Growth conditions for carbon-infiltrated carbon nanotubes induce corrosion sensitization in 316L stainless steel

Abstract

Carbon Infiltrated Carbon Nanotubes (CICNTs) show promise as a surface modification for medical devices and implants due to their potential structural resistance to bacterial colonization. However, when 316L stainless steel is used as the substrate for CICNT growth, the steel loses its passivating layer and experiences oxidative corrosion when placed in an aqueous physiological environment. This effect, confirmed by both energy dispersive x-ray analysis and electrochemical potentiokinetic reactivation, may be attributed to carburization of the alloy during CICNT production. One potential solution to this problem was investigated by employing an indirect CICNT growth method that utilized protective thin films under the CICNT surface and a nitrocellulose-based coating on other exposed edges. Samples that had been thus treated exhibited no significant corrosion over a 48 h testing period.

Keywords

• Stainless steel
• Carbon infiltrated carbon nanotubes
• Electrochemical potentiokinetic reactivation
• Carburization
• Energy dispersive x-ray analysis