β-ketoester-functionalized magnetoactive electrospun polymer fibers as Eu(III) adsorbents

Abstract

Blended polymer fibers based on a hydrophobic random copolymer having β-ketoester metal ion binding functionalities namely poly(methyl methacrylate)-random-poly(2-(acetoacetoxy) ethyl methacrylate) (PMMA-co-PAEMA) and the hydrophilic polyethylene oxide (PEO) were fabricated by electrospinning and further evaluated for the first time as adsorbents for the removal of Eu(III) from aqueous media. Moreover, magnetoactive fibrous analogues were prepared by incorporating preformed, oleic-acid coated Fe3O4 NPs within the polymer fibers during electrospinning. The Eu(III) adsorption was investigated as a function of pH and initial metal ion concentration whereas the effect of the Fe3O4 NPs and of the β-ketoester groups on the membrane adsorption efficacy was also investigated. The experimental data, which were well fitted by the Langmuir isotherm model, indicated increased affinity with increasing pH and reached maximum values (~ 95%) at pH 6.5. The presence of the β-ketoester functionalities as well as the incorporation of the Fe3O4 nanoparticles within the fibrous adsorbents affect positively the adsorption process and indicate the significance of chemical modification with respect to water purification and precious metal recovery using adsorbent-based technologies.