Ester-functionalized single-walled carbon nanotubes via addition of haloformates

Herein, a versatile method to introduce ester functional groups to the surface of single-walled carbon nanotubes (SWCNTs) was defined. Ester-modified SWCNTs were prepared via the direct reaction of haloformates with reduced SWCNTs [(nBu–SWCNT ^n? ) Li _n ⁺ ] generated by n-butyl lithium. Ultraviolet–Visible–near infrared and Raman spectroscopy verified the evidence of covalent surface functionalization. Solubility of functionalized SWCNTs (f-SWCNTs) enhanced compared to purified SWCNTs. Gold tagging to positively charged SWCNTs displayed the presence and distribution of functional groups, confirming the conversion of esters into amides. f-SWCNTs were further characterized by thermo-gravimetric analysis coupled with mass spectrometry and fourier-transform infrared spectroscopy.