Synthesis, characterization and investigation of adsorption potentials of super absorbent polymers with swelling/shrinking behavior

Objective: In this study, it was aimed to synthesize acrylamide-based hydrogels and semi-IPN hydrogels containing poly (ethylene glycol) using potassium 3-sulfopropyl methacrylate as co-monomer. Performing the characterization of hydrogels and semi-IPNs, it was aimed to investigate their swelling-shrinking behavior and adsorption properties. Material and Method: Hydrogels and semi-IPNs were synthesized by a free radical polymerization reaction in a solution medium in the presence of a chemical crosslinker, which is a well-known and frequently used method. Structural characterization of chemically cross-linked hydrogels using the Fourier transform infrared spectroscopy (FTIR/ATR) method has been elucidated. Scanning electron microscopy (SEM) images were taken to obtain information about the network structure of hydrogel and semi-IPN hydrogels. Dynamic swelling tests at 25oC were applied to examine the swelling properties of the synthesized cross-linked hydrogel and semi-IPN hydrogels. In order to investigate the shrinkage behavior of the cross-linked structures, they were first allowed to swell at 25oC; Afterwards, they were dried at a constant temperature at 25oC. Results: When the obtained data are evaluated, it has been determined that the synthesized acrylamide/potassium 3-sulfopropyl methacrylate hydrogels and acrylamide/potassium 3-sulfopropyl methacrylate/poly(ethylene glycol) semi-IPNs are superabsorbent polymers that can show swelling-shrinkage behavior. In addition to that, superabsorbent polymers successfully removed cationic dye such as Union Green B from aqueous solution by adsorbing a high percentage. Conclusion: It can be said that the synthesized cross-linked polymers have a high swelling capacity in water, show repeated swelling-shrinkage behavior, and are good adsorbents for Union Green B dye. Keywords: Adsorption, Shrinking, Hydrogel, swelling, semi-IPN