Dispersion and fluorescence properties of multiwalled carbon nanotubes modified with hyperbranched poly(phenylalanine-lysine)

Hyperbranched poly(phenylalanine-lysine) (HBP(P-L)) was synthesized by lysine, phenylalanine and N, N-dimethylbisacrylamide (MBA) via Michael addition reaction and characterized by Fourier transform infrared (FTIR) spectra, 13 CNMR and 1 HNMR. Furthermore, fluorescence spectroscopy indicates the fluorescence intensity of HBP(P-L) aqueous solutions increases with the concentration of HBP(P-L) increasing; Multiwalled carbon nanotubes (MWCNTs) were modified using HBP(P-L) for the purpose of preparing MWCNTs-HBP(P-L), which was characterized by FTIR, Raman analysis and thermogravimetric analysis (TGA). Visual inspection method, UV–vis absorption spectra and Zeta potential are adopted to evaluate the dispersion properties of MWCNT-HBP(P-L) aqueous solutions, and the results illustrate that HBP(P-L) does improve the dispersibility of MWCNT. Moreover, MWCNT-HBP(P-L) owns the best dispersibility in aqueous solution when the mass ratio is 1:60. Additionally, it presents an excellent linear relationship between the fluorescence intensity of MWCNTs-HBP(P-L) dispersion and the mass ratio of MWCNT-HBP(P-L). MWCNTs-HBP(P-L) exhibits unique dispersion properties as well as excellent fluorescence properties, which make the MWCNT-HBP(P-L) be potentially used in the field of optical materials.