Carbon Nanotubes Encapsulated in Wormlike Hollow Silica Shells

Marek Grzelczak, Miguel A. Correa-Duarte, and Luis M. Liz-Marzán

Small 2006, 2, 1174–1177

The worm turns: Carbon nanotubes (CNTs) are encapsulated within predesigned, wormlike, hollow silica capsules (see image). The preparation strategy comprises a two-step process; silica coating of the CNTs is followed by selective dissolution from the inside out. The silica coating involves the initial deposition of a thinner shell at low pH values, followed by the growth of an outer shell at higher pH values, with a controlled thickness that determines the final outer diameter of the capsule.