| Autor: |
Chaplanova, J., Larykava, S., Agabekov, V., Mikulich, V., Gracheva, E. |
| Předmět: |
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| Zdroj: |
Journal of Applied Spectroscopy; Sep2016, Vol. 83 Issue 4, p527-533, 7p |
| Abstrakt: |
Photoalignment of thin films of dipotassium 3,7-bis[1-(4-hydroxy-3-carboxylate)phenylazo]-5,5′-dioxodibenzothiophene (AtA-2) that were prepared by spin-coating of dye solutions in HO and DMF and aqueous solutions of polyvinylpyrrolidone (PVP) was studied. The UV absorption band of the dye cis-isomer, the position and intensity of which depended on the PVP concentration in the stock solutions, was recorded upon irradiation of films of AtA-2 in a PVP matrix [AtA-2(PVP)] with unfi ltered light from a DRT-1000 lamp in a vacuum or an Ar atmosphere. PVP facilitated trans-cis isomerization of AtA-2 and increased the stability of the cis-isomer with respect to thermal relaxation into the initial trans-isomer. The dichroic ratio (DR) of AtA-2(PVP) films irradiated with linearly polarized light (blue LED with λ = 450 nm, I = 15 mW/cm) increased by 1.5 times as the PVP concentration in the stock solutions increased from 1.0 to 10.0 mass%. The morphology and roughness of the films depended on the nature of the solvents used to prepare them. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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