Commun. Comput. Phys. doi: 10.4208/cicp.391011.260112s Vol. 13, No. 3, pp. 900-915 March 2013 Molecular Dynamics Simulations of Nanoparticle Interactions with a Planar Wall: Does Shape Matter? Andreas Fuchs 1, ∗ , David Kauzlari´ c 2 , Andreas Greiner 1 , Sauro Succi 2,3 and Jan. G. Korvink 1,2 1 Laboratory for Simulation, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-K¨ ohler-Allee 103, 79110 Freiburg, Germany. 2 School of Soft Matter Research, Freiburg Institute for Advanced Studies, University of Freiburg, Albertstr. 19, 79104 Freiburg, Germany. 3 Istituto Applicazioni Calcolo, CNR, via dei Taurini 9, 00185, Roma, Italy. Received 31 October 2011; Accepted (in revised version) 26 January 2012 Available online 29 August 2012 Abstract. We investigate the hydrodynamic interactions of spherical colloidal nano particles and nano tetrahedra near a planar wall by means of molecular dynamics (MD) simulations of rigid particles within an all-atom solvent. For both spherical and nano-tetrahedral particles, we find that the parallel and perpendicular components of the local diffusion coefficient and viscosity, show good agreement with hydrodynamic theory of Fax´ en and Brenner. This provides further evidence that low perturbations from sphericality of a nanoparticle’s shape has little influence on its local diffusive be- haviour, and that for this particular case, the continuum theory fluid dynamics is valid even down to molecular scales. PACS: 47.85.Dh, 47.11.Mn, 82.70.Dd Key words: Molecular dynamics simulation, nanoparticle, hydrodynamic interaction. 1 Introduction The diffusion of suspended particles in liquids is one of the most fundamental transport processes in physical chemistry, with many applications in material science, chemical engineering, and biology. Indeed, such diffusion processes may significantly affect the properties of the liquid suspension; for instance, it is known that particle diffusion sets the rate-limiting step to many chemical reactions in liquids [1], and that the addition of ∗ Corresponding author. Email addresses: fuchs@speag.com (A. Fuchs), david.kauzlaric@frias.uni-freiburg.de (D. Kauzlari´ c), andreas.greiner@imtek.uni-freiburg.de (A. Greiner), succi@iac.cnr.it (S. Succi), jan.korvink@imtek.uni-freiburg.de (J. G. Korvink) http://www.global-sci.com/ 900 c 2013 Global-Science Press