Assessment of characteristics and cytotoxic effects of 316L stainless steel coated with a new titanium oxide nano-structure coating method

Abstract

In order to fabricate the TiO₂ nano-structure coating on the Ti-free stainless steel with good adhesion, commercially obtained 316L stainless steel (316L SS) plates were chemically treated by KOH aqueous solution including TiH₂ powder at 60ºC for 3 days in an oil bath shaker, and subsequently heated up to 550–800ºC under the air atmosphere. The crystal structure, color, adhesive strength and cytotoxic effects of coating were investigated. Fiber-like hydrogen titanate nano-structures were formed on the 316L SS surface and made a fine network. X-ray diffraction (XRD) patterns showed that hydrogen titanate phase converted to anatase and rutile after heat treatment above 550ºC. The heat treated sample at 800ºC for 1 h showed the highest adhesive strength and the lowest cytotoxicity. The alkali treatment method in this study is expected to be used on the other Ti-free metals with further research.