Photochemical modification and functionalization of carbon surfaces with fluorine moieties

The photolysis of perfluoroazooctane in the presence of carbon materials, such as diamond powder, films, diamond-like carbon films, nanodiamond films and single-walled carbon nanotubes, led to the chemical modification of their surface by the introduction of perfluorooctyl functional groups, which was confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, time-of-flight secondary ionization mass spectrometry, Raman spectroscopy and mass spectroscopy measurements. The carbon materials modified with fluorine moieties exhibited a reduced friction coefficient and a reduction of their surface energy, evaluated by the contact angle with water, compared with those of pristine carbon materials.