A general approach to chemical modification of single-walled carbon nanotubes with peroxy organic acids and its application in polymer grafting

The previous work on the functionalization of single-walled carbon nanotubes (SWCNTs) with peroxytrifluoroacetic acid under ultrasonication is extended to other peroxy organic acids including m-chloroperbenzoic acid and 2-bromo-2-methylperpropionic acid (BMPPA). Systematic characterization of the treated SWCNTs shows that oxygen-based functional groups and the ester groups with CI or Br substituents were introduced to the nanotubes, demonstrating that the peroxy organic acid treatment is a general approach to chemical modification of SWCNTs. The extent of functionalization depends on the acidity, oxidizability, and concentration of the peroxy organic acids. Furthermore, the attached reactive moieties allow the chemical coupling of SWCNTs to other materials. By using BMPPA-SWCNTs as the initiator, poly(methyl methacrylate) was grafted to SWCNTs through atom transfer radical polymerization.