Indexed on: 25 Jan '17Published on: 25 Jan '17Published in: ACS Applied Materials & Interfaces
Plasma polymerization using hydrophobic monomers in the gas phase is a well known technology in order to generate hydrophobic coatings. However, synthesis of functional hydrophobic coatings using plasma technology in liquids has not yet been accomplished. This work is consequently focused on polymerization of a liquid fluorinated monomer on cotton fabric initiated by atmospheric plasma in dielectric barrier discharge configuration. Functional hydrophobic coatings on cotton were successfully achieved using in situ atmospheric plasma initiated polymerization of fluorinated monomer dissolved in ethanol. Gravimetric measurements reveals that the amount of polymer deposited on cotton substrates can be modulated with the concentration of monomer in ethanol solution and crosslinking reactions occur during plasma polymerization of fluorinated monomer even without the presence of a crosslinking agent. FTIR and XPS analysis were used in order to study the chemical composition of hydrophobic coatings and to get insights into the physicochemical processes involved in plasma treatment. SEM analysis reveals that at high monomer concentration, coatings posses a three dimensional pattern with a characteristic interconnected porous network structure. EDX analysis reveals that plasma polymerization of fluorinated monomers takes place preferentially at the surface of cotton fabric and negligible polymerization takes place inside cotton fabric. Wetting time measurements confirm the hydrophobycity of cotton coatings obtained although equilibrium moisture content was slightly decreased. Additionally, the abrasion behavior and resistance to washing of plasma coated cotton has been evaluated.