Structural Phase Transition in Liquid Crystal Doped with Gold Nanoparticles

Kopčanský, P.; Tomašovičová, Natália; Koneracká, M.; Τimko, M.; Mitróová, Z.; Závišová, V.; Éber, Nándor; Fodor‐Csorba, Katalin; Tóth-Katona, Tibor; Vajda, A.; Jadżyn, Jan; Beaugnon, Eric; Chaud, X.

doi:10.12693/aphyspola.118.988

Cited by 25 publications

(11 citation statements)

References 6 publications

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“…In particular, this results in a decrease of switching voltages and reduction of the switching times of LC displays (see, for example, refs. For example, a decrease of the N-I transition temperature is observed in nematics doped with approximately isotropic silver, [10] gold, [11] or aerosil particles, [12,13] while the N-I transition temperature increases if the nematic LC is doped with strongly anisotropic NPs including nanotubes, [14] magnetic nanorods, [15] and ferroelectric particles. Also, nematics doped with ferroelectric NPs are characterized by an enhanced dielectric and optical anisotropy, increased electro-optic response, [7,8] and improved photorefractive properties.…”

Section: Introductionmentioning

confidence: 99%

Molecular Theory of Phase Separation in Nematic Liquid Crystals Doped with Spherical Nanoparticles

Osipov

Gorkunov

2014

ChemPhysChem

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A molecular-statistical theory is developed, which enables one to describe the nematic-isotropic phase transition in liquid crystals doped with spherical nanoparticles taking into account the effects of phase separation. It has been shown that in the case of strong interaction between nanoparticles and mesogenic molecules the nematic nanocomposite possesses a number of unexpected properties. In particular, the nematic-isotropic co-existence region appears to be very broad, and the system either undergoes a direct transition from the isotropic phase into the phase-separated state, or undergoes the transition into the homogeneous nematic phase first and then phase-separates at a lower temperature. Phase separation does not occur at all if the concentration of the nanoparticles is sufficiently low, and in some cases it takes place only within a finite region of nanoparticle concentration. A number of temperature-concentration phase diagrams is presented and the molar fractions of nanoparticles in the co-existing isotropic and nematic phases are calculated numerically as functions of temperature.

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Section: Introductionmentioning

confidence: 99%

Molecular Theory of Phase Separation in Nematic Liquid Crystals Doped with Spherical Nanoparticles

Osipov

Gorkunov

2014

ChemPhysChem

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“…Indeed, the nematic-isotropic (N-I) phase transition temperature is decreased when the nematic liquid crystal is doped with isotropic silver [14], gold [15] or aerosil [16,17] NPs . At the same time, doping with strongly anisotropic NPs leads to an increase of the N-I transition temperature, which has been observed using nanotubes [18], magnetic nanorods (NRs) [19], and ferroelectric NPs [7,8].…”

Section: Introductionmentioning

confidence: 99%

Phase behavior and orientational ordering in block copolymers doped with anisotropic nanoparticles

et al. 2018

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This version is available at https://strathprints.strath.ac.uk/64399/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output.Phase behaviour and orientational ordering in block copolymers doped with anisotropic nanoparticles. A molecular field theory and coarse grained computer simulations with dissipative particle dynamics have been used to study the spontaneous orientational ordering of anisotropic nanoparticles in the lamellae and hexagonal phases of diblock copolymers and the effect of nanoparticles on the phase behaviour of these systems. Both a molecular theory and computer simulations indicate that strongly anisotropic nanoparticles are ordered orientationally mainly in the boundary region between the domains, and the nematic order parameter possesses opposite signs in adjacent domains. The orientational order is induced by the boundary and by the interaction between nanoparticles and the monomer units in different domains. In simulations, sufficiently long and strongly selective nanoparticles order also inside the domains. Nematic order parameter and local concentration profiles of nanoparticles have been calculated numerically using the model of a nanoparticle with two interaction centres and also determined using the results of computer simulations. A number of phase diagrams have been obtained which illustrate the effect of nanoparticle selectivity and molar fraction of the stability ranges of various phases. Different morphologies have been identified by analysing the static structure factor and a phase diagram has been constructed in coordinates nanoparticle concentration -copolymer composition. Orientational ordering of even a small fraction of nanoparticles may result in a significant increase of the dielectric anisotropy of a polymer nanocomposite which is important for various applications.

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“…Recently, it has been experimentally shown that the nematic-isotropic (N-I) phase transition temperature can be affected by the presence of various NPs. For example, a decrease of the N-I transition temperature is observed when the nematic phase is doped with isotropic silver [11], gold [12] or aerosil particles [13,14], while the N-I transition temperature increases if the nematic LC is doped with strongly anisotropic NPs including nanotubes [15], magnetic nanorods [16] and ferroelectric particles [17,18]. Recently a molecular-field theory of nematic LCs doped with both isotropic and anisotropic NPs has been developed [19] which enables one to describe the shift of the transition temperature and the effect of the orientational order of the anisotropic NPs on the nematic order of the host phase.…”

Section: Introductionmentioning

confidence: 99%