Liquid-Liquid Phase Transitions in Tetrahedrally Coordinated Fluids via Wertheim Theory.
Network interpenetration has been proposed as a mechanism for generating liquid-liquid phase transitions in one component systems. We introduce a model of four coordinated particles, which explicitly treats the system as a mixture of two interacting interpenetrating networks that can freely exchange particles. This model can be solved within Wertheim's theory for associating fluids and shows liquid-liquid phase separations (in addition to the gas-liquid) for a wide range of model parameters. We find that originating a liquid-liquid transition requires a small degree of interpenetrability and a preference for intranetwork bonding. Physically, these requirements can be seen as controlling the softness of the particle-particle interaction and the bond flexibility, in full agreement with recent findings [Smallenburg, F.; Filion, L.; Sciortino, F. Nat. Phys. 2014, 10, 653].
†Department of Physics, Sapienza, Universitá di Roma, Piazzale Aldo Moro 2, I-00185 Roma, Italy.
Frank
F
Smallenburg
‡Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, Utrecht 3584 CC, The Netherlands.
Laura
L
Filion
†Department of Physics, Sapienza, Universitá di Roma, Piazzale Aldo Moro 2, I-00185 Roma, Italy.
Francesco
F
Sciortino