Purification and functionalization of single-walled carbon nanotubes through different treatment procedures

Single-walled carbon nanotubes (SWCNTs)were purified by the combined use of ultrasonic- and microwave-assisted acid digestion. The results show that the method efficiently eliminates impurities, reduces solvent consumption, and prevents damage to the structure of the SWCNTs. The purified SWCNTs were given functionalization treatments with a nitric acid/sulfuric acid mixture. These acid-treated SWCNTs (A-SWCNTs) were then grafted with 3-isocyanatopropyl triethoxysilane (A-SWCNTs-Si). The A-SWCNTs and A-SWCNTs-Siwere used to improve interfacial interactions with polymers and to produce awell-dispersed SWCNTcomposite.