Journal ArticleDOI
The puzzle of the nematic-isotropic phase transition
TLDR
In this article, the authors present experimental and theoretical results for the critical behavior in the isotropic phase of nematogens and discuss the possibility of tricritical behavior at the nematic-isotropic transition.Abstract:
The low value of , where is the nematic-isotropic phase transition temperature and denotes the virtual transition temperature, is a long-standing puzzle in the physics of liquid crystals. The present review presents experimental and theoretical results on this long-standing problem. New experimental and theoretical results for the critical behaviour in the isotropic phase of nematogens are reviewed. We calculate in a unified approach the low value of , at both critical and tricritical points. The possibility of tricritical behaviour at the nematic-isotropic transition is also discussed by means of Landau theory. The various predictions are compared with the available experimental results.read more
Citations
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Journal ArticleDOI
Self-reporting and self-regulating liquid crystals
Young-Ki Kim,Xiaoguang Wang,Xiaoguang Wang,Pranati Mondkar,Emre Bukusoglu,Emre Bukusoglu,Nicholas L. Abbott +6 more
TL;DR: It is shown that a range of stimuli can trigger pulsatile (transient) or continuous release of microcargo (aqueous microdroplets or solid microparticles and their chemical contents) that is trapped initially within LCs.
Journal ArticleDOI
Critical behavior at the isotropic-to-nematic phase transition in a bent-core liquid crystal.
D. B. Wiant,Strahinja Stojadinovic,Krishna Neupane,Sunil K. Sharma,Katalin Fodor-Csorba,Antal Jakli,James T. Gleeson,Samuel Sprunt +7 more
TL;DR: Magnetic birefringence and dynamic light scattering measurements of orientational order parameter fluctuations at the isotropic-nematic phase transition of a bent-core liquid crystal reveal a pretransitional temperature dependence consistent with the standard Landau-deGennes mean field theory.
Journal ArticleDOI
Phase transitions from the isotropic liquid to liquid crystalline mesophases studied by linear and nonlinear static dielectric permittivity
TL;DR: Despite significant differences between N, Sm-A, and Sm-E phases the same pretransitional behavior of epsilon and NDE in the isotropic phase, described by critical exponents gamma = 1 and alpha = 0.5, was found.
Journal ArticleDOI
Quasicritical behavior of dielectric permittivity in the isotropic phase of smectogenic n-cyanobiphenyls
TL;DR: It was found that pressure first decreases the discontinuity of the transition, and that next a gradual rise appears, unlike the one observed for the isotropic-nematic transition, where only an increase of delta T with rising pressure was observed.
Journal ArticleDOI
Critical behavior and scaling relationships at the SmA(d)-N and N-I transitions in nonyloxycyanobiphenyl (9OCB).
TL;DR: It is proved that both phase transitions are weakly first order, displaying a nearly tricritical behavior, and the width of metastable regions seems to be dependent on the physical magnitude, although specific heat and volumetric determinations allow for comparable results.
References
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Book
The physics of liquid crystals
P. G. de Gennes,Richard Alben +1 more
TL;DR: In this paper, the authors define an order parameter statistical theories of the nematic order phenomonological description of the nematic-isotopic mixtures and describe the properties of these mixtures.
Journal ArticleDOI
Eine einfache molekular-statistische Theorie der nematischen kristallinflüssigen Phase. Teil II
Wilhelm Maier,Alfred Saupe +1 more
TL;DR: In this paper, the authors describe a mittlere Innere Feld einer nematischen Molekülanordnung abgeleitet, and gezeigt, daß this Innere Field in einem gewissen Temperaturbereich einen nematicalhen Ordnungszustand bewirken muß and daß dieser ordnung sustand was with einer bestimmten Temperatur diskontinuierlich und unter Energieaufnahme in die isot
Journal ArticleDOI
Physics of liquid crystals
TL;DR: In this article, the physical properties of nematic, cholesteric, and smectic liquid crystals are discussed and a wide variety of phenomena in liquid crystals, including elastic distortions, disclinations, flow properties, fluctuations, light scattering, wave propagation, nuclear magnetic resonance, effects of magnetic and electric fields, electrohydrodynamics, and optical properties.
Journal ArticleDOI
Eine einfache molekulare Theorie des nematischen kristallinflüssigen Zustandes
W. Maier,Alfred Saupe +1 more
Book
Introduction to Liquid Crystals
TL;DR: In this paper, the authors present a model of the Nematic-Isotropic phase transition and its relation to the elastic continuuum theory of liquid crystals, which is used to describe the properties of liquid crystal structures.