Side-wall functionalization of single-walled carbon nanotubes with 4-hydroxymethylaniline followed by polymerization of ε-caprolactone

Nanotube functionalization with 4-hydroxymethylaniline (HMA) via the diazonium salt method has been done on SWNT produced by the CoMoCAT process. Thermal analysis indicates 1 out of every 33 C atoms remains functionalized. Raman, FTIR, and optical absorption spectroscopy confirm the side-wall functionalization and show that it can be reversed by thermolysis. The OH group that is generated from the functionalization was used to start the ring-opening polymerization of E-caprolactone. The polymer thus produced (PCL) remains grafted to the nanotube as demonstrated by FTIR and a dramatic increase in suspendibility in chloroform. By combining several techniques (TGA, TPD, and TPO) a quantification of the number of polymer chains attached to the nanotube and their average length has been attempted.