Preparation of poly (polyethylene glycol diacrylate -co- maleic anhydride) cryogels and its adsorption performance of cationic dyes

The treatment of dye pollutants in wastewater was a serious environmental issue. In this paper, freezing radical polymerization was used to prepare poly (polyethylene glycol diacrylate -co- maleic anhydride) (p(PEGDA-co-MA)) cryogels with redox initiators of ammonium persulfate / tetramethylethylene diamine in aqueous solution. The mechanical property and chemical structure of cryogels were characterized compression tests, IR, and XPS. After that, adsorption performance of p(PEGDA-co-MA) cryogels for cationic dyes was measured and the maximum adsorption capacity for methylene blue and crystal violet was 447.7 mg·g−1 and 329.5 mg·g−1 (pH = 7.0), respectively. Adsorption isotherm, adsorption kinetics and adsorption thermodynamics were investigated to reveal adsorption mechanism of cryogel materials, which showed that monolayer chemical adsorption was dominant and the adsorption capacity decreased with the increase of temperature. This p(PEGDA-co-MA) cryogels would not only partly developed the polymerization method of vinyl monomers but also strongly expanded the field of dye adsorption materials.