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dc.contributor.authorPaterson, Daniel A.
dc.contributor.authorGao, Min
dc.contributor.authorKim, Young-Ki
dc.contributor.authorRobles Hernández, Beatriz
dc.contributor.authorDíez Berart, Sergio
dc.contributor.authorSalud Puig, Josep
dc.contributor.authorLópez Pérez, David Orencio
dc.contributor.otherUniversitat Politècnica de Catalunya. Departament de Física
dc.date.accessioned2016-11-04T10:32:19Z
dc.date.available2016-11-04T10:32:19Z
dc.date.issued2016-08-28
dc.identifier.citationPaterson, D., Gao, M., Kim, Y., Robles-Hernández, B., Diez, S., Salud, J., Lopez, D. 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. "Soft matter", 28 Agost 2016, vol. 12, núm. 32, p. 6827-6840.
dc.identifier.issn1744-683X
dc.identifier.urihttp://hdl.handle.net/2117/91470
dc.description.abstractThe 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 transition is observed at 109 1C and a nematic–isotropic phase transition at 153 1C. The NTB phase assignment has been confirmed using polarised light microscopy, freeze fracture transmission electron microscopy (FFTEM), 2H-NMR spectroscopy, and X-ray diffraction. The effective molecular length in both the NTB and N phases indicates a locally intercalated arrangement of the molecules, and the helicoidal pitch length in the NTB phase is estimated to be 8.9 nm. The surface anchoring properties of CB6OCB on a number of aligning layers is reported. A Landau model is applied to describe high-resolution heat capacity measurements in the vicinity of the NTB–N phase transition. Both the theory and heat capacity measurements agree with a very weak first-order phase transition. A complementary extended molecular field theory was found to be in suggestive accord with the 2H-NMR studies of CB6OCB-d2, and those already known for CB7CB-d4. These include the reduced transition temperature, TNTBN/TNI, the order parameter of the mesogenic arms in the N phase close to the NTB–N transition, and the order parameter with respect to the helix axis which is related to the conical angle for the NTB phase.
dc.format.extent14 p.
dc.language.isoeng
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/3.0/es/
dc.subjectÀrees temàtiques de la UPC::Física::Física molecular
dc.subjectÀrees temàtiques de la UPC::Enginyeria química::Química física
dc.subject.lcshThermodynamics
dc.subject.lcshTransmission electron microscopy
dc.subject.lcshLiquid crystals
dc.subject.otherDimers
dc.subject.otherHexane
dc.subject.otherHigh resolution transmission electron microscopy
dc.subject.otherLiquid crystals
dc.subject.otherNematic liquid crystals
dc.subject.otherNuclear magnetic resonance spectroscopy
dc.titleUnderstanding the twist-bend nematic phase: the characterisation of 1-(4-cyanobiphenyl-4'-yloxy)-6-(4-cyanobiphenyl-4'--yl)hexane (CB6OCB) and comparison with CB7CB
dc.typeArticle
dc.subject.lemacTermodinàmica
dc.subject.lemacMicroscòpia electrònica de transmissió
dc.subject.lemacCristalls líquids
dc.identifier.doi10.1039/c6sm00537c
dc.rights.accessOpen Access
local.identifier.drac19242330
dc.description.versionPostprint (published version)
local.citation.authorPaterson, D.; Gao, M.; Kim, Y.; Robles-Hernández, B.; Diez, S.; Salud, J.; Lopez, D.
local.citation.publicationNameSoft matter
local.citation.volume12
local.citation.number32
local.citation.startingPage6827
local.citation.endingPage6840


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