Prussian Blue CAS 14038-43-8

What is Prussian Blue?

Prussian Blue, also known as Berlin Blue, Iron Blue, Hua Lan, Milori Blue, etc., and chemically named ferric ferrocyanide (ferric hexacyanoferrate(II)), is the first artificially synthesized pigment in human history. Its chemical formula is usually written as:

Fe4[Fe(CN)6]3·xH2O (CAS No.: 14038-43-8)

At room temperature, it is a deep blue powder or crystal, almost insoluble in water, but when dispersed in water, it presents a strong blue color. Prussian blue was accidentally discovered in Berlin in 1704 by the German pigment manufacturer Diesbach, thus ushering in the era of artificial synthetic pigments. Art masters such as Picasso, Van Gogh, and Katsushika Hokusai all used this blue in their paintings.

From a molecular structure perspective, Prussian blue is a coordination compound formed by iron ions and ferrocyanide ([Fe(CN)6]4-), belonging to the ferrocyanide family with a zeolite-like open framework structure. This structure allows it not only to function as a stable deep blue pigment, but also to selectively adsorb monovalent metal ions such as thallium and cesium like an ion sieve, while simultaneously possessing reversible electrochemical activity—this multi-functional combination of "pigment + adsorption + electrochemistry" forms the structural basis for its widespread application in artistic creation and scientific research.

Chemically, Prussian blue is stable, light- and weather-resistant, and almost insoluble in water and common solvents. It decomposes upon reaction with alkalis and is commonly used in analytical chemistry to test for ferrous ions (producing Tönnies blue precipitate). Store in a dry, sealed container.

Non-industrial grade Prussian blue refers to products intended for non-mass industrial applications such as art and scientific research, primarily including reagent-grade specifications. Compared to industrial grade, non-industrial grade products focus more on the following indicators:

Particle size and particle diameter

Scientific research applications require controllable particle size (nanoscale Prussian blue is often used in scientific research), and particle size directly affects adsorption performance and experimental results.

Hue and color

Art and fine pigments require a pure blue hue, stable color, and compliance with pigment quality standards.

What are the uses of Prussian Blue?

1. Cathode materials for sodium-ion batteries

Prussian blue analogues (PBA, chemical formula NaxM[Fe(CN)6]y·nH2O) have an open three-dimensional framework structure and reversible sodium storage capacity, making them a research hotspot for sodium-ion battery cathode materials. They are widely used in energy storage and low-speed electric vehicles, and are a typical example of how "old pigments" can be revitalized with new energy value.

2. Artistic Creation and Cyanotype Printing (Craft Grade)

Prussian blue is the core colorant in cyanotype printing, where artists use iron salts to create Prussian blue images on paper. It is also a classic blue in watercolors, oil paintings, and art pigments, carrying the artistic tradition from classical to contemporary times.

3. Scientific research and laboratory applications (reagent grade)

Prussian blue is a classic reagent in analytical chemistry for testing for ferrous ions (producing Tönnies blue precipitate). It is also an important object in coordination chemistry, materials science, and energy storage research. Nanoscale Prussian blue is used in sensing and electrochemical research and is a commonly used material in scientific research laboratories.

4. Pigment Industry (Core Application)

( 1 ) Prussian blue (iron blue) is the most classic deep blue inorganic pigment. It has the advantages of strong tinting power, light and weather resistance, and good hiding power. It is an important variety in the human pigment industry.

( 2 ) Prussian blue is used as a blue pigment component in printing inks and is also used to formulate blue writing inks. It has a pure hue and stable performance, and is an important blue raw material in the printing and stationery industries.

( 3 ) Prussian blue can be used for ceramic glazing and handicraft coloring. The production chain of blue porcelain and enamel products may indirectly involve it.

( 4 ) Prussian blue is used for coloring stationery products such as crayons, colored pencils, watercolor paints and blue inks. It is a common blue pigment in children's art and creative education.

( 5 ) Prussian blue is a classic dark blue inorganic pigment used in blue paint, industrial coatings and furniture paint. The blue walls and metal products around us may have used iron blue pigment.

5. Teaching and Popular Science Experiments

The synthesis and color change reaction of Prussian blue is a representative experiment for demonstration in chemistry teaching and it helps students learn the principles of coordination compounds, complexes and the identification of iron ions. It is a common laboratory teaching material in middle schools and universities for chemistry.

6. Catalysts and Environmental Remediation

Prussian blue can serve as an iron-based catalyst for the efficient degradation of pollutants such as organophosphorus pesticides and for environmental remediation. The "zeolite-like" adsorption activity of Prussian blue can be used for removing cesium and thallium ions from water and for adsorption and recovery of precious metals.

7. Other Applications

With the development of materials science, the application scope of non-industrial grade Prussian blue continues to expand, including areas such as customized nanomaterials, research and development of specialty pigments, and popular science and cultural creative products.

Summarize

Prussian Blue, also known as Berlin Blue or Iron Blue, is a deep blue ferrocyanide coordination compound and the first pigment to be artificially synthesized in human history. It has three functions: pigment, adsorption and electrochemical properties. In our daily lives it is met indirectly in the form of blue pigments used in stationery, paints, blueprints, printed products and ceramic glazes. In non-industrial applications, Prussian Blue is widely used in cyanotype art, art pigments, iron ion testing reagents, teaching experiments and nanomaterial research. It is an ancient but modern functional material connecting the “daily use” and the “health, art and scientific research.”