Han Wenchi, Tang Ping, Li Xuan, Qiu Feng, Zhang Hongdong, Yang Yuliang
Key Laboratory of Molecular Engineering of Polymer, Ministry of Education, Department of Macromolecular Science, Fudan University, Shanghai, China.
J Phys Chem B. 2008 Nov 6;112(44):13738-48. doi: 10.1021/jp801675z. Epub 2008 Oct 11.
Microphase separation and morphology of star ABC triblock copolymers confined between two identical parallel walls (symmetric wetting or dewetting) are investigated with self-consistent field theory (SCFT) combined with the "masking" technique to describe the geometric confinement of the films. In particular, we examine the morphology of confined near-symmetric star triblock copolymers under symmetric and asymmetric interactions as a function of the film thickness and the surface field. Under the interplay between the degree of spatial confinement, characterized by the ratio of the film thickness to bulk period, and surface field, the confined star ABC triblock copolymers are found to exhibit a rich phase behavior. In the parameter space we have explored, the thin film morphologies are described by four primary classes including cylinders, perforated lamellae, lamellae, and other complex hybrid structures. Some of them involve novel structures, such as spheres in a continuous matrix and cylinders with alternating helices structure, which are observed to be stable with suitable film thickness and surface field. In particular, complex hybrid network structures in thin films of bulk cylinder-forming star triblock copolymers are found when the natural domain period is not commensurate with the film thickness. Furthermore, a strong surface field is found to be more significant than the spatial confinement on changing the morphology of star triblock copolymers in bulk. These findings provide a guide to designing novel microstructures involving star triblock copolymers via geometric confinement and surface fields.
利用自洽场理论（SCFT）结合“掩膜”技术来描述薄膜的几何限制，研究了限制在两个相同平行壁之间的星形ABC三嵌段共聚物的微相分离和形态（对称润湿或去润湿）。特别地，我们研究了在对称和不对称相互作用下，受限近对称星形三嵌段共聚物的形态随薄膜厚度和表面场的变化。在以薄膜厚度与本体周期之比为特征的空间限制程度和表面场的相互作用下，发现受限星形ABC三嵌段共聚物表现出丰富的相行为。在我们探索的参数空间中，薄膜形态由四类主要形态描述，包括圆柱、穿孔片层、片层和其他复杂的混合结构。其中一些涉及新颖的结构，如连续基质中的球体和具有交替螺旋结构的圆柱体，在合适的薄膜厚度和表面场下观察到它们是稳定的。特别地，当本体圆柱形成星形三嵌段共聚物薄膜的自然畴周期与薄膜厚度不相称时，会发现复杂的混合网络结构。此外，发现在改变本体星形三嵌段共聚物的形态方面，强表面场比空间限制更显著。这些发现为通过几何限制和表面场设计涉及星形三嵌段共聚物的新型微观结构提供了指导。
