Deposition of 2-oxazoline-based plasma polymer coatings using atmospheric pressure helium plasma jet

We report on the use of helium plasma jet for plasma polymerisation of 2-methyl-2-oxazoline (OX) on heated silicon substrates. The X-ray photo electron spectroscopy (XPS) characterisation shows a substantial improvement in film stability in buffer solution when depositing at temperatures above 50°C. Principal component analysis of the time-of-flight–secondary ion mass spectrometry data shows excellent correlation with the XPS results, providing insights into the degree of crosslinking in the plasma coatings as a function of substrate temperature. Atomic force microscopy images showed the topography of OX plasma polymer coatings deposited at 80°C and 120°C to be smoother with lower surface roughness values compared to those produced at 50°C. Finally, an 80% reduction in the adhesion of Staphylococcus epidermidis is achieved at the centre of the plasma coatings deposited at 120°C.