Nanosecond pulsed DC Ar/C₂H₅OH atmospheric pressure plasma jets: spectroscopic analysis and application

Abstract Atmospheric pressure plasma jets (APPJs) are versatile tools for surface treatment and material processing due to their ability to generate reactive species in ambient conditions. This work presents the spectroscopic characteristics of an Ar/C 2 H 5 OH mixture plasma generated by an APPJ and its potential for surface modification. Optical emission spectroscopy (OES) was used to analyze the density of OH radicals, carbon species (C, CN, CH, C 2 ), and electron temperature under varying discharge parameters. Experimental findings reveal that increasing applied voltage led to a 60% increase in OH radical density, while electron temperature decreased from 3.5 eV to 2.2 eV. The wet argon flowrate was found to influence plasma chemistry significantly, with OH radical density peaking at 200 SCCM, beyond which a decline was observed. These findings offer valuable insights into optimizing plasma treatment conditions, with potential applications in enhancing the hydrophilic properties of glass substrates for material processing, environmental remediation, and biomedical engineering.