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Discotic Liquid Crystals (discotic + liquid_crystal)

Distribution by Scientific Domains
Polymers and Materials Science57%

Selected Abstracts

Planar Alignment of Columnar Discotic Liquid Crystals by Isotropic Phase Dewetting on Chemically Patterned Surfaces

ADVANCED FUNCTIONAL MATERIALS, Issue 6 2010
Jonathan P. Bramble
Abstract A novel method of creating planar aligned columnar discotic liquid crystals (cDLCs) on surfaces, which also gives control over the azimuthal angle, is presented. Surfaces are chemically patterned with stripes via microcontact printing of organothiol self-assembled monolayers (SAMs) on gold, or via deep UV patterning of organosilane SAMs on silicon. These are then used to isolate long droplets of cDLCs by dewetting in the isotropic phase. Upon cooling from the isotropic into the hexagonal columnar phase, polarizing microscopy reveals that the cDLC aligns in a planar orientation. Results for three triphenylene derivatives (HAT-6, HHTT, H7T) and for a phthalocyanine derivative (8H2Pc) are presented. H7T and HAT-6 are found to align with the director perpendicular to the stripe direction, but HHTT and 8H2Pc align parallel to the stripe direction. This relatively simple new method for creating planar aligned columnar phases of DLCs gives control over the azimuthal angle: a condition required for organic field-effect transistor applications of cDLCs. [source]

Liquid-Crystal Patterning: Lithographic Alignment of Discotic Liquid Crystals: A New Time,Temperature Integrating Framework (Adv. Mater.

ADVANCED MATERIALS, Issue 46 2009
46/2009)
Liquid crystals are a successful example of how the control of self-assembly via chemical design leads to novel applications. Massimiliano Cavallini, Fabio Biscari, and co-workers report on p. 4688 that direct patterning of a continuous metal-free mesogenic phthalocyanine film (discotic LCs) is achieved by spatial control of column orientation using unconventional lithography. These patterned films work as time,temperature integrators at the columnar rectangular,hexagonal transition temperature. [source]

Lithographic Alignment of Discotic Liquid Crystals: A New Time,Temperature Integrating Framework

ADVANCED MATERIALS, Issue 46 2009
Massimiliano Cavallini
Liquid crystals are a successful example of how the control of self-assembly via chemical design leads to novel applications. Direct patterning of a continuous metal-free mesogenic phthalocyanine film (discotick liquid crystals) is shown by the spatial control of columns orientation by unconventional lithography. These patterned films work as time,temperature integrators at a columnar rectangular,hexagonal transition temperature. [source]

ChemInform Abstract: Tristriazolotriazines: A Core for Luminescent Discotic Liquid Crystals.

CHEMINFORM, Issue 10 2009
Rodrigo Cristiano
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Ionic Discotic Liquid Crystals: Synthesis and Characterization of Pyridinium Bromides Containing a Triphenylene Core.

CHEMINFORM, Issue 38 2005
Sandeep Kumar
No abstract is available for this article. [source]

Planar Alignment of Columnar Discotic Liquid Crystals by Isotropic Phase Dewetting on Chemically Patterned Surfaces

ADVANCED FUNCTIONAL MATERIALS, Issue 6 2010
Jonathan P. Bramble
Abstract A novel method of creating planar aligned columnar discotic liquid crystals (cDLCs) on surfaces, which also gives control over the azimuthal angle, is presented. Surfaces are chemically patterned with stripes via microcontact printing of organothiol self-assembled monolayers (SAMs) on gold, or via deep UV patterning of organosilane SAMs on silicon. These are then used to isolate long droplets of cDLCs by dewetting in the isotropic phase. Upon cooling from the isotropic into the hexagonal columnar phase, polarizing microscopy reveals that the cDLC aligns in a planar orientation. Results for three triphenylene derivatives (HAT-6, HHTT, H7T) and for a phthalocyanine derivative (8H2Pc) are presented. H7T and HAT-6 are found to align with the director perpendicular to the stripe direction, but HHTT and 8H2Pc align parallel to the stripe direction. This relatively simple new method for creating planar aligned columnar phases of DLCs gives control over the azimuthal angle: a condition required for organic field-effect transistor applications of cDLCs. [source]

Quasi-one-dimensional systems: fluctuations, transport and interplay

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2008
A. V. Plyukhin
Abstract In a one dimensional lattice thermal fluctuations destroy the long-range order making particles of the lattice move on a scale much larger than the lattice spacing. We discuss the assumption that this motion may be responsible for the transport of localized electrons in a system of weakly coupled chains. The model with diffusing localization sites gives a temperature-independent mobility with a crossover to an activated dependence at high temperature. This prediction is consistent with and might account for experimental results on discotic liquid crystals and certain biopolymers. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]