Chain length effect on thermal transport in amorphous polymers and a structure–thermal conductivity relation

2019 ◽  
Vol 21 (28) ◽  
pp. 15523-15530 ◽  
Author(s):  
Xingfei Wei ◽  
Tengfei Luo
Keyword(s):  
Thermal Conductivity ◽  
Chain Length ◽  
Thermal Transport ◽  
Heat Exchangers ◽  
Amorphous Polymers ◽  
Electronics Packaging ◽  
Length Effect

The physics of thermal transport in polymers is important in many applications, such as in heat exchangers and electronics packaging.

Thermal transport in electrospun vinyl polymer nanofibers: effects of molecular weight and side groups

Soft Matter ◽  
2018 ◽  
Vol 14 (47) ◽  
pp. 9534-9541 ◽  
Author(s):  
Yin Zhang ◽  
Xin Zhang ◽  
Lin Yang ◽  
Qian Zhang ◽  
Matthew L. Fitzgerald ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Weight ◽  
Chain Length ◽  
Thermal Transport ◽  
Molecular Chain ◽  
Polymer Nanofibers ◽  
Vinyl Polymer

Thermal conductivity increases with molecular chain length for PE nanofibers, and is higher for vinyl polymer nanofibers with lighter and more symmetric side groups.

scholarly journals Thermal Transport in Polymers: A Review

2021 ◽  
Author(s):  
Xingfei Wei ◽  
Zhi Wang ◽  
Zhiting Tian ◽  
Tengfei Luo
Keyword(s):  
Thermal Conductivity ◽  
Structural Property ◽  
Thermal Transport ◽  
Large Scale ◽  
Applied Research ◽  
Amorphous Polymers ◽  
High Thermal Conductivity ◽  
Molecular Alignments ◽  
Amorphous States ◽  
Engineering Polymers

Abstract In this article, we review thermal transport in polymers with different morphologies from aligned fibers to bulk amorphous states. We survey early and recent efforts in engineering polymers with high thermal conductivity by fabricating polymers with large-scale molecular alignments. The experimentally realized extremely high thermal conductivity of polymer nanofibers are highlighted, and understanding of thermal transport physics from molecular simulations are discussed. We then transition to the discussion of bulk amorphous polymers with an emphasize on the physics of thermal transport and its relation with the conformation of molecular chains in polymers. We also discuss the current understanding of how the chemistry of polymers would influence thermal transport in amorphous polymers and some limited, but important chemistry-structural-property relationships. Lastly, challenges, perspectives and outlook of this field are presented. We hope this review will inspire more fundamental and applied research in the polymer thermal transport field to advance scientific understanding and engineering applications.

Thermal conductivity dependence on chain length in amorphous polymers

2013 ◽  
Vol 113 (18) ◽  
pp. 184304 ◽  
Author(s):  
Junhua Zhao ◽  
Jin-Wu Jiang ◽  
Ning Wei ◽  
Yancheng Zhang ◽  
Timon Rabczuk
Keyword(s):  
Thermal Conductivity ◽  
Chain Length ◽  
Amorphous Polymers

scholarly journals Decoupling electron and phonon transport in single-nanowire hybrid materials for high-performance thermoelectrics

2021 ◽  
Vol 7 (20) ◽  
pp. eabe6000
Author(s):  
Lin Yang ◽  
Madeleine P. Gordon ◽  
Akanksha K. Menon ◽  
Alexandra Bruefach ◽  
Kyle Haas ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Transport ◽  
Electrical Transport ◽  
High Performance ◽  
Figure Of Merit ◽  
Phonon Transport ◽  
Core Shell ◽  
Nanowire Diameter ◽  
High Performing ◽  
Polycrystalline Thin Films

Organic-inorganic hybrids have recently emerged as a class of high-performing thermoelectric materials that are lightweight and mechanically flexible. However, the fundamental electrical and thermal transport in these materials has remained elusive due to the heterogeneity of bulk, polycrystalline, thin films reported thus far. Here, we systematically investigate a model hybrid comprising a single core/shell nanowire of Te-PEDOT:PSS. We show that as the nanowire diameter is reduced, the electrical conductivity increases and the thermal conductivity decreases, while the Seebeck coefficient remains nearly constant—this collectively results in a figure of merit, ZT, of 0.54 at 400 K. The origin of the decoupling of charge and heat transport lies in the fact that electrical transport occurs through the organic shell, while thermal transport is driven by the inorganic core. This study establishes design principles for high-performing thermoelectrics that leverage the unique interactions occurring at the interfaces of hybrid nanowires.

scholarly journals Studies of Polymer Solvation by Dielectric Relaxation Spectroscopy III: Polyvinyl Pyrrolidone in N-Methyl-2-Pyrrolidone, Ethanediol, Methanol, and Water

1990 ◽  
Vol 45 (2) ◽  
pp. 126-134
Author(s):  
E. Dachwitz
Keyword(s):  
Dielectric Relaxation ◽  
Chain Length ◽  
Molar Mass ◽  
Polyvinyl Pyrrolidone ◽  
Dielectric Relaxation Spectroscopy ◽  
Length Effect ◽  
Repeat Units ◽  
Solvent Model ◽  
Spectral Components ◽  
High Concentrations

AbstractThe permittivity of the title solutions has been measured at frequencies between some MHz and 72 GHz at 20 °C. Polyvinyl pyrrolidone of relative molar mass ranging from 1200 to 360 000 has been used. Referring to the concentration of monomeric repeat units (x = 0.65 maximum) there is no significant chain length effect. The permittivity data are described in terms of discrete Debye type spectral components. Special attention is paid to the contributions ascribable to the solvents, which are discussed with respect to their solvation behaviour. This can be described by a three state solvent model as follows. Besides the "bulk" solvent a further contribution is found in any case which is due to loosely affected (slowed down) solvent. Moreover a part of the solvent appears to be tightly bound to the polymer at high concentrations. All the solvents considered show similar solvation properties, notwithstanding their different tendencies towards selfassociation.

scholarly journals Study of anisotropic thermal conductivity in textured thermoelectric alloys by Raman spectroscopy

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 24456-24465
Author(s):  
Rapaka S. C. Bose ◽  
K. Ramesh
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Transport Properties ◽  
Thermal Transport ◽  
Layered Crystal ◽  
Layered Crystal Structure ◽  
Thermal Transport Properties ◽  
Anisotropic Thermal Conductivity ◽  
P Type

Polycrystalline p-type Sb1.5Bi0.5Te3 (SBT) and n-type Bi2Te2.7Se0.3 (BTS) compounds possessing layered crystal structure show anisotropic electronic and thermal transport properties.

La2O3 Doped Y2O3 Stabilized ZrO2 TBC Prepared by EB-PVD

2006 ◽  
Vol 317-318 ◽  
pp. 501-504 ◽  
Author(s):  
Mineaki Matsumoto ◽  
Norio Yamaguchi ◽  
Hideaki Matsubara
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
High Resistance ◽  
Thermal Transport ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Microstructural Observation ◽  
Low Thermal Conductivity ◽  
Ysz Coating

Effect of La2O3 addition on thermal conductivity and high temperature stability of YSZ coating produced by EB-PVD was investigated. La2O3 was selected as an additive because it had a significant effect on suppressing densification of YSZ. The developed coating showed extremely low thermal conductivity as well as high resistance to sintering. Microstructural observation revealed that the coating had fine feather-like subcolumns and nanopores, which contributed to limit thermal transport. These nanostructures were thought to be formed by suppressing densification during deposition.

Constructing Three-dimensional Nano-crystalline Diamond Network within Polymer Composites for Enhanced Thermal Conductivity

Nanoscale ◽  
2021 ◽  
Author(s):  
Shaoyang Xiong ◽  
Yue Qin ◽  
Linhong Li ◽  
Guoyong Yang ◽  
Maohua Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Polymer Composites ◽  
Thermal Performance ◽  
Thermal Transport ◽  
High Performance ◽  
Rapid Development ◽  
Electronic Devices ◽  
Three Dimensional ◽  
Nano Crystalline ◽  
Enhanced Thermal Conductivity

In order to meet the requirement of thermal performance with the rapid development of high-performance electronic devices, constructing a three-dimensional thermal transport skeleton is an effective method for enhancing thermal...

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