Browsing by Author "Díez Berart, Sergio"
Now showing items 1-18 of 18
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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
(American Institute of Physics (AIP), 2022-11-21)
Article
Restricted access - publisher's policyWe 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 ... -
Cooperative behavior of molecular motions giving rise to two glass transitions in the same supercooled mesophase of a smectogenic liquid crystal dimer
(American Chemical Society (ACS), 2018-01-17)
Article
Restricted access - publisher's policyIn the present work, a detailed analysis of the glassy behavior and the relaxation dynamics of the liquid crystal dimer a-(4-cyanobiphenyl-4'-yloxy)-¿-(1-pyrenimine-benzylidene-4'-oxy) heptane (CBO7O.Py) throughout both ... -
Cylindrical sub-micrometer confinement results for the odd-symmetric dimer alpha,omega-Bis[(4-cyanobiphenyl)-4 '-yloxy]undecane (BCB.O11)
(American Chemical Society (ACS), 2010-05-05)
Article
Restricted access - publisher's policyBroadband dielectric spectroscopy (102 Hz to 1.9 × 109 Hz) and specific heat measurements have been performed on the odd-symmetric dimer R,ω-bis[(4-cyanobiphenyl)-4′-yloxy]undecane (BCB.O11) in the isotropic (I) and ... -
Dispersion of gamma-alumina nano-sized spherical particles in a calamitic liquid Crystal. Study and optimization of the confinement effects
(2014-03-01)
Article
Open AccessWe report an experimental study on confined systems formed by butyloxybenzylidene octylaniline liquid crystal (4O.8) + gamma-alumina nanoparticles. The effects of the confinement in the thermal and dielectric properties ... -
Distinctive dielectric properties of nematic liquid crystal dimers
(2017-01-01)
Article
Open AccessWe provide an overview of the effect of the molecular structure on the dielectric properties of dimers exhibiting nematic and twist-bend nematic phases with special focus on how the conformational distribution changes are ... -
Dynamics of orientationally disordered mixed crystal sharing Cl-adamantane and CN-adamantane
(2010-01-27)
Article
Restricted access - publisher's policyOrientationally disordered (OD) mixed crystals formed between cyanoadamantane (CN-A) and chloroadamantane (Cl-A) have been thermodynamically characterized by means of thermal analysis and X-ray diffraction. The dynamics ... -
Influence of internal flexibility on the double glass transition in a series of odd non-symmetric liquid crystal dimers characterised by dielectric measurements
(2017-04-11)
Article
Open AccessDielectric 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 ... -
Influence of liquid crystalline phases on the tunability of a random laser
(American Chemical Society (ACS), 2017-05-30)
Article
Restricted access - publisher's policyIn this paper, we report the temperature behavior of an optimized disordered photonic system-based liquid crystal by means of heat capacity and refractive index measurements. The scattering system is formed by a porous ... -
Influence of the chain length on the nematic-to-isotropic phase transition for the odd members of a highly non-symmetric pyrene-based series of liquid crystal dimers
(2016-01-02)
Article
Restricted access - publisher's policyThis paper describes a detailed study of the nematic (N)-isotropic (I) phase transition in the homologous series of liquid crystal dimers, the a-(4-cyanobiphenyl-4'-oxy)-¿-(1-pyreniminebenzylidene-4'-oxy)alkanes (CBOnO.Py) ... -
Miscibility studies of two twist-bend nematic liquid crystal dimers with different average molecular curvatures. A comparison between experimental data and predictions of a Landau mean-field theory for the NTB-N phase transition
(2016-01-14)
Article
Open AccessWe report a calorimetric study of a series of mixtures of two twist-bend liquid crystal dimers, the 1'',7''-bis(4-cyanobiphenyl)-4'-yl heptane (CB7CB) and 1''-(2',4-difluorobiphenyl-4'-yloxy)-9''-(4-cyanobiphenyl-4'-yloxy) ... -
Molecular dynamics of a binary mixture of twist-bend nematic liquid crystal dimers studied by dielectric spectroscopy
(American Chemical Society (ACS), 2016-06-21)
Article
Open AccessWe report a comprehensive dielectric characterization of a liquid crystalline binary mixture composed of the symmetric mesogenic dimer CB7CB and the nonsymmetric mesogenic dimer FFO9OCB. In addition to the high-temperature ... -
Order parameters and time evolution of mesophases in the lyotropic chromonic liquid crystal Sunset Yellow FCF by DNMR
(2018-09-21)
Article
Open AccessUniaxial order parameters of the nematic and columnar mesophases in the lyotropic chromonic liquid crystal Sunset Yellow FCF have been determined from deuteron nuclear magnetic resonance, where random confinement of the ... -
Solid phases in cycloheptanol: dynamic disorder and glass transitions
(2009-12-15)
Article
Restricted access - publisher's policyThe stable solid polymorphism of cycloheptanol (C7H14O, for short C7–OH) is revised in the present paper. Four solid stable phases, denoted on cooling from the liquid as phases I, II, III and IV are identified from ... -
Study of the critical behavior and scaling relationships at the N-to-I phase transition in hexyloxycyanophiphenyl
(2009-10-07)
Article
Restricted access - publisher's policyAn exhaustive analysis of the critical behavior of the nematic to isotropic (N-to-I) phase transition on the liquid crystal hexyloxycyanobiphenyl (6OCB) has been performed. To do so, the accurate evolution of various physical ... -
Termodinámica básica : ejercicios
(Edicions UPC, 2006)
Book
Restricted access to UB, UAB, UPC, UPF, UdG, UdL, URV, UOC, BC, UVic, UJI, URL, UIC usersEste libro pretende ser una introducción a la termodinámica básica del equilibrio y se dirige especialmente a los alumnos de primer ciclo de ciencias y enseñanzas técnicas universitarias. La obra consta de un total de ... -
Twist, tilt, and orientational order at the nematic to twist-bend nematic phase transition of 1 '',9 ''-bis(4-cyanobiphenyl-4 '-yl) nonane: A dielectric, H-2 NMR, and calorimetric study
(2015-12-02)
Article
Open AccessThe nature of the nematic-nematic phase transition in the liquid crystal dimer 1 '',9 ''-bis(4-cyanobiphenyl-4'-yl) nonane (CB9CB) has been investigated using techniques of calorimetry, dynamic dielectric response measurements, ... -
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
(2015-06-01)
Article
Open AccessIn 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 ... -
Understanding the twist-bend nematic phase: the characterisation of 1-(4-cyanobiphenyl-4'-yloxy)-6-(4-cyanobiphenyl-4'--yl)hexane (CB6OCB) and comparison with CB7CB
(2016-08-28)
Article
Open AccessThe synthesis and characterisation of the nonsymmetric liquid crystal dimer, 1-(4-cyanobiphenyl-40-yloxy)-6- (4-cyanobiphenyl-40-yl)hexane (CB6OCB) is reported. An enantiotropic nematic (N)–twist-bend nematic (NTB) phase ...
