Plasma-assisted Grafting of Polyethylene Glycol (PEG) to Solid Substrates

Summary form only given. In this work inductively coupled argon plasma facilitates grafting of polyethylene glycol (PEG) to solid substrates. A plasma-polymerized primer coat was followed by a dip-coating procedure in a PEG/water solution. The primer coat was fabricated from a di (ethylene glycol) vinyl ether (EO2V) monomer vapor fed directly into the argon plasma. The primer/PEG composite film was studied with profilometer, visible-light microscope, scanning electron microscope (SEM), and impedance spectroscopy (IS). A "tape test" was used to evaluate film adhesion. Response of the PEG composite film to an AC electric perturbation was studied as a function of hydration state using IS. Withdrawing the primed substrate from the PEG solution at a prescribed and controlled speed contributed to uniformity of the deposited composite film. Most substrates were type 316 stainless steel; however preliminary work was completed on glass as well. Profilometer measurements show that the full composite film had a thickness of 850 nm, 200 nm of which was the primer. Optical micrographs of the film before and after a "tape test\´" revealed effective adhesion of the primer/PEG composite film to polished SS substrate. Stability of processed coupons with primer/PEG coating was evaluated by immersing the coupons half way into a salt solution at room temperature for 48 hours. Samples were analyzed before and after immersion by optical microscopy, profilometry and SEM. Prospective applications include coatings on orthopedic implants and food processing equipment. The effectiveness of this composite film at reducing bacterial adhesion will be investigated.