Corrosion and Adsorption Mechanisms of VX Nerve Agent on Aerospace Aluminum Alloys: An Integrated Experimental & DFT Approach

Purpose: This study investigates the physicochemical degradation and surface evolution of aerospace-grade aluminum alloys following exposure to the persistent nerve agent VX, with the aim of elucidating degradation mechanisms and surface interaction pathways under realistic environmental conditions. Methods: Long-term static and dynamic exposure tests were conducted over nine months, combining controlled VX contamination protocols with UAV-based field trials. Surface morphological and chemical changes were characterized using SEM, EDS, and XPS. Complementary density functional theory (DFT) simulations were employed to model the adsorption behavior of VX and its hydrolysis intermediates on aluminum oxide surfaces. Results: VX exposure resulted in progressive surface deterioration, including microcrack formation, localized oxidation, and material loss. DFT calculations revealed strong adsorption of VX on Al2O3 surfaces (−2.27 eV), with formation of stable surface-bound intermediates resistant to desorption or hydrolysis. Experimental findings corroborated these results, showing persistent residue accumulation and corrosion even after standard decontamination. Conclusion: VX induces both chemical and structural degradation of aluminum through persistent adsorption and oxidation-driven mechanisms. These results underscore the urgent need for advanced, material-specific protection and decontamination strategies to ensure structural integrity and operational readiness in aerospace CWA exposure scenarios