Wang Yingying, Cui Jie, Han Yuanyuan, Jiang Wei
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Changchun 130022 , People's Republic of China.
University of Chinese Academy of Sciences , Beijing 100049 , People's Republic of China.
Langmuir. 2019 Jan 15;35(2):468-477. doi: 10.1021/acs.langmuir.8b03756. Epub 2018 Dec 31.
The phase behaviors of the giant surfactant constructed from a nanoparticle (NP) monotethered by a single AB diblock copolymer chain were investigated by combining self-consistent field theory and density functional theory. Three types of giant surfactants with different chain architectures were constructed via changing the location of NP on the diblock copolymer chain. The simulation results show that the introduction of the NP can induce phase separation of the originally disordered AB diblock copolymers, and phase diagrams as a function of the chain length ratio of A block and the attraction between A block and NP were constructed for the three giant surfactant systems. Via changing the location of NP from the end of B block to the AB-junction point and to the end of A block, the conformational entropies of the systems gradually decrease, leading to a significant difference in phase behaviors. When the NP is tethered to the end of B block, the giant surfactant system has the smallest phase-separation region in the phase diagram, and the resulting ordered structures have the smallest feature sizes. However, when the NP is tethered to the end of A block, the giant surfactant system has the largest phase-separation region, as well as the largest feature sizes of ordered structures. Moreover, the distributions of the NPs within microphase-separated domain can be well tailored by changing the chain length ratio of A block or the attraction between A block and NP in all of the three giant surfactant systems. These findings provide the guideline for the preparation of polymer-nanoparticle composites with controllable morphologies, desirable feature sizes, and precise NP distributions in experiments.
通过结合自洽场理论和密度泛函理论，研究了由单个AB二嵌段共聚物链单链连接的纳米粒子（NP）构建的巨型表面活性剂的相行为。通过改变NP在二嵌段共聚物链上的位置，构建了三种具有不同链结构的巨型表面活性剂。模拟结果表明，NP的引入可以诱导原本无序的AB二嵌段共聚物发生相分离，并针对三种巨型表面活性剂体系构建了作为A嵌段链长比和A嵌段与NP之间吸引力函数的相图。通过将NP的位置从B嵌段末端改变到AB连接点再到A嵌段末端，体系的构象熵逐渐降低，导致相行为存在显著差异。当NP连接到B嵌段末端时，巨型表面活性剂体系在相图中的相分离区域最小，所得有序结构的特征尺寸最小。然而，当NP连接到A嵌段末端时，巨型表面活性剂体系具有最大的相分离区域，以及有序结构的最大特征尺寸。此外，在所有三种巨型表面活性剂体系中，通过改变A嵌段的链长比或A嵌段与NP之间的吸引力，可以很好地调整NP在微相分离域内的分布。这些发现为在实验中制备具有可控形态、理想特征尺寸和精确NP分布的聚合物-纳米粒子复合材料提供了指导。
