Phase behavior of rod-coil diblock copolymer and homopolymer blends from self-consistent field theory.
Phase behavior of rod-coil diblock copolymer and homopolymer blends from self-consistent field theory.
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DOI：
10.1021/jp201972n
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发表时间：
2011-06
期刊：
影响因子：
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通讯作者：
Wendi Song;P. Tang;F. Qiu;Yuliang Yang;A. Shi
中科院分区：
文献类型：
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作者：
Wendi Song;P. Tang;F. Qiu;Yuliang Yang;A. Shi
用自洽场理论（SCFT）研究了棒状-卷曲嵌段共聚物与卷曲或棒状均聚物二元共混体系的相行为。杆块被建模为蠕虫状链和相应的SCFT方程求解使用混合方法，其中的取向相关的功能被离散的单位球，而位置空间相关的功能被处理使用谱方法。共混物的相图构造为均聚物的体积分数和相分离强度的函数。发现体系的相行为取决于均聚物的柔性。线圈均聚物的加入稳定了近晶相。低分子量卷曲均聚物倾向于与卷曲嵌段混合，而高分子量卷曲均聚物大多位于卷曲域的中心。另一方面，加入棒状均聚物强烈影响系统的取向有序，导致单层近晶-C，单层近晶-A和双层近晶-A相之间的过渡。
The phase behavior of binary blends of rod-coil diblock copolymers and coil or rod homopolymers is studied by the self-consistent field theory (SCFT). The rod blocks are modeled as wormlike chains and the corresponding SCFT equations are solved using a hybrid method, in which the orientation-dependent functions are discretized on a unit sphere, while the positional space-dependent functions are treated using a spectral method. Phase diagrams of the blends are constructed as a function of the homopolymer volume fraction and phase segregation strength. It is discovered that the phase behavior of the system depends on the flexibility of the homopolymers. The addition of coil-homopolymers stabilizes the smectic phases. Low-molecular weight coil-homopolymers tend to mix with the coil-blocks, whereas high-molecular weight coil-homopolymers are mostly localized at the center of the coil-domains. On the other hand, the addition of rod-homopolymers strongly affects the orientation ordering of the system, leading to transitions between monolayer smectic-C, monolayer smectic-A and bilayer smectic-A phases.