Controlled dispersion of multiwalled carbon nanotubes modified by hyperbranched polylysine

Abstract

ABSTRACTHyperbranched polymers have been found effective in controlling the dispersibility of carbon nanotubes in aqueous solutions. In this study, hyperbranched polylysine (HBPL) was synthesized using lysine and N,N′‐methylenebisacrylamide as precursors via Michael addition. The HBPL then was used to noncovalently modify multiwalled carbon nanotubes (MWCNTs) to prepare MWCNTs‐HBPL. The obtained MWCNTs‐HBPL composites were characterized using FTIR spectroscopy, Raman spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The results showed that the HBPL was successfully attached to the surface of MWCNTs via noncovalent interactions. The dispersibility of the MWCNTs‐HBPL composites in aqueous solutions was investigated using digital photographs, ultraviolet–visible absorption spectroscopy, and zeta potential measurements. The results demonstrated that both the mass ratio of MWCNT to HBPL and the pH of the solution had a significant impact on the dispersibility of the MWCNTs/HBPL solution, suggesting that HBPL treatment is an effective method of controlling the dispersibility of MWCNTs in aqueous solutions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46249.