Preparation of Hydrophobic Viscose Fabric Using Nitrogen DBD and Copper Ions Sorption

Plasma treatment of viscose cellulose fabric was performed using the atmospheric pressure dielectric barrier discharge (DBD) in nitrogen. Samples were treated using nonthermal plasma, and change of sorption properties with plasma energy density was investigated. It was found that using low energy of discharge, modified viscose samples become less hydrophilic and their wettability is significantly reduced. The observed hydrophobic effect was investigated and confirmed throughout series of experiments, by measuring a change in wetting time and in the level of aqueous liquid repellency. Structural changes were monitored using SEM, AFM, and XPS. It was established that increase of roughness combined with removal of hydrophilic polar groups from the surface of cellulose using plasma represents a novel approach to impart hydrophobicity onto hydrophilic textile. An additional binding of copper ions to nitrogen DBD treated cellulose produces a cross‐linking effect, i.e., an occupation of remaining hydrophilic groups on the fabric surface and provides so called “petal effect” where drops of water stick to the fabric surface when the fabric is tilted for 180°. This novel procedure for obtaining hydrophobic cellulose could be used for a preparation of special protective textile materials with cost and time effective methods and chemicals. Wettability of viscose is evaluated after DBD treatment in nitrogen and it is found that treatment reduced hydrophilicity of viscose. During DBD treatment, removal of polar hydroxyl groups and increase of roughness occurr on the fabric surface which impair interaction with water. Sorption of copper ions onto DBD treated viscose occupy remaining polar groups and cause the petal effect on viscose fabric.