Stabilizing the Frank-Kasper Phases via Binary Blends of AB Diblock Copolymers
Stabilizing the Frank-Kasper Phases via Binary Blends of AB Diblock Copolymers
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通过 AB 二嵌段共聚物的二元共混物稳定 Frank-Kasper 相
DOI：
10.1021/acsmacrolett.6b00685
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发表时间：
2016-10-01
影响因子：
7.015
通讯作者：
Shi, An-Chang
中科院分区：
文献类型：
--
作者：
Liu, Meijiao;Qiang, Yicheng;Shi, An-Chang
使用自洽场理论研究了 AB 二嵌段共聚物的二元混合物中复杂 Frank-Kasper 相的出现。通过比较自由能来检查不同有序相的相对稳定性，包括包含不同尺寸的非球形少数区域的 Frank-Kasper sigma 和 A15 相。所得相图显示西格玛相在系统的相空间中占据了很大的区域。通过两种不同长度和组成的二嵌段共聚物的分布阐明了α相的形成机制。特别是，两种类型的共聚物在不同域之间和每个域内发生的分离提供了调节少数域的大小和形状的机制，从而增强了 Frank-Kasper 相的稳定性。这些发现为理解软物质系统中 Frank-Kasper 相的形成提供了深入的了解，并提供了使用嵌段共聚物共混物获得复杂有序相的简单途径。
The emergence of the complex Frank-Kasper phases from binary mixtures of AB diblock copolymers is studied using the self-consistent field theory. The relative stability of different ordered phases, including the Frank-Kasper sigma and A15 phases containing nonspherical minority domains with different sizes, is examined by a comparison of their free energy. The resulting phase diagrams reveal that the sigma phase occupies a large region in the phase space of the system. The formation mechanism of the a phase is elucidated by the distribution of the two diblock copolymers with different lengths and compositions. In particular, the segregation of the two types of copolymers, occurring among different domains and within each domain, provides a mechanism to regulate the size and shape of the minority domains, thus enhancing the stability of the Frank-Kasper phases. These findings provide insight into understanding the formation of the Frank-Kasper phases in soft matter systems and a simple route to obtain complex ordered phases using block copolymer blends.