventional mesophases across varied compositions and temperatures. These mesophases manifest as A15, columnar rectangular (Colr), columnar hexagonal (Colh), and highly asymmetric lamellar (LAM) structures. Overall, these findings establish azobenzene-containing block copolymers as a versatile, configuration-tunable self-assembly platform. Both photoplastic and photodielectric behaviors enable precise macroscopic alignment and rapid defect repair, while side-chain anisotropic packing dictates the stabilization of nonclassical mesophases
