9 research outputs found
A microscopic model for thin film spreading
A microscopic, driven lattice gas model is proposed for the dynamics and
spatio-temporal fluctuations of the precursor film observed in spreading
experiments. Matter is transported both by holes and particles, and the
distribution of each can be described by driven diffusion with a moving
boundary. This picture leads to a stochastic partial differential equation for
the shape of the boundary, which agrees with the simulations of the lattice
gas. Preliminary results for flow in a thermal gradient are discussed.Comment: 4 pages, 3 figures. Submitte
Spreading Dynamics of Polymer Nanodroplets
The spreading of polymer droplets is studied using molecular dynamics
simulations. To study the dynamics of both the precursor foot and the bulk
droplet, large drops of ~200,000 monomers are simulated using a bead-spring
model for polymers of chain length 10, 20, and 40 monomers per chain. We
compare spreading on flat and atomistic surfaces, chain length effects, and
different applications of the Langevin and dissipative particle dynamics
thermostats. We find diffusive behavior for the precursor foot and good
agreement with the molecular kinetic model of droplet spreading using both flat
and atomistic surfaces. Despite the large system size and long simulation time
relative to previous simulations, we find no evidence of hydrodynamic behavior
in the spreading droplet.Comment: Physical Review E 11 pages 10 figure