[Surface modification of low temperature isotropic pyrolytic carbon artificial heart valve material]

In this study, nitrogen ion implantation and titanium oxide film synthesized by ion beam enhanced deposition were adopted to treat low temperature isotropic pyrolytic carbon (LTIC). The chemical composition and valence state of the modified layer were determined by X-ray photoelectron spectroscopy (XPS) and Auger eletron spectroscopy (AES). The electric resisitance and the surface energy were measured by the four-probe system and the contact angle method respectively. The blood compatibility of the modified LTIC was evaluated by clotting time measurement and platelet adhesion test. The results showed that carbon-nitride was formed on the LTIC surface after N+ ion implantation, which had some effect on the improvement of blood compatibility, and a significant improvement of blood compatibility of LTIC coated by TiO2-x film was verified.