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dc.contributor | Universitat Politècnica de Catalunya. Departament de Física |
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dc.contributor | Universitat Politècnica de Catalunya. DILAB - Laboratori de física dels materials dielèctrics |
dc.contributor | Universitat Politècnica de Catalunya. GRPFM - Grup de Recerca en Propietats Físiques dels Materials |
dc.contributor.author | Diego Vives, José Antonio |
dc.contributor.author | Sellarès González, Jordi |
dc.contributor.author | Díez Berart, Sergio |
dc.contributor.author | Salud Puig, Josep |
dc.contributor.author | Cañadas Lorenzo, Juan Carlos |
dc.contributor.author | Mudarra López, Miguel |
dc.contributor.author | López Pérez, David Orencio |
dc.contributor.author | de la Fuente Lavin, Maria Rosario |
dc.contributor.author | Ros, M Blanca |
dc.date | 2017-04-11 |
dc.identifier.citation | Diego, J., Sellarès, J., Diez, S., Salud, J., Cañadas, J.C., Mudarra, M., Lopez, D., de la Fuente, M., Ros, M. Influence of internal flexibility on the double glass transition in a series of odd non-symmetric liquid crystal dimers characterised by dielectric measurements. "Liquid crystals", 11 Abril 2017, vol. 44, núm. 6, p. 1007-1022. |
dc.identifier.citation | 0267-8292 |
dc.identifier.citation | 10.1080/02678292.2017.1309099 |
dc.identifier.uri | http://hdl.handle.net/2117/106422 |
dc.description.abstract | Dielectric measurements (thermally stimulated depolarisation currents and broadband dielectric spectroscopy) have been performed near the glass transition to study the glass transition on the odd non-symmetric liquid crystal (LC) dimers of the series -(4-cyanobiphenyl-4'-oxy)--(1-pyreniminebenzylidene-4'-oxy) alkanes (CBOnO.Py) with n ranging from 3 to 9. A previous study [S. Diez-Berart et al., Materials 8 (2015) 3334] carried out in CBO11O.Py showed the presence of two glass transition temperatures, attributed to different molecular motions of the terminal groups. The study performed allows us to analyse the molecular dynamics in the rest of the series and determine the role played by the flexible spacer. Parallel and perpendicular orientations of the molecular director with regards to the probe electric field have been investigated. The low and intermediate observed relaxations are explained in the framework of Stocchero's theoretical model [M. Stocchero, J. Chem. Phys. 121 (2004) 8079] for the dielectric behaviour of non-symmetric LCs dimers, as independent end-over-end rotations of each terminal semi-rigid unit. As the length of the spacer chain in the series of compounds decreases, the different relaxations become progressively more coupled at the glass transition. Numerical simulations of the calorimetric response from the obtained kinetic parameters show good agreement with experimental behaviour. |
dc.language.iso | eng |
dc.relation | http://www.tandfonline.com/doi/full/10.1080/02678292.2017.1309099 |
dc.rights | Attribution-NonCommercial-NoDerivs 3.0 Spain |
dc.rights | info:eu-repo/semantics/openAccess |
dc.rights | http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
dc.subject | Àrees temàtiques de la UPC::Física::Física de l'estat sòlid |
dc.subject | Dielectrics |
dc.subject | Solid state physics |
dc.subject | Solid state electronics |
dc.subject | Dimers |
dc.subject | Glass transition |
dc.subject | Thermally stimulated discharge currents |
dc.subject | Tool-Narayanaswamy-Moynihan model |
dc.subject | Relaxation time |
dc.subject | Broadband dielectric spectroscopy |
dc.subject | Differential scanning calorimetry |
dc.subject | Dielèctrics |
dc.subject | Física de l'estat sòlid |
dc.subject | Electrònica de l'estat sòlid |
dc.title | Influence of internal flexibility on the double glass transition in a series of odd non-symmetric liquid crystal dimers characterised by dielectric measurements |
dc.type | info:eu-repo/semantics/submittedVersion |
dc.type | info:eu-repo/semantics/article |