Sol-gel transcription of silica-based hybrid nanostructures using poly(N-vinylpyrrolidone)-coated [60]fullerene, single-walled carbon nanotube and block copolymer templates

This review concentrates on our recent achievements that have enabled us to construct the novel organic/inorganic-hybridized materials. In a natural system, biomineralization processes are initiated where organic elements meet inorganic counterparts. This situation implies that both elements of organic and inorganic species should interact selectively with each other. In other words, one cannot join the organic and inorganic elements if there is no strong interaction in between. Our approach to solve this dilemma includes the use of a 'chemical glue'. The glue is the third component for hybridizing organic/inorganic materials. The glue should be selected so as to interact with both organic and inorganic components. The inorganic precursors contact with the organic template and react with the help of catalysts, which leads to the accumulation of the inorganic material selectively on the surface of the organic template. This process, especially its initiation step resembles the natural processes except for the use of glue. To apply this idea to sol-gel reactions, we adopted three templates different in a hierarchical sense: that is, [60] fullerene as a zero-dimensional template, single-walled carbon nanotube as a one-dimensional template and a cast film of styrene/4-vinylpyridine block copolymer as a two-dimensional template. Firstly, we successfully obtained the [60] fullerene aggregate-silica spherical clusters and SWNTs-silica hybridized nanorods even though no strong interaction exists between silica and carbonclusters. Secondly, this concept was applied to a thin film system having periodic surface structures. The films were prepared from polystyrene-poly(4-vinylpyridine) diblock copolymer. Once AcOH is extended to the film, the protonated phase attracts the metallic components and also acts as a catalyst to mediate the sol-gel reaction. These methods are feasible for hybridizing organic and inorganic materials with the aid of the amphiphilic nature of the glue.