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The textile industry is one of the main consumers of dyes. The treatment of wastewater containing dyes is a major challenge worldwide for a sustainable and environmental friendly goods production. Therefore, it is necessary to develop an effective method for removing the dyes from wastewater. In this study, an economical and efficient white cast iron powder was reported to degrade reactive red 195A azo dye in an aqueous solution. The white cast iron powder was obtained by ball-milling a rapidly solidified cast iron ribbon, exhibiting unique metastable properties and a large surface area. These metastable phases are particularly effective in providing electrons for the dye degradation of NN double bonds, thereby improving the catalytic process, and enhancing the overall bond degradation efficiency. The influence of different parameters such as temperature, dye concentration, and reusability of metallic iron powder on the degradation efficiency was investigated. The experimental analysis revealed rapid and efficient dye degradation that was achieved within 15 min using 0.1 g of white cast iron powder. The study also demonstrated the effectiveness of the degradation rate improved significantly with an increase in temperature. Even after seven recycling experiments, the Fe82C15Si3 powders maintained high degradation efficiency toward the reactive red 195A solutions. This research will contribute to developing a new, highly efficient, and low-cost method for treating organic dye wastewater.

This study focuses on the design of a new Ti based multicomponent amorphous alloy for the development of biocompatible implant materials with enhanced hemocompatibility and cytocompatibility. While this class of amorphous alloys has shown its potential for biomedical implant applications, there are major concerns due to the presence of elements such as copper which can lead to cytotoxicity in the human body during long term implantation. Nevertheless, copper is indispensable in the development of an amorphous alloy. Thus, the objective of this work is to selectively remove copper from the surface of the Ti40Cu40Zr11Fe3Sn3Ag3 (at%) amorphous alloy using the dealloying technique and produce a patterned protective passivated surface rich in Ti and Zr oxides. Nitric acid (HNO3) has been found to be effective in depleting copper from the sample surface. Optimization of treatment parameters such as temperature (70 °C and room temperature) yielded drastic differences in the morphology of the samples studied using Field-Emission Scanning Electron Microscopy. The treated sample surface demonstrated good hemocompatibility and cytocompatibility with primary human osteoblast cells (HOb) and human osteosarcoma cell line (Saos-2). Additionally, the treated samples showed higher ability to produce reactive oxygen species with respect to pristine samples, which could be convenient for preserving the implant from bacterial contamination. These findings contribute to the advancement of producing copper-depleted nanostructured Ti based amorphous alloys for biomedical implant applications.

Magnetic vortices have been an interesting element in the past decades due to their flux-closure domain structures which can be stabilized at ground states in soft ferromagnetic microstructures. In this work, vortex states are shown to be nucleated and stabilized in Fe80Ga20 and Fe70Ga30 disks, which can be an upcoming candidate for applications in strain-induced electric field control of magnetic states owing to the high magnetostriction of the alloy. The magnetization reversal in the disks occurs by the formation of a vortex, double vortex or S-domain state. Micromagnetic simulations have been performed using the FeGa material parameters and the simulated magnetic states are in good agreement with the experimental results. The studies performed here can be essential for the use of FeGa alloy in low-power electronics.

In this work, Fe–X (X = Cu, Pd) submicron-scale structures were electrodeposited onto pre-patterned substrates prepared by e-beam lithography. The FeCu and FePd (with reduced Pd content) systems were investigated as attractive candidates for a variety of potential applications in magnetic data storage and biomedicine. Confined growth in the restricted cavities resulted in a nanoscale grain size leading to well-defined geometries with sharp edges and corners and an average height of up to 215 nm. Specifically, nine 100 μm × 100 μm arrays of three geometries (cylindrical, rectangular and cruciform) in three different sizes were created. In addition, the total deposition time ranged from 3.5 s (FeCu) to 200 s (FePd), i.e. much faster than by traditional physical vapor deposition approaches and was performed at ambient conditions. Magnetic force microscopy for the cylindrical and cruciform structures revealed virtually no contrast at zero field, suggesting magnetic curling effects (instead of coherent rotation) during magnetization reversal. These curling effects result in low values of remanent magnetization, which is advantageous in minimizing dipolar interactions between the structures either when they are deposited onto the substrate or eventually dispersed in a liquid (e.g. in biomedical applications, as drug delivery carriers, where particle agglomeration is undesirable).