Metastable liquid lamellar structures in binary and ternary mixtures of Lennard-Jones fluids.
We have carried out extensive equilibrium molecular dynamics simulations to investigate the liquid-vapor coexistence in partially miscible binary and ternary mixtures of Lennard-Jones fluids. We have studied in detail the time evolution of the density profiles and the interfacial properties in a temperature region of the phase diagram where the condensed phase is demixed. The composition of the mixtures is fixed, 50% for the binary mixture and 33.33% for the ternary mixture. The results of the simulations clearly indicate that in the range of temperatures 78<T<102 K-in the scale of argon-the system evolves towards a metastable alternated liquid-liquid lamellar state in coexistence with its vapor phase. These states can be achieved if the initial configuration is fully disordered-that is, when the particles of the fluids are randomly placed on the sites of an fcc crystal or the system is completely mixed. As temperature decreases these states become very well defined and more stables in time. We find that below 90 K, the alternated liquid-liquid lamellar state remains alive for 80 ns, in the scale of argon, the longest simulation we have carried out. Nonetheless, we believe that in this temperature region these states will be alive for even much longer times.
Díaz-Herrera
Enrique
E
Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Apartado Postal 55-534, México 09340, DF, Mexico.
Ramírez-Santiago
Guillermo
G
Moreno-Razo
José A
JA