Effective interactions, structure, and pressure in charge-stabilized colloidal suspensions: Critical assessment of charge renormalization methods.
| Autor: | Brito ME; Institute of Biological Information Processing, IBI-4, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany., Nägele G; Institute of Biological Information Processing, IBI-4, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany., Denton AR; Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050, USA. |
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| Jazyk: | angličtina |
| Zdroj: | The Journal of chemical physics [J Chem Phys] 2023 Nov 28; Vol. 159 (20). |
| DOI: | 10.1063/5.0180914 |
| Abstrakt: | Charge-stabilized colloidal suspensions display a rich variety of microstructural and thermodynamic properties, which are determined by electro-steric interactions between all ionic species. The large size asymmetry between molecular-scale microions and colloidal macroions allows the microion degrees of freedom to be integrated out, leading to an effective one-component model of microion-dressed colloidal quasi-particles. For highly charged colloids with strong macroion-microion correlations, nonlinear effects can be incorporated into effective interactions by means of charge renormalization methods. Here, we compare and partially extend several practical mean-field methods of calculating renormalized colloidal interaction parameters, including effective charges and screening constants, as functions of concentration and ionic strength. Within the one-component description, we compute structural and thermodynamic properties from the effective interactions and assess the accuracy of the different methods by comparing predictions with elaborate primitive-model simulations [P. Linse, J. Chem. Phys. 113, 4359 (2000)]. We also compare various prescriptions for the osmotic pressure of suspensions in Donnan equilibrium with a salt ion reservoir and analyze instances where the macroion effective charge becomes larger than the bare one. The methods assessed include single-center cell, jellium, and multi-center mean-field theories. The strengths and weaknesses of the various methods are critically assessed, with the aim of guiding optimal and accurate implementations. (© 2023 Author(s). Published under an exclusive license by AIP Publishing.) |
| Databáze: | MEDLINE |
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