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The increasing amount of europium in aqueous environment from rare earth industry has become a serious environmental challenge. Significant efforts have been focused on ion-imprinting membranes (IIMs) for selective separation of ions from analogues. Based on ion-imprinting technique, we have developed Eu 3+ -imprinted nanocomposite membranes (Eu-IIMs) for selectively separating Eu 3+ from La 3+ , Gd 3+ and Sm 3+ . Polydopamine (pDA) was previously synthesized on basal membranes to augment the interfacial adhesion. Grapheme oxide (GO) and modified silicon dioxide (kSiO 2 ) were synergistically stacked on pDA-modified substrates to form hydrophilic nanocomposite membranes. Ag nanoparticles were modified on the surface to enhance anti-fouling performance. The temperature-controlled selective recognition sites were formed using N-isopropylacrylamide (NIPAm) and acrylamide (Am) as functional monomers as well as europium ions as templates by RAFT (reversible addition-fragmentation chain transfer) method. Large enhanced Eu 3+ -rebinding capacity (101.14 mg g −1 ), adsorptive selectivity (1.82, 1.57, 1.45 for Eu 3+ /La 3+ , Eu 3+ /Gd 3+ , Eu 3+ /Sm 3+ ) and permselectivity (3.82, 3.47, 3.34 for La 3+ /Eu 3+ , Gd 3+ /Eu 3+ , Sm 3+ /Eu 3+ ) were achieved on Eu-IIMs with superior regeneration performance. Additionally, the negligible damage of the membranes after buried for 20 d indicated the superior anti-fouling property of the Eu-IIMs. The ion-imprinted nanocomposite membranes synthesized in this work have shown great potentials for selective separation of rare earth ions. [ABSTRACT FROM AUTHOR]

Significant efforts have been focused on the functionalization and simplification of membrane-associated molecularly imprinted materials, which can rapidly recognize and separate specific compound. However, issues such as low permselectivity and unstable composite structures are restricting it from developing stage to a higher level. In this work, with the bioinspired design of polydopamine (pDA)-assisted inorganic film, we present a novel molecular imprinting strategy to integrate multilevel nanocomposites (Ag/pDA) into the porous membrane structure. The molecularly imprinted nanocomposite membranes were then obtained through an in situ photoinitiated ATRP method by using tetracycline (TC) as the template molecule. Importantly, attributing to the formation of the Ag/pDA-based TC-imprinted layers, largely enhance TC-rebinding capacity (35.41 mg/g), adsorption selectivity and structural stability (still maintained 92.1% of the maximum adsorption capacity after 10 cycling operations) could been easily achieved. Moreover, largely enhanced permselectivity performance toward template molecule (the permeability factor β values were also more than 5.95) was also obtained. Finally, all synthesis methods were conducted in aqueous solution at ambient temperature, which was environmental friendly for scaling up without causing pollution. [ABSTRACT FROM AUTHOR]