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Nanostructure CeO2 powders were synthesized using tea waste extract as gel precursor. The as-prepared samples were characterized by thermogravimetric analyzer (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Based on the TGA/DTG analysis, the intermediates of cerium chloride hydrates (CeCl3.4H2O and CeCl3.H2O) and cerium anhydrous (CeCl3) were produced, and the formation temperature of CeO2 was estimated to be 773 K. The cubic fluorite structure of CeO2 was detected to be the predominant species and was completely formed at the calcination temperature of 773K–1073 K with a crystal size between 8.8 and 11.4 nm based on the XRD measurement. Moreover, the main chemical state of ceria on the surface of the synthesized samples was confirmed to be tetravalent ceria by XPS. All samples show a strong Raman signal at a well-defined chemical shift of 463 cm−1 and a significant symmetry feature was observed, suggesting that the tetravalent ceria is the dominant species throughout the bulk sample. All the synthesized CeO2 calcined at different temperatures showed higher adsorption efficiency for Congo red (CR) compared with commercial CeO2. The adsorption efficiency maintained a steady state of more than 95% when the concentration of CR and adsorption temperature were varied in this study. The kinetic analysis showed that the second-order model was the appropriate model to interpret the adsorption behavior of synthesized CeO2. The calculated adsorption capacity derived from the second-order model is in good agreement with the experimental data. The isotherm analysis revealed that the Freundlich and D-R models fit well for the synthesized CeO2 and represent physisorption with a multilayer mechanism. The thermodynamic parameters, including the changes in Gibb's free energy, enthalpy, and entropy, suggested that the adsorption of CR on the synthesized CeO2 sample was a spontaneous and endothermic process. [ABSTRACT FROM AUTHOR]

Imprinting techniques have been investigated extensively for the selective recognition of molecules and ions. However, few reviews focused on the state-of-the-art developments in ion imprinting technique. Ions and their analogs have a charge and usually similar physical and chemical properties, but less functional groups than molecules. The slight differences in charges, sizes and shapes of ions determine the structure–activity of metal–ligand complexes and imprinted materials. In this review, we focused on the internal connections between each component at coordination and polymerization stages with the affinity and selectivity of the imprinted materials. Advanced imprinting routes such as multiple-template, dual-template docking oriented ionic imprinting and nanocomposite ion imprinted membranes were elaborated. Computational simulation was highlighted for the prediction of functional monomers, binding mechanisms and selectivity. Multiple antifouling enhanced strategies for ion imprinted membranes were put forward to alleviate the trade-off relationship between treated volume and time. The review should provide researchers with new perspectives to explore ion imprinting technology and stimulate more creative breakthroughs in ion separation and purification fields. [ABSTRACT FROM AUTHOR]

Inspired by the surface self-assembly modification technique using dopamine, herein, a polydopamine (pDA)-modified nanocomposite was successfully obtained on the surfaces of TiO2 (pDA@TiO2). The key design of the as-reported ibuprofen-imprinted nanocomposite membranes (IINCMs) was the composite integration process of pDA@TiO2 and porous polyvinylidene fluoride (PVDF) membranes, in which the pDA@TiO2 was used as functional microspheres. As such, the novel porous IINCMs were developed and synthesized through a simple sol–gel method by using ibuprofen as the template molecule. Importantly, the as-prepared pDA-coating layers on TiO2 could largely enhance the rebinding capacity of IINCMs, and contribute to the blended functional pDA@TiO2 microspheres, and the as-prepared IINCMs revealed an outstanding adsorption amount (42.14 mg g−1) and regenerability. In addition, an excellent permselectivity performance (the βketoprofen/ibuprofen and βnaproxen sodium/ibuprofen were 4.42 and 4.46, respectively) could be achieved, which was beneficial for the adsorption and separation of ibuprofen. [ABSTRACT FROM AUTHOR]

Inspired from the highly bioadhesive performance of polydopamine (pDA)-based layers, a facile method was developed to modify GO nanosheets with pDA (pDA@GO). The key design of the molecularly imprinted nanocomposite membranes (MINMs) was integrated pDA@GO nanosheets into the porous PVDF membranes as the highly adjustable active domains. Dendrites-like 3D Ag microspheres were obtained on the surface of nanosheets-infiltrated nanocomposite membranes (NS-NMs) to obtain high performance membranes. The as-prepared pDA coating layers not only modified GO nanosheets, but also could be used as a versatile platform for the further immobilizing dendrites-like 3D Ag microspheres on the surface of NS-NMs to improve anti-fouling property. Attribute to the highly adjustable active domains and dendrites-like 3D Ag microspheres, the as-prepared MINMs revealed an outstanding adsorption amount (61.55 mg g −1 ), a better hydrophilicity and regenerability. Most importantly, excellent perm-selectivity performance ( β ketoprofen/ibuprofen and β naproxen sodium/ibuprofen were 6.55 and 6.63, respectively) could be also achieved, which is beneficial to adsorb and separate of ibuprofen. [ABSTRACT FROM AUTHOR]

The development of membrane-associated molecularly imprinted materials that can rapidly adsorb and separate specific compound has broad technological applications for areas ranging from sewage treatments to biomedical devices. However, issues such as low permselectivity and unstable composite structures are restricting it from developing stage to a higher level. Here, inspired by the bioadhesive technology of polydopamine (pDA), we present a novel molecular imprinting strategy to integrate multilevel nanocomposites (Br-Ag-pDA@SiO 2 ) into the porous membrane structure. The molecularly imprinted nanocomposite membranes (MINcMs) were then obtained through an in situ photoinitiated ATRP method by using propranolol as the template molecule, which was one of the pharmaceutically active compounds (PhACs). In this work, largely enhanced specific rebinding capacity (48.53 mg/g) and permselectivity (the permeability factor β values were also more than 9.6) had been successfully achieved, which should be attributing to the creation of high-stability and uniform growth of propranolol-imprinted polymer layers onto the nanoparticle-integrated nanocomposite membrane surfaces. Specifically, the as-prepared MINcMs not only exhibited rapid adsorption dynamics of template molecule, but also possessed excellent regeneration performance. Moreover, when the other PhACs were respectively imprinted, similar recognition selectivity could be observed dependent on the template molecule. Importantly in this case, all synthesis methods were conducted in aqueous at ambient temperature, which was environmental friendly for scaling up without causing pollution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biomimetic modification of polydopamine is used as the initial blot layer. • The stable loading of the blot GO sheet provides porosity and layered structure. • Sol-gel blotting and blot GO tablets co-selectively isolate artemisinin. • MIMs have good stability in continuous infiltration. Membrane-based separations can improve energy efficiency and reduce the environmental impact associated with conventional methods. However, conventional adsorbents encapsulate most of their functional sites in their dense structures, leading to issues of low selectivity and adsorption capacity. To overcome the above problems, the scalable basswood-based PDA/GO-embedded self-assembly membranes were prepared based a multilayer artemisinin (Ars)-imprinted nanocage (MA/SB-P/G-ESMs) for highly selective adsorption and transport to Ars. The double-layer imprinting strategy of graphene oxide based on polydopamine and κ-carrageenan using three-dimensional mesoporous basswood as the support membrane improved the effective imprinting platform. The final MA/SB-P/G-ESMs were prepared by a heat-initiated radical polymerization, acrylamide was used as a functional monomer to conveniently and efficiently form specific recognition sites on the membrane. Notably, the outcomes demonstrated that, despite interference with other rivals, MA/SB-P/G-ESMs displayed perfect rebinding selectivity (λ = 2.67, 2.89, 2.35) and perm-selectivity (β = 8.16, 5.43, 6.51) for Ars. The high regeneration rate (after 10 cycles, greater than93%) demonstrated the MA/SB-P/G-ESMs' practical application potential. The selective separation of Ars using the MA/SB-P/G-ESM preparation method showed substantial promise in this work. [ABSTRACT FROM AUTHOR]

• The phase inversion integrated with dip-coating method to prepare the membrane. • JIM realized the specific adsorption towards two kinds of objectives. • The adsorbed pollutions were severally collected to avoid the pollution. • JIM showed enhanced adsorption selectivity toward analogues. Janus imprinted membrane (JIM) fabricated through the connective method of phase inversion and dip-coating processes has gained considerable attention in the separation field. Herein, a JIM with specific artificial receptors was prepared for the selective adsorption and separation of tetrabromobisphenol A (TBBPA) and cadmium ion (Cd2+). Dip coating method performed on the smooth surface of plate glass was used for the growth of polyaniline (PANI) imprinted polymers with specific imprinted cavities for TBBPA. The casting solution was coated on the imprinted polymers, which was then immersed into the coagulating bath containing gallic acid (GA) to achieve a delayed phase inversion process. The adsorption results showed that the rebinding capacities of the JIM for TBBPA and Cd2+ were 58.279 mg g−1 and 83.159 mg g−1, respectively. Meanwhile, the JIM exhibited superior rebinding selectivity with selectivity coefficients of 2.56, 2.87, 3.07, 2.52, 3.53, 3.66 and 4.05 for Pb2+, Cu2+, Zn2+, Sn2+, Hg2+, Co2+ and Cr3+ and 2.44, 2.56, 2.67 for BP, BPA and BBPA, respectively. The synthesized JIM showed tiny changes in rebinding capacity after 10 times cycles, revealing desirable regeneration performance. Finally, the pollutants on membrane surface were severally collected to avert the secondary pollution. The current study demonstrated that connective method is a promising method for selective rebinding and sorting treatment of different pollutants. [ABSTRACT FROM AUTHOR]

Highlights: [•] WMIP as an efficient and promising adsorbent for SA was successfully synthesized. [•] Column performance was firstly investigated to adsorb SA by WMIP packed fixed bed. [•] WMIP exhibited excellent recognition selectivity for SA in fixed bed column. [•] Thomas mode could be used in the design of a fixed bed for practical application. [•] WMIP could be easily regenerated with desorption efficiency up to 96.02%. [Copyright &y& Elsevier]