Structural analyses of composite materials with nanocarbon as filler

I.Ion^a.b, A.Kuklin^a, Y. Kovalev^a, ^c F. Barca, I. Pasuk^b C. Banciu^b

^a Frank Laboratory of Neutron Physics, JINR, Dubna, Russia

^b Advanced Research Institute for Electrical Engineering Bucharest, Romania

^c Polytechnic University Bucharest, Coal Chemistry Laboratory ,Romania

Abstract

The carbon composite materials are now one of the major structural materials for many industrial applications because they present a lot of advantages over other structural materials, among them are the following: at high-temperature the mechanical properties don’t change much; they posses a low-density, a low coefficient of thermal expansion, as well as a good electrical conductivity, corrosion resistance, etc.

The coal tar pitch is a suitable precursor for preparation the advanced carbon material with controlled properties. The heat treatment of the coal tar pitch leads to more organized and staked arrangement of the aromatic sheet that can form a separate liquid-crystal like phase known as carbonaceous mesophase. The later has a spherical morphology, which arises, grows and manifests the coalescences during the heat treatment and forms a paracrystalline carbon structure, close to the graphite. The texture of mesophase is strongly controlled by rheological properties, temperature and the heating rate during the heat treatment, as well as the quantity and type of additives, which can inhibit or catalyze the formation, growing and coalescence of the mesophase spheres.

The sophisticated use of spontaneous and self-organizing materials may hold the key to develop new controlled properties materials, which can be used in many advanced technology industries. Structural order over many lengths scale can be create in self-organizing materials like carbon composite materials by additivation and different condition of carbonization process (pressure, temperature and hitting rate).

The embedding of the conductive particles into a polymer matrix modifies fundamentally structural crystalline features, the porosity systems, the electrical conductivity of the composite and another. The polymer matrix can become a semiconductive or conductive material, when it is doped with conductive additives, make this more suitable for electrical purpose.

The aim of our work is to design and develop in principal, this kind of composite material for EMI shielding and other electrical, chemical and biochemical applications.

This paper presents the results of complex investigations of structural modifications induced during the heat treatment at 440⁰ C and 900⁰ C in the coal tar pitch by adding different quantity (0.1, 0.5, 1 weight %) of nanocarbon.

They include studies of optical and electronic microscopy, x-ray diffraction, Raman spectroscopy and small-angle neutron scattering.

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