Stability of Two-Dimensional Dodecagonal Quasicrystalline Phase of Block Copolymers
Stability of Two-Dimensional Dodecagonal Quasicrystalline Phase of Block Copolymers
复制标题
嵌段共聚物二维十二方准晶相的稳定性
DOI：
10.1021/acs.macromol.8b01638
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发表时间：
2018-10-09
期刊：
影响因子：
5.5
通讯作者：
Shi, An-Chang
中科院分区：
文献类型：
--
作者：
Duan, Chao;Zhao, Mingtian;Shi, An-Chang
在包括自组装嵌段共聚物（BCP）熔体在内的各种凝聚态体系中都观察到准晶（QC）相。由于结构的非周期性，QC相热力学稳定性的理论研究是一个长期未解决的问题。本文采用组合方法研究了ABCB四嵌段共聚物形成的理想铺贴和随机铺贴两种模式的二维十二面准晶（DDQC）相的热力学稳定性。该方法利用自洽场理论结合Stampfli自相似构造精确计算周期DDQC近似的自由能，然后利用聚类模型预测非周期DDQC相位的稳定性。令人惊讶的是，我们发现了一个稳定的近似但亚稳态的理想平铺式DDQC结构。此外，随机平铺的DDQC结构作为相邻的两个周期子结构的介观共存可能会变得稳定。
Quasicrystalline (QC) phases have been observed in various condensed matter systems including self-assembling block copolymer (BCP) melts. Theoretical study of the thermodynamic stability of QC phases presents a long-standing unsolved problem because of the aperiodic nature of the structures. Here, we report a combination method to study the thermodynamic stability of two-dimensional dodecagonal quasicrystalline (DDQC) phase with both ideal tiling and random tiling patterns formed by ABCB tetrablock terpolymers. This method applies the self-consistent field theory coupled with the Stampfli self-similarity construction to accurately calculate the free energy of the periodic DDQC approximants and then uses a cluster model to predict the stability of aperiodic DDQC phase. Surprisingly, we find a stable DDQC approximant but metastable ideal tiling DDQC structures. Moreover, the random tiling DDQC structures as a mesoscopic coexistence of two neighboring periodic substructures of DDQC might become stable.