Title
The optimal structure-conductivity relation in epoxy-phthalocyanine nanocomposites
Author
Huijbregts, L.J.
Brom, H.B.
Brokken-Zijp, J.C.M.
Kemerink, M.
Chen, Z.
de Goeje, M.P.
Yuan, M.
Michels, M.A.J.
TNO Industrie en Techniek
Publication year
2006
Abstract
Phthalcon-11 (aquocyanophthalocyaninatocobalt (III)) forms semiconducting nanocrystals that can be dispersed in epoxy coatings to obtain a semiconducting material with a low percolation threshold. We investigated the structure-conductivity relation in this composite and the deviation from its optimal realization by combining two techniques. The real parts of the electrical conductivity of a Phthalcon-11/epoxy coating and of Phthalcon-11 powder were measured by dielectric spectroscopy as a function of frequency and temperature. Conducting atomic force microscopy (C-AFM) was applied to quantify the conductivity through the coating locally along the surface. This combination gives an excellent tool to visualize the particle network. We found that a large fraction of the crystals is organized in conducting channels of fractal building blocks. In this picture, a low percolation threshold automatically leads to a conductivity that is much lower than that of the filler. Since the structure-conductivity relation for the found network is almost optimal, a drastic increase in the conductivity of the coating cannot be achieved by changing the particle network, but only by using a filler with a higher conductivity level.
Subject
Atomic force microscopy
Coating techniques
Dielectric devices
Electric conductivity
Optimization
Percolation (solid state)
Epoxy coatings
Epoxy phthalocyanine nanocomposites
Percolation threshold
Semiconducting nanocrystals
Nanostructured materials
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http://resolver.tudelft.nl/uuid:9ac6473a-07c6-4849-9284-7d34bb145e86
TNO identifier
239610
Publisher
American Chemical Society ACS
ISSN
1520-6106
Source
Journal of Physical Chemistry B, 110 (46), 23115-23122
Document type
article