Plasma immersion ion implantation of polymers and silver-polymer nano composites

Biocompatibility and wear resistance are the outstanding properties of hydrogenated diamond like carbon (a-C:H), making it a very suitable material for medical applications, especially as a coating for joint replacing implants. Recently the demand for additional antimicrobial features of such coatings is becoming more and more pronounced. One possibility is the introduction of silver particles, which has already been done for a variety of polymer based products. We have developed a hybrid synthesis method to produce silver nano particle containing a-C:H based on the ion induced transformation of silver-polymer nano composites into Ag containing a-C:H. Now those results have been transferred to plasma immersion ion implantation (PIII), which allows a 3D treatment and thus is the next step towards industrial application. PIII experiments have been conducted with a mixture of CH4 and Ne as well as Ar with a pulsed bias of 40 M From beam line ion implantation experiments, the correlation of fluence and ion energy with film properties is well known, so this work is focused on the investigation of plasma etching and sputtering effects, caused by direct exposure to the plasma. It will be shown, that these effects can be compensated by adding hydrocarbon species to the plasma. Using this method, film properties like density, hydrogen content and sp(3) fraction comparable to those of typical a-C:H can be achieved. RBS, ERD and Raman spectroscopy are used to investigate and to understand the densification process. (C) 2009 Elsevier B.V. All rights reserved.