Résumé:
Thin films of metal oxides/polymers nanocomposites were deposited on glass substrates
by Spin-Coating and Dip-Coating techniques. The nanocomposites were elaborated by inserting,
in the matrices of polystyrene (PS) and polyvinyl chloride (PVC) polymers, of nanoparticles of
metal oxides such as copper oxide (CuO) and lead oxide (PbO). The nanoparticles of
semiconductor CuO and PbO were synthesized beforehand by the hydrothermal method. The xray diffraction characterization of the obtained powders have revealed a monoclinic phase for
CuO crystallites and an orthorhombic phase for PbO. The size of the crystallites of the two
semiconductors is of a nanometic order. Calcul the of gap energy indicate a shift towards high
energies compared to massive crystals. This shift is due to the effect of the quantum confinement
induced by the nanometric size of the crystallites of the semiconductors. These nanocrystals are
used for the preparation of the nanocomposites of CuO/PS, CuO/PVC, PbO/PS and PbO/PVC by
simple insertion of CuO and PbO nanoparticles in the PS and PVC polymers. The analysis of the
elaborated nanocomposites by X-ray diffraction has allowed to notice the incorporation of the
CuO and PbO crystallites into the PS and PVC polymers matrixes and analysis by Raman and
infrared spectroscopies has confirmed the presence of CuO and PbO crystallites in the PS and
PVC matrixes by revealing specific vibration modes to the Cu-O and Pb-O bonds. The surface
morphology and topography of thin films of nanocomposites were highlighted with the help of
atomic force microscopy (AFM) and have shown homogeneous dispersion of CuO and PbO
crystallites and a low surface roughness. the characterization by measurement of the optical
absorption in the UV-Visible domain allows to observe the increase in optical absorption which
is attributed to CuO and PbO nanocrystallites because PS and PVC are optically transparent in
the UV-Visible domain. A shift of the gap energy of the nanocomposites compared with the gap
energy of the pure polymers and the massive crystallites of CuO and PbO was observed. This
variation in gap energy is the result of the new optical behavior of the prepared nanocomposites.
The optical characterization by the measure of the photoluminescence has shown that the
elaborated samples present intense luminescence bands in the visible range, hence the possibility
of consider these matrices as optically active media and can be used for the making devices of
specific optics properties.
