Microphase-separated multicontinuous phase in low-molecular-mass thermotropic liquid crystals

Extensive application of chemical thermodynamics to exotic aggregation formed in thermotropic liquid crystals is briefly described. Through thermodynamic analyses and considerations of experimental results on liquid crystals, the unexpected sharing of common properties by thermo- and lyotropic liquid crystals is demonstrated. In some thermotropic liquid crystals, the terminal alkyl chain attached to the molecular core is highly disordered, as indicated by the magnitude of configurational entropy. The molten chain serves as intramolecular solvent (self-solvent), as evidenced by the close similarity between phase diagrams against chain length and composition in the binary system with n-alkane. These facts lead to the quasi-binary picture of thermotropic liquid crystals. Consideration of the thermodynamic potential expanded in terms of density fluctuation gives a new insight into the multicontinuous phases formed in simple systems consisting of anisotropic, rodlike particles.

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Novel Trends in Lyotropic Liquid Crystals

Crystals ◽

10.3390/cryst10070604 ◽

2020 ◽

Vol 10 (7) ◽

pp. 604 ◽

Cited By ~ 1

Author(s):

Ingo Dierking ◽

Antônio Martins Figueiredo Neto

Keyword(s):

Graphene Oxide ◽

Liquid Crystal ◽

Liquid Crystals ◽

Soft Matter ◽

Anisotropic Materials ◽

Lyotropic Liquid Crystals ◽

Electro Optic ◽

Thermotropic Liquid Crystals ◽

Active Liquid ◽

Biological Liquid

We introduce and shortly summarize a variety of more recent aspects of lyotropic liquid crystals (LLCs), which have drawn the attention of the liquid crystal and soft matter community and have recently led to an increasing number of groups studying this fascinating class of materials, alongside their normal activities in thermotopic LCs. The diversity of topics ranges from amphiphilic to inorganic liquid crystals, clays and biological liquid crystals, such as viruses, cellulose or DNA, to strongly anisotropic materials such as nanotubes, nanowires or graphene oxide dispersed in isotropic solvents. We conclude our admittedly somewhat subjective overview with materials exhibiting some fascinating properties, such as chromonics, ferroelectric lyotropics and active liquid crystals and living lyotropics, before we point out some possible and emerging applications of a class of materials that has long been standing in the shadow of the well-known applications of thermotropic liquid crystals, namely displays and electro-optic devices.

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Calculation of spectral shifts in UV–visible region and photo stability of thermotropic liquid crystals: Solvent and alkyl chain length effects

Journal of Molecular Liquids ◽

10.1016/j.molliq.2012.02.011 ◽

2012 ◽

Vol 169 ◽

pp. 110-116 ◽

Cited By ~ 4

Author(s):

P. Lakshmi Praveen ◽

Durga P. Ojha

Keyword(s):

Liquid Crystals ◽

Chain Length ◽

Alkyl Chain ◽

Visible Region ◽

Alkyl Chain Length ◽

Spectral Shifts ◽

Thermotropic Liquid Crystals ◽

Uv Visible ◽

Photo Stability ◽

Length Effects

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DETECTING PHASE EQUILIBRIA IN MODELS OF THERMOTROPIC AND LYOTROPIC LIQUID CRYSTALS

Modern Physics Letters B ◽

10.1142/s0217984993000230 ◽

1993 ◽

Vol 07 (04) ◽

pp. 217-232 ◽

Cited By ~ 8

Author(s):

ZHENGPING ZHANG ◽

OLE G. MOURITSEN ◽

MARTIN J. ZUCKERMANN

Keyword(s):

Phase Transitions ◽

Liquid Crystals ◽

Phase Equilibria ◽

Lipid Bilayer ◽

Finite Size ◽

Lyotropic Liquid Crystals ◽

Lyotropic Liquid Crystal ◽

Simulation Techniques ◽

Thermotropic Liquid Crystals ◽

Computer Simulation Techniques

New ways are discussed of numerically detecting the nature of phase transitions and the position of phase equilibria in models of thermotropic and lyotropic liquid crystals where the phase transitions are dominated by strong fluctuations. The cases of continuous transitions (critical points), first-order transitions, as well as the absence of transitions, are considered. It is shown how computer-simulation techniques, which operate on a free-energy level by using reweighting (histogram) techniques in combination with finite-size scaling theory, provide an effective tool for unambiguously determining the nature of the transition and the position of associated phase equilibria. Three specific models are considered: the Lebwohl–Lasher model of the nematic–isotropic transition in thermotropic liquid crystals, the mismatch model of the main chain-melting phase transition in lipid-bilayer lyotropic liquid crystals, and a model for critical mixing in a lipid-bilayer lyotropic liquid crystal incorporated with trans-bilayer polypeptides.

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