Non-covalent dispersion of multi-walled carbon nanotubes in aqueous solution with hyperbranched polyethylene-g-poly(methacrylic acid)

Abstract

Carbon nanotubes (CNTs) have great potential applications in biomedical materials. However, the poor solubility of CNTs in water hinders their practical applications. Thus, an amphiphilic hyperbranched polyethylene-g-poly(methacrylic acid) (HBPE-g-PMAA) was synthesized to improve the solubility of multi-walled carbon nanotubes (MWCNTs) in water. The HBPE segment provided the CH–π interactions between HBPE and MWCNTs, while the PMAA segment gave the de-bundled MWCNTs good solubility and stability. In this way, the bundled MWCNTs were found to be dispersed efficiently into individual nanotubes by the HBPE-g-PMAA. The dispersing efficiency of MWCNTs was evaluated by TGA, TEM, SEM and AFM. The maximum concentration of MWCNTs was found to be 135 mg L⁻¹. Hence, the HBPE-g-PMAA was an efficient amphiphilic polymer-based dispersant for dispersion of MWCNTs in water, and might find potential application in biomedical systems and devices.