Nonequilibrium mixture dynamics: A model for mobilities and its consequences
arXiv:2302.02775 · doi:10.1063/5.0147206
Abstract
Extending the famous Model B for the time evolution of a liquid mixture, we derive an approximate expression for the mobility matrix that couples the different mixture components. This approach is based on a single component fluid with particles that are artificially grouped into separate species labelled by ``colors''. The resulting mobility matrix depends on a single dimensionless parameter, which can be determined efficiently from experimental data or numerical simulations, and includes existing standard forms as special cases. We identify two distinct mobility regimes, corresponding to collective motion and interdiffusion, respectively, and show how they emerge from the microscopic properties of the fluid. As a test scenario, we study the dynamics after a thermal quench, providing a number of general relations and analytical insights from a Gaussian theory. Specifically, for systems with two or three components, analytical results for the time evolution of the equal time correlation function compare well to results of Monte Carlo simulations of a lattice gas. A rich behavior is observed, including the possibility of transient fractionation.
References in corpus (8)
- Structural relaxation of polydisperse hard spheres: comparison of the mode-coupling theory to a Langevin dynamics simulation
- Evolved interactions stabilize many coexisting phases in multicomponent liquids
- Dynamical density functional theory for dense suspensions of colloidal hard spheres
- Transient Casimir forces from quenches in thermal and active matter
- Phase behaviour and particle-size cutoff effects in polydisperse fluids
- Exact solution to integrable open multi-species SSEP and macroscopic fluctuation theory
- Phase separation dynamics of polydisperse colloids: a mean-field lattice-gas theory
- Multiphase coexistence in polydisperse colloidal mixtures