Wettability and bloodcompatibility of a-C:N:H films deposited by PIII-D

Wettability of amorphous carbon films can be adjusted by doping with other elements, including F, Si, Ti, O and N. In this study, nitrogen-doped hydrogenated amorphous carbon (a-C:H:N) films were deposited on silicon wafers (100) by plasma immersion ion implantation–deposition (PIII-D) using C2H2 + N2 gas mixtures. Film composition and bonding structure were analyzed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Surface morphology of the films was characterized using an extended multimode nanoscope atomic force microscope (AFM). Wettability examination was performed using the sessile drop method. Bloodcompatibility of the films was assessed by in vitro platelet adhesion test. The results suggest that a-C:N:H film synthesized at the highest N2/C2H2 flux ratio of 2/1 presents better anti-thrombotic property than the low temperature isotropic pyrolytic carbon (LTIC) and this improvement of bloodcompatibility can owe to the increase of hydrophilicity of the film caused by N incorporation in the carbon network and additional increase of surface roughness.