Molecular theory of phase separation in nematic liquid crystals doped with spherical nanoparticles

Mikhail Osipov, Maxim Gorkounov

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

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.
LanguageEnglish
Pages1496-1501
Number of pages6
JournalChemPhysChem
Volume15
Issue number7
Early online date3 Mar 2014
DOIs
Publication statusPublished - 19 May 2014

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molecular theory
Nematic liquid crystals
Phase separation
liquid crystals
Nanoparticles
nanoparticles
Liquid Crystals
Temperature
Phase diagrams
Nanocomposites
nanocomposites
Phase transitions
phase diagrams
Molecules
temperature
molecules

Keywords

  • liquid crystals
  • molecular theory
  • nanoparticles
  • nematic phase
  • phase transition

Cite this

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Molecular theory of phase separation in nematic liquid crystals doped with spherical nanoparticles. / Osipov, Mikhail; Gorkounov, Maxim.

In: ChemPhysChem, Vol. 15, No. 7, 19.05.2014, p. 1496-1501.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Molecular theory of phase separation in nematic liquid crystals doped with spherical nanoparticles

AU - Osipov, Mikhail

AU - Gorkounov, Maxim

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AB - 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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