Li Zhidong, Wu Jianzhong
Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521-0425, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2004 Sep;70(3 Pt 1):031109. doi: 10.1103/PhysRevE.70.031109. Epub 2004 Sep 24.
Density-functional theory (DFT) is applied to investigate the structural and thermodynamic properties of concentrated electrolyte and neutral component mixtures that are highly asymmetric in terms of both size and charge mimicking a crowded cellular environment. The excess Helmholtz energy functional is derived from a modified fundamental measure theory for the hard-sphere repulsion and a quadratic functional Taylor expansion for the electrostatic interactions. The direct correlation functions are obtained from the analytical solutions of the mean-spherical approximation. In the context of a primitive model where biomacromolecules are represented by neutral or charged hard spheres and the solvent is represented by a continuous dielectric medium, this DFT is able to take into account both the excluded-volume effects and the long-ranged electrostatic interactions quantitatively. The performance of the theoretical method has been tested with Monte Carlo simulation results from this work and from the literature for the pair correlation functions, excess internal energies, and osmotic coefficients for a wide variety of aqueous dispersions of charged and neutral particles.
密度泛函理论（DFT）被用于研究浓电解质和中性组分混合物的结构和热力学性质，这些混合物在尺寸和电荷方面高度不对称，模拟了拥挤的细胞环境。过量亥姆霍兹能量泛函由用于硬球排斥的修正基本度量理论和用于静电相互作用的二次泛函泰勒展开导出。直接相关函数通过平均球近似的解析解获得。在一个原始模型中，生物大分子由中性或带电硬球表示，溶剂由连续介电介质表示，这种DFT能够定量地考虑体积排除效应和长程静电相互作用。该理论方法的性能已通过这项工作以及文献中关于各种带电和中性粒子水分散体的对关联函数、过量内能和渗透系数的蒙特卡罗模拟结果进行了测试。
