The creation of hybrid hierarchical structures by combining colloidal organic and inorganic building blocks remains a challenge due to the difficulty of preparing organic structural units of precise size and shape. Here we describe a design strategy to generate controlled hierarchical organic-inorganic hybrid architectures by multistep bottom-up self-assembly. Starting with a suspension of large inorganic nanoparticles (silica nanoparticles or silica-coated nanorods), we anchor uniform block copolymer micelle crystallites onto the nanoparticle, taking advantage of the interactions between repeat units in the micelle corona and the nanoparticle surface. These colloidally stable multi-component particles can initiate the living growth of uniform cylindrical micelles from their surface, leading to three-dimensional architectures. Structures of greater complexity can be obtained by extending the micelles via addition of a second core-crystalline block copolymer. In Figure 1A   we show a TEM image of an example in which poly(ferrocenylsilane-block-2-vinylpyridine) (PFS30-b-P2VP300) micelle crystallites have been adsorbed to the surface of silica-coated nickel hydrazine nanorods. When a colloidal suspension of the seed-coated nanorods in 2-propanol is treated with a solution of additional block copolymer in THF, the butterfly structures shown in Figure 1B are formed. This controlled growth of polymer micelles from the surface of inorganic particles opens the door to the construction of previously inaccessible colloidal organic-inorganic hybrid structures.

Hierarchical fabrication of colloidal hybrid mesostructures based on core-crystalline block copolymer micelles

248th National Meeting (2014)

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