Dielectric properties of plasma polymerized poly(ethylene oxide) thin films

• Plasma polymerization increases non-fouling properties of poly(ethylene oxide).
• Plasma polymerization splits polyethylene oxide chain into oligomers and radicals.
• Oligomers and radicals recombine and construct a network including crosslinkings.
• Plasma power dependent crosslinking was investigated by dielectric spectroscopy.
• Dielectric and non-fouling properties of samples are optimized by changing plasma power.

Plasma polymerized poly(ethylene oxide) (pPEO) thin films were deposited by plasma assisted physical vapor deposition (PAPVD) with a constant thickness of 500 nm. The crosslinking density of pPEO films was controlled through the discharge power. Differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS) were applied to analyze the structural peculiarities of these coatings. Both DSC and BDS detected an increase of the crosslink density with power, which correlated with the increasing dynamic glass transition temperature (Tg). It was shown that plasma power changes the structure of plasma polymer, and dielectric spectroscopy may be a suitable technique for structural analysis.