Morphologies of Core-Shell-Cylinder-Forming ABC Star Triblock Copolymers in Nanopores

自己组装 ABC 星 triblock 共聚物的行为能导致很多 nanostructures。确实，许多新、有趣的结构已经被发现了并且证明是在软事物理研究的热点。在这个工作，我们在不同条件下面介绍 core-shell-cylinder-forming ABC 星 triblock 共聚物的不同阶段图，包括有不同尺寸的在里面体积和毛孔几何学。在毛孔尺寸几何学和他们的相应结构之间的关系也被揭示。表面潜力的不同性质显著地回答那影响自己组装 ABC 星 triblock 共聚物的过程也被调查。

Simulation of Surface-Induced Morphology Transition and Phase Diagram of Linear Triblock Copolymers under Spherical Confinement

In this work,the nanostructures and phase diagrams of lamella-forming and cylinder-forming ABC linear triblock copolymers confined in spherical cavities are investigated on the basis of real-space self-consistent field theory.We designate specific monomer-monomer interactions and block composition and study morphology transformation under spherical confinement with a neutral surface.Various potentially valuable morphological structures,such as two-or three-colored spheres,rotational structures,and biconcave disklike structures,are identified in the phase diagrams constructed on confining diameters.Single confinement induces an obvious transformation of self-assembled structures,which still retain some of the conformational properties of bulk structures.We then focus on phase morphology under preferential surfaces.Absorption can smooth out differences in block ratios,and similar structures can be assembled from block copolymers with different proportions.We incorporate a non-centrosymmetric feature into our spherical confinement model and design a Janus adsorption field to explore unpredictable microphase behavior.Results show that the unbalance of the block ratio causes adsorption to exert a stable shaping effect on conformation.The influence of confinement on the degree of freedom of polymer chains disrupts the influence of adsorption on the complexity and transformation activity of self-assembled structures.The theoretical results correspond to recent experimental observations and contribute to the field functional material synthesis.

链刚性和剪切场对环形聚合物熔体中纳米颗粒分散和空间分布的影响

目的:一般情况下,纳米粒子在环形聚合物熔体中处于聚集状态。本文通过增加链刚性或施加稳定的剪切场来诱导纳米粒子在环形聚合物熔体中的聚集-分散转变,使环形聚合物中的纳米粒子达到最优的分散状态。创新点:同时改变链刚性和剪切场强度,诱导纳米粒子在分散的同时进行有序排列。方法:利用分子动力学模拟方法,研究纳米粒子在环形聚合物熔体中的分散和空间分布。结论:1.在较弱的高分子/纳米粒子(polymer-NP)相互作用力下,增加环链的刚性或施加剪切场,可以诱导纳米粒子(NPs)从聚集态向分散态过渡。2.增加链的刚性可以提高NPs在环形聚合物熔体中的分散度;NPs被半刚性(或棒状)环形聚合物链包裹,有效地避免了NPs间的聚集,促使其分散。3.随着剪切场强度的增加,聚集的NPs也会因polymer-NP相互作用、NP-NP相互作用以及剪切场之间的竞争而趋于分散;由于polymer-NP相互作用强,所以NPs的空间分布具有良好的有序性和分散性。4.同时考虑剪切场和链刚性,可有效提高NPs在环形聚合物熔体中的分散度和空间分布,而链刚性的增加干扰了NPs的有序结构。