Process-Accessible States of Block Copolymers.
Process-Accessible States of Block Copolymers.
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DOI：
10.1103/physrevlett.118.067801
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发表时间：
2017-02
影响因子：
8.6
通讯作者：
De-Wen Sun;M. Müller
中科院分区：
文献类型：
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作者：
De-Wen Sun;M. Müller
过程导向的嵌段共聚物自组装是指可重复地将结构形成动力学从开始的不稳定状态引导到选择的亚稳介结构的热力学过程。我们研究了线性ACB三嵌段共聚物在中间C嵌段从B快速转化为a后的自组装动力学。这个原型过程（例如光化学转化）将ABB共聚物的初始平衡中间相转化为定义明确但不稳定的AAB共聚物的起始状态。从这种不稳定状态产生的自发结构形成被困在亚稳介结构中，我们系统地探索了通过改变初始和最终状态的嵌段共聚物组成可以制造哪些亚稳介结构。除了线性AB二嵌段共聚物的平衡介相外，该过程可达态图还包括7个亚稳周期介相结构，其中包括Schoen的F-RD周期最小表面。一般来说，我们观察到AAB共聚物的最终亚稳介相结构与ABB共聚物的初始平衡介相具有相同的对称性。
Process-directed self-assembly of block copolymers refers to thermodynamic processes that reproducibly direct the kinetics of structure formation from a starting, unstable state into a selected, metastable mesostructure. We investigate the kinetics of self-assembly of linear ACB triblock copolymers after a rapid transformation of the middle C block from B to A. This prototypical process (e.g., photochemical transformation) converts the initial, equilibrium mesophase of the ABB copolymer into a well-defined but unstable, starting state of the AAB copolymer. The spontaneous structure formation that ensues from this unstable state becomes trapped in a metastable mesostructure, and we systematically explore which metastable mesostructures can be fabricated by varying the block copolymer composition of the initial and final states. In addition to the equilibrium mesophases of linear AB diblock copolymers, this diagram of process-accessible states includes 7 metastable periodic mesostructures, inter alia, Schoen's F-RD periodic minimal surface. Generally, we observe that the final, metastable mesostructure of the AAB copolymer possesses the same symmetry as the initial, equilibrium mesophase of the ABB copolymer.