Raman Spectroscopy Evidence of Phototransformation in Poly (Vinyl-para-fluorocinnamate)

Barbet, F.; Bormann, D.; Warenghem, M.; Kurios, Yuri; Reznikov, Yuri; Khelifa, B.

doi:10.1080/10587259808024410

Cited by 6 publications

(1 citation statement)

References 11 publications

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“…Among the well-studied photoaligning materials are the polymers containing cinnamon acid derivatives in side fragments adjoined to different main chains (polyvinylalcohol, polysiloxane, cellulose). [2][3][4][5][6][7][8][9][10][11] The aligning properties of these materials are caused by anisotropic dimerization (cross-linking) of side fragments irradiated with polarized UV light, which can be accompanied by reversible trans-cis isomerization of the cinnamoyl fragments. Due to the strong absorption dichroism of the cinnamoyl groups, the first process results in anisotropic angular distributions of the crossed-linked cinnamoyl groups and of the remaining cinnamoyl fragments after irradiation with polarized UV light.…”

Section: Introductionmentioning

confidence: 99%

Anchoring and gliding of easy axis of 5CB on photoaligning PVCN‐F surface

Buluy¹,

Iljin²,

Ouskova³

et al. 2006

J Soc Info Display

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International audienceAbstract— The photoaligning properties of the popular photoaligning material polyvinyl-4(fluorocinnamate) (PVCN-F) are presented. The aligning quality and azimuthal and zenithal anchoring energy were measured and the drift of the easy orientation axis (gliding effect) on the PVCN-F surface, depending on UV exposure, was studied. Special attention is paid to unraveling the contribution of the adsorption liquid-crystal molecules onto the aligning surface to the anchoring properties of PVCNF and measuring the drift of the easy orientation axis over the PVCN-F surface. It is shown that a relatively weak azimuthal anchoring energy (Waz ∼ 10−7 − 10−5 J/m2) leads to strong drift of the easy axis in the azimuthal plane that was observed in a moderate (∼0.1–0.3 T) magnetic field. A much stronger polar anchoring (Wzen ∼ 10−4 J/m2) allowed us to observe the essential gliding of the easy axis in the zenithal plane in a rather strong electric field (∼5 V/μm)

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