Imperial College London
Professor Nick Quirke

ProfessorNickQuirke

Faculty of Natural Sciences, Department of Chemistry

Emeritus Professor
 
 
 
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Contact

 

+44 (0)20 7594 5844n.quirke

 
 
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Location

 

Molecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Wang:2014:10.1109/TDEI.2014.004387,
author = {Wang, Y and Wu, K and Cubero, D and Quirke, N},
doi = {10.1109/TDEI.2014.004387},
journal = {IEEE Transactions on Dielectrics and Electrical Insulation},
pages = {1726--1734},
title = {Molecular Modeling and Electron Transport in Polyethylene},
url = {http://dx.doi.org/10.1109/TDEI.2014.004387},
volume = {21},
year = {2014}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Polyethylene is commonly used as an insulator for AC power cables. However it is known to undergo chemical and physical change which can lead to dielectric breakdown. Despite almost eighty years of experimental characterization of its electrical properties, very little is known about the details of the electrical behaviour of this material at the molecular level. An understanding of the mechanisms of charge trapping and transport could help in the development of materials with better insulating properties required for the next generation of high voltage AC and DC cables. Molecular simulation techniques provide a unique tool with which to study dielectric processes at the atomic and electronic level. Here we summarise simulation methodologies which have been used to study the properties of PE at the molecular level, elucidating the role of morphology in the trapping of excess electrons. We find that polyethylene has localised states due to conformational trapping extending below the mobility edge (above which the electrons are delocalised), at -0.1¿¿0.1eV with respect to the vacuum level. These trap states with localisation lengths between 0.3 and 1.2nm have energies as low as -0.4+0.1eV in the amorphous and interfacial regions of polyethylene with more positive values in lamella structures. Crystalline regions have a mobility edge at +0.46 +0.1eV, so we would expect transport by electrons excited above the mobility edge to delocalised states to be predominantly through amorphous regions if they percolate the sample.
AU  - Wang,Y
AU  - Wu,K
AU  - Cubero,D
AU  - Quirke,N
DO  - 10.1109/TDEI.2014.004387
EP  - 1734
PY  - 2014///
SN  - 1558-4135
SP  - 1726
TI  - Molecular Modeling and Electron Transport in Polyethylene
T2  - IEEE Transactions on Dielectrics and Electrical Insulation
UR  - http://dx.doi.org/10.1109/TDEI.2014.004387
UR  - http://hdl.handle.net/10044/1/24034
VL  - 21
ER  -
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