The Concept of Localized Atomic Mobility: Unraveling Properties of Nanoparticles

Abstract

The concept of short time scale mean-square displacement (MSD) was used to get a picture of the distribution of atomic mobilities in different layers and regions of Au and Pt nanoparticles (NPs). The NPs were simulated in vacuum at different temperatures using molecular dynamics and the embedded-atom model. The calculated atomic mobilities were greater for atoms located at corner positions, followed by atoms on edges and planes, independently of the layer analyzed. The short time scale MSD was revealed to be an excellent alternative to predict melting temperatures of small (<100 atoms) transition-metal NPs. Finally, the combination of classical (MSD) and quantum (density of states) properties brought some insight into how the catalytic activity may locally change over the NP surface. The trends found for subnanometer-sized NPs indicate that corner, kinks, and defect regions play a major role for the catalytic activity of these particles.

pH-Responsive Coating of Silver Nanoparticles with Poly(2-(N,N-dimethylamino)ethyl methacrylate): The Role of Polymer Size and Degree of Protonation

“…A silver NP (AgNP) was modeled by a truncated polyhedron, as one of the most thermodynamic equilibrium shapes of colloidal silver in solution. , The silver core was approximated by a quasi-spherical nanocrystal containing the fixed number of 1397 silver atoms packed into a face-centered cubic (fcc) structure. The average diameter of such a NP core equals 3.9 nm, as shown in Figure a.…”

Carbon nanotube size effect on the mechanical properties and toughness of nanocomposites

“…The sonication process in this study involved using two types of sonicators: an ultrasonic bath and an ultrasonic probe with a 10-mm-diameter tip. These sonicators provide varying levels of ultrasound intensity to the nanotube-modified epoxy mixture [41]. The effect caused by the use of the different sonicators on nanotube dispersion was investigated by applying transmission optical microscopy on the uncured nanotube-modified epoxy samples.…”

Binding Preference of α-Cyclodextrin onto Gold Nanoparticles

“…A gold nanoparticle was modelled at the atomic level as a truncated polyhedron, which is known to be one of the thermodynamic equilibrium shapes of colloidal gold in solution [2,17]. The gold core was approximated by a quasi-spherical nanocrystal composed of the fixed number of 1007 gold atoms, which positions are generated from a face-centred cubic (f.c.c.)…”