Hydrothermally Produced Cobalt Oxide Nanostructures at Different Temperatures and Effect on Phase Transition Temperature and Threshold Voltage of Nematic Liquid Crystal Host

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

Download Full-text

The angular momentum of an isotropic cholesteric liquid crystal induced by a plane elliptically polarized wave near the phase transition temperature

Laser Physics Letters ◽

10.1088/1612-202x/ab3420 ◽

2019 ◽

Vol 16 (9) ◽

pp. 095501 ◽

Cited By ~ 1

Author(s):

V A Makarov ◽

V M Petnikova

Keyword(s):

Phase Transition ◽

Angular Momentum ◽

Liquid Crystal ◽

Transition Temperature ◽

Phase Transition Temperature ◽

Cholesteric Liquid Crystal ◽

Elliptically Polarized

Download Full-text

A Hexagonal Pillar Array of Thermo-responsive Soft Actuators Prepared by Nanoimprinting

MRS Proceedings ◽

10.1557/opl.2011.910 ◽

2011 ◽

Vol 1312 ◽

Author(s):

Ching-Mao Wu ◽

Szu-Yin Lin ◽

Kuo-Tung Huang

Keyword(s):

Phase Transition ◽

Liquid Crystal ◽

Transition Temperature ◽

Phase Transition Temperature ◽

Polymer Network ◽

Isotropic Phase ◽

Hexagonal Array ◽

Soft Actuators ◽

Response To Temperature ◽

Thermomechanical Effects

ABSTRACTThermo-responsive actuation (thermomechanical effects) based on nematic liquid crystal elastomers (LCEs) have become a research priority in the preparation of soft actuators. Nematic LCEs combine the anisotropic features of liquid crystal phases with the rubber elasticity of polymer network. When heated at nematic to isotropic phase transition temperature (N-to-I temp.), a uniaxial thermomechanical deformation of LCEs will undergo at nearly constant volume due to a change of LC director order. Recently, an array of the micro-sized LCE pillars related to such thermomechanical effects have been successfully constructed through a soft lithography technology (i.e., replica molding). The prepared LCE pillars are mono-dispersive and micro-sized. They also possess N-to-I temp. higher than 100°C, largely limiting the available application. By contrast, the present study will report a hexagonal array of nano-sized thermo-responsive pillar actuators that are able to contract and expand in response to temperature changes around a lower N-to-I temp. is manufactured via using reactive rod-like liquid crystal and ultraviolet nanoimprinting technology. According to atomic force microscope (AFM) observation, a hexagonal array of pillars can be easily constructed by nanoimprinting and a responsive surface with a thermo-stimuli-driven roughness change is achieved. The room-temperature AFM scans quantitatively represent the single pillar shows a diameter of ca. 270 nm and 140 nm in depth, and the pitch meaning the averaged inter-pillar distance is measured as ca. 425 nm, thus lying in a nano-sized range. Furthermore, temperature-variable AFM is also utilized to demonstrate the pillar behaves as a thermally-stimulated nano-sized actuator. In our case, when heated above N-to-I phase transition temperature (ca. 65°C), it is clearly observed that the pillar diameter is expanded in the order of over 12-15 % and then reversibly contracted in response to temperature drop.

Download Full-text

Soft Mode Contribution around Sm A-Sm C*Phase Transition Temperature under DC Bias Field in Ferroelectric Liquid Crystal

Japanese Journal of Applied Physics ◽

10.1143/jjap.27.l1996 ◽

1988 ◽

Vol 27 (Part 2, No. 11) ◽

pp. L1996-L1998 ◽

Cited By ~ 18

Author(s):

Masanori Ozaki ◽

Takashi Hatai ◽

Katsumi Yoshino

Keyword(s):

Phase Transition ◽

Liquid Crystal ◽

Transition Temperature ◽

Phase Transition Temperature ◽

Soft Mode ◽

Bias Field ◽

Ferroelectric Liquid Crystal ◽

Dc Bias ◽

Dc Bias Field

Download Full-text

Mechanical, Electrical, and Biological Properties of Mechanochemically Processed Hydroxyapatite Ceramics

Nanomaterials ◽

10.3390/nano11092216 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2216

Author(s):

Sujata Swain ◽

Rakesh Bhaskar ◽

Mukesh Kumar Gupta ◽

Sonia Sharma ◽

Sudip Dasgupta ◽

...

Keyword(s):

Phase Transition ◽

Cell Proliferation ◽

Transition Temperature ◽

Phase Transition Temperature ◽

Sintering Temperature ◽

Biological Properties ◽

Hydroxyapatite Ceramics ◽

Different Temperatures ◽

Orientational Motion ◽

Type Of Behavior

The effect of the sintering temperature on densification and the resultant mechanical, electrical, and biological properties of mechanochemically processed hydroxyapatite (HAp) samples was investigated. HAp samples were sintered at 1200, 1250, and 1300 °C for 4 h, respectively. HAp samples sintered at 1250 °C showed better mechanical properties, which was attributed to their smaller grain size compared to HAp samples at higher sintering temperatures. The nearly identical value of the dielectric constant (εr) and better cell proliferation was exhibited by HAp samples sintered at 1250 and 1300 °C, respectively. At ~210 °C, in all the samples sintered at different temperatures, a dielectric anomaly was obtained, which was attributed to the phase transition temperature of the HAp system. Dielectric properties near the phase transition temperature showed a dielectric relaxation-type of behavior, which was attributed to the re-orientational motion of OH− ions in the HAp system. Higher cell proliferation and viability were exhibited by the HAp1300 samples, whereas comparatively equivalent cell growth and higher mechanical strength were observed in the HAp1250 samples.

Download Full-text

Colorless High Dielectric Compounds for Low Voltage Liquid Crystal Application

MRS Proceedings ◽

10.1557/proc-559-235 ◽

1999 ◽

Vol 559 ◽

Cited By ~ 1

Author(s):

Shin-Tson Wu ◽

Robert N. Schwartz ◽

Qing T. Zhang ◽

Seth Marder ◽

Chain-Shu Hsu

Keyword(s):

Phase Transition ◽

Liquid Crystal ◽

Transition Temperature ◽

Absorption Spectra ◽

Phase Transition Temperature ◽

Low Voltage ◽

Dielectric Anisotropy ◽

Elastic Coefficient ◽

High Dielectric

ABSTRACTSeveral colorless compounds with dielectric anisotropy in the 10-50 range were studied. The absorption spectra, phase transition temperature, birefringence, dielectric anisotropy and visco-elastic coefficient of these compounds were measured.

Download Full-text