Large thermally irreversible photoinduced shift of selective light reflection in hydrazone-containing cholesteric polymer systems

0573328 - FZÚ 2024 RIV US eng J - Journal Article
Boychuk, A. - Shibaev, V. - Cigl, Martin - Hamplová, Věra - Novotná, Vladimíra - Bobrovsky, A.
Large thermally irreversible photoinduced shift of selective light reflection in hydrazone-containing cholesteric polymer systems.
ChemPhysChem. Roč. 24, č. 11 (2023), č. článku e202300011. ISSN 1439-4235. E-ISSN 1439-7641
R&D Projects: GA ČR(CZ) GC20-22615J
Institutional support: RVO:68378271
Keywords : cholesteric mesophase * helical twisting power * hydrazone photochrome * photoisomerization * photopatterning
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 2.9, year: 2022
Method of publishing: Limited access
https://doi.org/10.1002/cphc.202300011

In this work we synthesized and studied a comb-shaped hydrazone-containing copolyacrylate exhibited cholesteric liquid crystalline properties with the pitch length of the helix being tuned under irradiation with light. In the cholesteric phase selective light reflection in near IR spectral range was measured and large blue shift of reflection peak from 1650 nm to 500 nm was found under blue light irradiation. This shift is related to Z-E isomerization of photochromic hydrazone-containing groups and photochemically reversible. Improved and faster photooptical response was found after doping of copolymer with 10wt% of low-molar-mass liquid crystal. It is noteworthy that both isomers of the hydrazone photochromic group are thermally stable that enable to achieve pure photoinduced switch without any dark relaxation at any temperatures. Large photoinduced shift of the selective light reflection together with thermal bistability make such systems promising for the application in photonics.
Permanent Link: https://hdl.handle.net/11104/0343790