Journal Article

FZJ-2018-07456

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Clustering and dynamics of particles in dispersions with competing interactions: theory and simulation

Das, S.FZJ* ; Riest, J. ; Winkler, R. G. (Corresponding author)FZJ* ; Gompper, G. (Corresponding author)FZJ* ; Dhont, J. K. G. (Corresponding author)FZJ* ; Nägele, G.FZJ*

2018
Royal Soc. of Chemistry London

This record in other databases:      

Please use a persistent id in citations: doi:10.1039/C7SM02019H

Abstract: Dispersions of particles with short-range attractive and long-range repulsive interactions exhibit rich equilibrium microstructures and a complex phase behavior. We present theoretical and simulation results for structural and, in particular, short-time diffusion properties of a colloidal model system with such interactions, both in the dispersed-fluid and equilibrium-cluster phase regions. The particle interactions are described by a generalized Lennard-Jones-Yukawa pair potential. For the theoretical-analytical description, we apply the hybrid Beenakker–Mazur pairwise additivity (BM-PA) scheme. The static structure factor input to this scheme is calculated self-consistently using the Zerah-Hansen integral equation theory approach. In the simulations, a hybrid simulation method is adopted, combing molecular dynamics simulations of colloids with the multiparticle collision dynamics approach for the fluid, which fully captures hydrodynamic interactions. The comparison of our theoretical and simulation results confirms the high accuracy of the BM-PA scheme for dispersed-fluid phase systems. For particle attraction strengths exceeding a critical value, our simulations yield an equilibrium cluster phase. Calculations of the mean lifetime of the appearing clusters and the comparison with the analytical prediction of the dissociation time of an isolated particle pair reveal quantitative differences pointing to the importance of many-particle hydrodynamic interactions for the cluster dynamics. The cluster lifetime in the equilibrium-cluster phase increases far stronger with increasing attraction strength than that in the dispersed-fluid phase. Moreover, significant changes in the cluster shapes are observed in the course of time. Hence, an equilibrium-cluster dispersion cannot be treated dynamically as a system of permanent rigid bodies.

---

Contributing Institute(s):

1. Theorie der Weichen Materie und Biophysik (IAS-2)
2. Theorie der Weichen Materie und Biophysik (ICS-2)
3. Weiche Materie (ICS-3)

Research Program(s):

1. 553 - Physical Basis of Diseases (POF3-553) (POF3-553)

Appears in the scientific report 2018

---

Database coverage:
; Allianz-Lizenz / DFG ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; IF < 5 ; JCR ; National-Konsortium ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

---