Mechano-Chemical Stability of Gold Nanoparticles Coated with Alkanethiolate SAMs

Abstract

Molecular dynamics simulations are used to probe the structure and stability of alkanethiolate self-assembled monolayers (SAMs) on gold nanoparticles. We observed that the surface of gold nanoparticles becomes highly corrugated by the adsorption of the SAMs. Furthermore, as the temperature is increased, the SAMs dissolve into the gold nanoparticle, creating a liquid mixture at temperatures much lower than the melting temperature of the gold nanoparticle. By analyzing the mechanical and chemical properties of gold nanoparticles at temperatures below the melting point of gold, with different SAM chain lengths and surface coverage properties, we determined that the system is metastable. The model and computational results that provide support for this hypothesis are presented.

Photochemical reactivity of two gold(I) dinuclear complexes, cis/trans-(AupNBT)2dppee: Isomerization for the cis-(AupNBT)2dppee isomer, radical substitution for trans-(AupNBT)2dppee

“…The current interest in gold complexes extends beyond their medicinal applications. The binding of gold to sulfur is the basis of self assembled monolayers applications [5], biosensor devices [6], and attachments to gold nanoparticles [7]. Gold(I) complexes have shown promise as catalysts for water soluble addition reactions, rearrangements, and many other reaction types [8].…”

Forces between functionalized silica nanoparticles in solution

“…Other simulations have either relied upon implicit solvents [14] or studied nanoparticles in a vacuum [15,16].…”

“…Kim et al [13] used molecular dynamics (MD) simulations to study the relaxation of a fullerene molecule coated with poly(ethylene oxide) (PEO). Other simulations have either relied upon implicit solvents [14] or studied nanoparticles in a vacuum [15,16].…”

Modeling pressure-driven assembly of polymer coated nanoparticles

“…Gold atoms were modeled using the embedded atom method [17]. The gold-sulfur interactions were modeled with a Morse potential with parameterizations from Luedtke and Landman [18] and Henz et al [19]. Each S-Au interaction gives a different binding strength, i.e.…”

“…So, we selected two potentials which had binding energies of 9.2 kcal/mol from Luedtke and Landman [18] and 2.18 kcal/mol from Henz et al [19]. Figures 4 and 5 show that the binding energy has a significant effect on the final sinter separation, and in the degree to which chains are successfully cleared from the approaching cores.…”