Title: The Process-Directed Self-Assembly of Block Copolymer Particles Show Chinese title

Title: 块共聚物粒子的过程导向自组装

Abstract: The kinetic paths of structural evolution and formation of block copolymer (BCP) particles are explored using dynamic self-consistent field theory (DSCFT). It is shown that the process-directed self-assembly of BCP immersed in a poor solvent leads to the formation of striped ellipsoids, onion-like particles and double-spiral lamellar particles. The theory predicts a reversible path of shape transition between onion-like particles and striped ellipsoidal ones by regulating the temperature (related to the Flory-Huggins parameter between the two components of BCP, \chi_{AB}) and the selectivity of solvent toward one of the two BCP components. Furthermore, a kinetic path of shape transition from onion-like particles to double-spiral lamellar particles, and then back to onion-like particles is demonstrated. By investigating the inner-structural evolution of a BCP particle, it is identified that changing the intermediate bi-continuous structure into a layered one is crucial for the formation of striped ellipsoidal particles. Another interesting finding is that the formation of onion-like particles is characterized by a two-stage microphase separation. The first is induced by the solvent preference, and the second is controlled by the thermodynamics. The findings lead to an effective way of tailoring nanostructure of BCP particles for various industrial applications. Show Chinese abstract

Abstract: 结构演变和嵌段共聚物（BCP）粒子形成的动力学路径通过动态自洽场理论（DSCFT）进行探索。 结果显示，浸入不良溶剂中的BCP的过程导向自组装导致了条纹椭球、洋葱状粒子和双螺旋层状粒子的形成。 该理论预测通过调节温度（与BCP两种组分之间的Flory-Huggins参数，\chi _{AB}）以及溶剂对BCP一种组分的选择性，可以实现洋葱状粒子与条纹椭球粒子之间的可逆形状转变。 此外，展示了从洋葱状粒子到双螺旋层状粒子，然后再回到洋葱状粒子的形状转变的动力学路径。 通过研究BCP粒子的内部结构演变，确定将中间双连续结构转变为层状结构对于条纹椭球粒子的形成至关重要。 另一个有趣的发现是，洋葱状粒子的形成具有两阶段的微相分离特征。 第一阶段由溶剂偏好引起，第二阶段由热力学控制。 这些发现为针对各种工业应用定制BCP粒子的纳米结构提供了一种有效方法。