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Title: Three-dimensional patchy lattice model: Ring formation and phase separation

We investigate the structural and thermodynamic properties of a model of particles with 2 patches of type A and 10 patches of type B. Particles are placed on the sites of a face centered cubic lattice with the patches oriented along the nearest neighbor directions. The competition between the self-assembly of chains, rings, and networks on the phase diagram is investigated by carrying out a systematic investigation of this class of models, using an extension of Wertheim's theory for associating fluids and Monte Carlo numerical simulations. We varied the ratio r ≡ ε{sub AB}/ε{sub AA} of the interaction between patches A and B, ε{sub AB}, and between A patches, ε{sub AA} (ε{sub BB} is set to 0) as well as the relative position of the A patches, i.e., the angle θ between the (lattice) directions of the A patches. We found that both r and θ (60°, 90°, or 120°) have a profound effect on the phase diagram. In the empty fluid regime (r < 1/2) the phase diagram is reentrant with a closed miscibility loop. The region around the lower critical point exhibits unusual structural and thermodynamic behavior determined by the presence of relatively short rings. The agreement betweenmore » the results of theory and simulation is excellent for θ = 120° but deteriorates as θ decreases, revealing the need for new theoretical approaches to describe the structure and thermodynamics of systems dominated by small rings.« less
Authors:
 [1] ;  [2] ;  [3]
  1. Centro de Física Teórica e Computacional, Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisbon, Portugal and Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro 1, P-1950-062 Lisbon (Portugal)
  2. Instituto de Química Física Rocasolano, CSIC, Serrano 119, E-28006 Madrid (Spain)
  3. Centro de Física Teórica e Computacional, Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisbon, Portugal and Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, P-1749-016 Lisbon (Portugal)
Publication Date:
OSTI Identifier:
22255195
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COMPUTERIZED SIMULATION; FCC LATTICES; FLUIDS; INTERACTIONS; MONTE CARLO METHOD; PARTICLES; PHASE DIAGRAMS; THERMODYNAMIC PROPERTIES; THERMODYNAMICS