Selective atomic sieving across metal/oxide interface for super-oxidation resistance.

Surface passivation, a desirable natural consequence during initial oxidation of alloys, is the foundation for functioning of corrosion and oxidation resistant alloys ranging from industrial stainless steel to kitchen utensils. This initial oxidation has been long perceived to vary with crystal facet, however, the underlying mechanism remains elusive. Here, using in situ environmental transmission electron microscopy, we gain atomic details on crystal facet dependent initial oxidation behavior in a model Ni-5Cr alloy.

modeling of HS dissociative chemisorption on Ag(100).

Natural sulfidation of silver nanomaterials can passivate the surface, while preserving desirable optical and electrical properties, which is beneficial for limiting Ag release and cytotoxicity. But little is known at the atomic scale about silver sulfidation mechanisms, particularly on different crystallographic terminations. Using density functional theory (DFT) calculations, we examined the process of HS sorption and reaction on Ag(100) surfaces relevant to Ag nanowires (AgNWs).

Diffusion under Confinement: Hydrodynamic Finite-Size Effects in Simulation.

We investigate finite-size effects on diffusion in confined fluids using molecular dynamics simulations and hydrodynamic calculations. Specifically, we consider a Lennard-Jones fluid in slit pores without slip at the interface and show that the use of periodic boundary conditions in the directions along the surfaces results in dramatic finite-size effects, in addition to that of the physically relevant confining length. As in the simulation of bulk fluids, these effects arise from spurious hydrodynamic interactions between periodic images and from the constraint of total momentum conservation.