Features of the Formation of a Carbon Nano-Coating Obtained by Magnetron Sputtering on a Polyurethane Surface

Carbon coatings are used to modify the properties of surfaces (mechanical, biomedical, etc.). Of interest is the treatment of soft materials. In this paper, carbon is deposited onto the surface of two elastic polymers (polyurethanes) that differ in terms of the phase composition and stiffness by pulsed magnetron sputtering. As a result, an inhomogeneous carbon-containing coating with a thickness of 3 to 30 nm is formed. At the initial stage of treatment, carbon interacts with polymer atoms and the formation of hydrophobic coatings with a high surface energy occurs. As the thickness increases, the surface energy of the coating decreases, and a nanolayer of amorphous carbon forms on the surface. At a certain stage of coating deposition, a chaotic folded texture characterized by a spectrum of wavelengths and amplitudes is formed on the surface. The elastic modulus of the resulting coatings does not exceed several GPa. All the studied properties correlate both with the properties of the initial substrate and the number of carbon-deposition pulses. Due to their high activity and folded texture, such coatings are of potential interest in the creation of biomedical products.