Synthesis of Hydrogels from Low‐Grade Palygorskite and Its Adsorption Behavior for Methylene Blue

Abstract

A series of hydrogels were successfully prepared with low grade palygorskite and hydroxypropyl methyl cellulose as raw materials by free radical graft copolymerization method. The morphology, functional groups, crystalline phases and thermal stability of the hydrogels were characterized by SEM, FT‐IR, XRD and TG, respectively. The adsorption properties of hydrogels were tested. The water absorption rate of hydrogel with Jiangsu Xu Yu palygorskite (PGSH), Gansu Linze white grey palygorskite (WPGSH) and Gansu Linze red palygorskite (RPGSH) as raw materials was 1332 g/g, 1204 g/g and 1146 g/g, respectively. The three hydrogels showed excellent adsorption capacity for 100 mg/L methylene blue solution at room temperature, and the maximum adsorption capacities of PGSH, WPGSH and RPGSH were 236.44 mg/g, 227.72 mg/g and 223.01 mg/g, respectively. The adsorption kinetics of methylene blue over hydrogels was a pseudo two stage kinetic equation.