Spontaneous polar and chiral symmetry breaking in ordered fluids -- heliconical ferroelectric nematic phases

It is known that the chiral interaction described by Dzyaloshinskii-Moriya (DMI) term lead to the plethora of topological structures of magnetic spins, such as helical or skyrmion phases. Here we present the that analogues electrical DMI can lead to similar structural complexity of electric dipoles in soft matter. We report on a new polar liquid phase in which achiral molecules spontaneously form a heliconical structure. The helical pitch is comparable to the wavelength of visible light and unwinds critically at the transition to a uniformly polar, ferroelectric nematic phase. Although this new liquid crystalline phase resembles the twist-bend nematic phase, the mechanism of its formation is different and is attributed to electrical interactions that cause non-collinear arrangement of electric dipoles, similarly as observed for spins in magnetic systems

Intrinsically chiral ferronematic liquid crystals : An inversion of the helical twist sense at the chiral nematic – Chiral ferronematic phase transition

Funding Information: The research was supported by the National Science Centre (Poland) under the grant no. 2016/22/A/ST5/00319. C.T.I. and J.M.D.S. acknowledge the financial support of the Engineering and Physical Sciences Research Council [EP/V048775/1].Peer reviewedPostprin

Ferroelectric Nematic-Isotropic Liquid Critical End Point

Peer reviewedPublisher PD

Electron Paramagnetic Study On Radical Scavenging Properties Of Ceria Nanoparticles

Ultrafine ceria nanoparticles in the size regime of 3-5 nm were synthesized by chemical methods. The oxygen free radical scavenging properties of ceria nanoparticle was studied using electron paramagnetic resonance technique at the concentrations of 1 mM and 10 μM in the presence of a spin trap. The hydroxyl radical scavenging properties of ceria nanoparticles were found to vary, depending on the concentrations. At lower concentration the catalytic effect was found to be better compared to that at higher concentration, presumably due to the agglomeration at higher concentrations. © 2007 Elsevier B.V. All rights reserved