Abstract

The traditional theory of the effective interactions between charged colloidal particles (`macro-ions') treats the screening of the counter-ions on a linear response level resulting in the well-known screened Coulomb pair potential proposed by Derjaguin, Landau, Verwey and Overbeek. In general, however, due to non-linear counter-ion screening, the effective interactions involve many-body contributions. Using molecular dynamics simulation of the highly asymmetric primitive model with three macro-ions, we calculate the effective triplet forces and compare them with the pairwise contributions. Near touching of a macro-ion triplet, the triplet interaction represents a significant attractive correction to the repulsive pairwise interaction while it is small for large inter-particle separations. Furthermore, we compare our simulation results for the triplet forces with an analytical expression gained from a density functional perturbation approach. Upon performing a suitable renormalization, we find reasonable agreement for situations of weak and strong coupling as well as for situations with added salt ions.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.