DETERMINATION OF COAGULATION THRESHOLDS OF MOLYBDENUM-VANADIUM BLUE SOLS

Molybdenum-vanadium blue sols are colloidal dispersions known for their unique optical and chemical properties, making them important in catalysis, sensors, and materials science. The article discusses the coagulation threshold of the sol and the effect of electrolytes such as potassium nitrate, potassium chloride and calcium nitrate on sol coagulation. This work discusses the conditions for the occurrence of coagulations, and considers the experience of conducting an experiment to achieve the goal. During the experimental work, it was concluded that to determine the coagulation threshold of the sol, it is necessary to take reagents with high concentrations, both sol and electrolytes. Since it is known that Mo-V blue is aggregation stable. Thus, in the course of work, a sol Mo-V blue ratio [Mo]:[V] = 90:10 was synthesized using ascorbic acid as a reducing agent. The low content of ash and electrolyte, especially in the case of stable systems, such as molybdenum-vanadium blue, had to initiate reduced coagulation. To achieve significant effects, high temperatures or changes in environmental conditions (pH, temperature) are necessary. For sol Mo-V, the constants of fast coagulation and half-time of coagulation were determined for KNO3: kb = 5·10-4 m3/particle•s and Θ = 1563 s, for KCl: kb = 4·10-4 m3/particle·s and Θ = 1000 s.