Molecular imprinting science and technology: a survey of the literature for the years up to and including 2003

Herein, we present a survey of the literature covering the development of molecular imprinting science and technology over the years 2004-2011. In total, 3779 references to the original papers, rev ...

Molecular imprinting science and technology: a survey of the literature for the years 2004-2011.

The recovery of uranium (U) from seawater has been investigated for over six decades in efforts to secure uranium sources for future energy production. The majority of the research activities have focused on inorganic materials, chelating polymers, and nanomaterials. Previous studies of uranium adsorption from aqueous solutions, mainly seawater, are reviewed here with a focus on various adsorbent materials, adsorption parameters, adsorption characterization, and marine studies. Continuous progress has been made over several decades, with adsorbent loadings approaching 3.2 mg U/g adsorbent in equilibrium with seawater. Further research is needed to improve first, the viability including improved capacity, selectivity, and kinetics, and second, the sorbent regeneration for multicycle use. An overview of the status of the uranium adsorption technology is provided and future research needs to make this technology commercially competitive are discussed.

Recovery of Uranium from Seawater: A Review of Current Status and Future Research Needs

Preconcentration techniques for uranium(VI) and thorium(IV) prior to analytical determination-an overview.

Metal ion-imprinted polymers : Novel materials for selective recognition of inorganics

Major quantities of uranium find use as nuclear fuel in nuclear power reactors. In view of the extreme toxicity of uranium and consequent stringent limits fixed by WHO and various national governments, it is essential to remove uranium from nuclear power reactor effluents before discharge into environment. Ion imprinted polymer (IIP) materials have traditionally been used for the recovery of uranium from dilute aqueous solutions prior to detection or from seawater. We now describe the use of IIP materials for selective removal of uranium from a typical synthetic nuclear power reactor effluent. The IIP materials were prepared for uranyl ion (imprint ion) by forming binary salicylaldoxime (SALO) or 4-vinylpyridine (VP) or ternary SALO-VP complexes in 2-methoxyethanol (porogen) and copolymerizing in the presence of styrene (monomer), divinylbenzene (cross-linking monomer), and 2,2'-azobisisobutyronitrile (initiator). The resulting materials were then ground and sieved to obtain unleached polymer particles. Leached IIP particles were obtained by leaching the imprint ions with 6.0 M HCl. Control polymer particles were also prepared analogously without the imprint ion. The IIP particles obtained with ternary complex alone gave quantitative removal of uranyl ion in the pH range 3.5-5.0 with as low as 0.08 g. The retention capacity of uranyl IIP particles was found to be 98.50 mg/g of polymer. The present study successfully demonstrates the feasibility of removing uranyl ions selectively in the range 5 microg - 300 mg present in 500 mL of synthetic nuclear power reactor effluent containing a host of other inorganic species.

Removal of Toxic Uranium from Synthetic Nuclear Power Reactor Effluents Using Uranyl Ion Imprinted Polymer Particles

Ion imprinted polymer based sensor for monitoring toxic uranium in environmental samples

The preparation of solid reagent, (5,7-dichloroquinoline-8-ol) modified naphthalene for preconcentration of uranium is described. The uranium-5,7-dichloroquinoline-8-ol complex is quantitatively re...

Solid phase extractive preconcentration of uranium on to 5,7-dichloroquinoline- 8-ol modified naphthalene

Neodymium (III) ion-imprinted polymer (IIP) materials were prepared by the copolymerization of neodymium (III)–5,7-dichloroquinoline-8-ol–4-vinylpyridine ternary complex with styrene(monomer), divinyl benzene (crosslinking monomer) in the presence of 2,2′-azobisisobutyronitrile (initiator). The synthesis was carried out in 2-methoxy ethanol medium (porogen) and the resultant material was filtered, washed, dried and powdered to form unleached IIP particles. The imprint ion was removed by stirring the above particles with 50% (v/v) HCl for 6 h to obtain leached IIP particles with cavities in the polymer particles. Control polymer (CP) particles were similarly prepared without imprint ion, i.e. neodymium (III). CP, unleached and leached IIP particles were characterized by TLC, IR, microanalysis, XRD and UV–visible spectrophotometric studies. The preconcentration of 5–150 μg of neodymium (III) ions present in 500 ml of solution was possible with as little as 40 mg of neodymium (III) IIP particles in the pH range 7.5–8.0 with a detection limit of 50 ng/l. Five replicate determinations of 25 μg of neodymium (III) present in 500 ml of solution gave a mean absorbance of 0.120 with a relative standard deviation of 2.65%. The imprinting effect of IIP particles was noticed in all preconcentration and selectivity studies when compared with CP particles. Furthermore, the selectivity coefficients of neodymium (III) IIP particles were much higher compared with the reported separation factors for the best liquid–liquid extractants, viz. di-2-ethylhexyl phosphoric acid and 2-ethylhexyl-ethylhexyl phosphonate. Kinetic and isotherm studies during rebinding of neodymium (III) onto IIP particles were also carried out. Copyright © 2004 John Wiley & Sons, Ltd.

Selective recognition of neodymium (III) using ion imprinted polymer particles.

Uranyl ion imprinted polymer particles were prepared by the copolymerization of styrene monomer and a crosslinking agent divinyl benzene in the presence of -5,7-dichloroquinoline-8-ol-4-vinyl pyridine ternary complex as template where in is the imprint ion in presence of 2,2′-azo-bis-isobutyronitrile as initiator. The Uranyl ion was removed from the polymer particles by leaching with 1:1 HCl, which leaves cavities in the polymer particles. The leached polymer particles preconcentrate ion from dilute aqueous and synthetic seawater solutions. Further, these particles find use in the separation of ion from various bivalent, trivalent, and tetravalent, inorganic ions. The accuracy of the developed enrichment procedure was tested by analyzing marine sediment certified reference material supplied by National Research Council (NRC), Canada. Further, the developed procedure has been successfully employed to analyze real soil and sediment samples.

Joseph Mary Gladis

Papers

Removal of Toxic Uranium from Synthetic Nuclear Power Reactor Effluents Using Uranyl Ion Imprinted Polymer Particles

Ion imprinted polymer based sensor for monitoring toxic uranium in environmental samples

Solid phase extractive preconcentration of uranium on to 5,7-dichloroquinoline- 8-ol modified naphthalene

Selective recognition of neodymium (III) using ion imprinted polymer particles.

Synthesis and Analytical Applications of Uranyl Ion Imprinted Polymer Particles