MWCNT-based surfaces with tunable wettability obtained by He+ ion irradiation

Abstract A study of He+ ion irradiation influence on the wettability of the multi-walled carbon nanotubes is presented. Tablets of pressed nanotubes of two types with different diameters were prepared and irradiated by 80 keV He+ ions. Raman and X-ray photoelectron spectroscopies showed the differences in the rate of radiation-induced defect formation for different types of nanotubes. The formation of cross-links between the layers of nanotubes under ion irradiation was demonstrated by the molecular dynamics simulation. Contact angle changes drastically with an increase in the fluence for both types of nanotubes: at low fluences superhydrophobic surfaces are formed, with an increase in the fluence a significant reduction in contact angle is observed, especially for the nanotubes of smaller diameters.