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Atmospheric plasma has developed rapidly in recent decades. Because it does not require a vacuum, continuous processing, energy saving and environmental protection, etc., causing widespread concern. Especially with regard to the surface modification of materials, the atmospheric pressure plasma treatment is not only can make the material surface becomes rough, and can be introduced to a hydroxyl group (-OH), carbonyl group (-C = O) a hydrophilic group, thereby increasing the surface energy of the material, to improve the wettability and adhesion of the surface of the material. Carbon fiber with high strength, high modulus, fatigue resistance, excellent performance, carbon fiber-reinforced composite materials have been widely used in many areas of aerospace, weapons manufacturing, automotive parts. Have not been surface-treated carbon fiber is restricted due to the low activity of its own surface in the composite material on the application. In this thesis research often characteristic of the plasma surface treatment of carbon fiber, and to simulate the discharge physics. Firstly, the use of laboratory developed its own design of coaxial tubular fiber processing unit (PLA-PLA) atmospheric pressure plasma discharge experiment, diagnosis through analysis of the plasma electrical parameters and emission spectra, research in different supply power and gas composition conditions under the plasma state, results show that the discharge discharge by some very fine silk, with the increase of the power frequency discharge filaments began concentrated. According to the analysis of the emission spectrum data, wherein the existence of a large number of active particles and free radicals, such as Ar, OH, and O, and these active particles and a radical of the intensity with increasing discharge power is enhanced. The adding of oxygen causes the strength of the emission spectra of reduced. And then use this atmospheric pressure plasma device processing the PAN-based carbon fiber, and processing parameters such as the ratio of argon / oxygen, power and processing time. The changes in the morphology of the microstructure of the carbon fibers by scanning electron microscopy studies. By infrared absorption spectrum and X-ray photoelectron spectroscopy on the surface of the carbon fibers, the chemical composition has been studied. The changes of the hydrophilic change the mechanical properties of the carbon fiber surface by contact angle measurements and mechanical properties of the test. The results show that, with the lengthening of the plasma discharge power increase and the treatment time, the surface of the carbon fibers will access a large number of oxygen-containing polar functional group and its surface is etched out of the tiny pits will also increase. The argon / oxygen mixed gas to better access polar functional group on the surface of the carbon fiber. However, the processing time is too long, due to the etching effect, lead to reduction in the breaking strength of the carbon fiber, so the processing time must be controlled to avoid carbon fiber has too much damage. Finally, the establishment of a one-dimensional discharge model to simulate the argon plasma discharge, results of surface electron density increases with increasing frequency, this study compared with the results of the experiment show that plasma engraved on the carbon fiber The pitting role is mainly caused by the impact of high-energy electrons.
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