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Sellarès J, Diego JA, López DO, Salud J, Robles-Hernández B, de la Fuente MR, Cañadas JC, Mudarra M, López de Rioja V, Levit R, Diez-Berart S. Comparative dielectric and thermally stimulated-depolarization-current studies of the liquid crystal dimers 1″,9″-bis(4-cyanobiphenyl-4'-yl) nonane and heptane and a binary mixture between them, close to the glass transition. Phys Rev E 2022; 106:054702. [PMID: 36559473 DOI: 10.1103/physreve.106.054702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/27/2022] [Indexed: 06/17/2023]
Abstract
We have performed dielectric spectroscopy and thermally stimulated-depolarization-current experiments to study the molecular dynamics of the twist-bend nematic phase close to the glass transition of two members of the 1″,7'-bis(4-cyanobiphenyl-4'-yl)alkane homologous series (CBnCB): the liquid crystal (LC) dimers CB9CB and CB7CB, as well as a binary mixture of both. By doping CB9CB with a small quantity of CB7CB, the crystallization is inhibited when cooling the sample down, while the bulk properties of CB9CB are retained and we can investigate the supercooled behavior close to the glass transition. The study reveals that the inter- and intramolecular interactions of the mixture are similar to those of pure CB9CB and confirms that there is a single glass transition in symmetric LC dimers.
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Affiliation(s)
- Jordi Sellarès
- DILAB, Departament de Física, E.S.E.I.A.A.T. Universitat Politècnica de Catalunya, Colom 11, 08222 Terrassa, Spain
| | - José Antonio Diego
- DILAB, Departament de Física, E.S.E.I.A.A.T. Universitat Politècnica de Catalunya, Colom 11, 08222 Terrassa, Spain
| | - David O López
- Grup de les Propietas Físiques del Materials (GRPFM), Departament de Física, E.T.S.E.I.B. Universitat Politècnica de Catalunya, Avinguda Diagonal, 647, 08028 Barcelona, Spain
| | - Josep Salud
- Grup de les Propietas Físiques del Materials (GRPFM), Departament de Física, E.T.S.E.I.B. Universitat Politècnica de Catalunya, Avinguda Diagonal, 647, 08028 Barcelona, Spain
| | - Beatriz Robles-Hernández
- Donostia International Physics Center, Manuel Lardizabal Ibilbidea 4, 20018 Donostia, Spain
- Departamento de Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apartado 644, E-48080 Bilbao, Spain
| | - María Rosario de la Fuente
- Departamento de Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apartado 644, E-48080 Bilbao, Spain
| | - Juan Carlos Cañadas
- DILAB, Departament de Física, E.S.E.I.A.A.T. Universitat Politècnica de Catalunya, Colom 11, 08222 Terrassa, Spain
| | - Miguel Mudarra
- DILAB, Departament de Física, E.S.E.I.A.A.T. Universitat Politècnica de Catalunya, Colom 11, 08222 Terrassa, Spain
| | - Victor López de Rioja
- Grup de les Propietas Físiques del Materials (GRPFM), Departament de Física, E.T.S.E.I.B. Universitat Politècnica de Catalunya, Avinguda Diagonal, 647, 08028 Barcelona, Spain
| | - Rafael Levit
- Caracterització Elèctrica dels Materials i Dispositius (CEMAD), Departament de Física, E.T.S.E.I.B. Universitat Politècnica de Catalunya, Avinguda Diagonal, 647, 08028 Barcelona, Spain
| | - Sergio Diez-Berart
- Grup de les Propietas Físiques del Materials (GRPFM), Departament de Física, E.T.S.E.I.B. Universitat Politècnica de Catalunya, Avinguda Diagonal, 647, 08028 Barcelona, Spain
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