Soutenance publique de thèse de doctorat en Sciences physiques - Valentin Job
Development of Antipathogenic Surfaces by Magnetron Sputtering: From Fundamental Mechanisms to Antibacterial and Antiviral Applications
Date : 29/10/2026 16:00 - 29/10/2026 19:00
Lieu : Auditoire Adam Smith
Orateur(s) : Valentin Job
Organisateur(s) : Stéphane Lucas
Jury
- Prof. Benoît MUYLKENS (UNamur), Président
- Prof. Stéphane LUCAS (UNamur), Secrétaire
- Prof. Jean-Michel DOGNÉ (UNamur)
- Prof. Philippe STEYER (INSA de Lyon, Université de Lyon)
- Dr Sébastien PENNINCKX (UNamur)
- Dr Emile HAYE (Innovative Coating Solutions)
Résumé
Frequently touched surfaces (fomites) serve as reservoirs for pathogens, including bacteria and viruses, and act as vectors for contact-mediated transmission. They contribute to the spread of healthcare-associated infections and represent an increased risk during epidemic outbreaks, as highlighted by the COVID-19 pandemic. This thesis focuses on the development of antimicrobial coatings releasing silver (Ag) and copper (Cu), deposited by magnetron sputtering. Three coating matrices were investigated: hydrogenated amorphous carbon with or without chromium (a-C:H and Cr/CrN/a-CrC:H) and titanium aluminum nitride (TiAlN).
Antibacterial performance was evaluated against Staphylococcus aureus and Escherichia coli. To assess long-term efficacy, the antibacterial properties of the coatings were investigated through successive bacterial exposure cycles. Antiviral activity was evaluated against porcine respiratory coronavirus (PRCV), a member of the Orthocoronavirinae subfamily to which SARS-CoV-2 also belongs. For this purpose, a rapid high-throughput antiviral screening assay was developed. This original method represents a promising approach for the standardized evaluation of antiviral surfaces. In addition to antimicrobial activity, the coatings were required to exhibit adequate mechanical properties and an attractive black appearance suitable for high-touch surfaces.
The combination of Ag and Cu exhibited a synergistic effect, enhancing antimicrobial activity and broadening the spectrum of targeted pathogens. Optimization led to a TiAlN coating containing 0.9 at.% Ag and 1.7 at.% Cu, which provided the best compromise between mechanical, antibacterial, and antiviral performances. Tribological wear tests confirmed the preservation of its antimicrobial efficacy for up to two years. Perspectives for the further development and scientific validation of this prototype are discussed.
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