Al2PO42H2O

Aluminium phosphate dihydrate, commonly referred to as Al2PO42H2O, is a chemical compound that belongs to the family of aluminium phosphates. It is a white, crystalline solid that is soluble in water. The compound is formed when aluminium ions (Al3+) react with phosphate ions (PO4^3-) in the presence of water, resulting in the dihydrate form.

Aluminium phosphate dihydrate is often used as a flame retardant in various materials, including plastics and textiles. Its ability to release water upon heating makes it an effective fire retardant, as the water helps to dilute the combustible gases and reduce the peak heat release rate. Additionally, it can be used as a catalyst in chemical reactions and as a precursor in the synthesis of other aluminium phosphate compounds.

The compound can be synthesized through various methods, including the reaction of aluminium hydroxide with phosphoric acid, or the reaction of aluminium sulfate with sodium phosphate. The resulting compound can be characterized using techniques such as X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR).

Aluminium phosphate dihydrate is relatively stable under normal conditions but can decompose upon heating, releasing water and forming aluminium phosphate. It is also soluble in acids and bases, which can affect its chemical properties and reactivity. The compound is generally considered to be non-toxic, but like any chemical, it should be handled with care to avoid inhalation or skin contact.