A homeotropic main-chain tolane-type liquid crystal elastomer film exhibiting high anisotropic thermal conductivity

Soft Matter ◽  
2017 ◽  
Vol 13 (32) ◽  
pp. 5463-5468 ◽  
Author(s):  
Si-Jia Ge ◽  
Ti-Peng Zhao ◽  
Meng Wang ◽  
Lin-Lin Deng ◽  
Bao-Ping Lin ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Crystal ◽  
Main Chain ◽  
High Thermal Conductivity ◽  
Conductivity Anisotropy ◽  
Liquid Crystal Elastomer ◽  
Anisotropic Thermal Conductivity

Homeotropic aligned main-chain tolane-type liquid crystal elastomer films with high normal-to-plane thermal conductivity and high thermal conductivity anisotropy are described.

Effect of stretching angle on the stress plateau behavior of main-chain liquid crystal elastomers

Soft Matter ◽  
2021 ◽  
Vol 17 (11) ◽  
pp. 3128-3136
Author(s):  
Suzuka Okamoto ◽  
Shinichi Sakurai ◽  
Kenji Urayama
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Stress Plateau ◽  
Liquid Crystal Elastomer ◽  
Ultimate Elongation ◽  
Liquid Crystal Elastomers

Stretching angle for a main-chain liquid crystal elastomer has pronounced effects on the width of the stress plateau as well as the ultimate elongation, while it has no effect on the plateau height.

Conjugate Heat Transfer Simulations to Evaluate the Effect of Anisotropic Thermal Conductivity on Overall Cooling Effectiveness

2021 ◽  
pp. 1-26
Author(s):  
Carol E. Bryant ◽  
James L. Rutledge
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Ceramic Matrix Composites ◽  
Conductivity Anisotropy ◽  
Cooling Effectiveness ◽  
External Cooling ◽  
Anisotropic Thermal Conductivity ◽  
Overall Effectiveness

Abstract Ceramic matrix composites (CMCs) show promise as higher temperature capable alternatives to traditional metallic components in gas turbine engine hot gas paths. However, CMC components will still require both internal and external cooling, such as film cooling. The overall cooling effectiveness is determined not only by the design of coolant flow, but also by the conduction through the materiel itself. CMCs have anisotropic thermal conductivity, giving rise to heat flow that differs somewhat relative to what we have come to expect from experience with traditional metallic components. Conjugate heat transfer computational fluid dynamics (CFD) simulations were performed in order to isolate the effect anisotropic thermal conductivity has on a cooling architecture consisting of both internal and external cooling. Results show the specific locations and unique effects of anisotropic thermal conduction on overall effectiveness. Thermal conductivity anisotropy is shown to have a significant effect on the resulting overall effectiveness. As CMCs begin to make their way into gas turbine engines, care must be taken to ensure that anisotropy is characterized properly and considered in the thermal analysis.

scholarly journals Dual relaxation and structural changes under uniaxial strain in main-chain smectic-C liquid crystal elastomer

2015 ◽  
Vol 17 (1) ◽  
pp. 191-199 ◽  
Author(s):  
Dena M. Agra-Kooijman ◽  
Michael R. Fisch ◽  
Leela Joshi ◽  
Wanting Ren ◽  
Philip J. McMullan ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Relaxation Rate ◽  
Structural Changes ◽  
Main Chain ◽  
Uniaxial Strain ◽  
Liquid Crystal Elastomer ◽  
Smectic C ◽  
Dual Relaxation

Relaxation rate of the chevron angle, α becomes about ten times faster at strains exceeding 0.7 than at low strains.

The effect of alignment on the rate-dependent behavior of a main-chain liquid crystal elastomer

Soft Matter ◽  
2020 ◽  
Vol 16 (38) ◽  
pp. 8782-8798
Author(s):  
Cristina P. Martin Linares ◽  
Nicholas A. Traugutt ◽  
Mohand O. Saed ◽  
Alejandro Martin Linares ◽  
Christopher M. Yakacki ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Strain Field ◽  
Main Chain ◽  
Liquid Crystal Elastomer ◽  
Rate Dependent ◽  
Dependent Behavior

This study investigated the effect of alignment on the rate-dependent behavior of a main-chain liquid crystal elastomer (LCE). 3D-DIC was used to track the strain field and showed heterogeneous regions of strain from meson relaxation.

scholarly journals Extremely high thermal conductivity anisotropy of double-walled carbon nanotubes

AIP Advances ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 065104 ◽  
Author(s):  
Zhaoji Ma ◽  
Zhengrong Guo ◽  
Hongwei Zhang ◽  
Tienchong Chang
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
High Thermal Conductivity ◽  
Conductivity Anisotropy ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

On the possibility of anisotropic heat flow in the inner core

2001 ◽  
Vol 38 (6) ◽  
pp. 975-982 ◽  
Author(s):  
R A Secco ◽  
P S Balog
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Heat Flow ◽  
Seismic Anisotropy ◽  
Inner Core ◽  
Elevated Pressure ◽  
Conductivity Anisotropy ◽  
Anisotropic Thermal Conductivity ◽  
Thermally Driven

We consider the possibility of anisotropic heat flow in the inner core by examining the potential for anisotropic thermal conductivity of hexagonal close-packed (hcp-)Fe. Because hcp-Fe exists only at pressures above 13 GPa at room temperature, we investigate thermal conductivity anisotropy in analog material Gd by measuring the electrical conductivity and applying the Wiedemann–Franz Law to determine thermal conductivity (k). The electrical conductivity anisotropy of Gd was measured at pressures up to 1.4 GPa and temperatures up to 873 K in the hcp phase range. At elevated pressure, the variation with temperature of anisotropic thermal conductivity of Gd single crystal resembles the anisotropic behavior at high temperature and 1 atm observed in earlier work. The temperature range of anisotropy of thermal conductivity of Gd, where kc > ka, is extended by pressure, but the anisotropy disappears before the high temperature hcp[Formula: see text]bcc (body-centered cubic) transformation. Our results on hcp-Gd lead us to raise the question of the possibility of hcp-Fe exhibiting anisotropy of thermal conductivity. Together with the known seismic anisotropy of the inner core, and the inferred textural alignment of hcp crystals causing it, we suggest some implications that an anisotropy of thermal conductivity of hcp-Fe, and a concomitant anisotropy of inner core heat flow, could have on thermally driven core processes.

Discotic Liquid Crystal Epoxy Resins Integrating Intrinsic High Thermal Conductivity and Intrinsic Flame Retardancy

2021 ◽  
pp. 2100580
Author(s):  
Xiao Zhong ◽  
Xutong Yang ◽  
Kunpeng Ruan ◽  
Junliang Zhang ◽  
HaitianJunwei ZhangGu
Keyword(s):  
Thermal Conductivity ◽  
Liquid Crystal ◽  
Flame Retardancy ◽  
Epoxy Resins ◽  
High Thermal Conductivity ◽  
Discotic Liquid Crystal

Main-chain smectic liquid crystalline polymer exhibiting unusually high thermal conductivity in an isotropic composite

2013 ◽  
Vol 131 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Shusuke Yoshihara ◽  
Masatoshi Tokita ◽  
Toshiaki Ezaki ◽  
Mitsuru Nakamura ◽  
Masashi Sakaguchi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Main Chain ◽  
Crystalline Polymer ◽  
High Thermal Conductivity ◽  
Isotropic Composite

Highly anisotropic thermal conductivity of discotic nematic liquid crystalline films with homeotropic alignment

2017 ◽  
Vol 53 (58) ◽  
pp. 8227-8230 ◽  
Author(s):  
Dong-Gyun Kim ◽  
Yun Ho Kim ◽  
Tae Joo Shin ◽  
Eun Jung Cha ◽  
Da Som Kim ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Nematic Liquid Crystals ◽  
Free Standing ◽  
Conductivity Anisotropy ◽  
Anisotropic Thermal Conductivity ◽  
Crystalline Films ◽  
Homeotropic Alignment ◽  
Discotic Nematic Liquid Crystals

Homeotropic alignment and photo-crosslinking of discotic nematic liquid crystals yield free-standing films with high in-plane thermal conductivity and thermal conductivity anisotropy.

High thermal conductivity of polymerizable liquid-crystal acrylic film having a twisted molecular orientation

2006 ◽  
Vol 44 (10) ◽  
pp. 1419-1425 ◽  
Author(s):  
Takashi Kato ◽  
Takatoshi Nagahara ◽  
Yasuyuki Agari ◽  
Mitsukazu Ochi
Keyword(s):  
Thermal Conductivity ◽  
Liquid Crystal ◽  
Molecular Orientation ◽  
High Thermal Conductivity
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