Univ. Limoges, CNRS, SPCTS, UMR 7315, F-87000 Limoges, France.
Soft Matter. 2017 May 31;13(21):3909-3917. doi: 10.1039/c7sm00441a.
We employ the reverse non-equilibrium molecular dynamics method (RNEMD) of Müller-Plathe [Phys. Rev. E, 1999, 59, 4894] to calculate the shear viscosity of colloidal suspensions within the stochastic rotation dynamics-molecular dynamics (SRD-MD) simulation method. We examine the influence of different coupling schemes in SRD-MD on the colloidal volume fraction ϕ dependent viscosity from the dilute limit up to ϕ = 0.3. Our results demonstrate that the RNEMD method is a robust and reliable method for calculating rheological properties of colloidal suspensions. To obtain quantitatively accurate results beyond the dilute regime, the hydrodynamic interactions between the effective fluid particles in the SRD and the MD colloidal particles must be carefully considered in the coupling scheme. We benchmark the method by comparing with the hard sphere suspension case, and then calculate relative viscosities for colloids with mutually attractive interactions. We show that the viscosity displays a sharp increase at the onset of aggregation of the colloidal particles with increasing volume fraction and attraction.
我们采用 Müller-Plathe 的反向非平衡分子动力学方法（RNEMD）[Phys. Rev. E, 1999, 59, 4894]，在随机旋转动力学-分子动力学（SRD-MD）模拟方法中计算胶体悬浮液的剪切黏度。我们考察了 SRD-MD 中不同耦合方案对胶体体积分数 ϕ 相关黏度的影响，研究范围从稀相直至 ϕ = 0.3。结果表明，RNEMD 方法是计算胶体悬浮液流变性质的稳健可靠方法。为了在稀相范围之外获得定量准确的结果，必须在耦合方案中仔细考虑 SRD 中的有效流体粒子与 MD 胶体粒子之间的流体动力学相互作用。我们通过与硬球悬浮液的情况进行基准测试，然后计算出具有相互吸引相互作用的胶体的相对黏度。结果表明，随着体积分数和吸引力的增加，胶体粒子的聚集开始时黏度会急剧增加。
