Cluster formation in fluids with competing short-range and long-range interactions

Journal Article · Fri Mar 28 04:00:00 EDT 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4869109· OSTI ID:22253373

Fartaria, Rui ^[1]; Lue, Leo ^[2]

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1. Institute of Materials and Processes, School of Engineering, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)
2. Department of Chemical and Process Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom)

We investigate the low density behaviour of fluids that interact through a short-ranged attraction together with a long-ranged repulsion (SALR potential) by developing a molecular thermodynamic model. The SALR potential is a model of effective solute interactions where the solvent degrees of freedom are integrated-out. For this system, we find that clusters form for a range of interaction parameters where attractive and repulsive interactions nearly balance, similar to micelle formation in aqueous surfactant solutions. We focus on systems for which equilibrium behaviour and liquid-like clusters (i.e., droplets) are expected, and find in addition a novel coexistence between a low density cluster phase and a high density cluster phase within a very narrow range of parameters. Moreover, a simple formula for the average cluster size is developed. Based on this formula, we propose a non-classical crystal nucleation pathway whereby macroscopic crystals are formed via crystal nucleation within microscopic precursor droplets. We also perform large-scale Monte Carlo simulations, which demonstrate that the cluster fluid phase is thermodynamically stable for this system.

• OSTI ID: 22253373
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 12 Vol. 140; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
COMPUTERIZED SIMULATION
CRYSTALS
DEGREES OF FREEDOM
DENSITY
DROPLETS
INTERACTIONS
LIQUIDS
MONTE CARLO METHOD
SOLUTIONS
SOLVENTS
THERMODYNAMIC MODEL