Patra Chandra N
Theoretical Chemistry Section, Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400 085, India.
J Chem Phys. 2007 Feb 21;126(7):074905. doi: 10.1063/1.2567271.
A density functional theory is presented to study the effect of attractions on the structure of polymer solutions confined between surfaces. The polymer molecules have been modeled as a pearl necklace of freely jointed hard spheres and the solvent as hard spheres, both having Yukawa-type attractions and the mixture being confined between attractive Yukawa-type surfaces. The present theory treats the ideal gas free energy functional exactly and uses weighted density approximation for the hard chain and hard sphere contributions to the excess free energy functional. The attractive interactions are calculated using the direct correlation function obtained from the polymer reference interaction site model theory along with the mean spherical approximation closure. The theoretical predictions on the density profiles of the polymer and the solvent molecules are found to agree quite well with the Monte Carlo simulation results for varying densities, chain lengths, wall separations, and different sets of interaction potentials.
提出了一种密度泛函理论，用于研究吸引力对限制在表面之间的聚合物溶液结构的影响。聚合物分子被建模为自由连接的硬球的珍珠项链，溶剂为硬球，两者都具有 Yukawa 型吸引力，且混合物被限制在有吸引力的 Yukawa 型表面之间。本理论精确处理理想气体自由能泛函，并对硬链和硬球对过量自由能泛函的贡献采用加权密度近似。利用从聚合物参考相互作用位点模型理论获得的直接相关函数以及平均球近似闭合来计算吸引力相互作用。发现关于聚合物和溶剂分子密度分布的理论预测与不同密度、链长、壁间距以及不同相互作用势集的蒙特卡罗模拟结果相当吻合。
