Ammonium aluminum sulfate dodecahydrate (CAS 7784-26-1)

Ammonium aluminum sulfate dodecahydrate, commonly known as ammonium alum, is a chemical compound with the formula NH4Al(SO4)2·12H2O. This inorganic compound is a type of alum characterized by its crystalline structure and inclusion of water molecules, making it a hydrate with specific applications in various industries and research fields. Ammonium alum is distinguished by its ability to form double sulfate salts that are soluble in water and have strong astringent and acidic properties. In research, its primary use is as a mordant in dyeing processes, where it helps in the fixation of dyes on fabrics by combining with dye pigments to form insoluble colored complexes, thus enhancing the color fastness of the textiles. Additionally, ammonium aluminum sulfate dodecahydrate is used in the purification of drinking water. It functions as a flocculating agent, aiding in the aggregation of suspended particles to form larger ones that are more easily removed through sedimentation and filtration processes. This compound also serves a role in analytical chemistry, particularly in protein purification, where it helps in precipitating proteins by altering their solubility through the interaction with water molecules. Moreover, its role extends into areas like papermaking, where it is used to enhance paper strength and durability.