Igor Luisetto

Synthesis and Structural Characterization of Silver Nanoparticles Stabilized with 3-Mercapto-1-Propansulfonate and 1-Thioglucose Mixed Thiols for Antibacterial Applications

The synthesis, characterization and assessment of the antibacterial properties of hydrophilic silver nanoparticles (AgNPs) were investigated with the aim to probe their suitability for innovative applications in the field of nanobiotechnology. First, silver nanoparticles were synthetized and functionalized with two capping agents, namely 3-mercapto-1-propansulfonate (3MPS) and 1-β-thio-d-glucose (TG). The investigation of the structural and electronic properties of the nano-systems was carried out by means of X-ray Photoelectron Spectroscopy (XPS) and X-ray Absorption Spectroscopy (XAS). XPS data provided information about the system stability and the interactions between the metallic surface and the organic ligands. In addition, XPS data allowed us to achieve a deep understanding of the influence of the thiols stoichiometric ratio on the electronic properties and stability of AgNPs. In order to shed light on the structural and electronic local properties at Ag atoms sites, XAS at Ag K-Edge was successfully applied; furthermore, the combination of Dynamic Light Scattering (DLS) and XAS results allowed determining AgNPs sizes, ranging between 3 and 13 nm. Finally, preliminary studies on the antibacterial properties of AgNPs showed promising results on four of six multidrug-resistant bacteria belonging to the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp.).

Internal Methane Reforming High Temperature Proton Conductor (HTPC) Fuel Cells

High temperature proton conductor (HTPC) based fuel cells directly fed with methane mixtures were investigated. Doped barium zirconate was chosen as the electrolyte because of its good chemical stability in CO2 and H2O containing atmosphere. The sintering temperature of doped barium zirconate was decreased down to 1350°C by doping with 1 wt% ZnO. A co-pressing method was used for fabricating anode supported single cell. Flat and reproducible bottom cell of NiO BZYZn / BZYZn / LSCF were produced. OCV measurements, I-V curves, and impedance spectra were recorded in the 600-700°C temperature range. The addition of carbon dioxide to methane improved SOFC stability by suppressing coking in Ni anodes.

Spin-Coated La0.8Sr0.2Ga0.8Mg0.2O3-δ Electrolyte on Infiltrated Anodes for Biogas Utilization

Dense micrometric La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) films were deposited by spin-coating on porous LSGM scaffolds characterized by an homogeneous pore structure. Porous anodes were infiltrated with aqueous nickel nitrate solutions, dried and fired at 700 °C. Homogeneous metal coating with proper interconnections was observed by SEM, chemical stability was confirmed by XRD. Fuel cell tests and electrochemical impedance spectroscopy (EIS) were performed and discussed.