The effect of modulated electric field on characteristic of SDBD‐like plasma jet for surface modification

Abstract

In this paper, the dynamics and flow behaviour of an atmospheric argon plasma jet was studied in the new nozzle structure similar to the surface dielectric barrier discharge (SDBD) using the Schlieren imaging method. The effect of plasma jet driven by repetitive high-voltage microsecond pulses with low-frequency sinusoidal bias was measured qualitatively in a single mirror Schlieren optical system. The enhancement of plasma jet length and cross-section of plasma jet with surface in this condition is due to highly turbulent flow of argon plasma jet in this structure. This study revealed the important role of SDBD structure and modulated electric field on the behaviour of plasma jet in a high diameter nozzle. In practice, this technique allows us to increase the jet length of the nozzle output to 5 cm and under these conditions, the diameter of the plasma jet cross-section is increased to 8 mm, without increasing the electrical power consumption. Eventually, the hydrophilicity of the surface is also measured by the contact angle of a water droplet that decreases from 78 • to 8 • after surface treatment, implying we were able to reach a super-hydrophilic surface with this plasma jet structure. K E Y W O R D S hydrophilicity, modulated electric field, plasma jet, Schlieren imaging, surface dielectric barrier discharge (SDBD)

Plasma Modification Techniques for Natural Polymer-Based Drug Delivery Systems

“…Longer exposure times can result in more significant surface modification, but also increases the risk of damage to the substrate. Shorter exposure times are suitable for delicate substrates or when only minimal surface modification is required [ 31 , 32 ].…”

“…Scanning electron microscopy (SEM) and atomic force microscopy (AFM) are commonly used techniques for the surface morphology analysis of plasma-treated natural polymer surfaces. SEM provides high-resolution images of the surface topography, while AFM provides detailed information on the surface roughness, porosity, and surface area [ 32 , 35 ]. Contact angle measurement is another technique used to evaluate the wettability of plasma-treated natural polymer surfaces.…”