الفهرس 
Plasma State of MatterOnly 14 pages are availabe for public view
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Abstract
Low temperature (LT) (non-equilibrium) plasmas have found wide applications in materials processing. Particularly dielectric barrier discharge (DBD) offers one of the most effective non-thermal plasma sources at atmospheric pressure. Moreover, owing to the low operational and maintenance costs, simplicity of the equipment, and non-requirement of an expensive vacuum system. The system used has a planar geometry with ordinary glass (having a thickness of 2 mm) as a dielectric and operated with air, argon, and oxygen gases. This thesis aims to study the characteristics of DBD system and its application for surface treatment of some commercial materials like the viscose textile and the biaxially oriented polypropylene (BOPP) polymer which is used for packaging applications. Various electrical measurements were done on the DBD cell under varying conditions of gas type, gap distance and the peak value of the applied external voltage. A set of electrical measurements (dissipated power, dielectric capacitance and the charge transferred during one active discharge phase) were done by using the Lissajous figure method. The dissipated power is found to increase with peak voltage for all gases, but it has a non-monotonic relation with the gap width. At a gap width of 3 mm the power dissipated is maximum for all gases. The dielectric capacitance of the cell (measured from Lissajous figure) has a low value at low peak voltages and saturates to its true value at higher peak voltages. For all gases, the charge transferred during one active discharge phase increases with peak voltage. In the case of air plasma, a high value of the transferred charge is noticed at low peak voltages; this initial increase is caused by the water vapour content of ambient air. The charge transferred during one active discharge phase in the case of argon plasma is the highest. Polypropylene (PP) polymer is intrinsically hydrophobic. Because of this hydrophobicity it suffers from poor printability and thus does not adhere well to other substances. In this study air and oxygen plasmas, generated by a planar DBD cell with a 2 mm gap width and a 2 mm thick glass dielectric, have been used for enhancing the hydrophilicity of the BOPP polymer surface. The BOPP surfaces have been exposed to plasmas for different times at a discharge power of 16 W for both air and oxygen plasmas. Surface characterization is achieved by measuring water contact angle (CA),