三维自组装:从多分散的纳米粒子到单分散的超级纳米粒子

如何将具有特殊光、电性能的单个无机纳米粒子按照人类的意愿构建成宏观尺度、具有特定结构和性质的集合体,一直是当今科学界最具挑战性的前沿课题之一。我们发现,尺寸分布不均一的无机纳米粒子能自发组装为尺寸均一、具有核/壳结构的超级纳米粒子。这种多分散纳米粒子的自限制生长过程由纳米粒子自身的库仑排斥力和范德华吸引力间的平衡所控制。对这些相互作用力本质的认识为纳米粒子组装基元的可控设计和合成提供了理论基础,并可用于构建包括具有分级结构的胶体晶体在内的各种自组装结构,为纳米粒子的实际应用提供了新途经。此外,该研究结果对于理解单分散性的病毒等生物体系和聚合物等有机大分子超结构的形成具有指导意义。

Three-dimensional Self-assembly: From Polydisperse Nanoparticles to Monodisperse Supraparticles

One of formidable challenges for chemists and material scientists at present is how to construct macro-assembly with specific structures and properties by u sin g nanoparticles with special optical and electrical properties as building blocks. In the present work, we have found that polydisperse nanoparticles can self-assemble into monodisperse supraparticles with core/shell structures. This self-limiting growth process is governed by a balance between electrostatic repulsion and van der Waals attraction. The generic nature of the interactions creates flexibility in the composition, size and shape of the constituent nanoparticles, and leads to a large family of self-assembled structures, including hierarchically organized colloidal crystals. In addition to a novel approach for fabrication of functional nanomaterials, this study can help us to deep unders tan d the formation mechanisms of some organic superstructures, such as monodisperse virus particles and polymers.