## 2 Results and Discussion
### Characterization of Acrylic Coatings Containing Methyl-\(\beta\)-Cyclodextrin/AEDTA Complex  
To ascertain whether the complexation of the corrosion inhibitor enhances its permanence within acrylic coatings, coatings made of Paraloid(r) B44 and containing 5%, 15%, and 20% \(w/w\) of the methyl-\(\beta\)-cyclodextrintrin /AEDTA complex were prepared from the solutions described in paragraph 2.4. These coatings were then thermally aged at 80 \({}^{\circ}\)C, and AEDTA volatilization was monitored using FTIR, SPME-GC/MS, and TD-GC/MS.  
In Figure 8, the FTIR spectra recorded during the first 250 h of aging of the coatings containing 20% \(w/w\) of the complex, which corresponded to 2% \(w/w\) of AEDTA, were compared to the spectra of coatings containing 5% \(w/w\) of uncomplexed AEDTA and to the spectra of Incralac(r). For clarity, only part of the FTIR spectra is shown.  
In the coating with the complex, the characteristic peak of AEDTA at 1636 cm\({}^{-1}\) remained visible throughout the monitoring period, whereas in the coating with uncomplexed AEDTA, the same peak diminished rapidly and disappeared entirely after 100 h of aging. Similarly, in Incralac(r), the characteristic BTA peak at 740 cm\({}^{-1}\), attributed to the CH stretching vibration of the aromatic ring [30], decreased in intensity shortly after aging began. This demonstrates that including AEDTA in methyl-\(\beta\)-cyclodextrintrin significantly extends the inhibitor retention within the coating. Further confirmation of the improved coating performance was provided by TD-GC/MS and SPME-GC/MS analyses.  
SPME-GC/MS results are shown in Figure 9. Acrylic coatings treated with AEDTA released the inhibitor over time: in the headspace analysis of the unaged coating, AEDTA was clearly detected (Figure 9A), while the analysis of the coating thermally aged for 72 h did not show any AEDTA peak, which means that the inhibitor had left the coating (Figure 9B). In contrast, the chromatogram of the coating containing the methyl-\(\beta\)-cyclodextrintrin/AEDTA complex (data not shown) revealed no AEDTA peaks at either time zero or after 72 h of thermal aging. This result suggests that complexation prolongs the retention of AEDTA within the coating.  
Figure 8: FTIR monitoring during aging at 80 \({}^{\circ}\)C: acrylic coating with 2% \(w/w\) of complexed AEDTA (**left**); acrylic coating with 5% \(w/w\) of uncomplexed AEDTA (**centre**), and Incralac® (**right**).  
The presence or absence of the inhibitor in the coatings was double-checked by TD-GC/MS analysis at 250 \({}^{\circ}\)C (Figure 10). In coatings with uncomplexed AEDTA aged for 72 h, no AEDTA peak was observed, confirming that the corrosion inhibitor went away. On the contrary, the coating containing the methyl-\(\beta\)-cyclodextrintrin/AEDTA complex showed the peak of the corrosion inhibitor, providing clear evidence that complexation improves the permanence of the corrosion inhibitor in the coating. Based on these results, the use of cyclodext as nanocontaniers for corrosion inhibitors offers a highly effective and promising approach for developing long-lasting anti-corrosion coatings suitable for protecting outdoor bronze artworks.