CHARACTERIZATION OF SUPER HYDROPHILIC FILMS PRODUCED IN DBD PLASMA AT ATMOSPHERIC PRESSURE

This study focuses on the production of polyethylene glycol-like films (ppEG) under plasma conditions, using plasma discharge polymerization at atmospheric pressure. The plasma source consists of a dielectric barrier discharge (DBD) which operates in helium gas flow with a glass-like dielectric. The films were characterized by Atomic Force Microscopy (AFM) operating in tapping mode, contact angle measurements, Fourier transform infrared spectroscopy, UV-VIS spectroscopy and X-ray photoelectron spectroscopy. XPS analysis of ppEG films revealed peaks corresponding to the chemical C-C bonds, C-O bonds and C-O-C bonds, which are in good agreement with the chemical formula. The wettability of the ppEG films showed a super-hydrophilic character (the contact angles are smaller than 10 degrees). The topography of polymer films shows a granular structure with diameter less than 1 mu m. The value of the root mean square roughness (R-rms) is 6.9 nm immediately after the polymerization and increases to 15.5 nm after one week. This kind of surfaces obtained under plasma condition is excellently suited for medical applications like biosensor, biochip, drug delivery etc.