Recently, tremendous progress has been made in directed assembly of nanoscale building blocks by viewing entire NPs modified with various linkers (i.e., polymers, proteins, or DNAs) as molecular mimics. This strategy is opening new research frontiers in nanoscience and nanotechnology. Here we present a new strategy to fabricate supracolloidal molecules with well-defined valence via concurrent assembly of binary metallic NPs decorated with oppositely charged block copolymers (BCPs). The assembly of binary mixtures generated highly monodipersed dimer (AB), trimer (AB2), and tetramers (AB3), as well as AB4, AB5, AB6, with high purity by controlling the length of polymers, polymer brush density, and size ratio of NPs, and feed ratio of binary NPs. Our experimental and computational studies indicate that the nanostructures arise from the delicate interplay between the dimension match of the binary NPs, the charge density of BCP chains, and molecular weight of BCPs. More interestingly, this assembly approach constitutes a unique “self-limiting” assembly mechanism, that is, the neutralization of overall charges limits the further addition of NPs to the assembled supracolloids, arising from the flexibility of polymer tethers. The ability to construct multi-component assemblies with defined valence represents a promising step in the self-assembly of structurally complex functional materials.

Bottom-up design and self-assembly of supracolloidal molecules made from binary metallic nanoparticles

254th National Meeting (2017)

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