Browsing by Author "López Pérez, David Orencio"
Now showing items 1-20 of 22
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Bent-rod liquid crystal dimers: synthesis and mesomorphic properties
(Royal Society of Chemistry, 2014-01-01)
Article
Restricted access - publisher's policyThe synthesis and characterization of three bent-rod dimers are reported. Very long flexible spacers that include methylene units and either a phenyl ring or a triazole moiety as connecting structures join the bent-and ... -
Controllable coherent backscattering of light in disordered media filled with liquid crystal
(2018-05-09)
Article
Open AccessWe have investigated multiple scattering of light in a disordered system based on liquid crystals for a temperature-controllable random laser. Coherent backscattering measurements at several temperatures have been well ... -
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 ... -
Dielectric, calorimetric and mesophase properties of 1 ''-(2 ',4-difluorobiphenyl-4 '-yloxy)-9 ''-(4-cyano-biphenyl-4 '-yloxy) nonane: an odd liquid crystal dimer with a monotropic mesophase having the characteristics of a twist-bend nematic phase
(2014-10-21)
Article
Restricted access - publisher's policyThis paper reports a novel liquid crystal phase having the characteristics of a twist-bend nematic phase formed by a non-symmetric ether-linked liquid crystal dimer. The dimer 1 ''-(2',4-difluorobiphenyl-4'-yloxy)-9 ... -
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 ... -
Distortion-sensitive insight into the pretransitional behavior of 4-n-octyloxy-4 '-cyanobiphenyl (8OCB)
(Institute Of Physics Publishing Ltd, 2013-06)
Article
Restricted access - publisher's policyResults of studies of the static and dynamic dielectric properties in rod-like 4-n-octyloxy-40-cyanobiphenyl (8OCB) with isotropic (I)–nematic (N)–smectic A (SmA)–crystal (Cr) mesomorphism, combined with measurements of ... -
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) ... -
Liquid-crystalline hybrid materials based on (60) fullerene and bent-core structures
(2011-12-23)
Article
Restricted access - publisher's policyWhat a core-ker! By the appropriate combination of promesogenic bent-core structures and the C60 unit, lamellar polar liquid-crystal phases were induced (see scheme). The supramolecular organization of the functional ... -
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) ... -
Modeling and simulation of joint time-frequency properties of spectrum usage in cognitive radio
(2011)
Conference report
Restricted access - publisher's policyThe development of the Dynamic Spectrum Access/Cogni- tive Radio (DSA/CR) technology can signi cantly bene t from the availability of realistic models able to accurately capture and reproduce the statistical properties ... -
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 ... -
Self-assembly of Fmoc-tetrapeptides based on the RGDS cell adhesion motif
(2011-10-20)
Article
Restricted access - publisher's policySelf-assembly in aqueous solution has been investigated for two Fmoc [Fmoc = N-(fluorenyl)-9-methoxycarbonyl] tetrapeptides comprising the RGDS cell adhesion motif from fibronectin or the scrambled sequence GRDS. 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 ... -
Termodinàmica : problemes resolts
(Edicions UPC, 2000)
Book
Restricted access to the UPC academic communityAquest llibre vol oferir una col·lecció de 69 problemes multitemàtics als alumnes dels ensenyaments tecnològics i/o científics de primer cicle de les carreres universitàries que tenen l'assignatura de Termodinàmica. Així ... -
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, ...
