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Proton chelating ligands drive improved chemical separations for rhodium

成田 弘一*; Nicolson, R. M.*; 元川 竜平; 伊藤 文之*; 森作 員子*; 後藤 みどり*; 田中 幹也*; Heller, W. T.*; 塩飽 秀啓; 矢板 毅; et al.

Inorganic Chemistry, 58(13), p.8720 - 8734, 2019/07

 被引用回数:0 パーセンタイル:100(Chemistry, Inorganic & Nuclear)

Current industrial practices to extract rhodium from virgin ores carry a heavy environmental burden. Improving the efficiency of the hydrometallurgical processes to separate and recover rhodium from other precious metals provides an opportunity to improve the materials and energy balances, but the presence of mixed chloride-rhodium species following leaching by acid chloride media complicates the recovery process. In this work we have applied a broad range of analytical techniques (FT-IR spectroscopy, X-ray diffraction, EXAFS, water-transfer analysis, small-angle neutron scattering, NMR spectroscopy, and electrospray mass spectrometry), which together show that the amino-amide reagent preferentially transports chlorido-rhodium species as a 1:2 neutral assembly from aqueous 2.0 M HCl phase into an organic phase. The extractants then ligate in the outer coordination shell of the chloride-rhodium anion, making this an efficient separation process. In this study, we found that protonation to the extractants induced to form a proton chelate ring, which pre-organises the ligand to present an array of charge diffuse C-H bonds. This templated arrangement of positive dipoles favors complexation to the charge diffuse chloride-rhodium anion over the more charge-dense chloride anion.


A Telescoping view of solute architectures in a complex fluid system

元川 竜平; 小林 徹; 遠藤 仁; Mu, J.*; Williams, C. D.*; Masters, A. J.*; Antonio, M. R.*; Heller, W. T.*; 長尾 道弘*

ACS Central Science, 5(1), p.85 - 96, 2019/01

 被引用回数:10 パーセンタイル:10.25(Chemistry, Multidisciplinary)

We present a hierarchical aggregate model of an organic phase containing a coordination species that acts as a fundamental building unit of higher-order structures formed in the organic phase. We aimed to elucidate the fundamental aspects of the microscopic structure and phase separation occurring in ionic separation and recovery systems during solvent extraction. The coordination species aggregate through a hydrogen-bonding network formed by interaction between the hydrophilic part of the coordination species with extracted water and acid molecules. This reduces the hydrophilic surface area, resulting in subsequent formation of small primal clusters of 2 to 3 nm in diameter. The primal clusters further aggregate due to van der Waals interaction to form large aggregates of $$<$$ 10 nm in diameter. The size of the primal cluster does not depend on the concentration of the coordination species, whereas the size of the large aggregate increases as the aggregation number of the primal clusters increases. We conclude that hybrid interaction is a key driving force in the formation and growth of the hierarchical aggregate and the induction of phase separation of the organic phase.


Phase-transition kinetics of magnetic skyrmions investigated by stroboscopic small-angle neutron scattering

中島 多朗*; 稲村 泰弘; 伊藤 崇芳*; 大石 一城*; 大池 広志*; 賀川 史敬*; 吉川 明子*; 田口 康二郎*; 加倉井 和久*; 十倉 好紀*; et al.

Physical Review B, 98(1), p.014424_1 - 014424_5, 2018/07

 被引用回数:4 パーセンタイル:52.2(Materials Science, Multidisciplinary)



Hierarchically self-organized dissipative structures of filler particles in poly(styrene-$$ran$$-butadiene) rubbers

山口 大輔; 湯浅 毅*; 曽根 卓男*; 冨永 哲雄*; 能田 洋平*; 小泉 智*; 橋本 竹治*

Macromolecules, 50(19), p.7739 - 7759, 2017/10

 被引用回数:5 パーセンタイル:68.71(Polymer Science)




成田 弘一*; 鈴木 智也*; 元川 竜平

日本金属学会誌, 81(4), p.157 - 167, 2017/04

 被引用回数:3 パーセンタイル:66.31(Metallurgy & Metallurgical Engineering)

Most of the refineries for platinum group metals (PGMs) in Japan have adopted solvent extraction methods for mutual separation of PGMs. Few effective extractants for industrial use have been found although some industrial processes were established in 1970s. Recently, some compounds have been reported as candidates for practical PGM extractants in addition to new concepts for PGM extraction mechanisms. In this review article, we present well-known PGM recovery processes based on solvent extraction, industrial extractants and their properties, and conventional extraction mechanism for PGMs. Additionally, we discuss recent interesting extraction systems (amide-type compounds and ionic liquid) and then introduce new extraction concepts based on the specific interactions at the outer-sphere of a metal complex in the organic phase.


Contrast variation by dynamic nuclear polarization and time-of-flight small-angle neutron scattering, 1; Application to industrial multi-component nanocomposites

能田 洋平*; 小泉 智*; 増井 友美*; 間下 亮*; 岸本 浩通*; 山口 大輔; 熊田 高之; 高田 慎一; 大石 一城*; 鈴木 淳市*

Journal of Applied Crystallography, 49(6), p.2036 - 2045, 2016/12

 被引用回数:10 パーセンタイル:26.01(Chemistry, Multidisciplinary)

We have reported the first attempt with dynamic nuclear polarization (DNP) and contrast variation small-angle neutron scattering (SANS) experiments on model mixtures for industrial tyres conducted at the MLF of J-PARC. We performed time-of-flight SANS (TOF-SANS) experiments, employing neutrons with a wide range, which causes imperfect neutron polarization and variations in the coherent and incoherent scattering lengths. By carefully eliminating the effect of imperfect neutron polarization, separation of the partial scattering functions was successfully demonstrated for the ternary system styrene-butadiene-rubber/silica/carbon.


Nanoscopic structural investigation of physically cross-linked nanogels formed from self-associating polymers

関根 由莉奈; 遠藤 仁*; 岩瀬 裕希*; 竹田 茂生*; 向井 貞篤*; 深澤 裕; Littrell, K. C.*; 佐々木 善浩*; 秋吉 一成*

Journal of Physical Chemistry B, 120(46), p.11996 - 12002, 2016/11

 被引用回数:8 パーセンタイル:64.36(Chemistry, Physical)



Small-angle neutron scattering study of specific interaction and coordination structure formed by mono-acetyl-substituted dibenzo-20-crown-6-ether and cesium ions

元川 竜平; 小林 徹; 遠藤 仁*; 池田 隆司; 矢板 毅; 鈴木 伸一; 成田 弘一*; 阿久津 和宏*; Heller, W. T.*

Journal of Nuclear Science and Technology, 53(8), p.1205 - 1211, 2016/08

 被引用回数:0 パーセンタイル:100(Nuclear Science & Technology)

This study uses small-angle neutron scattering (SANS) to elucidate the coordination structure of the complex of mono-acetyl substituted dibenzo-20-crown-6-ether (ace-DB20C6) with Cs. SANS profiles obtained for the complex of ace-DB20C6 and Cs (ace-DB20C6/Cs) in deuterated dimethyl sulfoxide indicated that Cs coordination resulted in a more compact structure than the free ace-DB20C6. The data were fit well with SANS profiles calculated using Debye function for scattering on an absolute scattering intensity scale. For this theoretical calculation of the scattering profiles, the coordination structure proposed based on a density functional theory calculation. Consequently, we conclude that the SANS analysis experimentally supports the proposed coordination structure of ace-DB20C6/Cs and suggests the following: (1) the complex of ace-DB20C6 and Cs is formed with an ace-DB20C6/Cs molar ratio of 1/1; (2) the two benzene rings of ace-DB20C6 fold around Cs above the center of the crown ether ring of ace-DB20C6.


Photonic crystals fabricated by block copolymerization-induced microphase separation

元川 竜平; 谷口 竜王*; 熊田 高之; 飯田 優羽*; 青柳 翔太*; 佐々木 祐亮*; 桑折 道済*; 岸川 圭希*

Macromolecules, 49(16), p.6041 - 6049, 2016/08

 被引用回数:4 パーセンタイル:73.91(Polymer Science)

We present a method for fabricating photonic crystals (PCs) by polymerization-induced microphase separation of block copolymers (BCPs). Molecular weight of BCP for PCs is so large that it has been difficult for conventional solution casting and annealing methods to complete the microphase separation to form periodically-ordered submicron structures. Our method overcomes the difficulty by inducing the micro phase separation and transitions during the polymerization, when the molecular weight of the BCPs is small enough for the microphase separation and transitions. The microphase-separated structure is then enlarged while maintaining the self-similarity. We succeeded in fabricating PCs with reflection wavelength $$lambda$$m $$approx$$ 1000 nm and a full width at half maximum $$lambda$$ = 0.05 $$lambda$$m by living-radical bulk block-copolymerization of poly(methyl methacrylate)-block-polystyrene.


A Demonstration study of focusing geometry SANS using a magnetic neutron lens

奥 隆之; 鈴木 淳市; 笹尾 一*; 山田 悟; 古坂 道弘*; 安達 智宏*; 篠原 武尚*; 池田 一昭*; 清水 裕彦

Physica B; Condensed Matter, 356(1-4), p.126 - 130, 2005/02

 被引用回数:9 パーセンタイル:57.66(Physics, Condensed Matter)




鈴木 淳市

日本結晶学会誌, 46(6), p.381 - 389, 2004/12



Small-angle neutron scattering study on microstructure of poly($$N$$-isopropylacrylamide)-$$block$$-poly(ethylene glycol) in water

元川 竜平; 安中 雅彦*; 中平 隆幸*; 小泉 智

Colloids and Surfaces B; Biointerfaces, 38(3-4), p.213 - 219, 2004/11

水中において熱刺激応答性を持つN-イソプロピルアクリルアミドポリマー(PNIPA)とポリエチレングリコール(PEG)からなるジブロック共重合体を合成した。この水溶液は温度変化に応答し、ゾル,ゲル,相分離状態の三つの形態を示す。この相変化のメカニズムを理解するため、各相状態に対応した微細構造を中性子散乱により観察した。散乱実験は、原研に設置の中性子小角散乱装置SANS-J, PNOを用い、ナノからマイクロメートルに渡る空間スケールを観察した。その結果、15$$^{circ}$$C以上のゾル領域においてジブロック共重合体水溶液はミクロ相分離構造を形成することが明らかになった。30$$^{circ}$$C以上で形成される白濁ゲルでは、相分離界面の自由エネルギーを最小化する界面張力の効果と、凝集するPNIPA鎖の絡み合いによる粘弾性的な効果のバランスによりネットワークを作り、白濁ゲルを形成することが明らかになった。また、この中性子散乱プロファイルに対して、定量的な解析を行った結果、サイズが数ナノ程度の小さなドメインを形成していることが明らかとなった。以上のように中性子小角散乱を用いてNIPA-PEGジブロック共重合体水溶液の相挙動を、ミクロ相分離とゲル形成の相関に注目し詳細に解析を行った結果を国際MRS学術シンポジウム2003で発表する。


Feasibility study on application of a magnetic neutron lens to SANS experiments

奥 隆之; 鈴木 淳市; 笹尾 一*; 安達 智宏*; 篠原 武尚*; 池田 一昭*; 森嶋 隆裕*; 酒井 健二*; 鬼柳 善明*; 古坂 道弘*; et al.

Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.116 - 119, 2004/08

 被引用回数:18 パーセンタイル:22.91(Instruments & Instrumentation)



Effects of salt concentration on association of the amyloid protofilaments of hen egg white lysozyme studied by time-resolved neutron scattering

藤原 悟; 松本 富美子*; 米澤 康滋*

Journal of Molecular Biology, 331(1), p.21 - 28, 2003/08

 被引用回数:36 パーセンタイル:45.4(Biochemistry & Molecular Biology)



An Insight into the pathway of the amyloid fibril formation of hen egg white lysozyme obtained from a small-angle X-ray and neutron scattering study

米澤 康滋*; 田中 晋平*; 久保田 智巳*; 若林 克三*; 油谷 克英*; 藤原 悟

Journal of Molecular Biology, 323(2), p.237 - 251, 2002/10

 被引用回数:68 パーセンタイル:25.27(Biochemistry & Molecular Biology)



Precise study of vortex structures in Nb by small-angle neutron scattering

宮田 成紀*; 長村 光造*; 鈴木 淳市

Journal of the Physical Society of Japan, 70(7), p.2098 - 2101, 2001/07

 被引用回数:0 パーセンタイル:100(Physics, Multidisciplinary)



Small angle neutron scattering study on Pr$$_{0.7}$$Ca$$_{0.3}$$MnO$$_{3}$$; Evidence of two-phase coexistence

山田 安定*; 岩瀬 健*; 綿引 成哉*; 鈴木 淳市

Journal of the Physical Society of Japan, 70(6), p.1593 - 1597, 2001/06

 被引用回数:2 パーセンタイル:78.46(Physics, Multidisciplinary)



SANS study of slow dynamics in concetrated spin glasses

元屋 清一郎*; 日置 敬子*; 鈴木 淳市

Journal of the Physical Society of Japan, 70(Suppl.A), p.139 - 141, 2001/05



Frozen concentration fluctuations of a poly(N-isopropyl acrylamide) gel decomposed by neutron spin echo

小泉 智; Monkenbusch, M.*; Richter, D.*; Schwahn, D.*; 安中 雅彦*

Journal of the Physical Society of Japan, Vol.70, Supplement A, p.320 - 322, 2001/05



Small-angle neutron scattering study on ferromagnetic correlation in (La, Tb)$$_{2/3}$$Ca$$_{1/3}$$MnO$$_{3}$$

綿引 成哉*; 目時 直人; 鈴木 淳市; 及川 健一; Nie, J.*; 立木 昌*; 山田 安定

Journal of the Physical Society of Japan, 70(4), p.1090 - 1098, 2001/04

 被引用回数:6 パーセンタイル:56.22(Physics, Multidisciplinary)

(La, Tb)$$_{2/3}$$Ca$$_{1/3}$$MnO$$_{3}$$巨大磁気抵抗効果における強磁性相関の役割を明らかにした。磁場中で得られた中性子散乱強度の振舞いは、磁気抵抗の振舞いと良い一致を示すことから、短距離の強磁性揺らぎが磁気抵抗増大の要因であることがわかった。

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