What is Prussian Blue?
Prussian Blue, also known as ferric ferrocyanide, Berlin Bue, Gong Blue, Iron Blue, Milori Blue, Milori Blue, Chinese Blue, Chinese Blue and mineral blue, with the chemical formula Fe 4 [Fe (CN) 6 ] 3 , is a complex compound that can be used for glazing and as an oil dye.
- In the 18th century, a German named Diebach was a worker who made and used paints, so he was interested in all kinds of colored substances. total
- Prussian blue has a cubic structure, is stable at normal temperature and pressure, is insoluble in water, and soluble in acid and alkali. There are two kinds of colored light: blue light and red light. The color is bright, the tinting power is strong, and the hiding power is slightly poor. The powder is hard and difficult to grind. It is resistant to light and acid, but decomposes when boiled with concentrated sulfuric acid; weak alkali resistance, even dilute alkali can decompose it, and cannot be shared with alkaline pigments. In the event of fire, water and sand can be used to fight the fire. [2]
- Yellow blood salt method
- In chemical experiments, the reaction to generate Prussian blue is commonly used to test CN-: FeSO 4 + 6NaCN + 2Na 4 [Fe (CN) 6 ] + 4FeCl 3 = Fe 4 [Fe (CN) 6 ] 3 + 12NaCl + Na 2 SO 4 .
- In medical treatment, it can replace the iron on Prussian blue to form an insoluble substance, which will be excreted with feces. It has a certain effect on the treatment of acute and chronic radon poisoning. Dosage is usually 250mg / kg daily, divided into 4 times, dissolved in 50ml 15%
- Prussian blue should be stored in a ventilated, dry warehouse. Avoid contact with oxides, acids, ammonia and light during storage. [2]
- Fe reacts with [Fe (CN) 6 ] 4- to form a deep blue precipitate, which is called Prussian blue; and Fe reacts with [Fe (CN) 6 ] 3 - to produce a deep blue precipitate, which is called Teng's blue. The two products exhibit similar colors (blue) and contain identical chemical elements and formulas.
- One view is that these two substances have the same complex structure and have been determined by X-ray, magnetic susceptibility, photoelectron spectroscopy, and Mossbauer spectroscopy. Are the same substance. [3-4]
- Another view is that although Prussian blue and Teng's blue have the same structure, the color of Prussian blue is always slightly darker than Teng's blue. After comparing the Mossbauer spectra of the two substances, their electronic structures are slightly different, thus causing a difference in color. [5]
- All in all, Prussian blue and Teng's blue have the same chemical complex structure. As to whether they are the same substance, there is still controversy.