The Generation of Three-dimensional Anisotropies in Thin Polymer Films by Angular Selective Photoproduct Formation and Annealing
| Autor: | Joachim Stumpe, C. Christoph Jung, Regina Rosenhauer, Christian Kempe, Michael Rutloh |
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| Přispěvatelé: | Publica |
| Rok vydání: | 2005 |
| Předmět: |
chemistry.chemical_classification
Azo compound Materials science Polymers and Plastics Annealing (metallurgy) Organic Chemistry Polymer Polarization (waves) Molecular physics Inorganic Chemistry Photochromism chemistry.chemical_compound chemistry Polymer chemistry Materials Chemistry Side chain Thin film Anisotropy Computer Science::Databases |
| Zdroj: | Macromolecules. 38:4324-4330 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/ma0476846 |
| Popis: | Linearly polarized light can induce an order parallel to the polarization direction of light in polymer films containing different photochromic groups. In principle, this offers the possibility to generate prolate in-plane orders in polymer films. Two such photochemical processes are investigated in this paper. One of them is the irradiation of azobenzene-containing polymer films with linearly polarized red light after an unpolarized UV preirradiation step. The other one is the angular selective photocycloaddition of cinnamate-containing polymer films induced by linearly polarized UV light. Because in both cases the order is low after the irradiation, the liquid crystalline polymer films are annealed in their mesophase to modify the photoinduced order by thermotropic self-organization. The resulting threedimensional indicatrices, as determined by waveguide spectroscopy, are found to be prolate in-plane, biaxial, or homeatropic in dependence on the polymer structures, preparation conditions, and irradiation conditions of the films. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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