  Brownian dynamics simulations are utilized to study segregation phenomena far
from thermodynamic equilibrium. In the present study, we expand upon the
analysis of binary colloid mixtures and additionally introduce a third particle
species to further our understanding of colloidal systems. Gravitationally
driven, spherical colloids immersed in an implicit solvent are confined in
two-dimensional linear microchannels. The interaction between the colloids is
modeled by the Weeks-Chandler-Andersen potential, and the confinement of the
colloids is realized by hard walls based on the solution of the Smoluchowski
equation in half space. In binary and ternary colloidal systems, a difference
in the driving force is achieved by differing colloid sizes, but fixed mass
density. We observe for both the binary and ternary systems that a driving
force difference induces a nonequilibrium phase transition to lanes. For
ternary systems, we study the tendency of lane formation in dependence of the
diameter of the medium-sized colloids. Here, we find a sweetspot for lane
formation in ternary systems. Furthermore, we study the interaction of two
differently sized colloids at the channel walls. Recently, we observed that
driven large colloids push smaller colloids to the walls. This results in small
particle lanes at the walls at early simulation times. In this work, we
additionally find that thin lanes are unstable and dissolve over very long time
frames. Furthermore, we observe a connection between lane formation and the
nonuniform distribution of particles along the channel length. This nonuniform
distribution occurs either alongside lane formation or in shared lanes (i.e.
lanes consisting of two colloid types).
