## 3 Results and Discussion
### Raman Investigations  
[PERSON] et al. [14] showed that MIR spectroscopy study of CB and CBE failed to find vibrational modes that could differentiate CB from CBE, unlike Raman spectroscopy. In addition, [PERSON] et al. showed a vibrational behavior for AMF quite different from CB and CBE in Raman spectroscopy at room temperature [15]. Raman spectra at room temperature for the four mixtures are represented in Figure 7a, 7b and 7c respectively in the spectral zones 3100-600, 3100-2700 and 1770-1710 cm\({}^{-1}\). Figure 6: The MIR C-H stretching region (3050–27500 cm\({}^{-1}\)) fitted by Lorentzian curves of CB + 0.5 AMF + CBE at room temperature. The solid lines represent the components fitted by Lorentzian functions. Figure 7: The 3100–600 cm\({}^{-1}\) Raman spectral range (**a**), the 3100–2800 cm\({}^{-1}\) Raman spectral range (**b**) and the 1770–1710 cm\({}^{-1}\) Raman spectral range (**c**) of the four mixtures: CB + 0.5 AMF, CB + AMF, CB + 0.5 AMF + CBE and CB + AMF + CBE. The spectral region 1800-1700 cm\({}^{-1}\) corresponding to the vibration of elongation of the carbon-oxygen double bonds, noted v(C=O), was found to be very rich for the three pure compounds [14; 15]. It is therefore interesting to study this zone for mixtures. For this, one carries out modeling by Lorentzian functions for the four mixtures (see Figure 8b). In order to analyze this spectral region more easily, Raman spectra of the pure compounds at room temperature are presented (see Figure 8a). Modeling makes it possible to determine the value in cm\({}^{-1}\) of the center of the peaks (Table 4) as well as the areas of each peak (Table 5). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \(\upsilon\)**(C=0)** & \(\upsilon\)**(C=0)** & \(\upsilon\)**(C=0)** & \(\upsilon\)**(C=0)** \\  & **(cm\({}^{-1}\))** & **(cm\({}^{-1}\))** & **(cm\({}^{-1}\))** & **(cm\({}^{-1}\))** \\ \hline
**CB** & 1751 * & 1744 & 1736 & 1730 \\ \hline
**CBE** & 1755 * & 1743 & 1736 & 1730 \\ \hline
**AMF** & 1754 * & 1745 & _no peak_ & 1732 \\ \hline
**CB + 0.5 AF** & 1750 * & 1743 & 1736 & 1730 \\ \hline
**CB + AMF** & 1751 * & 1743 & 1735 * & 1729 \\ \hline
**CB + 0.5 AMF + CBE** & 1750 * & 1743 & 1735 & 1729 \\ \hline
**CB + AMF + CBE** & 1750 * & 1743 & 1735 & 1729 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Values of the v(C=O) (cm\({}^{-1}\)) of the peaks of Raman spectra of CB, CBE, AMF and mixtures at room temperature. * values obtained by Lorentzian modeling. Figure 8: The Raman carbonyl stretching region (1770–1710 cm\({}^{-1}\)) fitted by Lorentzian curves of CB, CBE and AMF (**a**) and of the four mixtures (**b**): CB + 0.5 AMF, CB + AMF, CB + 0.5 AMF + CBE and CB + AMF + CBE, at room temperature. The solid lines represent the components fitted by Lorentzian functions. The component at 1735 cm\({}^{-1}\) does not exist in AMF, whereas it exists in all other samples [13]. It can thus be used as a witness of the contribution of AMF in mixtures. In Table 1, it can be seen that between \"CB + 0.5 AMF\" and \"CB + AMF\" mixtures, the variations in the area ratios are very significant. The modes at 1743 and 1730 cm\({}^{-1}\) are common to all mixtures. Between these two mixtures, AMF's contribution is doubled. We notice that the ratio \(\tau_{1}=Area_{1743}/Area_{1735}\) is multiplied by four, which means that the contribution of the mode at 1743 cm\({}^{-1}\) has very strongly increased compared to that of the mode 1735 cm\({}^{-1}\). We also note that the ratio \(\tau_{2}=Area_{1743}/Area_{1730}\) was divided by approximately two by the contribution of AMF in \"CB + AMF\" mixture. This means that the contribution of the mode at 1730 cm\({}^{-1}\) has doubled compared to the mode at 1743 cm\({}^{-1}\). If we consider the ratio \(\tau_{3}=Area_{1735}/Area_{1730}\), we see that the addition of AMF in \"CB + AMF\" mixture was accompanied by a very favorable area ratio in the 1730 cm\({}^{-1}\) mode compared to that of the mode at 1735 cm\({}^{-1}\) (multiplied by 10).