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Journal Articles

Recent progress in ionic liquid extraction for the separation of rare earth elements

Okamura, Hiroyuki; Hirayama, Naoki*

Analytical Sciences, 37(1), p.119 - 130, 2021/01

 Times Cited Count:5 Percentile:83.92(Chemistry, Analytical)

This review summarizes recent progress in solvent extraction of rare earth elements (REEs) using an ionic liquid (IL) as the extraction solvent. These IL extraction systems are advantageous owing to the affinity of ILs for both charged and neutral hydrophobic species, in contrast to conventional organic solvent extraction systems. Herein, REE extraction studies using ILs are detailed and classified based on the type of extraction system. In IL extraction systems, the extracted complexes are often different from those in organic solvent systems, and the REE extraction and separation efficiencies are often significantly enhanced. Synergistic IL extraction is an effective approach to improving the extractability and separability of REEs. The development of novel task-specific ionic liquids (TSILs) suitable for IL extraction systems is also effective for REE separation.

Journal Articles

Synergistic enhancement of the extraction and separation efficiencies of lanthanoid(III) ions by the formation of charged adducts in an ionic liquid

Okamura, Hiroyuki; Mizuno, Masayoshi*; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

Industrial & Engineering Chemistry Research, 59(1), p.329 - 340, 2020/01

 Times Cited Count:6 Percentile:64.04(Engineering, Chemical)

The synergistic ionic-liquid extraction and extraction equilibrium of lanthanoid(III) (Ln(III)) ions have been investigated using 2-thenoyltrifluoroacetone (Htta) and trioctylphosphine oxide (TOPO) in the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C$$_{4}$$mim][Tf$$_{2}$$N]). The selective synergistic effect for heavier Ln(III) ions was found using a combination of Htta and TOPO in [C$$_{4}$$mim][Tf$$_{2}$$N], leading to enhanced separability among Ln(III) ions. The extracted Ln(III) species and the extraction constants in the Htta-TOPO system were determined by three-dimensional extraction equilibrium analysis. The selective synergism for heavier Ln(III) ions in the Htta-TOPO system was ascribed to the formation of hydrophobic, charged adducts, such as Ln(tta)$$_{2}$$(TOPO)$$_{3}$$$$^{+}$$ and Ln(tta)(TOPO)$$_{3}$$$$^{2+}$$, in [C$$_{4}$$mim][Tf$$_{2}$$N].

Journal Articles

Enhancement of element production by incomplete fusion reaction with weakly bound deuteron

Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.

Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07

 Times Cited Count:5 Percentile:62.37(Physics, Multidisciplinary)

Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for $$^{107}$$Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.

Journal Articles

Overview of JENDL-4.0/HE and benchmark calculations

Kunieda, Satoshi; Iwamoto, Osamu; Iwamoto, Nobuyuki; Minato, Futoshi; Okamoto, Tsutomu; Sato, Tatsuhiko; Nakashima, Hiroshi; Iwamoto, Yosuke; Iwamoto, Hiroki; Kitatani, Fumito; et al.

JAEA-Conf 2016-004, p.41 - 46, 2016/09

Neutron- and proton-induced cross-section data are required in a wide energy range beyond 20 MeV, for the design of accelerator applications. New evaluations are performed with recent knowledge in the optical and pre-equilibrium model calculations. We also evaluated cross-sections for p+$$^{6,7}$$Li and p+$$^{9}$$Be which have been highly requested from a medical field. The present high-energy nuclear data library, JENDL-4.0/HE, includes evaluated cross-sections for incident neutrons and protons up to 200 MeV (for about 130 nuclei). We overview substantial features of the library, i.e., (1) systematic evaluation with CCONE code, (2) challenges for evaluations of light nuclei and (3) inheritance of JENDL-4.0 and JENDL/HE-2007. In this talk, we also focus on the results of benchmark calculation for neutronics to show performance of the present library.

Journal Articles

Specific cooperative effect of a macrocyclic receptor for metal ion transfer into an ionic liquid

Okamura, Hiroyuki; Ikeda, Atsushi*; Saito, Takumi*; Aoyagi, Noboru; Naganawa, Hirochika; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Shimojo, Kojiro

Analytical Chemistry, 84(21), p.9332 - 9339, 2012/11

 Times Cited Count:23 Percentile:67.6(Chemistry, Analytical)

Journal Articles

Laser-induced fluorescence and infrared spectroscopic studies on the specific solvation of tris(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)europium(III) in an ionic liquid

Okamura, Hiroyuki; Sakae, Hiroki*; Kidani, Keiji*; Hirayama, Naoki*; Aoyagi, Noboru; Saito, Takumi*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

Polyhedron, 31(1), p.748 - 753, 2012/01

 Times Cited Count:24 Percentile:86.45(Chemistry, Inorganic & Nuclear)

Journal Articles

Synergistic effect of 18-crown-6 derivatives on chelate extraction of lanthanoids(III) into an ionic liquid with 2-thenoyltrifluoroacetone

Okamura, Hiroyuki; Hirayama, Naoki*; Morita, Kotaro*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

Analytical Sciences, 26(5), p.607 - 611, 2010/05

 Times Cited Count:48 Percentile:84.67(Chemistry, Analytical)

Journal Articles

Cooperative intramolecular interaction of diazacrown ether bearing $$beta$$-diketone fragments on an ionic liquid extraction system

Shimojo, Kojiro; Okamura, Hiroyuki; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

Dalton Transactions, 2009(25), p.4850 - 4852, 2009/07

A novel extractant $$beta$$-diketone-substituted diaza-18-crown-6 demonstrated very efficient extraction of Sr$$^{2+}$$ due to an intramolecular synergistic effect on the ionic liquid extraction system and recovery of Sr$$^{2+}$$ from the ionic liquid was successfully achieved under acidic conditions.

JAEA Reports

Benchmark problems for intermediate and high energy accelerator shielding

; Sakamoto, Yukio; Tanaka, Shunichi; ; Fukahori, Tokio; ; Sasamoto, Nobuo; Tanaka, Susumu; Nakamura, Takashi*; Shin, Kazuo*; et al.

JAERI-Data/Code 94-012, 90 Pages, 1994/09

JAERI-Data-Code-94-012.pdf:2.26MB

no abstracts in English

Oral presentation

Ionic liquid synergy extraction of lanthanides with beta-diketone and crown ether

Okamura, Hiroyuki; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

no journal, , 

no abstracts in English

Oral presentation

Synergy extraction of lanthanides using macrocyclic compounds into ionic liquids

Okamura, Hiroyuki; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

no journal, , 

no abstracts in English

Oral presentation

Intramolecular synergistic effect in ionic liquid extraction system of metal ions

Okamura, Hiroyuki; Shimojo, Kojiro; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

no abstracts in English

Oral presentation

Intramolecular synergistic extraction using crown ether bearing b-diketone fragments in an ionc liquid

Okamura, Hiroyuki; Shimojo, Kojiro; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

no abstracts in English

Oral presentation

Intramolecular synergy effect of crown ether bearing b-diketone fragments and development of ionic liquids extraction system

Shimojo, Kojiro; Okamura, Hiroyuki; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

no abstracts in English

Oral presentation

Analysis of extraction equilibria in ionic liquid synergistic extraction systems using crown ethers

Okamura, Hiroyuki; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

no journal, , 

no abstracts in English

Oral presentation

Intramolecular synergistic effect on an ionic liquid extraction system using crown ether bearing $$beta$$-diketone fragments

Okamura, Hiroyuki; Shimojo, Kojiro; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

no abstracts in English

Oral presentation

Structure analysis of complex extracted into an ionic liquid with X-ray absorption spectroscopy

Okamura, Hiroyuki; Shimojo, Kojiro; Ikeda, Atsushi; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

no abstracts in English

Oral presentation

Intramolecular synergistic effect on ionic liquid extraction system with crownn ether bearing $$beta$$-diketone fragments

Shimojo, Kojiro; Okamura, Hiroyuki; Ikeda, Atsushi; Saito, Takumi*; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

no abstracts in English

Oral presentation

Specific solvent effect of ionic liquids on the extraction of europium(III) with 2-thenoyltrifluoroacetone

Okamura, Hiroyuki; Morita, Kotaro*; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

no journal, , 

no abstracts in English

Oral presentation

Effective extraction of strontium(II) into an ionic liquid by cooperative intramolecular interaction

Okamura, Hiroyuki; Shimojo, Kojiro; Ikeda, Atsushi*; Saito, Takumi*; Aoyagi, Noboru; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

40 (Records 1-20 displayed on this page)