Position transitions of polymer-grafted nanoparticles in diblock-copolymer nanocomposites
Position transitions of polymer-grafted nanoparticles in diblock-copolymer nanocomposites
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DOI：
10.3144/expresspolymlett.2011.36
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发表时间：
2011
影响因子：
3.3
通讯作者：
Guangkui Xu;Xi-Qiao Feng
中科院分区：
文献类型：
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作者：
Guangkui Xu;Xi-Qiao Feng
嵌段共聚物/纳米粒子共混物的自组装在新型功能纳米材料的设计和制备中具有广阔的应用前景。精确控制嵌段共聚物基纳米材料中纳米粒子的空间位置对于实现某些特殊的物理性能和功能至关重要。在这里，我们采用自洽场方法从理论上研究了聚合物接枝纳米粒子在两嵌段共聚物中的自组装。研究发现，通过改变纳米粒子的尺寸和选择性，不仅可以制备各种自组装纳米结构，而且可以调节纳米粒子在纳米结构中的空间位置，无论是在共聚物界面还是在一个共聚物相的中心。较致密的接枝聚合物刷对纳米克莱斯起到屏蔽作用，并能将纳米粒子定位在一个共聚物相的中心。我们观察到的纳米结构转变是由熵和焓之间的竞争决定的。在大量模拟的基础上，构建了两个自流血的纳米结构的相图。该研究有助于优化设计具有所需纳米结构和增强性能的先进材料。
Self-assembly of block copolymer/nanoparticle blends has promising applications in the design and fabrication of novel functional nanomaterials. Precise control of the spatial positions of nanoparticles within block copolymer-based nanomaterials is crucial to achieve some special physical properties and functions. Here, we employ the self-consistent field method to theoretically investigate the self-assembly of polymer grafted-nanoparticles in a diblock copolymer. It is found that by varying the size and selectivity of nanoparticles, one can not only produce various self-assembled nanostruc- tures but also modulate the spatial positions of the nanoparticles, either at the copolymer interfaces or in the center of one copolymer phase, within the nanostructures. A denser grafted polymer brush plays a role of shielding effect on nanoparti- cles and can position them into the center of one copolymer phase. The nanostructural transition we observed is dictated by the competition between entropy and enthalpy. On the basis of a number of simulations, two phase diagrams of self-assem- bled nanostructures are constructed. This study may be helpful for optimal design of advanced materials with desired nanostructures and enhanced performance.