Structural relaxation dynamics of colloidal nanotrimers

Abstract

By Molecular Dynamics simulations, we investigated the dynamics of isotropic fluids of colloidal nanotrimers whose interactions are described by varying the strength of attractive and repulsive terms of the Mie potential. To provide a consistent comparison between the systems described by different force fields, we determined the phase diagram and critical points of each system, characterised the morphology of high-density liquid phases at the same reduced temperature and density, and finally investigated their long-time relaxation dynamics. In particular, we detected an especially complex dynamics that unveils the existence of slow and fast nanotrimers and the resulting occurrence of non-Gaussianity, which develops at intermediate time scales. Deviations from Gaussianity are temporary and vanish within the timescales of the system’s density fluctuations decay, when a Fickian-like diffusion regime is eventually observed.