dc.contributor
Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear
dc.contributor
Universitat Politècnica de Catalunya. DILAB - Laboratori de física dels materials dielèctrics
dc.contributor.author
Díez Berart, Sergio
dc.contributor.author
López Pérez, David Orencio
dc.contributor.author
Salud Puig, Josep
dc.contributor.author
Diego Vives, José Antonio
dc.contributor.author
Sellarès González, Jordi
dc.contributor.author
Robles Hernández, Beatriz
dc.contributor.author
De la Fuente, Maria Rosario
dc.contributor.author
Blanca Ros, María
dc.date.issued
2015-06-01
dc.identifier
Diez, S., Lopez, D., Salud, J., Diego, J., Sellarès, J., Robles-Hernández, B., De la Fuente, M., Blanca Ros, M. Two glass transitions associated to different dynamic disorders in the nematic glassy state of a non-symmetric liquid crystal dimer dopped with gamma-alumina nanoparticles. "Materials", 01 Juny 2015, núm. 6, p. 3334-3351.
dc.identifier
https://hdl.handle.net/2117/76783
dc.identifier
10.3390/ma8063334
dc.description.abstract
In the present work, the nematic glassy state of the non-symmetric LC dimer -(4-cyanobiphenyl-4-yloxy)--(1-pyrenimine-benzylidene-4-oxy) undecane is studied by means of calorimetric and dielectric measurements. The most striking result of the work is the presence of two different glass transition temperatures: one due to the freezing of the flip-flop motions of the bulkier unit of the dimer and the other, at a lower temperature, related to the freezing of the flip-flop and precessional motions of the cyanobiphenyl unit. This result shows the fact that glass transition is the consequence of the freezing of one or more coupled dynamic disorders and not of the disordered phase itself. In order to avoid crystallization when the bulk sample is cooled down, the LC dimer has been confined via the dispersion of -alumina nanoparticles, in several concentrations.
dc.description.abstract
Postprint (published version)
dc.format
application/pdf
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
Àrees temàtiques de la UPC::Enginyeria dels materials::Materials plàstics i polímers
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Anàlisi espectral
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Liquid crystal
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Glass transition
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Modulated differential scanning calorimetry (MDSC)
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Dielectric spectroscopy
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Thermally stimulated depolarization currents
dc.subject
Spectrum analysis
dc.title
Two glass transitions associated to different dynamic disorders in the nematic glassy state of a non-symmetric liquid crystal dimer dopped with gamma-alumina nanoparticles
