Plasma deposited silicon oxide films for controlled permeation of copper as antimicrobial agent

The aim of this study is to test silicon oxide (SiOx) coatings on copper surfaces as permeation barrier for copper ions affecting the release into the surrounding medium. SiOx films have been deposited on copper coated micro-structured titanium samples by means of a plasma jet. Siloxane layers have been formed from hexamethyldisiloxane (HMDSO) and oxygen using different mixing ratios. FT-IR spectroscopy reveal different SiOx layer characteristics depending on the HMDSO:O2 ratio. The permeation and release of copper is mainly determined by structural defects of the SiOx layer promoting pinhole corrosion and leading to enhanced Cu release compared to uncoated samples.