Efficient Copper Ion Removal from Wastewater Using Copolymeric Hydrogels Based on NIPAM, OEGMA, and Acids Synthesized via Gamma Radiation

We report the synthesis of copolymeric hydrogels based on N-isopropylacrylamide (NIPAM), oligo(ethylene glycol) methacrylate (OEGMA), and different acids (itaconic, acrylic, and methacrylic) with varying monomer ratios. These hydrogels were polymerized and crosslinked using gamma radiation, with a dose of 25 kGy administered at a rate of about 0.5 kGy per hour in aqueous media, eliminating the need for additional crosslinking agents. Characterization was performed using Fourier Transform Infrared (FTIR) spectroscopy to confirm chemical composition, and Scanning Electron Microscopy (SEM) to examine morphological features. Synthesized hydrogels exhibited variable water absorbency and distinct Volume Phase Transition Temperature (VPTT) responses, which were influenced by their composition and the pH of the swelling medium. This adaptability suggests their potential for diverse environmental applications. Reswelling tests demonstrated that the hydrogels can undergo swelling and deswelling without significant performance loss, indicating their reusability. In practical applications, we evaluated their effectiveness in removing copper ions (Cu) from contaminated water using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results reveal that hydrogels with acid comonomers are particularly effective for wastewater treatment and environmental remediation.