Аңдатпа
Relevance. The recovery of rubidium from aqueous media is relevant because of the growing demand for rare alkali metals and the need for efficient sorption materials capable of operating under mildly acidic conditions. Purpose. The study aimed to evaluate the sorption characteristics of polyfunctional anion exchangers based on 2-aminoethyl vinyl ether (vinyl ether of monoethanolamine, VEMEA), allyl glycidyl ether (AGE), and polyethyleneimine (PEI) toward Rb+ ions. Methods. The VEMEA–AGE– PEI anion exchanger was synthesized by polycondensation of pre-epoxidized VEMEA with AGE and PEI, followed by curing, fractionation, washing, and conversion to the OH− form. The material was characterized by FTIR spectroscopy and physicochemical parameters. Rubidium sorption was studied under static conditions using Rb2SO4 model solutions. The effects of initial concentration, contact time, and solution pH were evaluated, and the equilibrium data were analyzed using the Langmuir and Freundlich models. Residual rubidium was determined by atomic emission spectrometry. Results. The maximum experimental sorption capacity reached 11.34 mg/g. Equilibrium was attained within 1 h. The Langmuir model gave qmax = 8.78 mg/g and KL = 0.313 L/mg (R2 = 0.9993), while the Freundlich model gave Kf = 1.87 and n = 1.17 (R2 = 0.9981). Within the investigated pH range of 1.87–4.17, the highest sorption performance was observed at pH 4.17. FTIR spectral changes suggested the participation of amino and other donor groups in interactions with rubidium ions. Practical significance. The obtained results demonstrate the potential of VEMEA–AGE–PEI anion exchangers for rubidium extraction and concentration from weakly acidic aqueous media and for the development of functional ion-exchange materials.