Effects of centrifugation on the carboxyl modified single-walled carbon nanotubes suspension

Abstract

The centrifugal method is adopted to investigate the properties of carboxyl-terminated single-walled carbon nanotube (c-SWCNT) suspension. The chemical properties of each supernatant sample are confirmed with the Fourier transform infrared analysis (FTIR) and are not influenced by centrifugal process. The optical properties observed by ultraviolet-visible-near infrared spectroscopy (UV-VIS-NIR) show that the oxidation debris co-existed with c-SWCNTs in supernatant samples is a material creating perturbation at the electronic structure of the c-SWCNT. The G-band in the Raman results displays the red shift toward the low frequency side. The red shift of G-band is estimated because the removal of the oxidation debris by centrifugal method induces the de-doping effect on the electrical structure of SWCNTs.