Tuning Stoichiometry to Promote Formation of Binary Colloidal Superlattices

Abstract

The self-assembly of binary nanoparticle superlattices from colloidal mixtures is a promising method for the fabrication of complex colloidal co-crystal structures. However, binary mixtures often form amorphous or metastable phases instead of the thermodynamically stable phase. Here we show that in binary mixtures of differently sized spherical particles, an excess of the smaller component can promote -- and, in some cases, may be necessary for -- the self-assembly of a binary co-crystal. Using computer simulations, we identify two mechanisms responsible for this phenomenon. First, excess small particles act like plasticizers and enable systems to reach a greater supersaturation before kinetic arrest occurs. Second, they can disfavor competing structures that may interfere with the growth of the target structure. We find the phase behavior of simulated mixtures of hard spheres closely matches published experimental results. We demonstrate the generality of our findings for mixtures of particles of arbitrary shape by presenting a binary mixture of hard shapes that only self-assembles with an excess of the smaller component. mixtures of particles of arbitrary shape by presenting a binary mixture of hard shapes that only self-assembles with an excess of the smaller component.

References in corpus (19)

• Theoretical perspective on the glass transition and amorphous materials
• Crystal Nucleation in Liquids: Open Questions and Future Challenges in Molecular Dynamics Simulations
• Scaling behavior in the $\beta$-relaxation regime of a supercooled Lennard-Jones mixture
• Strong scaling of general-purpose molecular dynamics simulations on GPUs
• freud: A Software Suite for High Throughput Analysis of Particle Simulation Data
• In Search of Colloidal Hard Spheres
• Simple Data and Workflow Management with the signac Framework
• Evidence for out-of-equilibrium crystal nucleation in suspensions of oppositely charged colloids
• Scalable Metropolis Monte Carlo for simulation of hard shapes
• Inverse methods for design of soft materials
• Digital Alchemy for Materials Design: Colloids and Beyond
• Engineering Entropy for the Inverse Design of Colloidal Crystals from Hard Shapes
• Complex Crystals from Size-disperse Spheres
• Phase behaviour of deionized binary mixtures of charged colloidal spheres
• Can the packing efficiency of binary hard spheres explain the glass-forming ability of bulk metallic glasses?
• Inverse Design of Multicomponent Assemblies
• Inverse Design of Simple Pair Potentials for the Self-Assembly of Complex Structures
• Spontaneous Crystallization in Systems of Binary Hard Sphere Colloids
• Local order and crystallization of dense polydisperse hard spheres

Cited by in corpus (1)

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