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One of the greatest challenges worldwide is containing the spread of problematic microorganisms. A promising approach is the use of antimicrobial coatings (AMCs). The antimicrobial potential of certain metals, including copper and zinc, has already been verified. In this study, polyethylene terephthalate and aluminum (PET-Al) foils were coated with copper, zinc, and a combination of these two metals, known as core–shell particles, respectively. The resistance of the three different types of coatings to mechanical and chemical exposure was evaluated in various ways. Further, the bacteria Staphylococcus aureus and the bacteriophage ϕ6 were used to assess the antimicrobial efficacy of the coatings. The best efficacy was achieved with the pure copper coating, which was not convincing in the abrasion tests. The result was a considerable loss of copper particles on the surfaces and reduced effectiveness against the microorganisms. The core–shell particles demonstrated better adhesion to the surfaces after abrasion tests and against most chemical agents. In addition, the antimicrobial efficiency remained more stable after the washability treatment. Thus, the core–shell particles had several benefits over the pure copper and zinc coatings. In addition, the best core–shell loading for durability and efficacy was determined in this study. [ABSTRACT FROM AUTHOR]

Herein, copper particles are deposited on additively manufactured surfaces and investigations are performed to determine the mechanical properties and the impact of copper tracks on the surfaces. The basic investigation covers quasistatic tests, namely, tensile and three point bending, for three different printing orientations and two infill variations (+45°/−45° and 0°/90°), which shows no remarkable differences. In addition, a copper track is sprayed via atmospheric pressure plasma spraying (APPS) onto the polymeric samples and characterized regarding hardness and electric conductivity. Furthermore, a specific application for the copper track on the polymer substrate is recreated by a cyclic three point bending with a novel sample geometry (T‐shaped). The sprayed copper track has 60% of the hardness and 40% of the indentation modulus of bulk copper. Depending on the substrates' topography, the electric conductivity varies from 7% to 18% of bulk copper. The lifetime of the copper track (i.e., conductivity) is strongly dependent on the deformation and the fracture of the polymer underneath. The underlying failure mechanism is triggered either by the topography of the polymer substrate or as a consequence of the damage in the copper track, leading to superficial cracks in the polymer surface. [ABSTRACT FROM AUTHOR]

In this study, assessment of the antimicrobial activity of a novel, plasma-cured 2.5% (w/v) Cu(NO3)2-containing sol–gel surface was performed. In contrast to state-of-the-art sol–gel coatings, the plasma curing led to a gradient in cross-linking with the highest values at the top of the coating. As a result, the coating behaved simultaneously hard, scratch-resistant, and tough, the latter due to the more flexible bulk of the coating toward the substrate. Further, the diffusion and permeation through the coating also increased toward the substrate. In our study, tests according to ISO 22196 showed antibacterial activity of the 2.5% (w/v) Cu(NO3)2-containing sol–gel surface against all bacterial strains tested, and we expanded the testing further using a "dry" evaluation without an aqueous contact phase, which confirmed the antimicrobial efficacy of the 2.5% (w/v) Cu(NO3)2-containing sol–gel surface. However, further investigation under exposure to soiling with the addition of 0.3% albumin, used to simulate organic load, led to a significant impairment in the antibacterial effect under both tested conditions. Furthermore, re-testing of the surface after disinfection with 70% ethanol led to a total loss of antibacterial activity. Our results showed that besides the mere application of an antimicrobial agent to a surface coating, it is also necessary to consider the future use of these surfaces in the experimental phase combining industry and science. Therefore, a number of tests corresponding to the utilization of the surface should be obligative on the basis of this assessment. [ABSTRACT FROM AUTHOR]