为了理解聚合物共混、团聚以及溶剂挥发等实验过程的物理图像，本项目中我们将结合自洽场理论与分子动力学模拟来研究聚合物Globule之间的相互作用。首先，我们通过固定质心得到良溶剂下的局部涨落的单链Globule结构及其生成自由能，根据化学势相等的热力学相平衡条件，修正Flory理论相图；其次，研究两个Globule之间的相互作势及链密度分布随质心距离的变化，明确Globule融合时的平均作用势与相互作用参数及分子量之间的关系，并拓展到多链体系；最后结合分子动力学模拟来验证自洽场理论，从而理解高分子从稀溶液到亚浓溶液转变的物理图像，理论的团聚速率与实验巨大偏差以及高分子共混时边界处高分子链的穿插。通过理论与模拟相结合，从分子尺度上理解聚合物在溶剂挥发、团聚及共混三个实验过程中结构转变；同时所发展的理论方法及相关结果也有助于理解DNA凝聚、凝胶网络的塌缩以及分子之间的络合等有趣的自然现象。

In order to understand the chain physical picture during the process of polymer blends, aggregation and solvent evaporation, in this project, we propose to investigate the interaction between polymer globules by combining Self-Consistent Field Theory and Molecular Dynamics Simulation. First, to avoid the influence of translational entropy, we will obtain the single chain globule (or multi-chain cluster) density profile and corresponding free energy by fixing the polymer center of mass. In particular, phase diagram and solubility limit will be calculated by the respective equality of chemical potential of the polymer A and B in the two coexisting phases. With this single globule information as a guide, we then consider two globules interaction potential and corresponding physical picture as the function of the distance between two globules center of mass. Specifically, we will consider how the Flory-Huggins parameter χ and molecular weight affect the globules interaction potential. Multi-chain globules system will be performed to understand the physical picture during the transition from dilute solution to semi-dilute solution, the huge discrepancy of aggregation time between experiment and theory, and the interpenetration between A/B polymers at the interface in polymer blends. We expect that the theories developed in this proposal will provide a strategy as an effective mean of studying polymer blend, aggregation and solvent evaporation and serve as useful guide for many interesting phenomena, such as protein folding, DNA packing, gel network collapse and interpolymer complexation.