Orientational Ordering of Dyes in the Glassy State of Liquid-Crystalline Side Group Polymers

Ringsdorf, Helmut; Schmidt, Hans‐Werner; Baur, G.; Windscheid, F.

doi:10.1080/02678298608086665

Cited by 38 publications

(5 citation statements)

References 12 publications

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“…[5] In contrast to these systems, photoaddressable polymers containing azobenzene moieties represent a class of rewriteable materials. These polymers were introduced by Ringsdorf et al [6,7] . Their applicability as a holographic data storage medium was…”

Section: Introductionmentioning

confidence: 99%

Dynamic Behavior of the Minority Phase of Photoaddressable Block Copolymers

Kreger

Löffler

Walker

et al. 2007

Macro Chemistry & Physics

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We present an analysis of the temperature‐dependent dynamic behavior of the minority phase of photoaddressable block copolymers. Solid‐state 2H NMR investigations are compared with holographic experiments. The samples are diblock copolymers based on polystyrene (PS) and poly(1,2‐butadiene) (PB), where the PB minority segment is functionalized with different deuterated moieties. Solid‐state 2H NMR investigations were performed from 320 to 380 K in order to study the thermal behavior of the minority segment. Holographic experiments on thin films of the block copolymers yielded the photoinduced diffraction efficiency at different temperatures. The comparison of both datasets enables us to identify the glass transition temperature Tg of the minority phase.magnified image

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Section: Introductionmentioning

confidence: 99%

Dynamic Behavior of the Minority Phase of Photoaddressable Block Copolymers

Kreger

Löffler

Walker

et al. 2007

Macro Chemistry & Physics

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show abstract

“…In contrast to these systems, which can only be written once, a rewritable class of materials consists of photoaddressable polymers (PAP) containing azobenzene moieties. Polymers with photoaddressable azobenzene side chains were first introduced by Ringsdorf et al , Their applicability to holographic data storage was described by various groups. − Over the years, many different polymer systems were synthesized and the photoinduced trans−cis−trans isomerization of the azobenzene chromophores was investigated also in view of an application in optical data storage. For instance, Hvilsted et al.…”

Section: Introductionmentioning

confidence: 99%

Blends of Poly(methacrylate) Block Copolymers with Photoaddressable Segments

et al. 2007

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The paper presents the synthesis of azobenzene-functionalized block copolymers based on a poly-(methyl methacrylate) (PMMA) segment and an azobenzene-functionalized poly(hydroxyethyl methacrylate) segment, and a basic study of blending these block copolymers with homopolymers is given. Two diblock copolymers, prepared via different routes, were synthesized by a living anionic polymerization followed by a polymer analogous reaction to attach the azobenzene side groups. Self-assembly of the block copolymers resulted in phase-separated morphologies on the nanometer scale. The photoaddressable azobenzene segments are dispersed in the PMMA matrix and locally confined. Special focus is given to the preparation and characterization of block copolymer blends with PMMA homopolymer in order to dilute the phase-separated azobenzene morphology and reduce the optical density while maintaining the confinement. The block copolymer blends were characterized with respect to their morphology and initial holographic experiments were performed.

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“…The motions cause a reorientation of the chromophores perpendicular to the polarization direction of the incident light. [4] Polymers with photoaddressable azobenzene side chains were first introduced by Ringsdorf et al [5,6] Over the years the photoinduced isomerization of the azobenzene chromophores and their application in holographic data storage was investigated by several groups. [7][8][9][10][11][12][13][14][15] Although photoaddressable polymers develop stable holographic gratings, they also bring up a series of issues, their slow writing times being the most important one.…”

Section: Introductionmentioning

confidence: 99%

Optimization of the photochromic response of photoaddressable polymers with azobenzene-containing molecular glasses

et al. 2009

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This paper reports on a new series of photochromic azobenzene-containing molecular glasses which are investigated as blending materials to improve the photochromic response of photoaddressable polymers. In order to identify potential candidates for blending, a variety of molecular glasses are synthesized and screened with respect to their photochromic response. Various end groups at the azobenzene chromophore and different core compounds are employed to obtain high thermal stability and good glass-forming properties as well as high sensitivity and refractive-index modulation. The best combination of structural variations is chosen to tailor a photoaddressable material with optimized physical and photophysical properties. By doping this photochromic molecular glass former into a photoaddressable polymer we are able to combine the high stability of polymer systems with the faster response of molecular glasses, thus creating a system which has the advantages of both material classes. With this approach we achieve an increase of the low photochromic sensitivity of the polymer, which is the biggest problem of these materials. In order to obtain a better understanding of the influence of the photochromic molecular glass former on the photochromic response in a polymer system we conduct holographic experiments on a concentration series of the glass former in an inert polymer matrix. By inscribing the holographic gratings at elevated temperatures we are able to increase the sensitivity of our molecular glass further.

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Orientational Ordering of Dyes in the Glassy State of Liquid-Crystalline Side Group Polymers

Cited by 38 publications

References 12 publications

Dynamic Behavior of the Minority Phase of Photoaddressable Block Copolymers

Dynamic Behavior of the Minority Phase of Photoaddressable Block Copolymers

Blends of Poly(methacrylate) Block Copolymers with Photoaddressable Segments

Optimization of the photochromic response of photoaddressable polymers with azobenzene-containing molecular glasses

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