物理化学学报 >> 2006, Vol. 22 >> Issue (12): 1460-1465.doi: 10.3866/PKU.WHXB20061206

研究论文 上一篇    下一篇

基于密度泛函理论研究二元排斥Yukawa流体的表面结构性质

杨振;徐志军;杨晓宁   

  1. (南京工业大学化学化工学院, 南京 210009)
  • 收稿日期:2006-06-02 修回日期:2006-07-07 发布日期:2006-12-06
  • 通讯作者: 杨晓宁 E-mail:Yangxia@njut.edu.cn

Structures of Binary Hard-core Repulsive Yukawa Mixtures Near Solid Surfaces from DFT

YANG Zhen;XU Zhi-Jun;YANG Xiao-Ning   

  1. (College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, P. R. China)
  • Received:2006-06-02 Revised:2006-07-07 Published:2006-12-06
  • Contact: YANG Xiao-Ning E-mail:Yangxia@njut.edu.cn

摘要: 基于自由能密度泛函理论(DFT)考察了二元排斥Yukawa (HCRY)流体在不同外场下的密度分布. 基于微扰理论, 体系的Helmholtz自由能泛函采用硬球排斥部分和长程色散部分贡献之和, 其中Kierlik和Rosinberg的加权密度近似(WDA)被用来计算硬球排斥部分, 而色散部分采用平均场理论(MFT)进行描述. 为了验证DFT计算结果的合理性, 研究中采用巨正则Monte Carlo(GCMC)模拟计算了在不同主体相密度、硬核直径和位能参数比的条件下二元HCRY混合流体的密度分布. 结果表明, 该DFT计算结果与GCMC模拟值吻合良好.

关键词: Yukawa流体, 密度泛函理论, 密度分布, Monte Carlo模拟

Abstract: A free energy density functional theory (DFT) has been used to investigate the density profiles of binary hard-core repulsive Yukawa (HCRY) mixtures under the influence of various external fields. The representation of the excess Helmholtz free energy functional was based on the perturbation theory, where a weighted density approximation (WDA) theory, proposed by Kierlik and Rosinberg, was applied for the hard-core repulsive interaction and a mean field theory (MFT) was used for the long-range dispersion one. To test the validity of the DFT, the grand canonical ensemble Monte Carlo (GCMC) simulations were carried out to obtain the density profiles of binary HCRY mixtures under different bulk densities, hard-core diameters, and energy parameter ratios. The DFT calculations are in quite good agreement with the GCMC simulations.

Key words: Yukawa fluid, Density functional theory, Density profile, Monte Carlo simulation