Nanocomposites and nanomaterials

Study of aluminium containing multiwall carbon nanotubes

N. Barama1, S. Khelil1, M.C. Boulakleb1, T. Dorbani1, Y. Naoui1, 
S.G. Nedilko2, S. Revo2, S. Hamamda1

1 LTTSM, Mentouri Brothers Constantine 1 University, Algeria. 
E-mail: shamamda@yahoo.com
2 Taras Shevchenko National University of Kyiv, Volodymyrska St. 64/13, Kyiv 01601, Ukraine.

This abstract focuses on the dilatometric and structural variations of aluminium containing different concentrations of multiwall carbon nanotubes.
The use of planetary ball mill has allowed obtaining aluminium-based nanocomposites containing 0.1, 0.25, 1.0 and 1.5%MWCNTs, respectively. Their characterization was done using different experimental techniques such as differential scanning calorimetry, thermogravimetry, dilatometry, X-ray diffraction and IR and Raman spectroscopies.
The dilatometry measurements showed that the coefficient of thermal expansion measured along the perpendicular direction of the rolling plane of the different samples decreases drastically. It becomes of the order of the dilatation of the nanotubes themselves. On the other hand, in the directions perpendicular and parallel to the rolling direction, it is very significant. It is two to three times larger than the previous one. Thus, it is strongly anisotropic. This situation is certainly related to the dispersion of the MWCNTs.
As for calorimetry, it displays similar graphs. They have the same shape but their intensity depends strongly on the MWCNTs concentration. The differences are very strong. The intensities of the extreme heat capacities of the two samples Al+1.5%MWCNTs and Al+0.25%MWCNTs are equal to 0.5 mW/mg and 14.5mW/mg respectively. The rest ones are included in this range. Concerning the two other nanomaterials, the calorific value of Al+1.0%MWCNTs is 1/5 before that of Al+0.1%MWCNTs. The calorific value decreases with the concentration. 
The thermogravimetry of the samples is relatively comparable. The sample containing 1%MWCNTs appeared to be the most stable. The oxidation is very low. The infrared spectra are almost identical. They contain the same anomalies with relative intensities depending on the concentration.
The Raman technique displays spectra having the shapes each containing two characteristic peaks of carbon. The D and G peaks are more or less intense depending on the concentration of multiwall carbon nanotubes.