Molecular dynamics simulation for phase behavior of amphiphilic solution

• Published in: Computer physics communications Vol. 182; no. 1; pp. 192 - 194
• Main Authors: Fujiwara, Susumu, Funaoka, Daiki, Itoh, Takashi, Hashimoto, Masato
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2011
• Subjects: Amphiphilic solution; Attraction; C (programming language); Computer simulation; Hexagonal phase; Isotropic micellar phase; Lamellar phase; Mathematical models; Molecular dynamics; Molecular dynamics simulation; Phase behavior; Phase transformations; Quenching; Solvents; Isotropic micellar phase; Molecular dynamics simulation; Hexagonal phase; Phase behavior; Amphiphilic solution; Lamellar phase
• ISSN: 0010-4655; 1879-2944
• DOI: 10.1016/j.cpc.2010.07.013

The phase behavior of amphiphilic solution is investigated by molecular dynamics simulation of amphiphilic rigid dimers with explicit solvent molecules. Our simulations show that three kinds of phases (isotropic micellar, hexagonal and lamellar phases) are formed at a lower temperature by quenching from a random configuration of amphiphilic molecules in solution at a higher temperature. It is ascertained that an isotropic micellar phase changes into a hexagonal phase, and then into a lamellar phase as the amphiphilic concentration increases. It is also found that the global orientational order parameter can be used to distinguish these three kinds of phases. From the detailed analyses of the phase behavior, it is concluded that the hydrophilic repulsion plays an important role in the formation of the hexagonal phase while the hydrophobic attraction plays a crucial role in the formation of the lamellar phase.