用密度泛函理论预测带电半透膜性质

从分子水平上研究半透膜的性质在生命科学、化学以及化学工程中有着重要的作用。该文采用密度泛函理论研究了带电半透膜附近各种离子的分布情况,其中除静电作用外,膜与其附近的离子之间的色散能用方阱势能函数来表示。研究表明用密度泛函理论预测的不同膜面电荷密度和不同离子直径比情况下离子在半透膜附近密度分布与M on teC arlo模拟数据符合得很好。密度泛函理论预测结果表明,膜面电荷密度越大,被吸附到膜中的离子越多,膜面电荷对大离子密度分布的影响要大于小离子。

Prediction of properties of charged semipermeable membranes using density functional theory

The separation ability of semipermeable membranes needs to be understand from a molecular point of view for applications in the life sciences, chemistry, and chemical engineering. A density functional theory was developed to calculate the ionic profiles around a charged semipermeable membrane. The electrostatic potential and the square-well potential were used to describe the interactions between the membrane and the surrounding ions. The ionic density profiles predicted by the density functional theory are in excellent agreement with Monte Carlo results for various membrane surface charge densities and ionic diameter ratios. The results predicted using density functional theory show that a large number of ions are absorbed into the membrane at high charge density and that the membrane surface charges have a greater effect on the macroions than on the microions.