Abstract
In this work we study the self-di usion properties of a liquid of hollow spherical
particles (shells) bearing a smaller solid sphere in their interior (yolks). We model this system
using purely repulsive hard-body interactions between all (shell and yolk) particles, but assume
the presence of a background ideal solvent such that all the particles execute free Brownian motion
between collisions, characterized by short-time self-di usion coecients D0
s for the shells and D0
y
for the yolks. Using a softened version of these interparticle potentials we perform Brownian
dynamics simulations to determine the mean squared displacement and intermediate scattering
function of the yolk-shell complex. These results can be understood in terms of a set of e ective
Langevin equations for the N interacting shell particles, pre-averaged over the yolks' degrees
of freedom, from which an approximate self-consistent description of the simulated self-di usion
properties can be derived. Here we compare the theoretical and simulated results between them,
and with the results for the same system in the absence of yolks. We nd that the yolks, which
have no e ect on the shell-shell static structure, in
uence the dynamic properties in a predictable
manner, fully captured by the theory.
