Functionalized MWCNT

The solubilization and chemical modification of carbon nanotubes represent an emerging area in the research on nanotubes-based materials. These reactions may roughly be divided into two categories: a direct attachment of functional groups to the graphitic surface and the use of the nanotube-bound carboxylic acids.

For the solubilization of carbon nanotubes, the attachment of relatively large functional groups to the nanotubes is required. For the functionalization of multi wall carbon nanotubes and their solubility in common organic solvents &/or water the amidation of nanotube-bound carboxylic acids with long-chain alkylamines (octadecylamine, for example), a variety of oligomeric and polymeric compounds have been used.

The functionalization breaks the nanotube bundles, which is essential to the solubility. For various polymer functionalized carbon nanotubes, there is direct microscopy evidence for the wrapping of individual nanotubes by the polymers. The solubility of the functionalized carbon nanotubes is sometimes strongly dependent on the reaction routes.

The functionalized carbon nanotubes in solution can be deposited directly onto a surface for various microscopy analyses. The solubility also offers unique opportunities in the development of carbon nanotubes-based materials and in the use of the solubilized carbon nanotubes as starting materials for further chemical and biochemical modifications.

The solubility of the carbon nanotubes associated with the functionalization and chemical modification offers excellent opportunities not only in the characterization and understanding of carbon nanotubes but also in the utilization of carbon nanotubes for various nanomaterials. Parameters such as structure, surface area, surface charge, size distribution, surface chemistry, and agglomeration state as well as purity of the samples have considerable impact on the reactivity of carbon nanotubes.