scholarly journals Preparation and processing of porous sulfur foams having low thermal conductivity

RSC Advances ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 4397-4403 ◽  
Author(s):  
Vijay S. Wadi ◽  
Kishore K. Jena ◽  
Shahrukh Z. Khawaja ◽  
Vengatesan Muthukumarswamy Ranagraj ◽  
Saeed M. Alhassan
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Template Removal ◽  
Low Thermal Conductivity ◽  
Template Particle

Porous sulfur foams were prepared by combining inverse vulcanization and template removal techniques. The porosity of the foam was altered by varying the template particle size; which lead to drop in thermal conductivity.

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.

Thermal Conductivity of Fly Ash Cenospheres for Variable Particle Size Ranges

2016 ◽  
Vol 4 (2) ◽  
pp. 19
Author(s):  
MENEZES CRAIG ◽  
RATHOD AJIT P ◽  
WASEWAR KAILAS L. ◽  
◽  
◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Fly Ash ◽  
Fly Ash Cenospheres

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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