Model for Humidity-Mediated Diffusion on Aluminum Surfaces and Its Role in Accelerating Atmospheric Aluminum Corrosion

• DOI: 10.1021/acsami.3c02327
• Publication Date: 2023-05-24T03:35:45Z
• Authors: Jeremy A. Scher; Stephen E. Weitzner; Yue Hao; Tae Wook Heo; Stephen T. Caston...; Sylvie Aubry; Susan A. Carroll; Matthew P. Kroonb...

Bare aluminum metal surfaces are highly reactive, which leads to the spontaneous formation of a protective oxide surface layer. Because many subsequent corrosive processes mediated by water, structure and dynamics water at interface anticipated influence corrosion kinetics. Using molecular simulations with reactive force field, we model behavior aqueous ions in adsorbed onto across range ion concentrations film thicknesses corresponding increasing relative humidity. We find that diffusivity both depend strongly on humidity environment height within film. Aqueous diffusion rates films typical indoor 30% found be more than 2 orders magnitude slower self-diffusion bulk limit. Connections between reaction kinetics assessed parametrically reductionist based 1D continuum reaction-diffusion equation. Our results highlight importance incorporating properties specific interfacial predictive models corrosion.