Synthèse et caractérisation des films minces de nanocomposites à base de polypyrrole /nanoparticules d’argent et d'oxyde de titane pour une application antibactérienne

Abstract

To combat bacterial infections, particularly in medical environments where infection prevention is essential, this thesis focuses on the synthesis and evaluation of the antibacterial properties of polypyrrole (PPy)-based nanocomposites grafted with silver nanoparticles (AgNPs) and incorporated with titanium dioxide (TiO0NPs). This thesis focuses on two aspects. Firstly, to present a rapid method for the double-pulsed electrodeposition of silver nanoparticles on polypyrrole thin films, in order to improve electrical conductivity and antibacterial activity for biomedical applications. The electrodeposition and electrochemical behavior of the precipitates were studied using chronoamperometry and electrochemical impedance spectroscopy. SEM and XRD were used to characterize the morphological and microstructural properties of the precipitates. The antibacterial performance of the precipitates was tested against Escherichia coli and Staphylococcus aureus bacteria. In addition, Ag nanoparticles on the PPy surface showed the highest electrical conductivity and killing efficiency for both types of bacteria (100% against E.coli and 99.99% against S.aureus). The second part of the thesis addressed a potential problem in maintaining high and long-lasting antibacterial activity, given that AgNPs can separate from polypyrrole under different pressures. To address this issue, we explored the incorporation of TiO0NPs nanoparticles into the film, which, despite their lower bactericidal efficacy, can provide long-lasting and cost-effective antibacterial activity even when AgNPs are lost