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 × 10–3 S cm–1, which is much higher than that of neat PABS (5.4 × 10–7 S cm–1). The mid-IR spectrum confirmed the formation of an amide bond between the SWNTs and PABS. The 1H 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 semiconducting SWNTs and an absorption at 17 750 cm–1 due to the PABS addend.