Molecular dynamics simulations are carried out to study the translational and
rotational diffusion of a single Janus particle immersed in a dense
Lennard-Jones fluid. We consider a spherical particle with two hemispheres of
different wettability. The analysis of the particle dynamics is based on the
time-dependent orientation tensor, particle displacement, as well as the
translational and angular velocity autocorrelation functions. It was found that
both translational and rotational diffusion coefficients increase with
decreasing surface energy at the nonwetting hemisphere, provided that the
wettability of the other hemisphere remains unchanged. We also observed that in
contrast to homogeneous particles, the nonwetting hemisphere of the Janus
particle tends to rotate in the direction of the displacement vector during the
rotational relaxation time.Comment: Web reference added for
animations:http://www.wright.edu/~nikolai.priezjev/janus/janus.htm