Synthesis of 2-methylacrylamide/high-molecular-weight cellulose using gamma ray irradiation and preparation of cryogels for removing anionic dyes

We report a new method for treating high-molecular-weight cellulose with 60 Co gamma rays to simultaneously graft functional groups onto the natural polymer and promote its solubility. After exposing cellulose to a 40-kilogray dose of gamma rays in the presence of 2-methylacrylamide, numerous amide groups were grafted onto the cellulose chain and its solubility increased. Amide-functionalized cryogels were prepared via the sol–gel method using the irradiated product as a raw material. Compared with 40-kGy-irradiated high-molecular-weight-cellulose cryogel, the amide-functionalized cryogels had relatively high zero-point charge pH values and excellent adsorption capacities with regard to anionic dyes over the pH range 2–10. They were also stable in terms of reusability. Therefore, the 2-methylacrylamide/high-molecular-weight cellulose cryogel has great potential for use in the treatment of colored surface wastewater. The 60 Co gamma ray irradiation technique described herein is a stable and highly efficient method for the preparation of functionalized cellulose products. Graphical abstract