Dispersion of single-walled carbon nanotubes using polyelectrolytes

In order to produce high performance SWNT-based products, it is necessary to make them soluble, reaching a certain degree of dispersion and stability in solution. Since SWNTs are mostly inert, being neither hydrophilic nor lipophilic, their use suffers from poor dispersion capability and weak interaction with other partners. Therefore, activating and modifying their surface is an essential prerequisite to processing. We report on a versatile nondestructive strategy for the non-covalent functionalization of SWNT by polyelectrolytes based on maleic anhydride copolymers. To evaluate competing stabilization characteristics, we explored the dispersing power of a range of maleic anhydride copolymers functionalized with several chromophore units: pyrene, cholesterol and Disperse Red 1. The surface modification of SWNT is straightforward and efficient for making them dispersible in water and in other organic solvents and for producing nanometer-scale materials suitable for nanotechnology, medicinal chemistry and environment friendly solar cell applications.