Synthesis of clickable aminoguanidine-modified pullulan for selective samarium (III) recognition

Creating an effective adsorbent for Sm3+ in water-based waste is crucial for both environmental conservation and the recovery of valuable resources. This study presents an innovative method using pullulan (Pn)-derived adsorbents, uniquely modified with furan-aminoguanidine (FAG) through the precursor cyanoethyl Pn (CEP) to develop the FAG-Pn polymeric chelator. Sm3+ bond to the synthesized FAG-Pn, and an ion-imprinting technique is employed to establish selectivity towards Sm3+. This involves cross-linking the Sm3+/FAG-Pn complex with bis (maleimido) ethane (BMA) via Diels-Alder cyclization, followed by eluting the Sm3+ to obtain the Sm3+ ion-imprinted polymer (Sm-IIP). This polymer demonstrates a strong preference and high affinity for Sm3+. The synthesis process was comprehensively characterized using FTIR and NMR analysis, while the morphological characteristics were examined using scanning electron microscopy (SEM). The Sm-IIP particles exhibited remarkable affinity for Sm3+ compared to other interfering metals, showing peak uptake at a pH of 5. With an impressive adsorption capacity of 377 mg/g, the sorbent conformed to the Langmuir isothermal model and displayed pseudo-second-order kinetics. This research highlights the potential of FAG-Pn in the targeted extraction of Sm3+ from wastewater, offering an effective method for the selective uptake of specific heavy metals. •N-(Furan-2-ylmethyl)hydrazinecarboximidamide-pullulan derivative was prepared.•The resulted chelating polymer was interacted with targeted Sm3+.•Sm3+ ion-imprinting was performed by Diels-Alder cross-linking.•Sm3+ ions were removed to develop the Sm3+ ion-imprinted resin.