Mesoscale Simulation of Amphiphlic Molecules by VR Network

用耗散粒子动力学(DPD)算法对AB-二聚体在W溶液中的结构形成进行了介观模拟。作为模拟模型，采用改进的JUART模型[JUARY，S.et al.用耗散粒子动力学模拟两亲性中间相，物理。化学。化学。太棒了。Vol.1(1999)pp.2051-2056]，它代表了表面活性剂六甘醇十二烷基醚(C12E6)和水(H2O)的自组装机理。得到了与JUART结果相同的相图。我们还发现，形成六方相(H1)所需的时间比形成层状相(La)所需的时间要长。第二步，通过改变亲水分子与水分子之间的相互作用势，在耗散粒子动力学(DPD)模拟中使用JUAR模型，定性地阐明了相结构的亲水性依赖关系。通过改变亲水小球与水分子的相互作用势系数x=-20，0，10和20，在无因次温度T=0.5，两亲分子在φ水中的浓度=50%时，相结构发展为层状(x=-20)、六方(x=0)和胶束(x=10)相。当x=20时，亲水珠与水分子之间发生相分离。

Meso-scale simulation of structure formation for AB-dimers in solution W monomers was performed by dissipative particle dynamics (DPD) algorithm. As a simulation model, modified Jury Model was adopted [Jury, S. et al. "Simulation of amphiphilic mesophases using dissipative particle dynamics," Phys. Chem. Chem. Phys. Vol.1(1999) pp.2051-2056], which represents mechanics of self assembly for surfactant hexaethylene glycol dodecyl ether(C12E6) and water(H2O). The same phase diagram as Jury's result was obtained. We also found that it takes a longer time to form the hexagonal phase (H1) than to form the lamellar phase (La).As the second step, the hydrophilicity dependence of the phase structure was clarified qualitatively by varying the interaction potential between hydrophilic molecules and water molecules in a dissipative particle dynamics (DPD) simulation using the Jury model. By varying the coefficient of the interaction potential xbetween hydrophilic beads and water molecules as x=-20,0,10,and 20,at a dimensionless temperature of T=0.5 and a concentration of amphiphilic molecules in water of φ=50%, the phase structures grew to lamellar (x=-20), hexagonal (x=0), and micellar (x=10) phases. For x=20, phase separation occurs between hydrophilic beads and water molecules.