Surface modification of brass by atmospheric-pressure plasma jet treatment

Surface modification of brass by atmospheric pressure plasma remains relatively unexplored. As an alloy of reactive metals, brass provides an interesting substrate to study plasma-surface interaction. Surface modification of brass was performed using an argon-fueled atmospheric pressure plasma jet at room temperature. We focused on increasing the wettability of the surface by observing changes in the contact angle at the solid-liquid interface over time following the Young-Laplace equation. Contact angle of water droplets on treated brass surfaces decreased significantly when compared to untreated surfaces. The wettability decreased over time, and the contact angles reverted to their original values. By using Raman spectroscopy, we hope to identify the chemical species that produce this temporary and reversible surface modification. We present our experimental setup, analysis techniques, and preliminary results.