Extreme-Modulation of Liquid Crystal Viscoelasticity via Altering Ester Bond Direction

2021 ◽  
Author(s):  
Wentao Tang ◽  
Minghui Deng ◽  
Junichi Kogo ◽  
Li Ding ◽  
xiuhu zhao ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Material Design ◽  
Fundamental Question ◽  
Ester Bond ◽  
Molecular Chemistry ◽  
Fine Property ◽  
Material Behaviors ◽  
Bond Direction

The understanding of correlations between molecular-details and macroscopic material behaviors is a fundamental question of molecular chemistry/physics and offers practical interests in material design with fine-property-tunability. Herein, we demonstrate extreme...

scholarly journals Electrorheological Effect of Gold Nanoparticles Coated with Fluorescent Mesogenic Groups Dispersed in Nematic Liquid Crystal

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 192
Author(s):  
Kosuke Kaneko ◽  
Kosuke Yamashita ◽  
Daiki Fujioka ◽  
Kimiyoshi Kaneko ◽  
Kiyomi Fuchigami ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Gold Nanoparticles ◽  
Liquid Crystal ◽  
Composite Materials ◽  
Nematic Liquid Crystal ◽  
Material Design ◽  
Alkyl Chains ◽  
Simple Strategy ◽  
Electrorheological Effect ◽  
Surface Modified

The electrorheological (ER) properties of composite materials consisting of a nematic liquid crystal (LC) and gold nanoparticles (GNPs) coated with bistolane-based mesogenic groups were studied. The GNPs were coated by normal alkyl chains and the fluorescent LC compounds, of which the molecular structure was similar to that of the LC matrix. The dispersity of the GNPs in the nematic LC was investigated by polarizing optical microscopy (POM). In order to improve the ER effect of the composite, a simple strategy was investigated from the viewpoint of a material design in surface-modified GNPs by lateral substitution of the mesogenic groups. The presence of the GNPs in the nematic LC led to a slightly enhanced ER effect compared to that observed for only the nematic LC. This study demonstrates the potential of a hybrid system consisting of LCs and GNPs to yield a larger ER effect.

scholarly journals Reverse Mode Polymer Dispersed Liquid Crystal-based Smart Windows: A Progress Report

2021 ◽  
Vol 03 (04) ◽  
pp. 1-1
Author(s):  
Yang Zhang ◽  
◽  
Jiawen Chen ◽  
Xiaowen Hu ◽  
Wei Zhao ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Material Design ◽  
Smart Window ◽  
Smart Windows ◽  
Polymer Dispersed Liquid Crystal ◽  
Reverse Mode ◽  
Polymer Dispersed ◽  
Recent Developments ◽  
Polymer Stabilized

The reverse mode polymer dispersed liquid crystal (PDLC) is an emerging smart window technology. Unlike traditional PDLCs, a reverse mode PDLC can be transparent and opaque in the absence and presence of an external electric field. This report provides a brief introduction to several reverse modes PDLC smart window technologies, focusing on polymer-stabilized liquid crystals (PSLCs). The systems based on electrohydrodynamic instability (EHDI) of liquid crystals have also been discussed. The working principles, mode of material design, and recent developments are presented for each technology. The current obstacles have also been pointed out. The prospects of smart windows have also been presented.

Freeze-fracture TEM of the helical smectic A* phase

1992 ◽  
Vol 50 (1) ◽  
pp. 278-279
Author(s):  
K.J. Ihn ◽  
R. Pindak ◽  
J. A. N. Zasadzinski
Keyword(s):  
Liquid Crystal ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Freeze Fracture ◽  
Smectic Phase ◽  
Layer Spacing ◽  
Screw Dislocations ◽  
Smectic A ◽  
Smectic Phases ◽  
Discrete Amount

A new liquid crystal (called the smectic-A* phase) that combines cholesteric twist and smectic layering was a surprise as smectic phases preclude twist distortions. However, the twist grain boundary (TGB) model of Renn and Lubensky predicted a defect-mediated smectic phase that incorporates cholesteric twist by a lattice of screw dislocations. The TGB model for the liquid crystal analog of the Abrikosov phase of superconductors consists of regularly spaced grain boundaries of screw dislocations, parallel to each other within the grain boundary, but rotated by a fixed angle with respect to adjacent grain boundaries. The dislocations divide the layers into blocks which rotate by a discrete amount, Δθ, given by the ratio of the layer spacing, d, to the distance between grain boundaries, lb; Δθ ≈ d/lb (Fig. 1).

Attractive mode force microscopy of chiral liquid crystal surfaces

1992 ◽  
Vol 50 (1) ◽  
pp. 268-269
Author(s):  
B.D. Terris ◽  
R. J. Twieg ◽  
C. Nguyen ◽  
G. Sigaud ◽  
H. T. Nguyen
Keyword(s):  
Liquid Crystal ◽  
Crystal Surfaces ◽  
Free Surfaces ◽  
Control Range ◽  
Force Microscopy ◽  
Liquid Crystal Films ◽  
Chiral Liquid Crystal ◽  
Crystal Films ◽  
Electrostatic Charging ◽  
And Shifts

We have used a force microscope in the attractive, or noncontact, mode to image a variety of surfaces. In this mode, the microscope tip is oscillated near its resonant frequency and shifts in this frequency due to changes in the surface-tip force gradient are detected. We have used this technique in a variety of applications to polymers, including electrostatic charging, phase separation of ionomer surfaces, and crazing of glassy films.Most recently, we have applied the force microscope to imaging the free surfaces of chiral liquid crystal films. The compounds used (Table 1) have been chosen for their polymorphic variety of fluid mesophases, all of which exist within the temperature control range of our force microscope.

Development of liquid crystal light valves using Bi12SiO20 as the photoconductor. Part 2: Device performance

1986 ◽  
Vol 133 (1) ◽  
pp. 65
Author(s):  
W.L. Baillie ◽  
P.M. Openshaw ◽  
A.D. Hart ◽  
S.S. Makh
Keyword(s):  
Liquid Crystal ◽  
Device Performance
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