High electron affinity: a guiding criterion for voltage stabilizer design
Artikel i vetenskaplig tidskrift, 2015

Voltage stabilizers are an emerging class of additives that enhance the dielectric strength of an insulating polymer such as polyethylene. Several partially conflicting reports ascribe the stabilizing effect to either a high electron affinity or low ionization potential of the additive. Here, we report a clear correlation of the electron affinity and to a lesser extent the EHOMO–ELUMO difference of various voltage stabilizers with electrical tree initiation in cross-linked polyethylene. To facilitate a fair evaluation, the voltage-stabilizing efficiency of a set of 13 previously reported voltage stabilizers, which strongly differ in their chemical composition, is compared at equal stabilizer concentration and equivalent test methodology. These results are correlated with the electron affinity and EHOMO–ELUMO difference, as obtained from density functional theory (DFT) modeling, which agreed well with available literature values. Moreover, based on the here established strong correlation between dielectric strength and electron affinity, a new molecule with exceptionally high electron affinity is selected from the extended literature on organic photovoltaics. This malononitrile–benzothiadiazole–triarylamine based molecule with a high electron affinity of 3.4 eV gives rise to a 148% increase in tree initiation field compared to 40% obtained using anthracene, one of the most efficient previously reported voltage-stabilizers, under equivalent test conditions. Thus, we here propose to use the electron affinity as a guiding criterion for identifying novel high-efficiency voltage stabilizers, which opens up the vast library of organic semiconductors as potential candidates, as well as associated synthesis routines for the design of yet unexplored materials.

Författare

Markus Jarvid

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Anette Johansson

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

Villgot Englund

Innovation and Technology

Angelica Lundin

Chalmers

Stanislaw Gubanski

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

Christian Müller

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Mats Andersson

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Journal of Materials Chemistry A

2050-7488 (ISSN)

Vol. 3 14 7273-7286

Ämneskategorier

Polymerkemi

Styrkeområden

Nanovetenskap och nanoteknik

Energi

Materialvetenskap

DOI

10.1039/c4ta04956j

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Senast uppdaterat

2018-09-10