Plasma deposition of silver nanoparticles onto poly(ethylene terephthalate) surfaces for the preparation of antimicrobial materials

Poly(ethylene terephthalate) (PET) films were surface-modified according to microwave plasma activation allowing for dithiol functions grafting (1,6-hexanedithiol) in order to fabricate self-assembled photogenerated silver nanoparticles monolayers. The present study was carried out in constant discharge power conditions and the impact of the plasma treatment on PET wettability properties were reported. PET material modifications were characterized at various stages of the process: plasma activation, dithiol functionalization, and nanosilver grafting according to several experimental techniques: water contact angle measurements and X-ray photoelectron spectroscopy (XPS). The surface topography was studied by atomic force microscopy (AFM). Finally, antibacterial properties of PET material including silver nanoparticles were evaluated to determine the probability to reduce the surface bacterial adhesion of Staphylococcus aureus strain selected as pathogenic bacteria model. Surface grafted with silver nanoparticles was found to be particularly reactive and led to an inhibition of S. aureus adhesion around 96.2% in comparison with the unmodified PET material.