Hydrodynamic simulations of sedimenting dilute particle suspensions under repulsive DLVO interactions
| Autor: | Jung, David, Uttinger, Maximilian Johannes, Malgaretti, Paolo, Peukert, Wolfgang, Walter, Johannes, Harting, Jens |
|---|---|
| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Soft Matter 2022 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1039/D1SM01294K |
| Popis: | We present guidelines to estimate the effect of electrostatic repulsion in sedimenting dilute particle suspensions. Our results are based on combined Langevin dynamics and lattice Boltzmann simulations for a range of particle radii, Debye lengths and particle concentrations. They show a simple relationship between the slope $K$ of the concentration-dependent sedimentation velocity and the range $\chi$ of the electrostatic repulsion normalized by the average particle-particle distance. When $\chi \to 0$, the particles are too far away from each other to interact electrostatically and $K=6.55$ as predicted by the theory of Batchelor. As $\chi$ increases, $K$ likewise increases as if the particle radius increased in proportion to $\chi$ up to a maximum around $\chi=0.4$. Over the range $\chi=0.4-1$, $K$ relaxes exponentially to a concentration-dependent constant consistent with known results for ordered particle distributions. Meanwhile the radial distribution function transitions from a disordered gas-like to a liquid-like form. Power law fits to the concentration-dependent sedimentation velocity similarly yield a simple master curve for the exponent as a function of $\chi$, with a step-like transition from 1 to 1/3 centered around $\chi = 0.6$. Comment: 11 pages, 5 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|