Polyacrylamide (PAM) is a high molecular polymer with the chemical formula (C₃H₅NO)ₙ, which is polymerized from acrylamide monomers. It is easily soluble in water, and its aqueous solution is a viscous liquid with the properties of thickening, flocculation, and drag reduction. According to the ionic properties, it can be divided into non-ionic, anionic, cationic and zwitterionic types.