规则星形高分子之间的相互作用势的自洽场研究

用自洽场理论方法计算了星形高分子之间的相互作用势, 并与标度理论的推测以及基于粒子的分子动力学模拟方法的结果进行了比较. 自洽场理论计算得到的星形高分子之间的二体相互作用势与标度理论推测的结果基本一致: 当两个星形高分子核心之间的距离小于其对应的等效软球的半径R时, 二体相互作用势U与星形高分子核心之间的距离d及官能度f之间的关系为U(d)∝-f 3/2 ln(d/R). 当星形高分子核心间距离较小, 相互作用势与星形高分子核心间距离的对数呈线性关系时, 三体相互作用为吸引作用, 但其强度约等于二体作用的10%. 因此, 以二体作用为基础的基于粒子的模拟方法是基本合理的.

Effective Interaction Potentials Between Regular Star Polymers by Self-consistent Field Theory

The effective pair potential and triplet potential of regular star polymers in athermal solvent were calculated by using self-consistent field theory(SCFT), and were compared to the results of scaling arguments and other particle based simulations.  The pair potential is a function of the distance between cores of the two star polymers and their functionality, which has the scaling form: U(d)∝-f3/2ln(d/R).   The triplet potential is attractive when the closest distance among the cores of the three star polymers is less than the effective dimension of the star polymers and its magnitude is only 10% of the pair potential.  Therefore, the pair potential contributes largely to the total interaction potential, which validates the particle based on the simulations where only the pair potential was considered.