Functionalization of Carbon Nanotubes through Polymerization in Micelles: A Bridge between the Covalent and Noncovalent Methods

The fabrication of tailor-made functional hybrid materials that preserve and combine the properties of their building blocks is a central issue of nanosciences. In particular, the development of efficient techniques for the functionalization of carbon-based nanomaterials preserving their exceptional quality, while robustly enriching their functionalities (in particular their optical properties), is highly desirable for demanding applications. In this work, we describe a new method of functionalization of carbon nanotubes which combines most advantages of both covalent and noncovalent methods without their principal drawbacks. Our method is based on the controlled polymerization of hydrophobic molecules on nanotubes dispersed in micelles. This approach permits us to obtain carbon nanotube hybrids exhibiting high stability while preserving their π-conjugated system responsible for their outstanding optical and electrical properties. The nanotube hybrids can be purified, manipulated, and dispersed in various solvents without loss of their functionality. Extensive characterizations based on optical and microscopic measurements demonstrate the strength of this method for designing new functional materials.