Photochromic LC–polymer composites containing azobenzene chromophores with thermally stable Z-isomers

0435760 - FZÚ 2015 RIV GB eng J - Journal Article
Bobrovsky, A. - Shibaev, V. - Cigl, Martin - Hamplová, Věra - Hampl, F. - Elyashevitch, G.
Photochromic LC–polymer composites containing azobenzene chromophores with thermally stable Z-isomers.
Journal of Materials Chemistry C. Roč. 2, č. 22 (2014), s. 4482-4489. ISSN 2050-7526. E-ISSN 2050-7534
R&D Projects: GA ČR GA13-14133S; GA ČR(CZ) GAP204/11/0723
Institutional support: RVO:68378271
Keywords : liquid crystal * photosensitive * isomerization * polymer composite
Subject RIV: CC - Organic Chemistry
Impact factor: 4.696, year: 2014

Novel types of photochromic liquid crystalline (LC) polymer-based composites containing chiral photochromic azobenzene moieties were elaborated. For this purpose, a new chiral azobenzene-containing methacrylic monomer was synthesized. On one of the benzene rings of the azobenzene chromophore, there are methyl substituents in both positions ortho to the azo group. This substitution significantly increases the thermal stability of the photoinduced Z-form. The first type of novel photosensitive composite is a glass cell filled with cholesteric polymer-stabilized layers produced by thermal polymerization of a mixture containing a synthesized chiral photochromic azobenzene monomer, a nematic mixture of cyclohexane derivatives, mesogenic diacrylate and a thermal initiator. UV-irradiation of such samples leads to E–Z isomerization of the photochromic groups of the azobenzene monomer units, accompanied by a shift of the selective light reflection peak to a long wavelength spectral region
Permanent Link: http://hdl.handle.net/11104/0239572