The optimal structure-conductivity relation in epoxy-phthalocyanine nanocomposites
2006 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 110, no 46, 23115-23122 p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
American Chemical Society , 2006. Vol. 110, no 46, 23115-23122 p.
IdentifiersURN: urn:nbn:se:liu:diva-118200DOI: 10.1021/jp063567wISI: 000242045900029PubMedID: 17107152OAI: oai:DiVA.org:liu-118200DiVA: diva2:813495