Synthesis and characterization of pyrene bearing amphiphilic miktoarm star polymer and its noncovalent interactions with multiwalled carbon nanotubes

A novel amphiphilic miktoarm star polymer, polystyrene-poly(ethylene glycol)-poly(methyl methacrylate), bearing a pyrene group at the end of PS arm (Pyrene-PS-PEG-PMMA) was successfully synthesized via combination of atom transfer radical polymerization and click chemistry. The structure and composition of the amphiphilic miktoarm star polymer were characterized by gel permeation chromatography and ¹H NMR. The functionalization of multiwalled carbon nanotubes (MWCNTs) via "π-π" stacking interactions with pyrene-PS-PEG-PMMA miktoarm star polymer was accomplished and the resulting polymer-MWCNTs hybrid was analyzed by using ¹H NMR, UV-vis, fluorescence spectroscopy, and thermal gravimetric analysis. The high-resolution transmission electron microscopy and analytical techniques aforementioned confirmed that the noncovalent functionalization of MWCNT's with the amphiphilic miktoarm star polymer was successfully achieved. The MWCNT/pyrene-PS-PEG-PMMA exhibited significant dispersion stability in common organic solvents such as dimethyl formamide, chloroform, and tetrahydrofuran.