Organization of malonamides from the interface to the organic bulk phase

Micheau, C.; Ueda, Yuki; Motokawa, Ryuhei; Akutsu, Kazuhiro*; Yamada, Norifumi*; Yamada, Masako*; Moussaoui, S. A.*; Makombe, E.*; Meyer, D.*; Berthon, L.*; et al.

Journal of Molecular Liquids, 401, p.124372_1 - 124372_12, 2024/05

https://doi.org/10.1016/j.molliq.2024.124372

Supramolecular organization of extractant molecules impacts metal ions separation behavior. Probing bulk and interfacial structures of the relevant systems is expected to provide key insights into the metal ion selectivity and kinetic aspects. The supramolecular features of two solvent extraction systems based on malonamide extractants THMA in toluene and DBMA in n-heptane were studied using small-angle X-ray scattering for the organic bulk phases, as well as interfacial tension and neutron reflectivity measurements for the interfaces. In the bulk solution, THMA forms dimeric/trimeric associates but no aggregates in toluene, while DBMA forms large aggregates in n-heptane. On the other hand, THMA accumulates in a diffuse layer at the interface at high THMA concentration, whereas DBMA forms a compact but thinner layer. After Pd(II) extraction, the thickness of interfacial layers decreases in the case of THMA, and totally vanishes in the case of DBMA. Based on these new structural information, two mechanisms are proposed for Pd(II) and Nd(III) extraction with malonamides. In toluene, THMA associates slightly accumulate in the vicinity of the interface, then coordinate Pd(II) and diffuse into the organic bulk phase. In n-heptane, DBMA aggregates adsorb at the interface then pick up Nd(III) cations in their polar cores and finally diffuse into the bulk.

Recent progress in the energy recovery linac project in Japan

Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05

http://accelconf.web.cern.ch/AccelConf/IPAC10/papers/tupe091.pdf

Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.

Effect of colloid filtration by bentonite barrier altered in alkalic conditions

*; Shibata, Masahiro; Ueta, Shinzo*; *; Yui, Mikazu

JNC TN8400 2002-013, 33 Pages, 2002/03

JNC-TN8400-2002-013.pdf:1.23MB

In the construction of geological disposal repository for radioactive waste, cementitious material may be used, e.g. as a mechanical support for tunnel. Regarding such conditions, evaluation of bentonite buffer alteration by high-pH solution, which caused by groundwater-cementitious material interaction, is important. In this study, colloid filtration ability of bentonite buffer acceleratingly altered by high-pH solution was experimentally investigated. The compacted bentonite specimen were first hydrothermally treated at high-pH (pH 14 or pH 12.5, at 200C). Then the mineralogical alteration was identified by XRD, and colloid permeability test was conducted. In the case that the specimen was treated at pH 14, serious smectite dissolution and feldspar crystallization was observed, and colloid permeation was identified. From the results of this study, the importance of understanding of alteration behavior in the actual repository condition, and examinations of the colloid filtration ability of the alteration products are highlighted.

Investigation on water history using deuterium fuel cell

Koizumi, Satoshi; Putra, A.; Zhao, Y.; Noda, Yohei; Yamaguchi, Daisuke; Ueda, Satoru*; Gunji, Hiroyuki*; Eguchi, Mika*; Tsutsumi, Yasuyuki*

no journal, , 

In order to investigate water history during fuel cell operation, we employed deuterated gas (D) as a fuel (deuterium fuel cell). With exchange of H and D, we aim to perform a contrast variation as for polyelectrolyte film (Nafion). When D gas is used as a fuel, DO is produced at the cathode and diffuses back to the film. Then the film, originally swollen by HO, exhibits change of coherent scattering contrast. By changing a fuel gas from H to D, SANS quantitatively detected decrease of scattering intensity at scattering maximum originating from the ion-channel in the electrolyte. After quantitative analyses on scattering intensity, which is related to water ratio (HO/DO) in the ion channel, we could determine the water ration swelling a membrane.