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Flexoelectricity Of A Calamitic Liquid Crystal Elastomer Swollen With A Bent-Core Liquid Crystal, M. Chambers, R. Verduzco, J. T. Gleeson, S. Sprunt, Antal Jakli
Flexoelectricity Of A Calamitic Liquid Crystal Elastomer Swollen With A Bent-Core Liquid Crystal, M. Chambers, R. Verduzco, J. T. Gleeson, S. Sprunt, Antal Jakli
Antal Jakli
We have measured the electric current induced by mechanical distortion of a calamitic liquid crystal elastomer (LCE) swollen with a low molecular weight bent-core nematic (BCN) liquid crystal, and have determined, for the first time, the bend flexoelectric coefficient e(3) of such a BCN-LCE composite. In one method, we utilise air-pressure to induce a mechanical bend deformation and flexoelectric polarization in a BCN-LCE film, and then measure the polarization current as a function of time. An alternative technique uses a rotary-motor driven scotch yoke to periodically flex the BCN-LCE; in this case, the magnitude and phase of the induced current …
Rheological Properties Of Bent-Core Liquid Crystals, C. Bailey, K. Fodor-Csorba, J. T. Gleeson, Samuel N. Sprunt, Antal Jákli
Rheological Properties Of Bent-Core Liquid Crystals, C. Bailey, K. Fodor-Csorba, J. T. Gleeson, Samuel N. Sprunt, Antal Jákli
Antal Jakli
We show that bent-core liquid crystalline materials exhibit non-Newtonian flow in their optically isotropic liquid phase. We conjecture that this behavior is due to the existence of nanostructured, fluctuating clusters composed of a few smectic-like layers. Shear alignment of these clusters explains the shear thinning observed in bent-core liquid crystals having either a nematic phase or non-modulated smectic phase. By contrast, smectogens having a modulated smectic phase do not shear thin at low shear rates, but even show a slight shear thickening which may be due to entanglements of wormlike and/or helical clusters.
Acoustically Driven Oscillations Of Freely Suspended Liquid Crystal Filaments, J. Petzold, A. Nemes, A. Eremin, C. Bailey, N. Diorio, Antal Jakli, R. Stannarius
Acoustically Driven Oscillations Of Freely Suspended Liquid Crystal Filaments, J. Petzold, A. Nemes, A. Eremin, C. Bailey, N. Diorio, Antal Jakli, R. Stannarius
Antal Jakli
Some liquid crystalline phases of bent-core mesogens are known to form stable freely-suspended filaments with length to diameter ratios of 1000 and larger. These structures can behave like thin liquid chords. We study filament oscillations excited with harmonic sound waves. From amplitudes of the filament motion and phase shifts respective to the harmonic excitation signal we develop a model for the filament dynamics. Like in solid chords, the resonance frequency f(0) is inversely proportional to their length. The dependence of f(0) upon the filament radius allows one to draw conclusions on the nature of the filament tension. For thin filaments, …