Xu Jiayu

Compared with the traditional method for surface treatment, non-thermal plasmas have advantages such as low pollution, simple process and low cost. In the paper, non-thermal plasmas are generated by dielectric barrier discharge (DBD) excited by home-made nanosecond-pulse generator with a rise time of ~70 ns and a full with at half maximum of ~100ns. Such plasmas are used to modify the hydrophobicity of the surface of polyethylene terephthalate (PET) in atmospheric carbon tetrafluoride (CF4). The static water contact angle of the PET surface is measured before and after the treatments. The effects of the flow rate of CF4, treatment time and CF4 ratio in the CF4/N2 mixture on the surface treatment are presented. Experimental results show that the hydrophobicity of the PET surface can be enhanced after DBD plasma treatment in CF4. The static water contact angle of the PET surface can increase from 68° to 100°.