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| Hauptseite > Publikationsdatenbank > Methods for calculating effective interactions and pressure in charge-stabilized dispersions with applications to filtration |
| Hauptseite > Publikationsdatenbank > Methods for calculating effective interactions and pressure in charge-stabilized dispersions with applications to filtration |
| Talk (non-conference) (Invited) | FZJ-2020-01591 |
2018
Abstract: Charge-stabilized suspensions have interesting static features, reflected in properties such as the suspension osmotic pressure and ionic microstructure. These properties are determined by electro-steric interactions between all ionic species. Due to the large size asymmetry between colloidal macroions and small microions, the degrees of freedom of the latter can be integrated out, resulting in an effective one-component interaction potential describing microion-dressed colloidal quasi-particles. We present a comparison, and partial extension, of various methods of calculating effective colloidal interaction parameters including effective charges and screening constants as functions of concentration and ionic strength [1]. We discuss osmotic suspension pressure calculations for dispersions in Donnan equilibrium with a salt ion reservoir. Methods are discussed including cell-models, renormalized jellium models, and multi-colloid-centered mean-field models. The pros and cons of the various methods are assessed by comparison with primitive model based computer simulations. As an application to a technologically relevant process, a parameter-free model for cross-flow ultrafiltration is presented [2]. In this process, a dilute charge-stabilized dispersion is concentrated and purefied by continouosly pumping it though an array of cylindrical membranes having nano-sized pores.References[1] M. Brito, J. Riest, A. Denton and G. Nägele, to be submitted (2017).[2] M. Brito, J. Riest, O. Nir, M. Wessling and G. Nägele, work in progress.
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