Synthesis and properties of a water-soluble single-walled carbon nanotube-poly(m-aminobenzene sulfonic acid) graft copolymer

Poly(m-aminobenzene sulfonic acid) (PABS), was covalently bonded to single-walled carbon nanotubes (SWNTs) to form a water-soluble nanotube-polymer compound (SWNT-PABS). The conductivity of the SWNT-PABS graft Copolymer was about 5.6 x 10(-3) S cm(-1), which is much higher than that of neat PABS (5.4 x 10(-7) S cm(-1)). The mid-IR spectrum confirmed the formation of an amide bond between the SWNTs and PABS. The H-1 NMR spectrum of SWNT-PABS showed the absence of free PABS, while the UV/VIS/NIR spectrum of SWNT-PABS showed the presence of the interband transitions of the semi-conducting SWNTs and an absorption at 17 750 cm(-1) due to the PABS addend.