Synthesis of aniline-based azopolymers for surface relief grating

Abstract

Epoxy-based azopolymers were synthesized by the reaction of the diglycidyl ether of bisphenol A (DGEBA) or N,N-diglycidyl aniline (DGA) with disperse orange 3 (DO3) to give poly(DGEBA-co-DO3) or poly (DGA-co-DO3), respectively. Aniline-based azopolymers prepared from poly(DGA-co-An) precursors, synthesized by the reaction of DGA with aniline, were produced by the post-azo coupling reaction with diazonium salts containing various substituents. Holographic gratings were carried out to measure the diffractive efficiencies (DE) for the interference patterns of the Ar + laser from 50 to 300 mW/cm 2 intensity. The shorter repeating unit with higher chromophore density induced deeper surface relief gratings (SRG). Large surface gratings were observed for the anilinebased azopolymers with -COOH substituents, as compared with those for epoxy-based azopolymers. The anilinebased azopolymers with dimerized chromophores and various substituents were also synthesized to observe the effect of chromophore substituents and dimerization on the holography. The dimerized chromophores were more sensitively photoisomerized by the Ar + laser beam, and demonstrated a larger grating than that with one azo bond.

Liquid‐crystalline azobenzene‐containing ferrocene‐based polymers: study on synthesis and properties of main‐chain ferrocene‐based polyesters with azobenzene in the side chain

“…The difference in the position of the MLCT band of the MFPAS is due to the difference in the electron‐withdrawing ability of R. The electron‐withdrawing ability of R in the MFPAS is in the order of polymer PPFD‐NT > PPFD‐CN > PPFD‐CA, and the MLCT band blue shifted in the same order. Similar behaviors were found by Qiu et al and He et al Moreover, the presence of the MLCT band in the UV–VIS absorption spectra of the MFPAS confirmed the successful post‐polymerization azo‐coupling reactions of PPFD …”

“…Both PPFD and MFPAS exhibited two absorption bands at 222 and 255 nm, which were attributed to the π–π* transition and the ring MO–MO* transition, respectively . In addition, the MFPAS possessed a broad absorption band around 450 nm that was assigned to the azo‐bond containing benzene ring . The metal‐to‐ligand charge transfer (MLCT) band was found at 469, 432, and 442 nm for PPFD‐NT, PPFD‐CA, and PPFD‐CN, respectively.…”

Surface properties, thermal behavior, and molecular simulations of azo-polysiloxanes under light stimuli. Insight into the relaxation

“…14 Owing to the photoisomerization, azo-based polymers are able to form SRGs through mass transport in inhomogeneous light fields. 7,8,12,13 The photo-induced flowing state of the macromolecular material at the supramolecular level, induces important physical properties modifications of film surfaces 23,24 and their thickness due to a photo-expansion effect. 25 These modifications are the results of three more or less concomitant physical processes: i) the variation of the azobenzene-groups dipole moment, through a photoinduced trans-cis isomerization; ii) the thermal backward cis-trans relaxation; iii) the re-ordering phenomenon that takes place at supramolecular level i.e.…”

“…The photo-induced isomerization process has very interesting potential applications, as e.g. surface relief gratings (SRGs) for holographic storage and optical switching, [7][8][9][10][11][12] in the field of the nanomanipulation of molecules, 13,14 those of the controlled drug delivery 5,6,15 and of the mechano-sensitive channels technology as well. 16 Moreover, due to the azo-groups dipole moment modification as a consequence of the transcis photo-isomerization process, polymers films having photoswitchable wettability can be obtained.…”

Study on the optimization of cationic ring opening polymerization of silicone-based epoxy monomers for holographic photopolymers

“…Recently, new photopolymer systems based on the sol-gel process, [11][12][13] or azopolymers 14,15 have been extensively studied for holographic application. Many researches have also focused on the photopolymers including the dual functional monomers such as epoxide and acrylate 16 or methacrylate.…”