Molecular simulation of nanoparticle diffusion at fluid interfaces

► Rotational motion of nanoparticle in bulk solvent well described by Stokes-Einstein-Debye relation with rescale prefactor. ► Nanoparticles are strongly bound to the liquid-liquid interface, undergoing rapid two-dimensional diffusion. ► At the interface rotational diffusion for small particles is more rapid than in bulk solvent; on increasing nanoparticle size this difference disappears.