Catalytically active nanostructures derived from self-assembled block copolymer templates for rationally synthesizing single-walled carbon nanotubes and understanding the growth mechanism

Employing self-assembled catalyst-containing block copolymer templates, we have successfully generated a variety of highly ordered and uniform-sized catalytically active transition metal nanostructures. These catalystcontaining nanostructures have been used to produce highquality and single-walled carbon nanotubes (CNTs) with narrow size distribution. By tailoring the chain length of each block, we have rationally adjusted the size and spacing of catalyst nanostructures and subsequently the density and diameter of CNTs. Combining this bottom-up self-assembly technique with conventional top-down microfabrication processing, lithographically selective growth of CNTs on surfaces and CNTs suspended across trenches over a large surface area has been obtained. This facile and highly manufacturable method has enabled the investigation of the fundamental CNT growth mechanism. The interplay between catalyst and local environment, such as carbon gas concentration and substrate on CNT growth will be presented.