%0 Journal Article
%T Chemical-Physical Characterization of a Binary Mixture of a Twist Bend Nematic Liquid Crystal with a Smectogen
%+ Laboratoire Charles Coulomb (L2C)
%+ Physique des Systèmes Complexes - UR UPJV 4663 (PSC)
%+ Département Optique (IMT Atlantique - OPT)
%+ Laboratoire de Physique des Solides (LPS)
%A Aouini, Abir
%A Nobili, Maurizio
%A Chauveau, Edouard
%A Dieudonne-George, Philippe
%A Dameme, Gauthier
%A Stoenescu, Daniel
%A Dozov, Ivan
%A Blanc, Christophe
%< avec comité de lecture
%Z L2C:20-181
%@ 2073-4352
%J Crystals
%I MDPI
%V 10
%N 12
%P 1110
%8 2020-12
%D 2020
%R 10.3390/cryst10121110
%K liquid crystals
%K nematic twist-bend
%K binary mixtures
%K nematic elastic constants
%Z Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
%Z Engineering Sciences [physics]/MaterialsJournal articles
%X Nematic twist-bend phases (N-TB) are new types of nematic liquid crystalline phases with attractive properties for future electro-optic applications. However, most of these states are monotropic or are stable only in a narrow high temperature range. They are often destabilized under moderate cooling, and only a few single compounds have shown to give room temperature N-TB phases. Mixtures of twist-bend nematic liquid crystals with simple nematogens have shown to strongly lower the nematic to N-TB phase transition temperature. Here, we examined the behaviour of new types of mixtures with the dimeric liquid crystal [4 ',4 '-(heptane-1,7-diyl)bis(([1 ',1 ''-biphenyl]4 ''-carbo-nitrile))] (CB7CB). This now well-known twist-bend nematic liquid crystal presents a nematic twist-bend phase below T approximate to 104 degrees C. Mixtures with other monomeric alkyl or alkoxy -biphenylcarbonitriles liquid crystals that display a smectic A (SmA) phase also strongly reduce this temperature. The most interesting smectogen is 4 '-Octyl-4-biphenylcarbonitrile (8CB), for which a long-term metastable N-TB phase is found at room and lower temperatures. This paper presents the complete phase diagram of the corresponding binary system and a detailed investigation of its thermal, optical, dielectric, and elastic properties.
%G English
%2 https://hal.science/hal-03113887/document
%2 https://hal.science/hal-03113887/file/crystals-10-01110-v3.pdf
%L hal-03113887
%U https://hal.science/hal-03113887
%~ INSTITUT-TELECOM
%~ CNRS
%~ UNIV-PICARDIE
%~ L2C
%~ UNIV-PARIS-SACLAY
%~ MIPS
%~ UNIV-MONTPELLIER
%~ IMTA_OPT
%~ IMT-ATLANTIQUE
%~ INSTITUTS-TELECOM
%~ TEST-HALCNRS
%~ UNIVERSITE-PARIS-SACLAY
%~ GS-CHIMIE
%~ GS-PHYSIQUE
%~ GS-LIFE-SCIENCES-HEALTH
%~ INSTITUT-SCIENCES-LUMIERE
%~ U-PICARDIE
%~ PSC
%~ LPSO
%~ URP-LPS
%~ UM-2015-2021