Effects of preparation temperature of SiC intermediate layers on the hemocompatibility of SiC/F-DLC composite film

Abstract

A series of SiC intermediate layers with different preparation temperatures is prepared by radio frequency magnetron sputtering on 316L stainless steel substrates by use of SiC crystal target and Argon as source gases. And then depositing fluorinated diamond-like carbon films (F-DLC) on a series of SiC intermediate layers under the same deposition condition with trifluromethane (CHF3) and Argon as source gases, and pure graphite as a target, a series of SiC/F-DLC composite films are obtained. The results show that the composite films have stronger adhesion and better hemocompatibility than that of the F-DLC films. The structure evolves with preparation temperatures of SiC intermediate layers and SiC/F-DLC composite films are studied by their Raman and Infrared transmission spectra. The results show that the proportion of C=C bonds and density of C-C unsaturated bonds in the SiC intermediate layers can be modulated by controlling the preparation temperature of SiC intermediate layers. The composite films have better hemocompatibility, especially with about 500 ℃ preparation temperature, may be attributed to holding higher proportion of aromatic ring structure and higher ratio of F/C in the composite films than the others. Formation of a considerable number of Si-C bonds and C=C bonds between SiC and F-DLC films may be the direct cause of strong adhesion. The addition of modest SiC intermediate layers between 316L stainless steel substrates and F-DLC films is feasible and effective to enhance films adhesion and improve film hemocompatibility.