Distribution patterns of reactive species in the interaction between atmospheric pressure plasma jet and fiber membrane

Surface modification of polymer fiber membranes using atmospheric pressure low-temperature plasma has gained significant attention in recent years. The effectiveness of surface modification determined by the uniform distribution of reactive species when plasma touching the fibers. In this study, we investigated the distribution patterns of plasma reactive species on the fibers surface with different fiber spacings by both experiment and modeling. The results revealed that reduced fiber spacing produced an obstructive effect on the propagation of reactive species. This obstruction was primarily caused by the accumulation of a significant charge on the windward side of the fiber. Consequently, there was a substantial difference in the fluxes of reactive species between the windward and leeward sides of the fiber membrane, resulting in poor uniformity of the reactive species distribution. It was worth noting that the fluxes of reactive species exhibited a double-peak distribution on the circumferential surface of the fiber filaments. This phenomenon was attributed to the coupling effect between the fiber filaments, wherein the electric field strength was higher within the gap. High electric field strength facilitated the generation and propagation of reactive species. However, as the fiber spacing decreased, the propagation of high field strength became limited until it merged into the fiber gap.