2008/03/14 by P. Tarazona, Pedro Tarazona, Umberto Marini Bettolo Marconi · 1 citation
Chemistry · Materials Science · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Material Dynamics and Properties #cond-mat.soft #cond-mat.stat-mech #thermodynamics and calorimetric analyses
paper · pdf · doi:10.1063/1.2904881
21 pages, 7 figures To appear in Journal of Chemical Physics
arxiv created 2008/03/14 · openalex publication_date 2008/04/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Motivated by recent studies on the dynamics of colloidal solutions in narrow channels, we consider the steady state properties of an assembly of noninteracting particles subject to the action of a traveling potential moving at a constant speed, while the solvent is modeled by a heat bath at rest in the laboratory frame. Here, since the description we propose takes into account the inertia of the colloidal particles, it is necessary to consider the evolution of both positions and momenta and study the governing equation for the one-particle phase-space distribution. First, we derive the asymptotic form of its solutions as an expansion in Hermite polynomials and their generic properties, such as the force and energy balance, and then we particularize our study to the case of an inverted parabolic potential barrier. We numerically obtain the steady state density and temperature profile and show that the expansion is rapidly convergent for large values of the friction constant and small drifting velocities. On the one hand, the present results confirm the previous studies based on the dynamic density functional theory (DDFT): On the other hand, when the friction constant is large, it display effects such as the presence of a wake behind the barrier and a strong inhomogeneity in the temperature field which are beyond the DDFT description.