| Autor: |
Bobrovsky, Alexey, Shibaev, Valery, Piryazev, Alexey, Anokhin, Denis V., Ivanov, Dimitri A., Sinitsyna, Olga, Hamplova, Vera, Kaspar, Miroslav, Bubnov, Alexej |
| Předmět: |
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| Zdroj: |
Macromolecular Chemistry & Physics; Aug2017, Vol. 218 Issue 16, p1-N.PAG, 10p |
| Abstrakt: |
Synthesis and investigation of the phase behavior and photo-optical properties of two chiral liquid-crystalline polymers with azobenzene-containing side groups having different spacer lengths, 6 and 10 methylene groups (PMAzo-6 and PMAzo-10, respectively) are described. Formation of different smectic phases and high-temperature cholesteric phase is studied by polarizing optical microscope, differential scanning calorimetry, and X-ray investigations. It is shown that UV-irradiation induces effective reversible E-Z photoisomerization in polymer solutions and films. Atomic force microscopy (AFM) study reveals substantial changes in the surface topography of the polymer PMAzo-6 film after UV-irradiation, whereas PMAzo-10 surface remains the same. Irradiation by polarized light (457 nm) results in photo-orientation process in polymer films consequential in significant alignment of the chromophores in direction perpendicular to the polarization plane of the incident light. A significant difference is found in thermal stability of the photoinduced alignment; an annealing of PMAzo-10 irradiated samples results in a slight decrease of dichroism values (down to 0.57); whereas the dichroism increases up to very high values (0.91) for PMAzo-6. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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