Thin Film Deposition on Open-Cell Foams by Atmospheric Pressure Dielectric Barrier Discharges

Thin films are deposited on open-cell polyurethane (PU) foams using an atmospheric pressure dielectric barrier discharge (DBD) fed with helium and hexafluoropropene (C3F6). During deposition processes, a foam substrate is sandwiched between the dielectric-covered electrodes of a parallel plate DBD reactor, so that the discharge can ignite also inside its three-dimensional (3D) interconnected porous structure. This affords the deposition of a fluorocarbon coating on both the exterior and interior of the foam. Scanning electron microscopy (SEM) observations allow estimating the thickness of the coating deposited on the foam struts, while X-ray photoelectron spectroscopy (XPS) analyses show moderate changes in surface chemical composition moving from the outer to the inner surfaces of the plasma-treated foams under all explored experimental conditions.