Dielectric relaxation in bulk and cylindrically confined octylcyanobiphenyl (8CB) |
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Authors: | Sergio Diez Miguel Ángel Pérez Jubindo David O. López Josep Salud Josep LI. Tamarit |
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Affiliation: | 1. Laboratori de Caracterització de Materials (LCM) , Departament de Física i Enginyeria Nuclear , E.T.S.E.I.B. Universitat Politècnica de Catalunya , Diagonal 647, 08028 Barcelona , Spain;2. Departamento de Física Aplicada II , Facultad de Ciencia y Tecnología , Universidad del País Vasco , Apdo. 644, 48080 Bilbao , Spain |
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Abstract: | The dielectric relaxation spectrum over the frequency range 102 to 1.8×109 Hz of 4‐octyl‐4′‐cyanobiphenyl, 8CB, in bulk and confined to 200 nm diameter cylindrical pores is reported. We used matrices with parallel cylindrical pores, obtaining different alignments of the molecular director depending on the treatment. Results show that there are two relaxations in the isotropic phase and in the mesophases for parallel alignment and three for perpendicular alignment. The molecular origin of theses modes and the effect of the confinement on their dynamics are discussed. To compare properly the results for bulk and confined 8CB, a re‐scaling of the experimental data is proposed. |
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Keywords: | liquid crystal nanocomposites cluster formation in liquid crystals electro-optics of nematics holography and liquid crystals |
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