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Zamak is a non-ferrous alloy, with considerable resistance to mechanical efforts. The alloy is widely used to produce objects in common use, such as door handles, faucets and handrails. These objects are potential transmission mechanisms for viruses and bacteria in places with high traffic of people. In this sense, several studies show that silver nanoparticles (AgNPs) have an antimicrobial spectrum. The objective of this work was to incorporate silver nanoparticles in Zamak 5 samples, anodized and sealed. Thus, the Zamak 5 samples were anodized in 0.3 M oxalic acid, and subsequently sealed in a plant extract based on Psidium guajava L. + 0.1 mM silver nitrate (AgNO3). Morphological analyzes and chemical mapping using Scanning Electron Microscope (SEM) were performed to evaluate the incorporation mechanisms. In addition, bacterial growth assays were performed with Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The results show that there was incorporation of silver (Ag) in the form of particles and agglomerates of particles, homogeneously arranged on the surface of the samples. However, it is concluded that the incorporation of silver element particles (Ag) in anodized Zamak 5, with the increase in the time of sealing the samples in plant extract, showed a reduction (30% on average) of the biofilm formed by Pseudomonas aeruginosa in the analysis of antimicrobial behavior. [ABSTRACT FROM AUTHOR]

Ferritic stainless steel has good electrical conductivity and corrosion resistance, enabling its use as an interconnector for low temperature fuel cells. The performance of these electrodes is related to the surface porosity, which can be obtained through the anodizing process. However, the stainless steel anodizing process has been mainly done for coloring ferritic stainless steel with pulsed current application. Thus, the objective of this work deals with the anodizing of ferritic stainless steel to obtain a porous surface through the application of direct current. For this purpose, anodization was performed in INCO electrolyte (2.5 M CrO3 + 5 M H2SO4) with time variation. Scanning electron microscope (SEM) analyzes showed the formation of a porous surface, and the anodizing time does not seem to have influenced the process. Electrochemical analysis showed that the anodizing time may have favored the formation of barrier oxide. However, the dissolution process that occurs during anodizing may have been more intense than the oxide formation, causing similar electrical conductivity measurements between samples without and with anodizing. In this case, it is possible to obtain a porous and conductive surface by anodizing INCO electrolyte with the application of direct current. [ABSTRACT FROM AUTHOR]