Multi-scale analysis of the dielectric properties and structure of resin/carbon-black nanocomposites

¹ DCMM PUC-Rio, PO Box 38008, Gávea, Rio de Janeiro, RJ, 22453-900, Brazil
² Centre des Matériaux, École des Mines de Paris, BP 87, 91003 Evry Cedex, France
³ Centre de Morphologie Mathématique, École des Mines de Paris, 35 rue Saint-Honoré, 77300 Fontainebleau, France
⁴ CEMES/CNRS, BP 4347, 31055 Toulouse Cedex, France

Corresponding author: alain.thorel@mat.ensmp.fr

Received: 24 July 2002
Revised: 20 September 2002
Accepted: 1 October 2002
Published online: 29 November 2002

Abstract

Dielectric properties of resin/carbon-black nanocomposites were measured and shown to differ from results given by a random sets modeling approach. The origin of the discrepancies was traced back to the presence of sets of carbon planes, detached from the carbon-black particles during the composite preparation. These planes are dispersed in the resin matrix and are nearly invisible, even in HRTEM images. EELS measurements revealed the signature of bonding states typical of graphite-like compounds, in regions of the matrix previously supposed to be free of carbon-black. A new approach to texture characterization of HRTEM images, using Haralick parameters based on pixel intensity co-occurrence matrices, showed strong differences between pure resin and regions of the composite between carbon particles. The nano-scale characterization results explain the values obtained in macroscopic measurements.