I got my PhD in the IMP Lyon, and worked then in ASPG -Saarbrücken (Germany)- and SOR (Nancy).

The related articles of these works are available in the bibliography tab.

Postdoctoral training in Nancy (France): Nanostructures and ferroelectric nanocomposites: Synthesis, caracterisation, applications

Abstract: The aim of this project is to develop new nanocomposite materials with piezo and ferroelectric properties, and with various mechanical properties and shapes. The piezoelectric nanocrystal is the lithium niobate, which has never been synthesized as a nanofiller with a controlled size. The lithium niobate is piezoelectric in his mono-crystal form. It will be dispersed in various polymers, such as epoxy-amine systems or PVDF (in order to increase its piezoelectric properties). Then, the formed nanocomposite will be sudied by dielectric and brillouin spectroscopy and used to make Surface Acoustic Waves devices (SAW), as a collaboration with the LPMIA lab (SAW and piezoelectric materials specialist) takes place in Nancy.

Postdoctoral training in Saarbrücken (Germany): Study of DGEBA Prepolymer and Epoxy Network by DES.

Abstract: Dielectric spectroscopy is an extremely effective method for characterizing the molecular dynamics over a large range of time scales. Even if the ceramics are not well-known to be studied by dielectric spectroscopy, their dielectric behaviour makes them interesting as dielectric spectroscopy media. The mechanisms of polarization are the same than in polymers or other materials. Then we interested in the fitting programs. All of them are able to fit curves, and use the least squares method. These programs penalty are:

In order to solve all these problems, SADE (Sivia Applied to DiElectric spectroscopy) was used. Sade came from the program SIVIA, which is an algorithm imagined by Luc JAULIN and designed in order to solve set inversion problems. SIVIA was first designed for robotic localization problems, but RAISSI tried to apply it to DES problems. The advantages of SADE are: S.A.D.E (as S.I.V.I.A. Applied to DiElectric spectroscopy) program, developed with Adrien Brochier is available upon request.

PhD Thesis: Physico-chemical characterization of epoxy-amine / metal interphases, characterization of their constituents

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Slides used during the defense (Pdf).

Abstract: Epoxy-diamines are used as adhesives or paints in many industrial applications. When they were applied on metallic substrates and cured, an interphase, having chemical, physical, and mechanical specified properties, was created between the substrate and the polymer. The amine dissolved the hydrated metallic oxide layer and, at the same time, chemisorbed on the metal. The amine chemically reacted to form an organometallic complex. Then, complexes reacted with the epoxy monomer to form a new network. When over the complexes solubility limit, the chelates crystallized. Such crystals acted as short fibers, changing the mechanical properties of the coatings. Therefore, the different chemical, physical, and mechanical properties of these systems were determined and correlated to the formation and/or precipitation of the chelates. This occurred using two amines: the isophorone diamine, which crystallized after the reaction onto metal, and the diethylenetriamine, which never crystallized.

Last update : June 2012