Figure 1.
(color online) (a) A schematic of the process of the sample preparation.
(b) An optical microscope image of the silica spheres (
) suspended near the water-decalin interface at an area fraction of
(note that the water is on the top and the decalin is on the bottom).
Figure 2.
(color online) The curves of single-particle mean square displacement (MSD) for PS spheres and silica spheres.
The area fractions are
(square black symbols) for PS spheres,
(dot red symbols)and
(triangle green symbols) for silica spheres.
Figure 3.
(color online) The measured self-diffusion coefficient scaled by
as a function of the particle area fraction
for silica and PS spheres.
Different symbols represent data for different particles. The solid lines show the second-order polynomial fitting .
Table 1.
The distance from particle's center to the interface and the fitted values of the
,
and
in Fig. 3. Here
is the radius of the particles.
Figure 4.
(color online) The measured correlated diffusion coefficient (solid symbols) and
(open symbols) as a function of the inter-particle distance
with various values of the area fraction
for (a) PS and (b) silica spheres.
The solid lines with slopes are visual guides. The geometry of measuring the correlated diffusion is depicted in the inset.
Figure 5.
(Color online) (a) The mean correlated diffusion coefficient (solid symbols) and
(open symbols) as a function of
for PS and silica particles.
(b) The mean correlated diffusion coefficient (solid symbols) and
(open symbols) as a function of
for PS and silica particles. The square represents data for the PS particles and the dots represent the silica particles. The solid lines with slopes
and
are visual guides.