LOW THERMAL CONDUCTIVITY COMPOSITE SKIN MATERIALS

2021 ◽  
Author(s):  
STEVE SCHOENHOLTZ ◽  
ARTHUR GAVRIN ◽  
CHENGGANG CHEN
Keyword(s):  
Thermal Conductivity ◽  
Sandwich Panel ◽  
Thermal Protection ◽  
Scale Up ◽  
Skin Surface ◽  
Heat Shield ◽  
Equivalent Thickness ◽  
Low Thermal Conductivity ◽  
Aerospace Applications ◽  
Stage Of Development

Triton Systems, Inc. and our academic partner University of Dayton Research Institute (UDRI) developed and demonstrated a lightweight, affordable composite heat shield sandwich panel for aerospace applications capable of protecting an underlying Polymer Matrix Composite (PMC) sandwich panel from 500℉ external impingement. Our design outperforms the incumbent heat shield, a bolt-on metallic sheet with an air gap, in both thermal protection (15% lower skin surface temperature) and weight (40% lighter) at an equivalent thickness (about 0.3”). Our panel has very low thermal conductivity (0.08 W/mK) but is also impact resistant, strong (~300 psi flatwise tensile strength), and tolerant to typical aerospace environmental conditions. Additionally, we demonstrated that our design could be produced as a curved panel configuration to match vehicle outer mold lines (OML’s). Now at Technology Readiness Level (TRL) 4, Triton’s panel design is ready to move to the next stage of development which we envision to be additional proof-of-concept testing including chemical and additional environmental exposure, cold exposure, thermal shock, and vibration as we scale up to a larger 4’x8’ panel. STEVE SCHOENHOLTZ

Low Thermal Conductivity YSZ Thermal Barrier Coatings Made by the Solution Precursor Plasma Spray Process

2014 ◽  
Author(s):  
E. H. Jordan ◽  
C. Jiang ◽  
M. Gell ◽  
J. Roth
Keyword(s):  
Thermal Conductivity ◽  
Thermal Barrier Coatings ◽  
Plasma Spray ◽  
Thermal Protection ◽  
High Fracture Toughness ◽  
Thermal Barrier ◽  
Solution Precursor Plasma Spray ◽  
Barrier Coatings ◽  
Low Thermal Conductivity ◽  
Solution Precursor

The vast majority of thermal barrier coatings (TBCs) are made using 7 wt% yttria stabilized zirconia (7YSZ) due to its high thermal expansion coefficient, high fracture toughness, relatively low thermal conductivity and modest use of rare earth elements (Y). Lower thermal conductivity in TBCs is highly desirable because it would allow thinner coatings and/or improved thermal protection. By arranging the porosity in layers using the solution precursor plasma spray (SPPS) process it has been demonstrated that a 7YSZ coating with 15–23% porosity can be reproducibly fabricated having a thermal conductivity of about 0.6W/m·K, approximately half of the thermal conductivity of air plasma spray (APS) TBCs. Preliminary tests show that both cyclic furnace durability and erosion resistance are comparable to APS TBCs.

scholarly journals Short-Chain Modified SiO2 with High Absorption of Organic PCM for Thermal Protection

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 657 ◽  
Author(s):  
Fuxian Wang ◽  
Shiyuan Gao ◽  
Jiachuan Pan ◽  
Xiaomei Li ◽  
Jian Liu
Keyword(s):  
Thermal Conductivity ◽  
Phase Change Materials ◽  
Thermal Protection ◽  
Short Chain ◽  
High Porosity ◽  
Step Method ◽  
Hydrophobic Property ◽  
Low Thermal Conductivity ◽  
Hydrophobic Sio2 ◽  
High Absorption

Organic phase change materials (PCMs) have great potential in thermal protection applications but they suffer from high volumetric change and easy leakage, which require “leak-proof” packaging materials with low thermal conductivity. Herein, we successfully modify SiO2 through a simple 2-step method consisting of n-hexane activation followed by short-chain alkane silanization. The modified SiO2 (M-SiO2) exhibits superior hydrophobic property while maintaining the intrinsic high porosity of SiO2. The surface modification significantly improves the absorption rate of RT60 in SiO2 by 38%. The M-SiO2/RT60 composite shows high latent heat of 180 J·g−1, low thermal conductivity of 0.178 W·m−1·K−1, and great heat capacity behavior in a high-power thermal circuit with low penetrated heating flow. Our results provide a simple approach for preparing hydrophobic SiO2 with high absorption of organic PCM for thermal protection applications.

Structure and Thermoelectric Properties of New Quaternary Tin and Lead Bismuth Selenides, K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1+xSn5-xBi11+xSe22

2000 ◽  
Vol 626 ◽  
Author(s):  
Antje Mrotzek ◽  
Kyoung-Shin Choi ◽  
Duck-Young Chung ◽  
Melissa A. Lane ◽  
John R. Ireland ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Single Crystal ◽  
Thermoelectric Properties ◽  
Three Dimensional ◽  
Structure Type ◽  
Narrow Gap ◽  
Low Thermal Conductivity ◽  
Seebeck Coefficients ◽  
Metal Atoms ◽  
Anionic Framework

ABSTRACTWe present the structure and thermoelectric properties of the new quaternary selenides K1+xM4–2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22. The compounds K1+xM4-2xBi7+xSe15 (M= Sn, Pb) crystallize isostructural to A1+xPb4-2xSb7+xSe15 with A = K, Rb, while K1-xSn5-xBi11+xSe22 reveals a new structure type. In both structure types fragments of the Bi2Te3-type and the NaCl-type are connected to a three-dimensional anionic framework with K+ ions filled tunnels. The two structures vary by the size of the NaCl-type rods and are closely related to β-K2Bi8Se13 and K2.5Bi8.5Se14. The thermoelectric properties of K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22 were explored on single crystal and ingot samples. These compounds are narrow gap semiconductors and show n-type behavior with moderate Seebeck coefficients. They have very low thermal conductivity due to an extensive disorder of the metal atoms and possible “rattling” K+ ions.

A Novel Poly(Ionic Liquid) as the Thermal Insulating Material

2020 ◽  
Vol 13 (3) ◽  
pp. 241-247
Author(s):  
Wenxin Wei ◽  
Guifeng Ma ◽  
Hongtao Wang ◽  
Jun Li
Keyword(s):  
Thermal Conductivity ◽  
Ionic Liquid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Flame Resistance ◽  
Insulating Material ◽  
Low Thermal Conductivity ◽  
Thermal Insulating ◽  
Poly Ionic Liquid

Objective: A new poly(ionic liquid)(PIL), poly(p-vinylbenzyltriphenylphosphine hexafluorophosphate) (P[VBTPP][PF6]), was synthesized by quaternization, anion exchange reaction, and free radical polymerization. Then a series of the PIL were synthesized at different conditions. Methods: The specific heat capacity, glass-transition temperature and melting temperature of the synthesized PILs were measured by differential scanning calorimeter. The thermal conductivities of the PILs were measured by the laser flash analysis method. Results: Results showed that, under optimized synthesis conditions, P[VBTPP][PF6] as the thermal insulator had a high glass-transition temperature of 210.1°C, high melting point of 421.6°C, and a low thermal conductivity of 0.0920 W m-1 K-1 at 40.0°C (it was 0.105 W m-1 K-1 even at 180.0°C). The foamed sample exhibited much low thermal conductivity λ=0.0340 W m-1 K-1 at room temperature, which was comparable to a commercial polyurethane thermal insulating material although the latter had a much lower density. Conclusion: In addition, mixing the P[VBTPP][PF6] sample into polypropylene could obviously increase the Oxygen Index, revealing its efficient flame resistance. Therefore, P[VBTPP][PF6] is a potential thermal insulating material.

Origin of low thermal conductivity in monolayer PbI2

2021 ◽  
Vol 327 ◽  
pp. 114223
Author(s):  
E. Bolen ◽  
E. Deligoz ◽  
H. Ozisik
Keyword(s):  
Thermal Conductivity ◽  
Low Thermal Conductivity

Thermoelectric properties of PEDOT:PSS aerogel secondary-doped in supercritical CO2 atmosphere with low thermal conductivity

Polymer ◽  
2020 ◽  
Vol 206 ◽  
pp. 122912
Author(s):  
Naoya Yanagishima ◽  
Shinji Kanehashi ◽  
Hiromu Saito ◽  
Kenji Ogino ◽  
Takeshi Shimomura
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Supercritical Co2 ◽  
Low Thermal Conductivity ◽  
Co2 Atmosphere
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