Anisotropic self-assembly of spherical polymer-grafted nanoparticles
Anisotropic self-assembly of spherical polymer-grafted nanoparticles
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DOI：
10.1038/nmat2404
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发表时间：
2009-04-01
期刊：
影响因子：
41.2
通讯作者：
Douglas, Jack F.
中科院分区：
文献类型：
--
作者：
Akcora, Pinar;Liu, Hongjun;Douglas, Jack F.
具有各向异性形状或相互作用的颗粒（例如钴纳米颗粒或蛋白质）自组装成高度延伸的结构是很容易理解的。然而，还没有通过实验建立的策略来从常见的球形纳米粒子创建一系列各向异性结构。我们证明，均匀接枝有大分子（“纳米粒子两亲物”）的球形纳米粒子，当它们分散在相应的均聚物基质中时，可以稳健地自组装成各种各向异性的超结构。理论和模拟表明，这种自组装反映了颗粒核心接近时的能量增益与接枝聚合物扭曲的熵之间的平衡。因此，粒子相互作用的有效方向性质是多体涌现性质。我们的实验表明，这种纳米粒子自组装方法可以对具有增强机械性能的聚合物纳米复合材料的产生进行相当大的控制。因此，接枝纳米粒子是用于创建具有重要实际应用的可调节和功能性粒子超结构的多功能构建块。
It is easy to understand the self-assembly of particles with anisotropic shapes or interactions ( for example, cobalt nanoparticles or proteins) into highly extended structures. However, there is no experimentally established strategy for creating a range of anisotropic structures from common spherical nanoparticles. We demonstrate that spherical nanoparticles uniformly grafted with macromolecules ('nanoparticle amphiphiles') robustly self-assemble into a variety of anisotropic superstructures when they are dispersed in the corresponding homopolymer matrix. Theory and simulations suggest that this self-assembly reflects a balance between the energy gain when particle cores approach and the entropy of distorting the grafted polymers. The effectively directional nature of the particle interactions is thus a many-body emergent property. Our experiments demonstrate that this approach to nanoparticle self-assembly enables considerable control for the creation of polymer nanocomposites with enhanced mechanical properties. Grafted nanoparticles are thus versatile building blocks for creating tunable and functional particle superstructures with significant practical applications.