Effect of the surface coating on the magnetic nanoparticle smectic-A liquid crystal interaction

Abstract

The behavior of smectic-A liquid crystals with magnetic particles has not been very well characterized. The authors have studied the interaction of a smectic-A liquid crystal with magnetic nanoparticles. They concentrate on the effect of the particles’ surface coating or functionalization compound. The surface coating in a nanoparticle is used to avoid phase separation and in biological applications to identify a particular cell or protein. Thus it is important to see how the surface coating interacts with the liquid crystal in conjunction with the magnetic nanoparticles. They have found out that depending on the surface coating the interaction of the nanoparticles with the liquid crystal varies. This variation is related to how the surface coating aligns the liquid crystal, how it contributes to the relative concentration of the nanoparticles in the liquid crystal-nanoparticle mixture, and how it affects the magnetic energy of the system.

Interaction of a bi-molecular liquid crystal film with functionalized nanoparticles

“…Interaction of a bi-molecular liquid crystal film with functionalized nanoparticles Composites consisting of a mixture of nanoparticles and ordered liquid crystals have been considered for bioengineering applications 1,2 to improve the electric or magnetic response of an organic display, [3][4][5][6] in photovoltaic applications, [7][8][9] or to align anisotropic particles. [10][11][12][13][14] Our group has shown that the ordering of bulk liquid crystals is influenced by the presence of functionalized nanoparticles.…”

Tuning Quantum‐Dot Organization in Liquid Crystals for Robust Photonic Applications

“…[1][2][3][4][5] Recently, significant work has been carried out on developing hybrid liquid crystal (LC)/nanoparticle materials. Studies have looked at creating stable dispersions of metallic, magnetic, and semiconductor particles in the nematic, [6,7] smectic, [8,9] and columnar [10,11] thermotropic phases. [12] Different nanoparticles have been shown to readily localize in regions of low order in the LC phases and to stabilize the defect-rich blue phases [13] and the twist grain boundary phase [14] over a wide temperature range.…”

Impact of nanoscale particles and carbon nanotubes on current and future generations of liquid crystal displays

“…47 As for non-nematic LCD technologies such as surface-stabilized ferroelectric LC (SSFLC) displays, examples dealing with nanoparticle-filled smectic phases in general are rather rare. This likely arises from the fact that comparatively little is known about nanoparticle interactions in smectic 48 and higher ordered LC phases, apart from so-called ferrosmectics [49][50][51][52] (smectic phases filled with magnetic nanoparticles) dating back to the early theoretical work of Brochard and de Gennes. 53 Matsui and Yasuda reported on using amorphous TiO 2 nanoparticles ($17 nm in diameter) randomly dispersed in a ferroelectric LC mixture (based on the SmC*), and demonstrated the usefulness of such mixtures for video-rate greyscale ferroelectric LC (FLC) devices.…”