Clickable aminoguanidine‐modified ion‐imprinted polymer for highly selective neodymium(<scp>III</scp>) recovery

Abstract BACKGROUND Neodymium (Nd 3+ ) is a critical rare earth element, with widespread use in advanced technology, requiring effective recovery mechanisms due to increasing demand. A novel neodymium ion‐imprinted polymer (Nd‐IIP) was here synthesized from aminoguanidine‐functionalized phenolic resin as the functional matrix. Polymerization entailed the Diels–Alder crosslinking mechanism, which created well‐organized and selective recognition sites for Nd 3+ ions. Stabilization following crosslinking ensured high specificity, mechanical stability, and reusability of the polymer. RESULTS The effective introduction of the functional groups was confirmed by Fourier transform infrared spectroscopy and solid‐state 13 C nuclear magnetic resonance, while X‐ray photoelectron spectroscopy, scanning electron microscopy, and Brunauer–Emmett–Teller analysis provided information regarding the adsorption mechanism. Thermogravimetric analysis/differential thermal analysis was used for thermal stability confirmation of the polymer. Adsorption study illustrated maximum adsorption capacity of ~400 mg g −1 , which was found to be roughly twice that of non‐imprinted polymer. Adsorption followed Langmuir isotherm model and pseudo‐second‐order kinetics, confirming monolayer, chemisorption‐based adsorption. Thermodynamic analysis confirmed that the process was spontaneous and endothermic in nature. Selectivity analysis revealed that Nd‐IIP was 30–40‐fold more selective for Nd 3+ than for interfering metal ions. CONCLUSION Nd‐IIP maintained 95% of its adsorption capacity after five cycles of regeneration, affirming its high reusability and durability. The results emphasize Nd‐IIP as a highly selective and effective polymeric sorbent for the removal and recovery of Nd 3+ from aqueous solutions, with great potential for the sustainable extraction of rare earth elements. © 2025 Society of Chemical Industry (SCI).