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How broad band (from radio frequency to microwaves) dielectric parameters describe synthetic chemical reactions
Authors:Olivier Meyer  Michel Delmotte  Jean‐Christophe Lacroix  Raphaël Weil  André Loupy  François Maurel  Arlette Fourrier‐Lamer
Institution:1. Laboratoire de Génie Electrique de Paris LGEP, CNRS UMR 8507, SUPELEC, UPMC Univ. Paris‐Sud, 11 rue Joliot‐Curie, Plateau de Moulon, F‐91192 Gif sur Yvette Cedex, France;2. Laboratoire de Microstructure et Mécanique des Matériaux (LM3, UMR 8006) ENSAM, 151 Bd de L'H?pital, 75013 Paris, France;3. Laboratoire de l'Interface, des Traitements, de l'Organisation et de la Dynamique des Systèmes (ITODYS, Paris 7 UMR 7086), 2 place Jussieu, 75252 Paris Cedex 05, France;4. Laboratoire des Réactions Sélectives sur Supports, ICMMO, UMR 8182, Université de Paris‐Sud, batiment 410, 15 rue Georges Clémenceau, 91405 Orsay Cedex, France
Abstract:Large differences in the dielectric responses of isolated molecules and associated reactive mixtures are observed over a wide frequency spectrum ranging from low to microwave frequencies. We present the results obtained for the curing (cross‐linking) of a resin mixed with a hardener. Electrical dipoles contribute to orientation polarization whose responses lie in the 1 kHz to over 1 GHz frequency range, which is predominantly higher than the 0.1 Hz–10 kHz range in which ionic conductivity is observed. It is the relaxation frequency of the reactive mixture that will be considered as the reaction marker. We also describe the results obtained with the saponification of an ester in the presence of a catalyst, with the reactive mixture containing – as in the previous case – electric dipoles and ions, but with responses superimposed in the 1 MHz–10 GHz frequency band. In this case, and for simplification reasons, the low frequency band ionic conductivity is the reaction marker. The aim of this paper is to translate synthetic chemical reactions into electronic terms, in order to allow electronics engineers to understand the interaction between electromagnetic waves and materials. Copyright © 2008 John Wiley & Sons, Ltd.
Keywords:broad band dielectric measurement  saponification  curing  ionic conduction  dipolar relaxation frequency
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