دل ارام محمودي اشلقي

That's an interesting research study on the synthesis and properties of vanadium oxides, particularly focusing on vanadium dioxide (VO2). Vanadium oxides have indeed shown potential applications in various industries due to their unique properties, including different polymorphic structures.One specific application is the use of vanadium oxides in thermochromic glass for smart windows. Thermochromic coatings in smart windows can dynamically adjust their optical properties based on temperature changes, allowing for energy efficiency and comfort control in buildings. The three parameters mentioned — Transition temperature, solar modulation, and luminous transmittance — are crucial for eva‎luating the effectiveness of such coatings.The synthesis method employed in the research is the solution combustion synthesis method. This method involves an exothermic oxidation-reduction reaction and offers advantages in terms of economy and time efficiency. By adjusting the combustion parameters, such as the type and amount of fuel used, it is possible to modify the phase composition, morphology, and properties of the synthesized products.In this study, a solution was prepared using ammonium metavanadate, ammonium nitrate, deionized water, and various fuels (citric acid, glycine, and ethylene glycol) with different molar ratios (of two, four, and six). After the evaporation of water, the desired gel was synthesized by heating in a furnace at 600 degrees Celsius, resulting in the production of vanadium oxide powder.The study provided measurements of particle size and critical temperature for vanadium dioxide synthesized with different molar ratios of citric acid, glycine, and ethylene glycol. The values obtained for particle size were 0.687 nm, 1.171 nm, and 0.674 nm, while the critical temperatures were 65 ℃, 70 ℃, and 66 ℃, respectively.Finally, the optical properties of the synthesized vanadium were eva‎luated by coating a glass slide with a solution containing PVP (polyvinylpyrrolidone), ethanol, and the synthesized vanadium dioxide powder. The parameters Tlum (luminous transmittance) and ∆Tsol (solar modulation) were measured for each molar ratio of citric acid, glycine, and ethylene glycol. The values obtained for Tlum were 55%, 43%, and 62%, while ∆Tsol values were 12.3%, 10.1%, and 12.7%, respectively.Overall, this research provides valuable insights into the synthesis and properties of vanadium oxides, specifically focusing on vanadium dioxide and its potential application in thermochromic coatings for smart windows.

اكسيد واناديم , سنتز احتراق محلولي

Vanadium oxide , Solution combustion synthesis

Delaram Mahmoodi

Dr. Soltaniye