多体耗散粒子动力学在流体可压缩性和弗洛里－哈金斯理论上的广义映射

Generalized mapping of multi-body dissipative particle dynamics onto fluid compressibility and the Flory-Huggins theory.

作者信息

Jamali Safa, Boromand Arman, Khani Shaghayegh, Wagner Jacob, Yamanoi Mikio, Maia Joao

机构信息

Department of Macromolecular Science and Engineering, Case Western Reserve University, 2100 Adelbert Rd., Cleveland, Ohio 44106, USA.

出版信息

J Chem Phys. 2015 Apr 28;142(16):164902. doi: 10.1063/1.4919303.

DOI:10.1063/1.4919303

PMID:25933786

Abstract

In this work, a generalized relation between the fluid compressibility, the Flory-Huggins interaction parameter (χ), and the simulation parameters in multi-body dissipative particle dynamics (MDPD) is established. This required revisiting the MDPD equation of state previously reported in the literature and developing general relationships between the parameters used in the MDPD model. We derive a relationship to the Flory-Huggins χ parameter for incompressible fluids similar to the work previously done in dissipative particle dynamics by Groot and Warren. The accuracy of this relationship is evaluated using phase separation in small molecules and the solubility of polymers in dilute solvent solutions via monitoring the scaling of the radius of gyration (Rg) for different solvent qualities. Finally, the dynamics of the MDPD fluid is studied with respect to the diffusion coefficient and the zero shear viscosity.

摘要

在这项工作中，建立了流体压缩性、弗洛里-哈金斯相互作用参数（χ）与多体耗散粒子动力学（MDPD）模拟参数之间的广义关系。这需要重新审视文献中先前报道的MDPD状态方程，并建立MDPD模型中所用参数之间的一般关系。我们推导了与不可压缩流体的弗洛里-哈金斯χ参数的关系，类似于Groot和Warren先前在耗散粒子动力学中所做的工作。通过监测不同溶剂性质下的回转半径（Rg）标度，利用小分子中的相分离和聚合物在稀溶剂溶液中的溶解度来评估这种关系的准确性。最后，研究了MDPD流体在扩散系数和零剪切粘度方面的动力学。