Efficient ferronematic coupling with polymer-brush particles

Abstract

Switching of liquid crystal phases is of enormous technological importance and enables digital displays, thermometers and sensors.

Viscoelastic and dielectric properties of 5CB nematic liquid crystal doped by magnetic and nonmagnetic nanoparticles

“…This limit is high compared to many previous works where the limit is mostly found around [29,30,[45][46][47]. Aggregation occurring for a large NP volume fraction has been related to the functionalization with the polydimethylsiloxane (PDMS) [4], and to the corresponding weak planar anchoring in contrast with ligands inducing homeotropic anchoring [22,30,31]. These findings point out that, in order that NPs significantly affect the nematic properties, the NP concentration could not exceed the limit.…”

“…However, a lot of contradictory results have been obtained, in particular regarding the evolution of the elastic constants in presence of NPs, responsible for most interesting LC characteristics. Different behavior for , and have been observed sometimes with the same behavior for , and [20][21][22], sometimes not [23,24], sometimes increasing [25,26], sometimes decreasing [27,28]. As a result, other physical parameters are accordingly affected like dielectric and viscoelastic properties [23,25,29].…”

“…As a result, other physical parameters are accordingly affected like dielectric and viscoelastic properties [23,25,29]. One difficulty is that NPs of different nature are used, but also of different shape, size and nature of the ligands [22,30,31]. This latter parameter may be a key parameter because the nature of the ligands usually determines the nature of the LC anchoring on the surface of the NPs.…”

Magnetic Tilting in Nematic Liquid Crystals Driven by Self‐Assembly

“…Dendritic ligands with mesogenic entities not only kinetically stabilize the MNPs but also reduce both the disturbance of the LC order in the proximity of the MNPs as well as the axial distortion and equatorial depletion of the the flexible ligand shell, preventing MNP agglomeration and phase separation. [ 12,13 ] Additionally, the mesogenic ligands critically control the coupling strength between the LC host and the magnetic moments m of the MNPs. Recently, also a remarkable, through‐space amplification of chirality was observed for minute amounts of nanorods capped with chiral ligands in an achiral N‐LC.…”

Ferromagnetic Ordering Theory of Colloidal Suspension of Magnetic Particles in Liquid Crystal

“…Таким композитным материалам свойственна более высокая чувствительность к внешним магнитным и электрическим полям, что, например, проявляется в понижении порога перехода Фредерикса [13,14]. Наличие примеси также может увеличивать и уменьшать температуру перехода упорядоченная фазаизотропная жидкость [15][16][17]. Наряду с этим уникальной является способность ЖК-среды поддерживать ферромагнитное упорядочение дисперсных частиц при комнатных температурах даже в отсутствие внешнего магнитного поля [10].…”