The inhibitory ability of the boiling extracts from the aerial parts of Chenopodium album and Polygonum aviculare on the corrosion of mild steel EN Fe37-3FN in 0.5 M hydrochloric acid medium was investigated using electro-chemical methods and EIS. It was shown that the addition of 90 mg/l of the Chenopodium album aerial parts extract reduces the corrosion rate by 35%, and that of of 1 g/l and more – by 75%, whereas the addition of 120 mg/l of the Polygonum aviculare aerial parts extract reduces the corrosion rate by 40%, and that of of 1 g/l and more – by 85%. The adsorption of the extract components on a steel surface follows the Langmuir adsorption model, and the nature of adsorption is physical. The Chenopodium album and Polygonum aviculare aerial parts extracts show themselves as perspective and environmentally friendly substances for reducing the steel corrosion rate in acidic environments.
The study examines the influence of the composition and additives in beeswax mixtures used in historical ceroplastics on their long-term stability. Based on analyses of historical recipes and research into collection items, experimental wax mixtures with various additives (lard, Venetian turpentine, dammar, paraffin, pigments) were prepared and subsequently subjected to workability tests, measurements of physical properties, and artificial aging. The results show that additives significantly affect not only the rheological properties of the mixtures, but also their chemical and thermal stability. While some additives contribute to increased stability, others (especially combinations of pigments with reactive components) can initiate degradation processes. The study provides new insights into historical technologies and provides a basis for the formulation of methodological recommendations in the field of preventive conservation and restoration of ceroplastic works.
This study investigates the formation of zinc oxide (ZnO) layers on zinc substrates under various environmental conditions and their characterization. Zinc samples were subjected to controlled exposure regimes including aqueous solutions and water vapour environments to stimulate the formation of ZnO. The resulting layers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM/EDS), and optical microscopy. The analysis reveals correlations between exposure parameters and layer morphology, thickness, and phase composition. The study identifies key factors affecting ZnO layer quality and proposes pathways for optimizing these layers for potential sensing applications.
Abstract This review paper studied the potential of using metal oxides as a green corrosion inhibitor for different alloys in various aggressive corrosive environments. Metal oxides are widely used for various applications such as sensors, environmental remediation, nanoelectronics devices, solar cells, biomedical applications and clean energy production due to their unique electronic structure. Metal oxides exhibit low corrosion inhibition efficiency when used as corrosion inhibitors in bulk form but attain significantly higher inhibition efficiencies when used in nanostructured form. Increasing the concentration of the metal oxides significantly reduced the corrosion rate and enhanced the corrosion inhibition efficiency for various samples studied under different operating conditions due to the increased surface area to volume ratio as well as the enhanced adsorption of the oxides onto the surface of the substrates, thereby reducing the corrosion rate by decreasing the available sites for the dissolution reaction. However, the challenges of agglomeration and poor dispersion of nanoparticles were frequently reported at higher concentrations which contributed to observed reduced efficiencies. Barrier protection, electro-chemical inhibition, synergistic interactions with other inhibitors, self-healing properties, adsorption and passivation have been widely reported as the mechanism by which metal oxides protect the various substrates studied. The chemical and thermal stability of metal oxides in aggressive salt environments is a comparative advantage over other traditional organic and green inhibitors. The various methods of synthesis and characterization of metal oxide nanoparticles as well as their cost and associated safety and environmental concerns have also been discussed.
This study evaluates the suitability of selected lignocellulosic papers as packaging materials for the long-term preservation of diazotype records. To assess possible packaging materials, five types of paper were tested under artificial ageing conditions that simulate long-term storage. Their optical, chemical, and mechanical properties were systematically analysed. The results revealed that two tested alkaline papers exhibited high optical and mechanical stability, alkaline pH values, and limited release of harmful volatile organic compounds. Whatman No. 1 unsized paper showed good optical stability and chemical neutrality. Two types of acidic paper sized with rosin performed poorly, releasing volatile acids and displaying low mechanical resistance. In general, both alkaline papers are recommended as packaging materials for the preservation of the diazotype, while Whatman No. 1 represents a possible compromise. Acidic papers are unsuitable because of their acidity, the emission of harmful degradation products, and their insufficient durability.
