## 3 Results and Discussion
### Inhibitor Releasing Characteristics and Mechanism of OIMs@PAM  
#### 3.2.1 Release Behavior of GE-EP@OIMs in Different pH Environment  
The release behavior of OIMs from GE-EP@OIMs in NaCl solution was evaluated at 20 \({}^{\circ}\)C, 50 \({}^{\circ}\)C, and 80 \({}^{\circ}\)C. As shown in Figure 8, the OIM release was notably high, with concentrations reaching 313 mg/L, 497 mg/L, and 703 mg/L at 20 \({}^{\circ}\)C, 50 \({}^{\circ}\)C, and 80 \({}^{\circ}\)C,  
Figure 7: (**a**) Tensile stress–strain curve of GE-EP and GE-EP@OIMs after vacuum-drying for 72 h at 45 \({}^{\circ}\)C; (**b**) the values of the tensile strength and the elongation at break of OIMs and OIMs@PAM. respectively. The accelerated release rate at 80 \({}^{\circ}\)C (703 mg/L) promoted rapid inhibitor film formation, as elevated temperatures enhanced molecular mobility, effectively suppressing corrosion in a shorter duration. Over time, the OIM concentration decreased significantly, declining to 9 mg/L, 99 mg/L, and 19 mg/L after 60 days at 20 \({}^{\circ}\)C, 50 \({}^{\circ}\)C, and 80 \({}^{\circ}\)C, respectively. This reduction is attributed to two primary factors: (1) the OIM release pathway progressively extended from the surface to the interior and (2) the diminishing OIM content within GE-EP@OIMs reduced the driving force for release. During the initial 1-30 days, higher temperatures facilitated greater OIM release due to increased thermal motion, enhancing molecular migration through the water-based epoxy resin and curing agent network [32]. Figure 8 depicts the concentration and cumulative release of OIMs from GE-EP@OIMs within a NaCl solution at temperatures of 20 \({}^{\circ}\)C, 50 \({}^{\circ}\)C, and 80 \({}^{\circ}\)C. At the commencement, the release of OIMs from GE-EP@OIMs is exceedingly pronounced, with the OIM concentration reaching 313 mg/L, 497 mg/L, and 703 mg/L at 20 \({}^{\circ}\)C, 50 \({}^{\circ}\)C, and 80 \({}^{\circ}\)C, respectively. At 80 \({}^{\circ}\)C, the elevated release rate of OIMs (703 mg/L) expedites the formation of the inhibitor film. This is because the augmented temperature facilitates molecular motion, thereby effectively suppressing corrosion within a brief temporal span. As time progresses, the concentration of OIMs gradually diminishes. After 60 days of immersion at 20 \({}^{\circ}\)C, 50 \({}^{\circ}\)C, and 80 \({}^{\circ}\)C, the OIM concentrations decline to 9 mg/L, 99 mg/L, and 19 mg/L, respectively. The continuous reduction in the released concentration of OIMs can be ascribed to two principal factors: (1) the release pathway of OIMs progressively extends from the surface towards the interior; and (2) the continuous depletion of OIM content within GE-EP@OIMs lessens the driving force for its release. During the initial 1-30 days within the same release period, the concentration of released OIM augments with an increase in temperature. This phenomenon can be attributed to the fact that higher temperatures stimulate the thermal motion of OIMs, which accelerates their migration among the molecular chains constituted by the water-based epoxy resin and the curing agent [32]. The OIM release concentration follows the pattern of 50 \({}^{\circ}\)C \(>\) 80 \({}^{\circ}\)C \(>\) 20 \({}^{\circ}\)C within the 30-60-day period. This can be attributed to the fact that the cumulative release of OIMs in GE-EP@OIMs reaches 81% in the first 30 days at 80 \({}^{\circ}\)C, which leads to a sharp decrease in the residual content of the OIM corrosion inhibitor within the sample, from 34.75% to 6.60%. As shown in Figure 8, the cumulative release of GE-EP@OIMs after immersion in 80 \({}^{\circ}\)C, 50 \({}^{\circ}\)C, and 20 \({}^{\circ}\)C solutions for 60 days is 96%, 86%, and 36%, respectively. After 30 days of immersion in the 20 \({}^{\circ}\)C solution, the cumulative release of the sample no longer increases significantly, indicating that the release of GE-EP@OIMs has stopped; GE  
Figure 8: The concentration (**a**) and the cumulative release (**b**) of OIMs from GE-EP@OIMs in different temperature.