Research on Homogeneous Multilayer DBD Driven by Submicrosecond Pulsed Power at Atmospheric Pressure Air

Multilayer dielectric barrier discharge (DBD) can efficiently enlarge the volume of homogeneous plasma and its interactional surface area with materials in vertical space, which seems attractive to the industry application. In this paper, a new plasma generator of DBD structure which has multilayers of dielectric barrier boards excited by repetitive submicrosecond pulsed power (0 to -100 kV, 130 Hz-1 kHz, pulsewidth 230 ns, and rise time 120 ns) is introduced, and homogeneous plasma has been obtained in atmospheric pressure air. Experiments on high-speed photography with an exposure time of 5 ns have been carried out to the discharge with three layers of dielectric barrier boards with each gap width of 2 mm. It demonstrates that luminance of the discharge distributes uniformly throughout the upper and the lower gaps. Also, the result of the time evolution image of a three-layer DBD is discussed in this paper, which shows that the two layers of luminous intensity keep good consistency with each other, and this indicates that breakdown of each gap layer happens at the same time in a multilayer DBD. A preliminary processing experiment for polytetrafluoroethylene film has been carried out by adopting homogeneous triple-layer DBD plasma. By testing the water contact angle of the polymer surface before and after the treatment, it was found that hydrophilism of the surface and efficiency of treatment could be effectively improved by the processing of each layer of discharge plasma.