## 3 Results and Discussion
### Corrosion Protection Evaluation  
#### 3.2.1 Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy  
The SEM images of the mild steel panel prior its subjection to corrosive environment (Mild Steel-blank) are depicted in Figure 5. Taking into account these images, the existence of scratches and dents on the metal surface that are ascribed to either the fabrication of the specimens or the cleaning process can be observed. Considering the EDS analysis, it can be seen that the wt.% iron concentration was 95.1, whereas the oxygen concentration was roughly 1.7, denoting the absence of iron oxide products (Table 3).  
Figure 4: XRD pattern of Ce\({}_{x}\)Ti\({}_{y}\)O\({}_{2}\) nanocontainers loaded with ATT.  
Figure 5: (a,b) SEM images and the corresponding (c) EDS analysis of mild steel (Mild Steel-blank).  
The SEM images as well as the corresponding EDS analysis of the mild steel panel surface after its exposure to 3.5 wt.% NaCl for 144 h in the absence of inhibitors (Mild Steel-3.5%NaCl) are illustrated in Figure 6. Considering these images, it is clearly denoted that the mild steel surface has been damaged due to the presence of the corrosive environment. Signs of etched layers appear onto the metal surface that can be attributed to the corrosion phenomena accelerated by chloride anions.  
Crystalline tubular forms appear that are assigned to either hematite or goethite or lepidococite [35; 36; 37]. The corresponding EDS analysis depicts elevated oxygen value concentration compare to that of the sample Mild Steel-blank due to the formation of the previously mentioned iron oxides (Table 3).  
The surface SEM images of Mild Steel-3.5%NaCl-ATT after subject to 3.5 wt.% NaCl for 144 h are illustrated in Figure 7. It can be seen that layers of spongy agglomerations were created (Figure 7a). According to the literature, these agglomerations can be assigned to maghemite, lepidococite and precursors of green rust (as magnetite), created in the saline solution [38] because of the prolonged exposure process [37; 39]. Furthermore, several lamellas structures are observed [37] that can be ascribed to hematite and goethite \(\alpha\) phases [40; 41; 42] (Figure 7c). The ruptured layer indicates the inhibitor (ATT) interaction with the metal surface [41; 43; 44] (Figure 7b). The corresponding EDS analysis of Figure 7d-i reveals elevated oxygen wt.% concentration compare to that of the sample Mild Steel-blank because of the aforementioned iron oxides formation along with the presence of sulfur and nitrogen that are ascribed to the adsorbed organic ATT (Table 3).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multirow{2}{*}{**Spectrum at**} & \multicolumn{5}{c}{**wt.\% Element Concentration**} \\ \cline{3-6}  & & **O** & **Fe** & **C** & **S** & **N** \\ \hline _Mild Steel-blank_ & Figure 5 & 1.7 & 96.1 & 3.1 & - & - \\ _Mild Steel-3.5\%NaCl_ & Figure 6 & 47.7 & 46.8 & 5.5 & - & - \\ _Mild Steel-3.5\%NaCl-ATT_ & Figure 7d & 12.2 & 11.6 & 18.4 & 30.8 & 27.0 \\ _Mild Steel-3.5\%NaCl-ATT_ & Figure 7e & 9.8 & 20.2 & 11.9 & 43.9 & 14.2 \\ _Mild Steel-3.5\%NaCl-ATT_ & Figure 7f & 32.5 & 50.6 & 6.5 & 5.9 & 4.6 \\ _Mild Steel-3.5\%NaCl-ATT_ & Figure 7g & 30.6 & 29.7 & 8.9 & 20.4 & 10.5 \\ _Mild Steel-3.5\%NaCl-ATT_ & Figure 7h & 33.3 & 42.6 & 8.5 & 7.9 & 7.6 \\ _Mild Steel-3.5\%NaCl-ATT_ & Figure 7i & 11.0 & 11.1 & 18.0 & 32.8 & 27.0 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Tabulated values of wt.% element concentration of mild steel panels prior and after their exposure to 3.5 wt.% NaCl, for 144 h, in the presence of Ce\({}_{x}\)Ti\({}_{y}\)O\({}_{2}\) nanocontaniers loaded with ATT or not.  
Figure 6: (a,b) SEM images and the corresponding (c) EDS analysis of mild steel immersed into 3.5 wt.% NaCl for 144 h (Mild Steel-3.5%NaCl).