کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5190980 | 1381223 | 2006 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Photoinduced optical anisotropy and reorientation in copolymers containing 4-methoxyazobenzene side groups and methyl methacrylate units using linearly polarized 633Â nm light
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Liquid crystalline (LC) and non-LC copolymers that contain 4-methoxyazobenzene side groups and methyl methacrylate units were synthesized to compare the photoinduced reorientation behavior using the polarization absorption spectra of thin films. Irradiating with non-polarized 365Â nm light saturated the Z-isomer in the copolymer films and subsequent exposure to a linearly polarized (LP) 633Â nm light generated a photoinduced optical anisotropy (ÎA) for all Z-isomer films based on an axis-selective Z-to-E photoisomerization. When a copolymer did not exhibit a LC nature, ÎA gradually increased until 60-80Â mol% of the Z-isomers isomerized to the E-isomers, but decreased upon further photoisomerization reaction. On the other hand, the magnitude of the photoinduced ÎA of a film continuously increased for LC copolymers until E-isomer formation was saturated. Thermal amplification of the photoinduced ÎA was observed for LC copolymers, but the thermal treatment resulted in the disappearance of the photoinduced ÎA for the non-LC copolymers. The axis-selective Z-to-E photoisomerization that preserves the direction of the transition moment of both isomers caused the photoinduced ÎA and increased the liquid crystalline nature of the film during the Z-to-E photoisomerization to induce the self-organization of the mesogenic groups.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 47, Issue 7, 22 March 2006, Pages 2322-2329
Journal: Polymer - Volume 47, Issue 7, 22 March 2006, Pages 2322-2329
نویسندگان
Emi Uchida, Nobuhiro Kawatsuki,