Elastic and dielectric properties of ferroelectric nanoparticles/bent-core nematic liquid crystal blend.

Eur Phys J E Soft Matter

Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, 700 009, Kolkata, India.

Published: September 2017

Bent-core liquid crystals present the first evidence of forming polar superstructures from achiral molecules. The nematic phase is the newest member of the bent-core family and turns out to be extremely interesting owing to its distinct features compared to its calamitic counterpart. Here the investigation of one achiral unsymmetrical 2-methyl-3-amino-benzoic acid (2,6-substituted toluene)-derived four-ring bent-core nematic (BCN) liquid crystals (11-2M-F) is presented after nanodispersion. Ferroelectric nanoparticles significantly affect the phase transition temperature, threshold voltage, dielectric permittivity, elastic constants and splay viscosity of the pristine BCN. In most bent-core nematic liquid crystals the bent elastic constant (K) is usually lower than the splay elastic constant (K) owing to the presence of short-range smectic-C-like correlations in the nematic phase. Thus the elastic anisotropy ([Formula: see text]) is usually negative in bent-core nematics unlike in rod-like nematic liquid crystals where K is always greater than K. Here we report a short-core bent-shaped nematic liquid crystal whose negative elastic anisotropy was turned to positive by minute addition of ferroelectric nanoparticles.

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http://dx.doi.org/10.1140/epje/i2017-11564-xDOI Listing

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