Antibacterial Thin Films Deposited from Propane-Butane Mixture in Atmospheric Pressure Discharge.

Antibacterial coatings on biomedical instruments are of great interest because they can suppress bacterial colonization on these instruments. In this study, antibacterial polymeric thin coatings were deposited on teflon substrates using atmospheric pressure plasma polymerization from a propane-butane mixture. The plasma polymerization was performed by means of surface dielectric barrier discharge burning in nitrogen at atmospheric pressure. The chemical composition of plasma polymerized propane-butane films was studied by energy-dispersive X-ray spectroscopy (EDX) and FTIR. The film surface properties were studied by SEM and by surface energy measurement. The EDX analysis showed that the films consisted of carbon, nitrogen and oxygen from ambient air. The FTIR analysis confirmed, in particular, the presence of alkyl, nitrile, acetylene, imide and amine groups. The deposited films were hydrophilic with a water contact angle in the range of 13-23°. The thin film deposited samples were highly active against both S. aureus and E. coli strains in general. On the other hand, the films were cytocompatible, reaching more than 80% of the cell viability threshold compared to reference polystyrene tissue.