Molecular Dynamics Simulations of Binary Sphere Mixtures

Abstract

Explicit simulations of fluid mixtures of highly size-dispersed particles are constrained by numerical challenges associated with identifying pair-interaction neighbors. Recent algorithmic developments have ameliorated these difficulties to an extent, permitting more efficient simulations of systems with many large and small particles of disperse sizes. We leverage these capabilities to perform molecular dynamics simulations of binary sphere mixtures with elastically stiff particles approaching the hard sphere limit and particle size ratios of up to 50, approaching the colloidal limit. The systems considered consist of 500 large particles and up to nearly 3.6 million small particles with total particle volume fractions up to 0.51. Our simulations confirm qualitative predictions for correlations between large particles previously obtained analytically and for simulations employing effective depletion interactions, but also reveal additional insights into the near-contact structure that result from the explicit treatment of the small particle solvent. No spontaneous crystal nucleation was observed during the simulations, suggesting that nucleation rates in the fluid-solid coexistence region are too small to observe crystal nucleation for feasible simulation system sizes and timescales.

References in corpus (16)

• Depletion potential in hard-sphere mixtures: theory and applications
• In Search of Colloidal Hard Spheres
• Crystal nucleation of hard spheres using molecular dynamics, umbrella sampling and forward flux sampling: A comparison of simulation techniques
• Entropic Forces in Binary Hard Sphere Mixtures: Theory and Simulation
• Random close packing of polydisperse hard spheres
• Numerical Solution of Hard-Core Mixtures
• Depletion potentials in highly size-asymmetric binary hard-sphere mixtures: Comparison of accurate simulation results with theory
• Glassy dynamics in asymmetric binary mixtures of hard-spheres
• Sub-Jamming Transition in Binary Sphere Mixtures
• Spontaneous Crystallization in Systems of Binary Hard Sphere Colloids
• Short-time transport properties of bidisperse suspensions and porous media: a Stokesian Dynamics study
• Jamming of Bidisperse Frictional Spheres
• Large-scale frictionless jamming with power-law particle size distributions
• Structural properties of additive binary hard-sphere mixtures
• Contact values for disparate-size hard-sphere mixtures
• Selective-pivot sampling of radial distribution functions in asymmetric liquid mixtures