  The vertical drying of a colloidal film containing rod-like particles was
studied by means of kinetic Monte Carlo (MC) simulation. The problem was
approached using a two-dimensional square lattice and the rods were represented
as linear $k$-mers (i.e., particles occupying $k$ adjacent sites). The initial
state before drying was produced using a model of random sequential adsorption
(RSA) with isotropic orientations of the $k$-mers (orientation of the $k$-mers
along horizontal $x$ and vertical $y$ directions are equiprobable). In the RSA
model, overlapping of the $k$-mers is forbidden. During the evaporation, an
upper interface falls with a linear velocity of $u$ in the vertical direction
and the $k$-mers undergo translation Brownian motion. The MC simulations were
run at different initial concentrations, $p_i$, ($p_i \in [0, p_j]$, where
$p_j$ is the jamming concentration), lengths of $k$-mers ($k \in [1, 12]$), and
solvent evaporation rates, $u$. For completely dried films, the spatial
distributions of $k$-mers and their electrical conductivities in both $x$ and
$y$ directions were examined. Significant evaporation-driven self-assembly and
orientation stratification of the $k$-mers oriented along the $x$ and $y$
directions were observed. The extent of stratification increased with
increasing value of $k$. The anisotropy of the electrical conductivity of the
film can be finely regulated by changes in the values of $p_i$, $k$ and $u$.
