Molecular Dynamics Simulation of the Oriented Attachment of Gold Nanoparticles in Liquid n-Hexane

Parallel molecular dynamics (MD) simulations were used to probe the oriented attachment of two gold nanoparticles immersed in liquid n-hexane solvent. For the free moving and for nanoparticles with fixed orientation at different centers of mass separation distances, we have calculated quantitative and qualitative characteristics of the nanocrystal orientations. Preferable vertex to vertex and facet to facet orientations have been observed similar with previous experimental studies of silver nanoparticles in N,N dimethylformamide (Giersig et al. J. Mater. Chem., 2004, 14,607) . Direct computation of the densities of the surrounding fluid exhibited a preferential localization of n-hexane molecules on the facets of the gold nanocrystals avoiding the edges and vertices of the nanocrystals. In addition, visualization of the confined fluid in the interparticle region have shown very interesting ordering and layering effects.