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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">bsuir</journal-id><journal-title-group><journal-title xml:lang="ru">Доклады БГУИР</journal-title><trans-title-group xml:lang="en"><trans-title>Doklady BGUIR</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">1729-7648</issn><issn pub-type="epub">2708-0382</issn><publisher><publisher-name>БГУИР</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.35596/1729-7648-2019-125-7-28-31</article-id><article-id custom-type="elpub" pub-id-type="custom">bsuir-2000</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>СЕКЦИЯ 1. ЖИДКИЕ КРИСТАЛЛЫ И ЭЛЕКТРООПТИЧЕСКИЕ ЭФФЕКТЫ</subject></subj-group></article-categories><title-group><article-title>PHOTOTUNABLE SELECTIVE REFLECTION OF CHOLESTERIC LIQUID CRYSTALS</article-title><trans-title-group xml:lang="en"><trans-title>PHOTOTUNABLE SELECTIVE REFLECTION OF CHOLESTERIC LIQUID CRYSTALS</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Chepeleva</surname><given-names>D. S.</given-names></name><name name-style="western" xml:lang="en"><surname>Chepeleva</surname><given-names>D. S.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Chepeleva Dominika Sergeevna, Junior researcher of the Laboratory “Materials and Technologies of LC Device”</p><p>220141, Republic of Belarus, Minsk city, st. F. Skoriny, 36</p><p>tel. +375 17 237-67-88</p></bio><bio xml:lang="en"><p>Chepeleva Dominika Sergeevna, Junior researcher of the Laboratory “Materials and Technologies of LC Device”</p><p>220141, Republic of Belarus, Minsk city, st. F. Skoriny, 36</p><p>tel. +375 17 237-67-88</p></bio><email xlink:type="simple">dominika.chepeleva@mail.ru</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Yakovleva</surname><given-names>A. S.</given-names></name><name name-style="western" xml:lang="en"><surname>Yakovleva</surname><given-names>A. S.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Junior researcher of the Laboratory “Materials and Technologies of LC Device”</p><p>220141, Republic of Belarus, Minsk city, st. F. Skoriny, 36</p><p>tel. +375 17 237-67-88</p></bio><bio xml:lang="en"><p>Junior researcher of the Laboratory “Materials and Technologies of LC Device”</p><p>220141, Republic of Belarus, Minsk city, st. F. Skoriny, 36</p><p>tel. +375 17 237-67-88</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Murauski</surname><given-names>A. A.</given-names></name><name name-style="western" xml:lang="en"><surname>Murauski</surname><given-names>A. A.</given-names></name></name-alternatives><bio xml:lang="ru"><p>PhD, Leading Researcher of the Laboratory “Materials and Technologies of LC Device”</p><p>220141, Republic of Belarus, Minsk city, st. F. Skoriny, 36</p><p>tel. +375 17 237-67-88</p></bio><bio xml:lang="en"><p>PhD, Leading Researcher of the Laboratory “Materials and Technologies of LC Device”</p><p>220141, Republic of Belarus, Minsk city, st. F. Skoriny, 36</p><p>tel. +375 17 237-67-88</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Kukhta</surname><given-names>I. N.</given-names></name><name name-style="western" xml:lang="en"><surname>Kukhta</surname><given-names>I. N.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Researcher of the Laboratory “Materials and Technologies of LC Device”</p><p>220141, Republic of Belarus, Minsk city, st. F. Skoriny, 36</p><p>tel. +375 17 237-67-88</p></bio><bio xml:lang="en"><p>Researcher of the Laboratory “Materials and Technologies of LC Device”</p><p>220141, Republic of Belarus, Minsk city, st. F. Skoriny, 36</p><p>tel. +375 17 237-67-88</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Muravsky</surname><given-names>A. A.</given-names></name><name name-style="western" xml:lang="en"><surname>Muravsky</surname><given-names>A. A.</given-names></name></name-alternatives><bio xml:lang="ru"><p>PhD, Assoc. Prof., head of the Laboratory “Materials and Technologies of LC Device”</p><p>220141, Republic of Belarus, Minsk city, st. F. Skoriny, 36</p><p>tel. +375 17 237-67-88</p></bio><bio xml:lang="en"><p>PhD, Assoc. Prof., head of the Laboratory “Materials and Technologies of LC Device”</p><p>220141, Republic of Belarus, Minsk city, st. F. Skoriny, 36</p><p>tel. +375 17 237-67-88</p></bio><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>Institute of Chemistry of New Materials NAS Belarus</institution></aff><aff xml:lang="en"><institution>Institute of Chemistry of New Materials NAS Belarus</institution></aff></aff-alternatives><pub-date pub-type="collection"><year>2019</year></pub-date><pub-date pub-type="epub"><day>06</day><month>12</month><year>2019</year></pub-date><volume>0</volume><issue>7 (125)</issue><issue-title>Спецвыпуск</issue-title><fpage>28</fpage><lpage>31</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Chepeleva D.S., Yakovleva A.S., Murauski A.A., Kukhta I.N., Muravsky A.A., 2019</copyright-statement><copyright-year>2019</copyright-year><copyright-holder xml:lang="ru">Chepeleva D.S., Yakovleva A.S., Murauski A.A., Kukhta I.N., Muravsky A.A.</copyright-holder><copyright-holder xml:lang="en">Chepeleva D.S., Yakovleva A.S., Murauski A.A., Kukhta I.N., Muravsky A.A.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://doklady.bsuir.by/jour/article/view/2000">https://doklady.bsuir.by/jour/article/view/2000</self-uri><abstract><p>The dependence of the helical pitch of a cholesteric liquid crystal based on a composite photosensitive chiral dopant (cChD) on the intensity of light irradiation was studied. The transmission spectra and the selective reflection spectra of cholesteric liquid crystal cells were measured. The concentration of the cChD additive is calculated, so that the peak of selective reflection and its rearrangement occurs in the visible range of the electromagnetic radiation spectrum (380-780 nm). The possibility of photo-control by shifting the peak of the selective reflection of the cChD additive was studied, when exposed to LEDs with wavelengths of 365 nm and 450 nm, while reducing or increasing the intensity, a change in the spiral pitch was observed. Depending on the light intensity, part of the molecules of the chiral additive containing the azo group underwent isomerization, i.e. molecules in the trans-form passed to the cis-form, which led to a spectral shift of the selective reflection peak. If a small intensity of the 365 nm LED was applied, then some of the molecules were forced to transition from the trans- to the cis-form, and then, when illuminated with a 450 nm LED, from the cisto the trans-form. After reversible rearrangement, the properties of cholesteric liquid crystal changes due to interaction with light, because under the influence of light, the equilibrium ratio of the trans- and cis-isomers of the molecules of the substance changed, which macroscopically changed the torsion force of the chiral additive. Using two LEDs of 365 nm and 450 nm with different emission spectra, a reversible control of the cChD selective reflection peak in the visible range was obtained. The maximum displacement occurred at approximately 145 nm.</p></abstract><trans-abstract xml:lang="en"><p>The dependence of the helical pitch of a cholesteric liquid crystal based on a composite photosensitive chiral dopant (cChD) on the intensity of light irradiation was studied. The transmission spectra and the selective reflection spectra of cholesteric liquid crystal cells were measured. The concentration of the cChD additive is calculated, so that the peak of selective reflection and its rearrangement occurs in the visible range of the electromagnetic radiation spectrum (380-780 nm). The possibility of photo-control by shifting the peak of the selective reflection of the cChD additive was studied, when exposed to LEDs with wavelengths of 365 nm and 450 nm, while reducing or increasing the intensity, a change in the spiral pitch was observed. Depending on the light intensity, part of the molecules of the chiral additive containing the azo group underwent isomerization, i.e. molecules in the trans-form passed to the cis-form, which led to a spectral shift of the selective reflection peak. If a small intensity of the 365 nm LED was applied, then some of the molecules were forced to transition from the trans- to the cis-form, and then, when illuminated with a 450 nm LED, from the cisto the trans-form. After reversible rearrangement, the properties of cholesteric liquid crystal changes due to interaction with light, because under the influence of light, the equilibrium ratio of the trans- and cis-isomers of the molecules of the substance changed, which macroscopically changed the torsion force of the chiral additive. Using two LEDs of 365 nm and 450 nm with different emission spectra, a reversible control of the cChD selective reflection peak in the visible range was obtained. The maximum displacement occurred at approximately 145 nm.</p></trans-abstract><kwd-group xml:lang="ru"><kwd>cholesteric liquid crystals</kwd><kwd>selective reflection</kwd></kwd-group><kwd-group xml:lang="en"><kwd>cholesteric liquid crystals</kwd><kwd>selective reflection</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Alaverdyan R. B., Allahverdyan K. R., Gevorgyan A. A., Nersisyan S. TS, Chilingaryan A. D. The effect of selective reflection of light from a layer of cholesterol liquid crystal with induced inhomogeneity of the spiral step. Izvestiya NAS of Armenia, Physics. 2008: 43, 3: 174-181.</mixed-citation><mixed-citation xml:lang="en">Alaverdyan R. B., Allahverdyan K. R., Gevorgyan A. A., Nersisyan S. TS, Chilingaryan A. D. The effect of selective reflection of light from a layer of cholesterol liquid crystal with induced inhomogeneity of the spiral step. 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