Journal ArticleDOI
Thermotropic uniaxial and biaxial nematic and smectic phases in bent-core mesogens.
Reads0
Chats0
TLDR
Optical polarizing microscopy and synchrotron X-ray scattering studies of two azo substituted achiral bent-core mesogens reveal the existence of the thermotropic uniaxial and biaXial nematic and three smectic phases at different temperatures in these single component small molecule systems.Abstract:
Two azo substituted achiral bent-core mesogens have been synthesized. Optical polarizing microscopy and synchrotron X-ray scattering studies of both compounds reveal the existence of the thermotropic uniaxial and biaxial nematic and three smectic phases at different temperatures in these single component small molecule systems. The transition from the uniaxial to biaxial nematic phase is confirmed to be second order. The transitions from the biaxial nematic to the underlying smectic phase and between the smectic phases have barely discernible heat capacity signatures and thus are also second order.read more
Citations
More filters
Journal ArticleDOI
Biaxial nematic phases
TL;DR: An overview of the current state of research in the field of biaxial nematic liquid crystalline materials is given in this paper, where the major theoretical concepts are outlined, including the classification to different symmetries, the importance of cooperativity and cluster formation for the development of BN order and the conditions for the establishment of field induced and spontaneous BN in nematic phases.
Journal ArticleDOI
Nematic phases of bent-core mesogens
TL;DR: In this article, a temperature dependent stepwise transition from cybotactic nematic phases to different types of non-polar and tilted smectic phases (SmC(I) and SmC(II)) is observed with a mesophase composed of elongated, but not yet fused cybactic clusters (CybC) as an intermediate state of this transition.
Journal ArticleDOI
Bent-core liquid crystals in the route to functional materials
Jesús Etxebarria,M. Blanca Ros +1 more
TL;DR: Several results on bent-core liquid crystals considered as new supramolecular functional materials with potential for applications are reviewed in this article, where various topics are discussed where these materials present unique attributes with clear advantages over conventional mesogens.
Journal ArticleDOI
Insights into the cybotactic nematic phase of bent-core molecules
TL;DR: In this article, X-ray diffraction evidence for clusters exhibiting a skewed cybotactic supramolecular structure in the nematic phase of the butyloxy-phenyl diester, ODBP-Ph-OC4, a bent core mesogenic diester of the nonlinear diol 2,5-bis-(p-hydroxyphenyl)-1,3,4-oxadiazole (ODBP).
Journal ArticleDOI
Computer Simulations of Biaxial Nematics
TL;DR: An overview of the simulation work performed so far is given, and relying on the recent experimental findings, focuses on the still unanswered questions which will determine the future challenges in the field.
References
More filters
Journal ArticleDOI
Thermotropic biaxial nematic liquid crystals.
TL;DR: Polarized microscopy and conoscopy indicate that liquid crystal mesogens based on a nonlinear oxadiazole unit that exhibit nematic phases near 200 degrees C are biaxial nematics, and unambiguous and quantitative evidence for biaXiality is achieved using 2H NMR spectroscopy.
Journal ArticleDOI
Biaxial nematic phase in bent-core thermotropic mesogens.
TL;DR: The unique low-angle x-ray diffraction patterns in the nematic phases exhibited by three rigid bent-core mesogens clearly reveal their biaxiality.
Journal ArticleDOI
Biaxial nematic liquid crystals: fact or fiction?
TL;DR: A review of the thermotropic materials for which a biaxial nematic has now been claimed can be found in this article, where it is suggested that deuterium NMR spectroscopy is a powerful method with which to determine this.
Journal ArticleDOI
Liquid crystal phase transitions in mixtures of rodlike and platelike molecules
TL;DR: In this article, the character of the nematicisotropic phase transition can be continuously changed from first to second order and a new biaxial liquid crystal phase can be obtained by mixing suitable platelike and rodlike molecules.