Equilibrium clusters in suspensions of colloids interacting via potentials with a local minimum

Abstract

In simple colloidal suspensions, clusters are various multimers that result from colloid self-association and exist in equilibrium with monomers.There are two types of potentials that are known to produce clusters: a) potentials that result from the competition between short-range attraction and long-range repulsion and are characterized by a global minimum and a repulsive tail and b) purely repulsive potentials which have a soft shoulder. Using computer simulations, we demonstrate in this work that potentials with a local minimum and a repulsive tail, not belonging to either of the known types, are also capable of generating clusters. A detailed comparative analysis shows that the new type of cluster-forming potential serves as a bridge between the other two. The new clusters are expanded in shape and their assembly is driven by entropy, like in the purely repulsive systems but only at low density. At high density, clusters are collapsed and stabilized by energy, in common with the systems with competing attractive and repulsive interactions.

arXiv comment12 pages, 7 figures

References in corpus (12)

• Colloidal Gels: Equilibrium and Non-Equilibrium Routes
• Core-softened potentials and the anomalous properties of water
• Exact Criterion for Determining Clustering vs. Reentrant Melting Behavior for Bounded Interaction Potentials
• Phase behavior of a fluid with competing attractive and repulsive interactions
• Observation of condensed phases of quasi-planar core-softened colloids
• Structural and dynamical features of multiple metastable glassy states in a colloidal system with competing interactions
• A model colloidal fluid with competing interactions: bulk and interfacial properties
• Systematic characterization of thermodynamic and dynamical phase behavior in systems with short-ranged attraction
• Monte-Carlo simulation of string-like colloidal assembly
• Freezing and correlations in fluids with competing interactions
• Lamellar order, microphase structures and glassy phase in a field theoretic model for charged colloids
• Novel Ground-State Crystals with Controlled Vacancy Concentrations: From Kagomé to Honeycomb to Stripes

Cited by in corpus (1)

• Probabilistic inverse design for self assembling materials