Directed self-assembly of a colloidal kagome lattice
Directed self-assembly of a colloidal kagome lattice
复制标题
DOI：
10.1038/nature09713
复制
发表时间：
2011-01-20
期刊：
影响因子：
64.8
通讯作者：
Granick, Steve
中科院分区：
文献类型：
--
作者：
Chen, Qian;Bae, Sung Chul;Granick, Steve
在材料化学和物理学中，一个具有挑战性的目标是自发地从设计好的构件中形成预期的上层结构。在晶体工程(1)和多孔材料设计（2-4）等领域，这通常涉及有机分子的构建块，有时与金属离子或簇一起工作。将这些想法转化为纳米颗粒和胶体大小的构建块可能会为新材料和新特性打开大门（5-7），但实现这一目标的途径仍未确定。在这里，我们展示了如何诱导胶体球自组装成复杂的预定胶体晶体-在这种情况下是胶体kagome晶格(8-12)-通过用简单的疏水区域图案装饰它们的表面。构建块是简单的微米大小的球体，具有相互作用（中间的静电排斥，两极的疏水吸引，我们称之为“三块Janus”），这些球体也很简单，但球体自组装成开放的kagome结构与之前已知的紧密排列的球体周期安排形成对比（13-15）。这种开放网络之所以有趣，有几个理论上的原因（8-10）。为了可能增强的功能，所得到的晶格结构具有两种孔系，一种在孔的边缘是疏水的，另一种是亲水的。这种从易于制造的（16）胶体构建块进行“收敛”自组装的策略对目标超胶体结构进行编码，不是在局部吸引点，而是在大的冗余吸引区域，并且可以扩展以形成其他超胶体网络。
A challenging goal in materials chemistry and physics is spontaneously to form intended superstructures from designed building blocks. In fields such as crystal engineering(1) and the design of porous materials(2-4), this typically involves building blocks of organic molecules, sometimes operating together with metallic ions or clusters. The translation of such ideas to nanoparticles and colloidal-sized building blocks would potentially open doors to new materials and new properties(5-7), but the pathways to achieve this goal are still undetermined. Here we show how colloidal spheres can be induced to self-assemble into a complex predetermined colloidal crystal-in this case a colloidal kagome lattice(8-12)-through decoration of their surfaces with a simple pattern of hydrophobic domains. The building blocks are simple micrometre-sized spheres with interactions (electrostatic repulsion in the middle, hydrophobic attraction at the poles, which we call 'triblock Janus') that are also simple, but the self-assembly of the spheres into an open kagome structure contrasts with previously known close-packed periodic arrangements of spheres(13-15). This open network is of interest for several theoretical reasons(8-10). With a view to possible enhanced functionality, the resulting lattice structure possesses two families of pores, one that is hydrophobic on the rims of the pores and another that is hydrophilic. This strategy of 'convergent' self-assembly from easily fabricated(16) colloidal building blocks encodes the target supracolloidal architecture, not in localized attractive spots but instead in large redundantly attractive regions, and can be extended to form other supracolloidal networks.