## 3 Results and Discussions
### Electrochemical Analysis
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**C\({}_{\text{inh}}\), mM/SD \({}^{*}\)** & **E\({}_{\text{corr}}\), V** & \(I_{corr}\), A-cm\({}^{-2}\)** & **-\(\beta\)c, V-decade\({}^{-1}\)** & \(\beta\)a, V-decade\({}^{-1}\)** & \(R_{p}\), Ohm\(\cdot\)cm\({}^{-2}\)** & _CR mm\(\cdot\)Year\({}^{-1}\)** \\ \hline
0 & \(-0.930\pm-0.06\) & \(\begin{array}{c}8.54\times 10^{-4}\pm\\ 1.33\times 10^{-6}\end{array}\) & \(0.320\pm 0.025\) & \(0.162\pm 0.012\) & \(38\pm 2\) & \(0.942\pm 0.042\) \\ \hline \(0.5\) & \(-0.612\pm-0.011\) & \(\begin{array}{c}6.81\times 10^{-4}\pm\\ 0.82\times 10^{-6}\end{array}\) & \(0.225\pm 0.003\) & \(0.280\pm 0.007\) & \(380\pm 7\) & \(0.812\pm 0.007\) \\ \hline
1 & \(-0.524\pm-0.013\) & \(\begin{array}{c}6.10\times 10^{-5}\pm\\ 0.41\times 10^{-6}\end{array}\) & \(0.122\pm 0.073\) & \(0.095\pm 0.016\) & \(439\pm 6\) & \(0.750\pm 0.021\) \\ \hline
2 & \(-0.532\pm-0.009\) & \(\begin{array}{c}5.84\times 10^{-5}\pm\\ 1.87\times 10^{-7}\end{array}\) & \(0.114\pm 0.009\) & \(0.088\pm 0.014\) & \(866\pm 6\) & \(0.421\pm 0.003\) \\ \hline
3 & \(-0.514\pm-0.021\) & \(\begin{array}{c}5.21\times 10^{-5}\pm\\ 0.92\times 10^{-7}\end{array}\) & \(0.114\pm 0.014\) & \(0.031\pm 0.002\) & \(977\pm 11\) & \(0.408\pm 0.004\) \\ \hline
4 & \(-0.520\pm-0.019\) & \(\begin{array}{c}3.83\times 10^{-5}\pm\\ 1.05\times 10^{-7}\end{array}\) & \(0.105\pm 0.023\) & \(0.042\pm 0.010\) & \(988\pm 7\) & \(0.402\pm 0.008\) \\ \hline
5 & \(-0.518\pm-0.013\) & \(\begin{array}{c}1.45\times 10^{-5}\pm\\ 1.16\times 10^{-7}\end{array}\) & \(0.114\pm 0.017\) & \(0.031\pm 0.004\) & \(1062\pm 17\) & \(0.215\pm 0.011\) \\ \hline \hline \end{tabular} \({}^{*}\): Standard deviation.  
\end{table} 
Table 2: Electrochemical parameters for carbon steel in a 3% NaCl solution with different concentrations of EEA4 NB at 25 \({}^{\circ}\)C.  
This means that the IE values calculated from potentiodynamic polarization curves are nearly equal to the values obtained by the EIS method. The experimental results obtained reveal a higher surface coverage of the electrode and a decrease in corrosion currents in the presence of EEA4 NB in saline media. In the literature, \(p\)-nitrobenzoic acid is reported as a compound capable of providing low surface coverage of a carbon steel electrode, and consequently, it exhibits low inhibition of corrosion [36]. Additionally, a surface coverage of 49% for aluminum immersed in NaOH with a content of 100 ppm \(p\)-nitro carboxylic acid was reported [37]. The poor inhibition indicates that the anchoring group during adsorption is only the aromatic ring (\(\pi\) electrons). Amino or hydroxyl groups favor delocalization and offer more inhibition. A possible explanation for the higher surface coverage of carbon steel in saline media in the presence of EEA4 NB results from the coexistence of both \(p\)-nitrobenzoic anions and ethyletanolmonium cations in the solution. The electrode surface is likely to be covered by both carboxylate anions and ethyletanolammonium cations. These assumptions are based  
Figure 4: (**a**) SEM photograph of the bare carbon steel surface, (**b**) SEM photograph covered with an EEA4 NB film, (**c**) EDX image of the carbon steel electrode, and (**d**) EDX image of the carbon steel electrode in the presence of EEA4 NB. on the amine's ability to provide corrosion inhibition, form hydrogen bonds with oxide or hydroxide species on the metal surface, or engage in van der Waals interactions between the surface and anions. When the electrode is exposed to a saline solution containing EEA4 NB, there is a potential shift from positive to negative on the surface. This change in charge, resulting from the adsorption of Cl\({}^{-}\) at the electrode surface, facilitates the physical adsorption of the salt cations. Thus, the adsorbed Cl\({}^{-}\) ions on the metal surface will favor the electrostatic adsorption of protonated ethyletanolamonium molecules, promoting the physical adsorption of ethyletanolamonium on the Fe surface. Similar results are reported by Ebenso [38].