Enhanced Hydrogen Generation through Low-Temperature Plasma Treatment of Waste Aluminum for Hydrolysis Reaction.

This study investigates the low-temperature hydrogen plasma treatment approach for the improvement of hydrogen generation through waste aluminum (Al) reactions with water and electricity generation via proton-exchange membrane fuel cell (PEM FC). Waste Al scraps were subjected to ball milling and treated using two different low-temperature plasma regimes: Diode and magnetron-initiated plasma treatment. Hydrolysis experiments were conducted using powders with different treatments, varying molarities, and reaction temperatures to assess hydrogen generation, reaction kinetics, and activation energy. The results indicate that magnetron-initiated plasma treatment significantly enhances the hydrolysis reaction kinetics compared to untreated powders or those treated with diode-generated plasma. Analysis of chemical bonds revealed that magnetron-initiated hydrogen plasma treatment takes advantage by promoting a dual procedure: Surface cleaning and Al nanocluster deposition on top of Al powders. Moreover, it was modeled that such H2 plasma could penetrate up to 150 Å depth. Meanwhile, electricity generation tests demonstrate that only 0.2 g of treated Al powder can generate approximately 1 V for over 300 s under a constant 2.5 Ω load and 1.5 V for 2700 s with a spinning fan.

Keratoprosthesis surgery as an alternative to keratoplasty.

Corneal transplant surgery after chemical or thermal burns has a very low success rate. Vision in these patients can be restored by using an artificial cornea (keratoprosthesis). In this report, we present 5 clinical cases of implanting a fresh corneal graft with Boston type 1 keratoprosthesis in patients with corneas inappropriate for standard corneal transplantation. The mean follow-up was 26.4 months (range, 12 to 36 months; SD, 13.1). The main measures of outcomes were visual acuity and keratoprosthesis stability. At least 1 year after the operation (5 eyes), vision acuity was >0.1 in 100% of the eyes and >0.4 in 50% of the eyes. Retention of the initial keratoprosthesis was 100%. The results of this study seem to be similar to those reported internationally. The anatomical and visual functions of the eyes were stable after keratoprosthesis implantation, though for a longer follow-up period, additional surgical procedures may be required.

Development of Antibacterial Cotton Textiles by Deposition of Fe2O3 Nanoparticles Using Low-Temperature Plasma Sputtering.

Antibacterial textiles can help prevent infections from antimicrobial-resistant pathogens without using antibiotics. This work aimed to enhance the cotton fabric's antimicrobial properties by depositing Fe2O3 nanoparticles on both sides of its surface. The nanoparticles were deposited using low-temperature plasma technology in a pure oxygen atmosphere, which is environmentally friendly. The Fe2O3 nanoparticles formed clusters on the fabric surface, rather than thin films that could reduce the airflow of the textile. The optimal conditions for the nanoparticle deposition were 200 W of plasma power, 120 min of immersion time, and 5 cm of Fe cathode-textile sample distance. The received antimicrobial textile was tested and the high efficiency of developed materials were successfully demonstrated against 16 microbial strains (Gram-positive and Gram-negative bacteria and fungi).

Antimicrobial Properties of CuO Particles Deposited on a Medical Mask.

Medical face masks help to reduce the transmission of pathogens, however, the number of infections caused by antimicrobial-resistant pathogens continues to increase. The aim of this study was to investigate the antimicrobial effect of an experimental medical mask layer coated with copper oxide using an environmentally friendly non-thermal physical vapour deposition approach. Pure CuO nanoparticles were successfully deposited on the middle layer of a face mask. The particles were distributed in different size clusters (starting from less than 100 nm dots going up to about 1 µm cluster-like structures). The CuO clusters did not form uniform films, which could negatively influence airflow during use of the mask. We investigated the antimicrobial properties of the experimental mask layer coated with CuO NPs using 17 clinical and zoonotic strains of gram-negative, gram-positive, spore-forming bacteria and yeasts, during direct and indirect contact with the mask surface. The effectiveness of the coated mask layer depended on the deposition duration of CuO. The optimal time for deposition was 30 min, which ensured a bactericidal effect for both gram-positive and gram-negative bacteria, including antimicrobial-resistant strains, using 150 W power. The CuO NPs had little or no effect on Candida spp. yeasts.

Production of Gamma Alumina Using Plasma-Treated Aluminum and Water Reaction Byproducts.

High purity hydrogen and solid-state byproducts are produced using a proposed plasma-activated aluminum and water reactions approach. These byproducts could be transformed into pure gamma Al2O3 powder material, while hydrogen can be used for electricity generation. Various chemical methods can be used for the synthesis of gamma alumina, but most could result in high levels of remaining impurities. Boehmite is a cost-effective starting material for the production of high-purity Al2O3. Herein, we present a novel method for the synthesis of boehmite and its transformation into high-specific-surface-area γ-alumina. Specifically, this method implicates the direct reaction between distilled water and plasma-treated aluminum powder. The results show the structural and morphological changes of the byproduct of the aluminum/water reaction to boehmite and γ-Al2O3 after a simple heating procedure (at 280 and 500 °C respectively). The high-purity hydrogen produced during the aluminum/water reaction can be used for the high-efficiency and environmentally friendly production of electrical energy.

Floating TiO2 photocatalyst for efficient inactivation of E. coli and decomposition of methylene blue solution.

The anatase phase TiO2 films with nanocrystalline structure were successfully deposited on a water-floating non-expanded polystyrene (PS) beads via magnetron sputtering. The combination of UVB light and PS beads with TiO2 film was used for decomposition of methylene blue as well as inactivation tests for intact and EDTA-treated Escherichia coli bacteria. Crystal structure, elemental composition, elemental mapping, surface morphology and chemical bonds of TiO2 film were investigated. E. coli inactivation experiments showed that such floating photocatalyst could destroy >90% bacteria in 45 min under UVB irradiation. Results demonstrated that combination of TiO2 and UVB light leads to disruption of the outer membrane which causes effective inactivation of E. coli bacteria.