Mesoscopic dynamics of colloids simulated with dissipative particle dynamics and fluid particle model
Mesoscopic dynamics of colloids simulated with dissipative particle dynamics and fluid particle model
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DOI：
10.1007/s00894-001-0068-3
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发表时间：
2002-01-01
影响因子：
2.2
通讯作者：
Boryczko, K
中科院分区：
文献类型：
--
作者：
Dzwinel, W;Yuen, DA;Boryczko, K
我们报告的复杂流体的数值模拟结果，使用离散粒子方法的组合。我们的分子模拟系统包括三种模拟技术：分子动力学（MD），耗散粒子动力学（DPD）和流体粒子模型（FPM）。这种类型的模型可以描述复杂流体中发现的多分辨率分子结构（见图），从单胶束，胶体晶体，大规模胶体聚集体到大部分胶体悬浮液中流体动力学不稳定性的中尺度过程。我们可以模拟不同的胶体结构，其中胶体床的大小与溶剂颗粒相当。这一任务是完成与两级离散颗粒模型组成的MD范式与Lennard-Jones（L-J）型潜在的定义胶体颗粒系统和DPD或FPM建模的溶剂。我们观察到自发出现的球形或棒状胶束和它们的结晶在稳定的六角形或蠕虫状结构，分别。利用粒子模型得到的有序阵列与实验室中观察到的二维胶体晶体相似。胶束的形状及其疏水或亲水特性取决于胶体-胶体和胶体-溶剂之间相互作用的标度因子之间的比值。与胶束阵列不同，胶体聚集体涉及由DPD力规定的胶体-溶剂相互作用。与平衡增长的假设不同，两级粒子模型可以显示更真实的分子物理，这允许在非常宽的条件范围内模拟各种类型的胶体和溶剂液体的聚集。我们讨论了在一个三能级模型中结合MD，DPD和FPM技术的潜在前景。最后，我们提出了从大规模模拟的瑞利-泰勒不稳定性和分散的胶体平板在2D和3D的结果。本文的电子补充材料可通过位于http://dx.doi.org/10.1007/s00894-001-0068-3的Springer LINK服务器获得。
We report results of numerical simulations of complex fluids, using a combination of discrete-particle methods. Our molecular modeling repertoire comprises three simulation techniques: molecular dynamics (MD), dissipative particle dynamics (DPD), and the fluid particle model (FPM). This type of model can depict multi-resolution molecular structures (see the Figure) found in complex fluids ranging from single micelle, colloidal crystals, large-scale colloidal aggregates up to the mesoscale processes of hydrodynamical instabilities in the bulk of colloidal suspensions. We can simulate different colloidal structures in which the colloidal beds are of comparable size to the solvent particles. This undertaking is accomplished with a two-level discrete particle model consisting of the MD paradigm with a Lennard-Jones (L-J) type potential for defining the colloidal particle system and DPD or FPM for modeling the solvent. We observe the spontaneous emergence of spherical or rod-like micelles and their crystallization in stable hexagonal or worm-like structures, respectively. The ordered arrays obtained by using the particle model are similar to the 2D colloidal crystals observed in laboratory experiments. The micelle shape and its hydrophobic or hydrophilic character depend on the ratio between the scaling factors of the interactions between colloid-colloid to colloid-solvent. Unlike the miscellar arrays, the colloidal aggregates involve the colloid-solvent interactions prescribed by the DPD forces. Different from the assumption of equilibrium growth, the two-level particle model can display much more realistic molecular physics, which allows for the simulation of aggregation for various types of colloids and solvent liquids over a very broad range of conditions. We discuss the potential prospects of combining MD, DPD, and FPM techniques in a single three-level model. Finally, we present results from large-scale simulation of the Rayleigh-Taylor instability and dispersion of colloidal slab in 2D and 3D. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00894-001-0068-3.