Volume 39, Issue 2, 2018
Friday, February 2, 2018
Low temperature plasmas generated under atmospheric pressure condition has been gaining popularity for the surface treatment of materials due to their many advantages over conventional methods of treatment. This paper reports the study of surface modification of Polyethylene Terephthalate (PET) and Polypropylene (PP) by using atmospheric pressure dielectric barrier discharge (DBD) to improve their hydrophilicity. The discharge was generated by using a high voltage power supply (Vpp=50 kV) operating at line frequency (50 Hz). The electrical discharge was characterized by measurement of current and voltage. The samples before and after the treatment were studied using contact angle measurements, surface free energy calculations and scanning electron microscopy (SEM). Contact angles of three test liquids: distilled water, glycerol and diiodomethane with the polymer sample were used to determine total surface free energy and its polar and dispersive components. The results showed a remarkable decrease in contact angle with plasma treated samples indicating an improvement in hydrophilicity after the treatment. SEM analysis revealed that the treatment in DBD increases the roughness of the polymer surface resulting an increase in hydrophilicity. It was also observed that addition of a small quantity of argon to the discharge can significantly enhance the surface treatment.