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X-ray diffraction study of the smectic mesophase of some azobenzene-containing polyacrylates |
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| Authors: | Oriano Francescangeli Bin Yang Emo Chiellini Giancarlo Galli Annino Sante Angeloni Michele Laus |
| Affiliation: | 1. Dipartimento di Scienze dei Materiali e della Terra , Università di Ancona , Via Brecce Bianche, 60131 , Ancona , Italy;2. Istituto di Scienze Fisiche, Università di Ancona , Via Ranieri 65, 60131 , Ancona , Italy;3. Dipartimento di Chimica e Chimica Industriale , Università di Pisa , Via Risorgimento 35, 56126 , Pisa , Italy;4. Dipartimento di Chimica Industriale e dei Materiali , Università di Bologna , Viale Risorgimento 4, 40136 , Bologna , Italy |
| Abstract: | Abstract An X-ray study is performed on powder specimens and on stretched oriented fibres of two liquid crystalline polyacrylates containing the azobenzene mesogenic unit with either a 4′-n-pentyloxy (sample 1–4) or 4′-n-hexyloxy (sample 1–5) substituent. The X-ray diffraction patterns of both samples showed the presence of a bilayer smectic C mesophase with the mesogneic groups tilted by an angle β ～ 45° (1–4) or β ～ 38° (1–5) with respect to the layer normal. The electron density profile p(z) along the direction normal to the smectic layers was calculated by Fourier inversion and possible structural models of the smectic mesophase are discussed. A partial interdigitation of the terminal alkyloxy substituents appears to occur. |
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