Micelle-Encapsulated Carbon Nanotubes: A Route to Nanotube Composites

Abstract

The unique properties of single-walled carbon nanotubes (SWNTs) have led researchers to investigate their use in composite materials for a variety of applications, including electrostatic discharge,1 structural reinforcement,2 and thermal dissipation.3 Despite this potential, the study of SWNT composite materials has been hindered by the poor solubility and processibility of SWNTs. Researchers have addressed these problems by high-energy sonication or processing techniques,4 by wrapping nanotubes with polymer chains,5 and by modifying the surfaces of nanotubes both co-valently6 and noncovalently.7 Herein, we report an alternative, noncovalent method of modifying SWNTs by encasing the nano-tubes within cross-linked, amphiphilic copolymer micelles. This encapsulation significantly enhances the dispersion of SWNTs in a wide variety of polar and nonpolar solvents and polymer matrices. In addition, because the copolymer shell is permanently fixed, th