以目标结构为导向的嵌段共聚物自组装的理论研究

在本项目中，我们将基于异相成核的概念，在嵌段共聚物体系中实现三类感兴趣的目标结构：大尺度多层球结构、单一手性螺旋结构、具有图案化分布的缺陷结构，分别使用含时金兹堡-朗道理论模拟方法和自洽平均场理论研究嵌段共聚物自组装形成这些目标结构的动力学过程和热力学稳定性。具体包括：（1）设计诱导图案，在三维空间实现球状相的异相成核生长，获得大尺度有序的单层和多层球有序结构；（2）在圆柱内表面引入手性诱导图案，针对多种嵌段共聚物体系（AB，ABA，ABn星型等），预测形成单一手型螺旋结构的诱导图案，揭示手性图案诱导嵌段共聚物形成单一手型螺旋结构的内在机理；（3）设计晶核形状和位置，诱导多个相区的成核生长，通过相区融合在相区边界形成形态各异的缺陷，包括单个缺陷、多个缺陷以及带状缺陷，研究单个缺陷的产生和演化过程，探索多个缺陷的相互作用机理，以及调控带状缺陷的取向和位置形成感兴趣的缺陷图案。

In the proposal, we aim to obtain three types of desired interesting phase-separated structures from the block copolymer self-assembly via the.heterogeneous nucleation strategy that is proceeded by coupling the nucleation process with the external nuclei, including the large-scale ordered multi-layer spherical structures, helical structures with a specific handedness, and defects packed into desired patterns. The self-consistent field theory and the time-dependent Ginzburg-Landau theory simulation are applied to study the thermodynamics and kinetics of the self-assembly of block copolymers into these targeted structures, respectively. The main research includes: (1) designing direction patterns to achieve the heterogeneous nucleation and growth of spherical phases in three-dimensional space and thus to obtain large-scale ordered singleand multi-layer spherical structures; (2) introducing chiral patterns onto the inner-surface of cylindrical nanopores for various block copolymers (AB, ABA, ABn multi-arm, etc) under the cylindrical confinement, to obtain the helical structures with a specific chirality and thus to reveal their formation conditions as well as the underlying mechanism; (3) programming the positions and shapes of external nuclei, to yield multiple domain grains of block copolymers that merge into each other leading to the formation of distinct defects, including single or.multiple defects and clusters of defects. We will explore the creation and annihilation mechanisms of these defects, their interactions, as well as the regulations of the clusters of defects into desired defect patterns.