Phase Behavior of Rod鈥揅oil Diblock Copolymer and Homopolymer Blends from Self-Consistent Field Theory

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• 作者：Wendi Song ; Ping Tang ; Feng Qiu ; Yuliang Yang ; An-Chang Shi
• 刊名：Journal of Physical Chemistry B
• 出版年：2011
• 出版时间：July 7, 2011
• 年：2011
• 卷：115
• 期：26
• 页码：8390-8400
• 全文大小：1029K
• 年卷期：v.115,no.26(July 7, 2011)
• ISSN：1520-5207

文摘

The phase behavior of binary blends of rod鈥揷oil 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.