| The surface-modification technique of materials by low temperature plasma (LTP) has been developed rapidly in past dozens of years, because it is a kind of sanitary and "dry" processing technique that has many attractive and competitive advantages. Therefore, it is a subject that has important academic significance and practical profit. Interest has grown in applying atmospheric pressure plasma to plasmas processing for the benefits this can offer to existing and potential new processes, because they do not require expensive vacuum systems and batch processing.Dielectric barrier discharge (DBD), also referred as silent discharge (SD), is characterized by the presence of at least one insulating layer in contact with the discharge between two planar or cylindrical electrodes connected to an ac power supply. As an effective method of producing non-equilibrium plasma, it has been paid much attention to due to its prospective applications in plasma chemical engineering, material surface modification, preparation of nanometer material, environmental protection and so on.In this thesis, a continuous modification embryo device of DBD is brought forward and developed, based on previous results of our research group and "Studies on the Surface Modification to Synthetic Fibers and Fabrics Using Atmospheric Pressure Dielectric BarrierDischarge" (No: 02SG28) supported by the "Dawn Project" of Shanghai Municipal Education Commission. The developing device is great significant to the designing and manufacture of the same type instruments, and also to the industrial application of atmospheric pressure plasma.Discharge power is measured by Lissajous figure of the oscilloscope in this thesis. The spectrum lines of nitrogen, helium and argon plasma emission at atmospheric pressure were separately recorded and qualitatively analyzed using spectral diagnosis equipment of atmospheric pressure DBD plasma. The spectrum lines of the second positive system of nitrogen (C 3 -B3g)3 two characteristic spectrum lines of helium (31P1 -21S0,33D-33P), and all of neutral argon atom spectrum lines in the range 680 to 780nm are recognized. For controlling the process of material surface modification promptly, the electron temperature of DBD plasma is quantitatively analyzed using relative intensity of argon spectrum lines.Ultrahigh molecular weight polyethylene (UHMWPE) fibers are very low density, high strength, high modulus, excellent energy absorbance, good impact resistance, good corrosion resistance and so on. However, UHMWPE fibers and its composites have not been extensively applied in reality, because UHMWPE fibers don't have heavy polar group, ultrahigh drawn fibers' surface is quite smooth, and fiber-matrix interfacial adhesive strength is low. It is difficult for both fibers and resin to form chemical bond. Thus, UHMWPE fibers' surface was modified continuously using atmospheric pressure argon DBD plasma. It is observed that the surface of treated fibers has formed the shallow holes of etching by scanning electron microscope (SEM) micrographs, and the bonding property between plasma treated fiber and epoxy resin has been improved greatly.Polypropylene (PP) fiber's interfacial adhesion is bad either, because its surface is smooth and fiber-matrix interfacial adhesivestrength is low. It is so difficult for both fibers and resin to form chemical bond that mechanics performances of the fiber composite are influenced. It is observed that the PP fibers' hydrophily and hygroscopicity are improved greatly due to etching effect after continuous plasma modification of atmospheric pressure DBD.It is investigated that the permittivity and thickness of the dielectric materials affect the wettability of textile materials, which are treated by DBD plasma. The experimental result demonstrates that it is beneficial for the surface modification of the material along with the permittivity increase and the thickness decrease.Atmospheric pressure DBD plasma has become higher and higher with its ever-increasing applications, but the...
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