publié le , mis à jour le
Involved researchers : J.L. Bantignies, R. Almairac, L. Alvarez, R. Parret, A. Zahab, V. Leon
collaboration B. Doyle - ELECTRA (Trieste, Italie), Ph. Parent - LCPMR Orsay
Many studies have been made using thermoset and functionalized CNTs. The key role of nanotube functionalization in the interfacial adhesion has been demonstrated. Controversial results concerning the improvement of the physical properties of the composite materials are obtained. We focus on the understanding of the fundamental physical interaction between the functionalized nanotubes (amino-functionalized double-walled carbon nanotubes (NH2-DWNT)) and the epoxy matrix. Covalent functionalization of the external tube of DWNTs by amino-terminated molecules is demonstrated using NEXAFS and Raman spectroscopy. The structure of the inner tube is preserved in this case. The structural investigation of the composites by X-ray diffraction shows the coupling between epoxy molecules and DWNTs. A long range structural order model of the composites is proposed (figure 1). Functionalization improves the interface between NH2-DWNT loads and the epoxy resin. The covalent functionalization does not affect the electronic transport properties of the DWNTs-epoxy composites. The average composite is semiconducting and the temperature dependence of the electrical transport measurements highlights a percolation network of nanotubes in the composite formed only by crossed metallic tubes.