Hydrodynamic simulations of sedimenting dilute particle suspensions under repulsive DLVO interactions.
Soft Matter
; 18(11): 2157-2167, 2022 Mar 16.
Article
in En
| MEDLINE
| ID: mdl-35212700
ABSTRACT
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 χ of the electrostatic repulsion normalized by the average particle-particle distance. When χ â 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 χ increases, K likewise increases as if the particle radius increased in proportion to χ up to a maximum around χ = 0.4. Over the range χ = 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 χ, with a step-like transition from 1 to 1/3 centered around χ = 0.6.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Soft Matter
Year:
2022
Document type:
Article
Affiliation country:
Germany