We present a novel and facile method enabling synthesis of iron oxide nanoparticles, which are composed mainly of maghemite according to X-ray diffraction (XRD) and Mössbauer spectroscopy studies. The proposed process is realized by anodic iron polarization in deaerated LiCl solutions containing both water and ethanol. Water seems to play an important role in the synthesis. Morphology of the product was studied by means of transmission electron microscopy and XRD. In the solution containing almost 100% of water a black suspension of round shaped maghemite nanoparticles of 20–40 nm size is obtained. Regulating water concentration allows to control nanoparticle size, which is reduced to 4–6 nm for 5% of water with a possibility to reach intermediate sizes. For 3% or lower water concentration nanoparticles are of a needle-like shape and form a reddish suspension. In this case phase determination is problematic due to a small particle size with the thickness of roughly 3 nm. However, XRD studies indicate the presence of ferrihydrite. Coercivities of the materials are similar to those reported for nanoparticle magnetite powders, whereas the saturation magnetization values are considerably smaller.

Chitosan coatings are deposited on the surface of Mg20Zn magnesium alloy by means of the spin coating technique. Their structure was investigated using Fourier Transform Infrared Spectroscopy (FTIR) an X-ray photoelectron spectroscopy (XPS). The surface morphology of the magnesium alloy substrate and chitosan coatings was determined using Scanning Electron Microscope (FE-SEM) analysis. Corrosion tests (linear sweep voltamperometry and chronoamperometry) were performed on uncoated and coated magnesium alloy in the Hank’s solution. In both cases, the hydrogen evolution method was used to calculate the corrosion rate after 7-days immersion in the Hank’s solution at 37 °C. It was found that the corrosion rate is 3.2 mm/year and 1.2 mm/year for uncoated and coated substrates, respectively. High corrosion resistance of Mg20Zn alloy covered by multilayer coating (CaP coating + chitosan water glass) is caused by formation of CaSiO₃ and Ca₃(PO₄)₂ compounds on its surface.

An attempt has been made to determine the effect of an addition of colloidal suspensions of the nanoparticles of magnesium oxide on the structure of water glass, which is a binder for moulding and core sands. Nanoparticles of magnesium oxide MgO in propanol and ethanol were introduced in the same mass content (5wt.%) and structural changes were determined by measurement of the FT-IR absorption spectra.

Overly fast corrosion degradation of biodegradable magnesium alloys has been a major problem over the last several years. The development of protective coatings by using biocompatible, biodegradable, and non-toxic material such as chitosan ensures a reduction in the rate of corrosion of Mg alloys in simulated body fluids. In this study, chitosan/TiO₂ nanocomposite coating was used for the first time to hinder the corrosion rate of Mg19Zn1Ca alloy in Hank’s solution. The main goal of this research is to investigate and explain the corrosion degradation mechanism of Mg19Zn1Ca alloy coated by nanocomposite chitosan-based coating. The chemical composition, structural analyses, and corrosion tests were used to evaluate the protective properties of the chitosan/TiO₂ coating deposited on the Mg19Zn1Ca substrate. The chitosan/TiO₂ coating slows down the corrosion rate of the magnesium alloy by more than threefold (3.6 times). The interaction of TiO₂ (NPs) with the hydroxy and amine groups present in the chitosan molecule cause their uniform distribution in the chitosan matrix. The chitosan/TiO₂ coating limits the contact of the substrate with Hank’s solution.