Multi Scale Mechanics (MSM), TS, CTW, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands.
J Chem Phys. 2012 Mar 28;136(12):124508. doi: 10.1063/1.3694030.
We study bi- and polydisperse mixtures of hard sphere fluids with extreme size ratios up to 100. Simulation results are compared with previously found analytical equations of state by looking at the compressibility factor, Z, and agreement is found with much better than 1% deviation in the fluid regime. A slightly improved empirical correction to Z is proposed. When the density is further increased, excluded volume becomes important, but there is still a close relationship between many-component mixtures and their binary, two-component equivalents (which are defined on basis of the first three moments of the size distribution). Furthermore, we determine the size ratios for which the liquid-solid transition exhibits crystalline, amorphous or mixed system structure. Near the jamming density, Z is independent of the size distribution and follows a -1 power law as function of the difference from the jamming density (Z → ∞). In this limit, Z depends only on one free parameter, the jamming density itself, as reported for several different size distributions with a wide range of widths.
我们研究了具有高达 100 的极端尺寸比的硬球流体的双分散和多分散混合物。通过比较压缩因子 Z，我们将模拟结果与以前发现的分析状态方程进行了比较，发现它们在流体区的偏差小于 1%。我们提出了对 Z 进行稍微改进的经验修正。当密度进一步增加时，排斥体积变得重要，但多组分混合物与其二元、双组分等效物（基于尺寸分布的前三个矩定义）之间仍然存在密切关系。此外，我们确定了液体-固体转变表现出晶体、无定形或混合系统结构的尺寸比。在接近堵塞密度时，Z 与尺寸分布无关，并且作为与堵塞密度的差值的函数遵循-1 次幂律（Z→∞）。在这个极限下，Z 仅取决于一个自由参数，即堵塞密度本身，正如针对几种不同的尺寸分布报告的那样，其宽度范围很广。
