Heterogeneous aggregation in binary colloidal alloys

TL;DR

This study uses molecular dynamics simulations to explore how different types of particles aggregate in colloidal suspensions, revealing structural differences and the potential for diverse structures through heterogeneous aggregation.

Contribution

It demonstrates the structural differences in binary colloidal gels compared to monodisperse systems using MD simulations, highlighting the effects of particle heterogeneity.

Findings

Significant differences in RDFs between binary and monodisperse systems.

Higher average coordination number in monodisperse aggregation.

Heterogeneous aggregation yields diverse structures.

Abstract

Molecular dynamics (MD) simulation has been employed to study the nonequilibrium structure formation of two types of particles in a colloidal suspension, driven by type-dependent forces. We examined the time evolution of structure formation as well as the structural properties of the resulting aggregation by studying the radial distribution function (RDF). The resulting aggregation is well described by a binary colloidal gelation. We compared the structural properties to those for one type of particles. From the MD results, it is evident that there are significant differences between the RDF's of the two cases. Moreover, we found that the average coordination number is generally larger in the monodisperse case for all area fractions considered. Thus, by means of heterogeneous aggregation, it is possible to obtain a wide variety of structures while more close-packed structures are formed for monodisperse colloidal aggregation.