The influence of cobalt manganese ferrite nanoparticles (Co0.5Mn0.5Fe2O4) on reduction of hazardous effects of vanadate in adult rats

Effect of cobalt manganese ferrite nanoparticles (M-NPs) (Co0.5Mn0.5Fe2O4) on vanadium hazards was assessment in the present study. Four groups of adult male albino rats [control group and three variably treated groups with ammonium metavanadate accompanied with or without cobalt M-NPs] were studied. The oral administration of ammonium metavanadate (Am.V) (20 mg/kg b.wt.) demonstrated the facility of vanadium to distribute and accumulate in the distinctive body organs and ordered as kidney > liver > lung > brain > spleen. Also, Am.V administration induce a significant disturbance in many physiological parameters (RBS, cholesterol, triglyceride, aspartate transaminase, alanine transaminase, Alb., bilirubin, Alk.Ph., urea, creat., Hb%, red blood cell count and packed cell volume) which might be expected to the liberation of free radicals according to the vanadium intoxication or its ability to disturb many body metabolisms. On the other hand, the intraperitoneal administration of 5% M-NPs in parallel with Am.V orally administration showed the ability of M-NPs to reduce Am.V dangerous impacts, which might be resulted from the essentiality of M-NPs metals to the body metabolism and to its free radicals scavenging properties. So, M-NPs could reduce Am.V hazardous effects.

Tailoring the Size and Shape—New Path for Ammonium Metavanadate Synthesis

Ammonium metavanadate, NH4VO3, plays an important role in the preparation of vanadium oxides and other ammonium compounds, such as NH4V3O8, (NH4)2V3O8, and NH4V4O10, which were found to possess interesting electrochemical properties. In this work, a new route for the synthesis of NH4VO3 is proposed by mixing an organic ammonium salt and V2O5 in a suitable solvent. The one-step procedure is carried out at room temperature. Additionally, the need for pH control and use of oxidants necessary in known methods is eliminated. The mechanism of the NH4VO3 formation is explained. It is presented that it is possible to tailor the morphology and size of the obtained NH4VO3 crystals, depending on the combination of reagents. Nano- and microcrystals of NH4VO3 are obtained and used as precursors in the hydrothermal synthesis of higher ammonium vanadates. It is proven that the size of the precursor particles can significantly affect the physical and chemical properties of the resulting products.

Corrosion resistance of hot-dip galvanized steel in chloride-containing medium

Today, corrosion and corrosion protection of metals are the most important scientific, technical, economic and environmental problems. The effect of additions of sodium molybdate, ammonium metavanadate, a mixture of sodium molybdate and ammonium metavanadate, thiourea and sodium orthophosphate on the corrosive behavior of hot-dip galvanized steel in a neutral and slightly alkaline chloride-containing medium has been studied. The experimental results obtained by weight and electrochemical methods proved sodium molybdate, ammonium metavanadate, a mixture of sodium molybdate and ammonium metavanadate, thiourea and sodium orthophosphate to be corrosion inhibitors that slow down the rate of destruction of hot-dip galvanized steel in a neutral and slightly alkaline chloride-containing medium by 1.5–11 times.

Redetermination of ammonium metavanadate

The crystal structure of ammonium metavanadate, NH4VO3, a compound widely used as a starting material for the synthesis of vanadium and polyoxidovanadate compounds, had been determined twice using single-crystal X-ray data [Syneček & Hanic (1954). Czech. J. Phys. 4, 120–129 (Weissenberg data); Hawthorne & Calvo (1977). J. Solid State Chem. 22, 157–170 (four-circle diffractometer data)]. Its structure is now redetermined at higher resolution using Ag Kα radiation, and the result is compared with the former refinements. Structural data for the polymeric [VO3]∞ chain remain unchanged, while more accurate parameters are obtained for the ammonium cation, improving the description of hydrogen-bonding interactions in the crystal structure.