ELECTRON-BEAM CROSSLINKING OF ALGINATE/ACRYLIC ACID HYDROGELS: SWELLING BEHAVIOR, RELEASE KINETICS, AND MIGRATION EFFECTS

Abstract

Hydrogels, characterized as three-dimensional polymeric networks, possess a high capacity to absorb and retain large amounts of water, making them suitable for soil–plant applications. In this study, eight hydrogel formulations were prepared by electron-beam irradiation using different proportions of sodium alginate, carboxymethyl cellulose (CMC), acrylic acid, and potassium persulfate as initiator. Swelling degree was evaluated to assess water uptake capacity and superabsorbent behavior. Controlled-release tests investigated water and nutrient delivery in soil, while migration analyses in swelling water examined the release of low-molecular-weight components. Swelling results indicated superior performance for CMC-free hydrogels, reaching 9233.51% after 48 h in water, approximately four times higher than hydrogels containing CMC. In nutrient solution, swelling ratios decreased due to ionic interactions. Soil burial experiments showed water release values of 62-80% over 3-7 days, whereas nutrient release remained limited (2-24%), confirming controlled-release behavior. Migration assessed through radish seed germination showed indices of 60-109%, with no apparent phytotoxic effects. These results support the use of CMC-free hydrogels as water-retention materials in soil-plant systems.