Optimal Discharge Parameters for Biomedical Surface Sterilization in Radiofrequency AR/O2 Plasma

• Published in: Energies (Basel) Vol. 15; no. 4; p. 1589
• Main Authors: Elaissi, Samira, H. Alkallas, Fatemah, Ben Gouider Trabelsi, Amira, Abu El Maati, Lamia, Charrada, Kamel
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.02.2022
• Subjects: Atoms & subatomic particles; Chemical reactions; Efficiency; Electric discharges; Electrodes; Electron density; Energy; Flow velocity; Gas flow; Gases; Helium; Microorganisms; numerical model; Oxygen atoms; oxygen–argon mixture; Parameters; Particle density (concentration); Plasma etching; plasma parameters; Radio frequency; radiofrequency; sterilization
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en15041589

Plasma parameters of radiofrequency discharge generated at low pressures in an argon-oxygen mixture addressed for biomedical surface sterilization have been optimized. Numerical results illustrate the density distributions of different species and electron temperatures during the electrical discharge process. The current discharge acting in the abnormal range decreases at higher oxygen gas flow rates. The temperature of electrons drops with pressure while it rises by adding oxygen. Nevertheless, electron density displays an adverse trend, exhibited by the electron’s temperature. The average particle density of the reactive species is enhanced in Ar/O2 compared to He/O2, which ensures a better efficiency of Ar/O2 in sterilizing bacteria than He/O2. The impact of oxygen addition on the discharge mixture reveals raised oxygen atom density and a reduction in metastable oxygen atoms. A pronounced production of oxygen atoms is achieved at higher frequency domains. This makes our findings promising for biomedical surface sterilization and leads to optimal parameter discharges used for sterilization being at 30% of oxygen gas ratio and 0.3 Torr pressure.