A TEM and EPR Investigation of the Competitive Binding of Uranyl Ions to Starburst Dendrimers and Liposomes:  Potential Use of Dendrimers as Uranyl Ion Sponges

Langmuir ◽  
2000 ◽  
Vol 16 (19) ◽  
pp. 7368-7372 ◽  
Author(s):  
M. Francesca Ottaviani ◽  
Paolo Favuzza ◽  
Massimo Bigazzi ◽  
Nicholas J. Turro ◽  
Steffen Jockusch ◽  
...  
Keyword(s):  
Competitive Binding ◽  
Uranyl Ion ◽  
Uranyl Ions ◽  
Potential Use

Preconcentration of Uranium(VI) on Modified and Unmodified Amberlite XAD 4 Sorbent

1993 ◽  
Vol 58 (8) ◽  
pp. 1813-1820 ◽  
Author(s):  
Jan Vácha ◽  
Lumír Sommer
Keyword(s):  
Spectrophotometric Determination ◽  
Uranyl Ion ◽  
Sodium Diethyldithiocarbamate ◽  
Uranyl Ions ◽  
Methanolic Solution

The sorption of uranyl ions on columns with the macrophorus hydrophobic sorbent Amberlite XAD 4 modified with 1-(2-pyridylazo)-2-naphthol and sodium diethyldithiocarbamate was examined. Following elution of the uranyl ion with HNO3 (2 - 4 mol l-1) or of the diethyldithiocarbamate UO22+-chelate with a methanolic solution of HCl (0.1 mol l-1), uranium was determined spectrophotometrically with 4-(2-pyridylazo)resorcinol or with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol. The preconcentration of uranium on Amberlite XAD 4 type sorbents is convenient for its spectrophotometric determination in waters.

scholarly journals Recognition and adsorption of uranyl ion by ion imprinted polymer based materials

2021 ◽  
Vol 290 ◽  
pp. 01007
Author(s):  
Jin Bai ◽  
Yang Yi ◽  
Xilin Xiao ◽  
Yi Ge
Keyword(s):  
Nuclear Power ◽  
Three Dimensional ◽  
Environmental Water ◽  
Uranyl Ion ◽  
Ion Imprinted Polymer ◽  
Uranyl Ions ◽  
Imprinted Polymer ◽  
Military Industry ◽  
Ion Imprinted ◽  
Cavity Structure

Ion imprinted polymer is a kind of three-dimensional material with special cavity structure. Its cavity site has the function of specifically recognizing and binding target ions. It is a kind of materials that can selectively combine, enrich and remove target ions in the environment. Uranium is an important radioactive element, which has been widely used in nuclear power, military industry, science and technology and other fields. However, the accumulation of uranyl ions in environmental water causes serious health hazards to human body. Therefore, the detection and enrichment of uranyl ions in water is of great significance. In this paper, the theory, technology and application status of ion imprinted polymer for micro detection and adsorption of uranyl particles in wastewater were reviewed, and the development of uranyl ion imprinted polymer was prospected.

Selective separation of thorium from uranyl ions using ultrasonic-assisted solidified floating organic drop microextraction

2021 ◽  
Author(s):  
Ghada El-Gamal ◽  
Wael Mortada ◽  
Mohammed Hassanien ◽  
Amr Awad Ibrahim ◽  
Yasmeen Gaber Abou El-Reash
Keyword(s):  
Accurate Determination ◽  
Selective Separation ◽  
Uranyl Ion ◽  
Uranyl Ions ◽  
Ultrasonic Assisted

The accurate determination of thorium (Th4+) in the existence of uranyl ion (UO22+) is a challenge facing analytical chemists. In this article, a solidified floating organic drop microextraction procedure (SFODME)...

A new organic-silica based nanocomposite prepared for spectrophotometric determination of uranyl ions

RSC Advances ◽  
2016 ◽  
Vol 6 (12) ◽  
pp. 9563-9570 ◽  
Author(s):  
A. A. Elabd ◽  
O. A. Elhefnawy ◽  
A. M. El Nahrawy
Keyword(s):  
Sodium Silicate ◽  
Spectrophotometric Determination ◽  
Uranyl Ion ◽  
Uranyl Ions ◽  
Silicate Nanocomposites ◽  
Organic Silica

A new organic-silica based nanocomposite has been prepared for uranyl ion (UO22+) determination based on the absorbance enhancement of tartrazine incorporated copper sodium silicate nanocomposites (T-CSS).

scholarly journals Photosensitized degradation of dinitrosalicylic acid by uranyl ions

2003 ◽  
Vol 5 (4) ◽  
pp. 219-221 ◽  
Author(s):  
A. A. I. Essawy ◽  
M. S. A. Abdel-Mottaleb
Keyword(s):  
Electron Transfer ◽  
Fluorescence Quenching ◽  
Transfer Process ◽  
Radical Pair ◽  
Initial Step ◽  
Uranyl Ion ◽  
Uranyl Ions ◽  
Electron Transfer Process ◽  
Conjugate Acid ◽  
Naoh Solution

The photodegradation of dinitrosalicylic acid (DNS) by photoexcited uranyl ion was studied in aqueous solutions. The failure of DNS to degrade directly with light highlights the importance of the photoexcited uranyl ion in controlling the photochemical processes. Fluorescence quenching studies showed that an electron-transfer process from the DNS to the excited uranyl ion is involved leading to the formation ofUO2+/DNS•+radical pair complex as an initial step. Illumination of theUO22+/DNS solution in presence of oxygen results in mineralization of DNS. The results are explained on the basis of a catalytic cycle involvingUO22+ion and molecular oxygen that generates reactive superoxideO2•−anion and its conjugate acidHO2•. The efficiency of the photocatalytic cycle is enhanced markedly by addition of dilute NaOH solution.

Electroreduction of uranyl ion in aqueous calcium nitrate solutions

1981 ◽  
Vol 59 (10) ◽  
pp. 1515-1520 ◽  
Author(s):  
Narottam P. Bansal ◽  
James A. Plambeck
Keyword(s):  
Cyclic Voltammetry ◽  
Calcium Nitrate ◽  
Uranyl Ion ◽  
Calcium Nitrate Tetrahydrate ◽  
Uranyl Ions ◽  
Nitrate Tetrahydrate ◽  
Nitrate Solutions

The electroreduction of uranyl ions in buffered and unbuffered 0.5 M calcium nitrate has been studied using polarography, cyclic voltammetry, chronopotentiometry, and chronoamperometry. The results are compared with those in molten calcium nitrate tetrahydrate.

Description and classification of uranium oxide hydrate sheet anion topologies

1996 ◽  
Vol 11 (12) ◽  
pp. 3048-3056 ◽  
Author(s):  
Mark L. Miller ◽  
Robert J. Finch ◽  
Peter C. Burns ◽  
Rodney C. Ewing
Keyword(s):  
Structural Unit ◽  
Uranium Oxide ◽  
Uranyl Ion ◽  
Zigzag Chain ◽  
Stacking Sequence ◽  
Uranyl Ions ◽  
Oxide Hydrate ◽  
Structural Relationships ◽  
A Chain

The sheets of uranyl ions (U6+O2)2+ in the structures of all uranyl oxide hydrates (UOH) (and the structurally related α- and β-forms of U3O8) are based on only four structural unit chains. Each sheet type may be reduced to its underlying sheet anion topology to determine the chains present within each topology and to describe the structural relationships among these phases. Each sheet type is described by a chain stacking sequence. The four chain types required to construct the UOH sheet anion topologies are the H-chain, the R-chain, the P-chain, and the directional “arrowhead” chains denoted by U and D. The H-chain is found only in the sheet anion topology of α-UO2(OH)2 and consists of hexagonal sites sharing opposing edges. In α–UO2(OH)2, all hexagons are populated with uranyl ions. The “arrowhead” chain is composed of pentagonal sites populated with uranyl ions and sharing edges and alternating with vacant triangular sites. Arrowhead chains are present in the sheet anion topologies of all other UOH sheets. Arrowhead chains are directional and can occur in both U and D “senses” within a single anion topology. The P-chain consists of edge-sharing pentagonal sites populated with uranyl ions forming a zigzag chain. The P-chain is flanked on both sides by arrowhead chains of the same “sense”. The remaining structural unit is a discontinuous “chain” of rhombic sites. This “R-chain” is produced when nested; adjacent U and D “arrowhead” chains are translated diagonally. The R-chain occurs in the sheet anion topologies of sheets which contain only 4-coordinate uranyl ions and those containing both 4- and 5-coordinate uranyl ions. The rhombic sites may be populated with a uranyl ion, a U4+ or other cation and two apical oxygens, or they may be vacant.

The growth of mica polytypes as studied by conventional and high-resolution TEM

1983 ◽  
Vol 41 ◽  
pp. 174-177
Author(s):  
A. Baronnet ◽  
M. Amouric
Keyword(s):  
Water Pressure ◽  
Point Of View ◽  
Temperature Fields ◽  
Natural Occurrence ◽  
Growth Mechanisms ◽  
Long Period ◽  
High Resolution Tem ◽  
Layer Stacking ◽  
Experimental Works ◽  
Potential Use

The origin of mica polytypes has long been a challenging problem for crystal- lographers, mineralogists and petrologists. From the petrological point of view, interest in this field arose from the potential use of layer stacking data to furnish further informations about equilibrium and/or kinetic conditions prevailing during the crystallization of the widespread mica-bearing rocks. From the compilation of previous experimental works dealing with the occurrence domains of the various mica "polymorphs" (1Mr, 1M, 2M1, 2M2 and 3T) within water-pressure vs temperature fields, it became clear that most of these modifications should be considered as metastable for a fixed mica species. Furthermore, the natural occurrence of long-period (or complex) polytypes could not be accounted for by phase considerations. This highlighted the need of a more detailed kinetic approach of the problem and, in particular, of the role growth mechanisms of basal faces could play in this crystallographic phenomenon.

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