Surface Activation and Coating on Leather by Dielectric Barrier Discharge (DBD) Plasma at Atmospheric Pressure

In this study investigations of the effect of atmospheric pressure plasma activation and plasma coating on leather surface properties were performed. The plasma treatments of leather samples were carried out with a planar dielectric barrier discharge (DBD) at atmospheric pressure. Different gases (O-2, N-2) were used for activating the leather surface and thin layers were deposited on to the finished leathers with hexamethyldisiloxane (HMDSO) and tetraethyl orthosilicate (TEOS) precursors. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to characterize the surface properties of the treated leathers. The chemical composition of the leather surfaces was evaluated by energy dispersive x-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The surface state of the leathers was evaluated by contact angle measurements. After plasma treatment, the uneven surface of natural leather tends to become smooth by ionic bombardment of the plasma. Experiments show that plasma treatment with TEOS and HMDSO improves the waterproof quality of leather while plasma activation with gases increases its hydrophilic property. It was concluded that application of plasma activation in combination with plasma coating can be useful for enhancing the hydrophobic and fastness properties of leathers.