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Malonamide derivatives, which are the most extensively investigated extractants for solvent extraction of lanthanides, actinides, and platinum group metal ions, were deuterated by using Pd/C and Rh/C catalysts in a D2O/2-propanol mixture. This method replaces 1H atoms in the malonamides with 2H atoms at a controllable deuteration rate. The maximum rate reached about 75%, determined by nuclear magnetic resonance and electrospray ionization – mass spectrometry. The extraction behavior of metal ions by the malonamides was unchanged by the deuteration. Deuterated malonamides are a powerful tool for fundamental research on solvent extraction systems and for structural analysis of organic phases. The large difference in the cross section of coherent neutron scattering between 1H and 2H leads to a large difference in neutron scattering length density of malonamide derivatives before and after the deuteration. Therefore, using deuterated malonamides in small-angle neutron scattering and neutron reflectivity studies may help to reveal the microscopic structure of the specific solute species in the bulk organic phase and at the liquid–liquid interface, respectively. In this paper, we report the advantage of the deuterated malonamides for a contrast-matching method in the SANS experiment. This deuteration method could be generalized and extended to a wide variety of extractant molecules.

Spin-contrast-variation neutron reflectivity obtains multiple reflectivity curves from a single sample and a single beam source. We used the strong point of the technique to reveal that, although methylated-perhydropolysilazane-derived silica layer has a higher porosity near the interface with acrylic urethane resin, the resin did not permeate the pore network., スピンコントラスト変調中性子反射率法は一つの試料一つのビームラインから複数の反射率曲線が得られる手法である。我々はその特徴を生かしてメチル化ポリシラザンから作られた多孔質シリカ界面においてアクリルウレタン樹脂は多孔質体内に入り込まないことを見出した。

This study investigated the surface characteristics of denture base resin coatings prepared using a novel silica-based film containing hinokitiol and assessed the effect of this coating on Candida albicans adhesion and growth.Silica-based coating solutions (control solution; CS) and CS containing hinokitiol (CS-H) were prepared. C. albicans biofilm formed on denture base specimens coated with each solution and these uncoated specimens (control) were analyzed using colony-forming unit (CFU) assay, fluorescence microscopy, and scanning electron microscopy (SEM). Specimen surfaces were analyzed by measuring the surface roughness and wettability and with Fourier-transform infrared (FT-IR) and proton nuclear magnetic resonance (CS-H and CS-H-1w contained significantly lower CFUs than those present in the control and control-1w, which was also confirmed via SEM. Fluorescence microscopy from the CS-H group identified several dead cells. The values of surface roughness from coating groups were significantly less than those from the control and control-1w. The surface wettability from all coating groups exhibited high hydrophobicity. FT-IR analyses demonstrated that specimens were successfully coated, andA silica-based denture coating that incorporates hinokitiol inhibits C. albicans growth on denture.We provide a novel antifungal denture coating which can be helpful for the treatment of denture stomatitis.

Glassy magnetic behavior has been observed in a wide range of crystalline magnetic materials called spin glass. Here, we report spin glass behavior in a structural glass of a magnetic ionic liquid, C4mimFeCl4. Magnetization measurements demonstrate that an antiferromagnetic ordering occurs at TN = 2.3 K in the crystalline state, while a spin glass transition occurs at TSG = 0.4 K in the structural glass state. In addition, localized magnetic excitations were found in the spin glass state by inelastic neutron scattering, in contrast to spin-wave excitations in the ordered phase of the crystalline sample. The localized excitation was scaled by the Bose population factor below TSG and gradually disappeared above TSG. This feature is highly reminiscent of boson peaks commonly observed in structural glasses. We suggest the “magnetic” boson peak to be one of the inherent dynamics of a spin glass state.

Introducing magnetic order into a topological insulator (TI) system has been attracting much attention with an expectation of realizing exotic phenomena such as quantum anomalous Hall effect (QAHE) or axion insulator states. The magnetic proximity effect (MPE) is one of the promising schemes to induce the magnetic order on the surface of TI without introducing disorder accompanied by doping magnetic impurities in TI. In this study, we investigate the MPE at the interface of a heterostructure consisting of a topological crystalline insulator (TCI) SnTe and Fe by employing polarized neutron reflectometry. The ferromagnetic order penetrates $\sim$ 3 nm deep into the SnTe layer from the interface with Fe, which persists up to room temperature. Our findings demonstrate that the interfacial magnetism is induced by the MPE on the surface of TCI preserving the coherent topological states, which is essential for the bulk-edge correspondence, without introducing disorder arising from a random distribution magnetic impurities. This opens up a way for realizing next generation electronics, spintronics, and quantum computational devices by making use of the characteristics of TCI.

Masks are effective for preventing the spread of COVID-19 and other respiratory infections. If antimicrobial properties can be applied to the non-woven fabric filters in masks, they can become a more effective countermeasure against human-to-human and environmental infections. We investigated the possibilities of carrying antimicrobial agents on the fiber surfaces of non-woven fabric filters by applying silica-resin coating technology, which can form silica-resin layers on such fabrics at normal temperature and pressure. Scanning electron microscopy and electron probe microanalysis showed that a silica-resin layer was formed on the fiber surface of non-woven fabric filters. Bioassays for coronavirus and quantitative reverse transcription-polymerase chain reactions (RT-PCR) revealed that all antimicrobial agents tested loaded successfully onto non-woven fabric filters without losing their inactivation effects against the human coronavirus (inhibition efficacy: >99.999%). These results indicate that this technology could be used to load a functional substance onto a non-woven fabric filter by vitrifying its surface. Silica-resin coating technology also has the potential of becoming an important breakthrough not only in the prevention of infection but also in various fields, such as prevention of building aging, protection of various cultural properties, the realization of a plastic-free society, and prevention of environmental pollution.

A novel Sr2+ fluorescent probe, N-(2-hydroxy-3-(1H-benzimidazol-2-yl)-phenyl)-1-aza-18-crown-6-ether (BIC), was synthesized and its fluorescence properties, equilibria, and local structure in solution were studied in detail. The fluorescence intensity of BIC in DMSO was enhanced selectively upon addition of Sr2+ but not Na+, K+, Mg2+, Ca2+, and Ba2+. To employ this rather hydrophobic BIC probe in aqueous media, a sodium laurate (LaNa) micellar solution was used as a good solvent. The detection limit of said LaNa micelle-BIC system (2.02 μM) is lower than that of the H2O system (309 μM), but higher than that of the DMSO system (0.04 μM). Therefore, it is clear that the LaNa micelles have an effect on the detection of Sr2+ by BIC in aqueous solutions. Further structural studies by extended X-ray absorption fine structure and speciation analyses revealed that BIC undergoes complexation equilibria corresponding to the formation of [Sr(BIC)]+ species in all solution types. It was concluded that the changes in the Sr2+-BIC fluorescence in solution are attributed to the formation of such [Sr(BIC)]+ complexes.

We developed a technique of spin-contrast-variation neutron reflectometry (SCV-NR). Polarized-neutron reflectivity curves of film samples vary as a function of their proton-polarization P. The P-dependent reflectivity curves of a polystyrene film was precisely reproduced using a common set of structure parameters and the P-dependent neutron scattering length. The reflectivity curve of poly (styrene-block-isoprene) (PSPI) presented a shoulder attributed to holes with the depth corresponding to one period of periodic lamellae on the free surface only at a specific P. In this way, structural information about specific surfaces or interfaces can be obtained by controlling the P., スピンコントラスト変調中性子反射率法を用いて高分子膜の測定を行った。ポリスチレン薄膜の測定においては核偏極に従って変化する反射率曲線は全て同一の構造因子を用いて綺麗に再現することができた。本結果は、スピン拡散機構によって表面や界面を含めて試料が均一に偏極していることを示したものであり、本手法から構造因子を高い信頼性をもって得られることを担保する結果となった。また、ミクロ相分離したブロック共重合体の測定では、核偏極によって特定の界面構造が選択的に得ることができることを示した。

A large background scattering originating from the sample matrix is a major obstacle for fine-structure analysis of a nanometric layer buried in a bulk material. As polarization analysis can decrease undesired scattering in a neutron reflectivity (NR) profile, we performed NR experiments with polarization analysis on a polypropylene (PP)/perhydropolysilazane-derived SiO2 (PDS)/Si substrate sample, having a deep-buried layer of SiO2 to elucidate the fine structure of the nano-PDS layer. This method offers unique possibilities for increasing the amplitude of the Kiessig fringes in the higher scattering vector (Qz) region of the NR profiles in the sample by decreasing the undesired background scattering. Fitting and Fourier transform analysis results of the NR data indicated that the synthesized PDS layer remained between the PP plate and Si substrate with a thickness of approximately 109 Å. Furthermore, the scattering length density of the PDS layer, obtained from the background subtracted data appeared to be more accurate than that obtained from the raw data. Although the density of the PDS layer was lower than that of natural SiO2, the PDS thin layer had adequate mechanical strength to maintain a uniform PDS layer in the depth-direction under the deep-buried condition.

Complexation properties of N-methyl-N-tolyl-2-(1H-benzimidazol-2-yl)pyridine-6-carboxamide (MeTolBIZA) with trivalent lanthanides were investigated by spectroscopic titration study and discussed ba...

We combined the deuterium labeling and neutron reflectivity techniques to determine the fine structure of the electric double layer structure in an imidazolium ionic liquid (IL). For this, a simple and large scale deuteration method for imidazolium ILs was developed, where the deuteration level can be systematically controlled.

When designing some functions in thin film systems, one of the key concepts is the structure of the constituent layers and interfaces. In an actual system, the layers and interfaces are often inhomogeneous in different scales, from hundreds of microns to several nanometers, causing differences in properties, despite very similar average structures. In this case, the choice of the observation point is critical to clarify the problem. Another critical aspect is the identification of these points by surveying the entire inhomogeneous thin film system. This article presents a description of a novel promising solution that is suitable for nondestructive visualization of inhomogeneous buried layers and interfaces in thin films. Such observations have been impossible until now. In this investigation, a unique extension of neutron reflectometry is proposed. While conventional neutron reflectivity just gives average depth-profiling of the scattering length density of layered thin films, the present method provides full picture of the inhomogeneity. In general, achieving a high spatial-resolving power for neutron scattering is not straightforward because the neutron counts become fairly limited at the sample or the detector position when the beam size is reduced. As a result, XY scanning of a sample with a small neutron beam is fairly difficult because of the required long measurement time. To address these issues, new concepts have been introduced for neutron reflectivity. The proposed method uses a wide beam instead of reducing the beam size. In addition, it measures the projection reflection profile instead of the total integrated intensity. These profiles are collected at a set of different in-plane angles. Similar to computed tomography, it is possible to obtain the specimen’s two-dimensional (2D) neutron reflectivity distribution as one image. Because the spatial resolution is limited by the detection method, a Hadamard coded mask is employed to measure the reflection projection with only 50% loss of the primary neutron intensity. When the time-of-flight (ToF) mode is used for the neutron experiment, one can obtain many images as a function of ToF, i.e., the wavevector transfer. Such series of images can be displayed as a video. This indicates that the neutron reflectivity profiles of local points can be retrieved from the above video images. This paper presents the first report on the development of neutron reflectivity with imaging capability, and the analysis of local points in inhomogeneous layered thin-films without utilizing a small neutron beam. In the present work, the feasibility of the proposed method with approximately 1 mm spatial resolution was examined. In addition, further improvements of the approach are discussed. It is anticipated that this technique will facilitate new opportunities in the study of buried function interfaces.

A quantitative analysis method for monitoring liquid penetration into nanosize thin layer samples was developed using neutron reflectivity (NR). In this study, we synthesized a partly deuterated ionic liquid (IL) and studied its penetration behavior in perhydropolysilazane-derived silica (PDS) thin layers using NR. The penetration depth of the deuterated IL was estimated to be 184 A for the 24 h IL-submerged sample and 410 A for the 72 h IL-submerged sample. In addition, using the obtained penetration depth, an apparent penetration rate constant (kapp) of 0.024 h−1 was evaluated. Thus liquid penetration behavior in PDS thin layer samples can be quantitatively discussed by evaluation of kapp using NR analysis.

We evaluated the influence on milk production of feeding early lactation cows a diet that included 14.5% crude protein (CP) and that did not meet methionine (Met) requirements or that met them by supplying rumen‐protected Met (RPMet). Thirty‐nine multiparous Holstein cows were allocated into two groups. For 15 weeks after calving, each group was fed one of the two total mixed rations, Control (n = 20) or Treatment (n = 19). The Treatment group received added RPMet at 0.034% (8 g/day) of the Control diet on dry matter basis. The adequacies of Met for the Control and Treatment groups were 96% and 106%, respectively, and for other amino acids, >110%. The CP level (14.5%) was 1 percentage point lower than that recommended by the Japanese Feeding Standard (2006). No between‐group differences were found in milk yield (40 kg/day), milk composition, plasma profile, rumen fermentation, nitrogen balance, or cow health. Met intake and the amount of rumen‐undegradable feed Met were higher in the Treatment group (p

The multilayer structure of Fe/Si and Fe/Ge systems fabricated by ion beam sputtering (IBS) was investigated using X-ray and polarized neutron reflectivity measurements and scanning transmission electron microscopy with energy-dispersive X-ray analysis. The obtained result revealed that the incorporation of sputtering gas particles (Ar) in the Ge layer gives rise to a marked reduction in the neutron scattering length density (SLD) and contributes to the SLD contrast between the Fe and Ge layers almost vanishing for spin-down neutrons. Bundesmann et al. (2015) have shown that the implantation of primary Ar ions backscattered at the target is responsible for the incorporation of Ar particles and that the fraction increases with increasing ion incidence angle and increasing polar emission angle. This leads to a possibility of fine-tuning of the SLD for the IBS, which is required to realize a high polarization efficiency of a neutron polarizing supermirror. Fe/Ge polarizing supermirror with m = 5 fabricated under the same condition showed a spin-up reflectivity of 0.70 at the critical momentum transfer. The polarization was higher than 0.985 for the q z range where the correction for the polarization inefficiencies of the beamline works properly. The result of the polarized neutron reflectivity measurement suggests that the “magnetically-dead” layers formed at both sides of the Fe layer, together with the SLD contrast, play a critical role in determining the polarization performance of a polarizing supermirror.

Single-alkyl chain-containing amphiphilic oligomers with a terminal alkyl chain and several sugar side chains (i.e., C n -mGEMA, where n represents alkyl chain lengths of 12 or 16 and m represents the polymerization degree of glycosyloxyethyl methacrylate (GEMA) units of 3.0–7.1), and multi-alkyl chain-containing amphiphilic oligomers with several sugar side chains (i.e., xC12-mGEMA, where x represents the average number of alkyl chains and x–m is 0.2–6.6, 1.8–4.7, and 3.4–3.7), were synthesized via the radical oligomerization of one or two monomers in the presence of alkanethiol or 2-aminoethanethiol hydrochloride. Surface tension, pyrene fluorescence, and small-angle neutron scattering (SANS) measurements were used to characterize the solution properties of the oligomers and the nanostructures of their aggregates. Both amphiphilic oligomers are highly efficient in reducing the surface tension of water (42–48 mN m−1 for C n -mGEMA and 36–46 mN m−1 for xC12-mGEMA), despite the relatively large structures of the hydrophilic parts in sugar GEMA units. The critical micelle concentration (CMC) of C n -mGEMA and xC12-mGEMA increased with an increase in the degree of polymerization for hydrophilic GEMA units and a decrease in the alkyl chain length. The results of SANS determined that C n -mGEMA formed prolate ellipsoid micelles with a radius of 1.96 nm and an axial ratio of 1.58 for a low degree of polymerization (m = 3.0) in solution. However, the radius decreased to 1.33 nm and the axial ratio increased to 5.04 as the degree of polymerization of the amphiphilic oligomers increased to m = 7.1, indicating structural transformation to an asymmetric ellipsoid. On the other hand, the structure of the aggregates formed by xC12-mGEMA changed from ellipsoidal to an ellipsoidal cylinder shape with increasing number of alkyl chains, i.e., decreasing the number of GEMA units.

A novel Sr2+ fluorescent probe, N-(2-hydroxy-3-(1H-benzimidazol-2-yl)-phenyl)-1-aza-18-crown-6-ether (BIC), was synthesized and its fluorescence properties, equilibria, and local structure in solution were studied in detail. The fluorescence intensity of BIC in DMSO was enhanced selectively upon addition of Sr2+ but not Na+, K+, Mg2+, Ca2+, and Ba2+. To employ this rather hydrophobic BIC probe in aqueous media, a sodium laurate (LaNa) micellar solution was used as a good solvent. The detection limit of said LaNa micelle-BIC system (2.02 μM) is lower than that of the H2O system (309 μM), but higher than that of the DMSO system (0.04 μM). Therefore, it is clear that the LaNa micelles have an effect on the detection of Sr2+ by BIC in aqueous solutions. Further structural studies by extended X-ray absorption fine structure and speciation analyses revealed that BIC undergoes complexation equilibria corresponding to the formation of [Sr(BIC)]+ species in all solution types. It was concluded that the changes in the Sr2+-BIC fluorescence in solution are attributed to the formation of such [Sr(BIC)]+ complexes.

Mesoporous aluminum oxide (MAO) films with perpendicularly oriented cylindrical mesopores (pore diameter: ca. 10 nm) were successfully deposited on a glass substrate by a surfactant-templating approach using aluminum nitrate as an aluminum source. The perpendicular orientation of mesopores was confirmed by grazing-incidence small-angle X-ray scattering and neutron reflection experiments. The thickness of the MAO film was around 100 nm, with a surface roughness of less than 6 nm. Since the inner surface of MAO pores was positively charged, negatively charged glucose oxidase molecules could be densely loaded into the cylindrical mesopores without significant loss of enzymatic activity. The present MAO film is potentially useful as an inorganic host material for an enzyme toward the development of a biocatalytic system.

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 cesium ions (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 fitted 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 density functional theory calculation was used. 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 and (2) the two benzene rings of ace-DB20C6 fold around Cs+ above the center of the crown ether ring of ace-DB20C6.

We develop a closed-cycle dynamic nuclear polarization (DNP) system for spin-contrast-variation (SCV) small-angle neutron scattering (SANS) and neutron reflectometry (NR) to increase the use of these techniques. Compared with our cryogen-filled DNP system, the closed-cycle system is made compact and can change the sample in a comparable time-scale, but achieved proton-polarization is only 11.2 and 20$\pm$3% for bulk and thin-film samples, respectively, whereas 32-37% is achieved with the cryogen-filled system. This is because cooling power of the recycling cold helium gas in the closed-cycle system is lower than that of superfluid helium in the cryogen-filled one. In order to improve the polarization with the closed-cycle system, we have to improve thermal contact between the sample and cold helium gas to minimize microwave heating of the sample.

2-(2'-Hydroxyphenyl)benzimidazole derivatives (X-HBIs), modified by various substituents X (X=H, CH3, OH, OCH3, NO2, NHCOCH3, NH2, N(CH3)2), were synthesized and their fluorescent behaviors and equilibriums in aqueous solution were studied. Strong fluorescence attributed to the tautomer emission was observed in aqueous solution at pH 7.4. The fluorescence intensities of the X-HBIs were enhanced selectively by addition of Zn(2+) but not by addition of Na(+), K(+), Mg(2+), Ca(2+), Mn(2+), Fe(2+), Co(2+), Ni(2+), and Cu(2+). Additionally, the effective ratiometric fluorescence response to Zn(2+) addition was observed in 5-NH2-HBI and 5-N(Me)2-HBI. The pH-titration and speciation studies proved that the X-HBIs have two or three protonation equilibriums and one complexation equilibrium corresponding to the formation of the [Zn(X-HBI)](+) complex. Further structural studies using extended X-ray absorption fine structure analyses and density functional theory calculations identified the dominant Zn(2+) species as the [Zn(HBI)(H2O)3](+) complex in aqueous solution. Based on the substituent effect on the fluorescence properties of X-HBIs and their Zn(2+) complexes in aqueous solution, the maximum fluorescence excitation and fluorescence wavelengths of both the tautomeric form and the Zn(2+) complexes were dependent on the Hammett substituent constants of X, which was attributed to the change of the π-π* energy gap of HBI by introduction of the substituent.

We present evidence that the organic/third phase transition, as may be observed in the Plutonium Uranium Reduction EXtraction process (PUREX) at high metal loading, is an unusual transition between two isotropic, bi-continuous micro-emulsion phases. As this system contains so many components, however, we seek first to investigate the properties of a simpler system, viz. the related metal-free, quaternary system of water/n-dodecane/nitric acid/tri-butyl phosphate (TBP). Under appropriate conditions, this system exhibits three coexisting phases, namely the light organic phase, the third phase and the aqueous phase. In this paper, we focus on the two phase coexistence between the light organic and the third phase. Using Gibbs Ensemble Monte Carlo (GEMC) simulations, we find phase-coexistence between a phase rich in nitric acid and dilute in n-dodecane (the third phase) with a phase more dilute in nitric acid and rich in n-dodecane (the light organic phase). The compositions and densities of these two co-existing phases are in good agreement with experiment. Because the systems are dense and the molecules involved are not simple, the particle exchange rate in the GEMC simulation can be rather low. To show that the system, at a composition intermediate between that of the observed third and organic phases, is indeed unstable with respect to phase separation, we use the Bennett acceptance ratio method to calculate the Gibbs energies of the homogeneous phase and the weighted average of the two co-existing phases, where the compositions of these phases were taken both from GEMC and from experiment. Both demixed states have a statistically significant lower Gibbs energy than the uniform, mixed phase, providing confirmation that GEMC correctly predicts phase separation. Snapshots from the simulations as well as the cluster analysis of the organic and third phases reveal structures akin to bi-continuous micro-emulsion phases, where the polar species reside within a mesh whose surface consists of amphiphilic TBP molecules. The non-polar n-dodecane molecules are outside this mesh. The large-scale structural differences between the two phases lie solely in the dimensions of the mesh. Evidence for the correctness of these structures comes from small-angle X-ray scattering (SAXS), where the profiles obtained for both the organic and third phases agree well with those calculated from simulation. Finally we look at the microscopic structures of the two phases. In the organic phase, the basic motif is that of one nitric acid molecule hydrogen bonded to a TBP. In the third phase, the most common structure was that of the hydrogen bonded chain TBP–HNO3–HNO3. A cluster analysis provides evidence that the TBP forms an extended, connected network in both phases. Studies of the effects of metal ions on these systems will be presented elsewhere, but suffice it to say here that these ions do not change the basic bi-continuous structure of the phases. The metal ions reside inside the mesh along with the other polar molecules.

The structure of perhydropolysilazane (PHPS)-derived silica (PDS) waterproof thin layers synthesized by curing at 60 °C for 1 h and allowed to stand for 48 h at 20 °C on various kinds of substrates was studied. Neutron reflectivity (NR) analysis suggested that uniform PDS thin layers were synthesized on the substrates, and the density of the layers varied depending on the type of substrate. Additionally, since the change in PDS density is correlated with the pKa value of the OH group on the substrate, it can be suggested that the acidity of the substrate would be one of the main factors determining the density of the coated PDS thin layers. For the water penetration structure study, NR analysis revealed that the depth of water penetration into the PDS layers was below 500 A, and the hydration number of the SiO2 molecule was estimated to be 8.0–9.0. From these results, we concluded that water penetration occurred by the formation of water-pool structures in the PDS layers, and the randomly formed nano-air holes lead to a reduction in the probability of water penetration into the deep regions of the PDS layers.

A refined model for tri-n-butyl phosphate (TBP), which uses a new set of partial charges generated from our ab initio density functional theory calculations, has been proposed in this study. Molecular dynamics simulations are conducted to determine the thermodynamic properties, transport properties, and the microscopic structures of liquid TBP, TBP/water mixtures, and TBP/n-alkane mixtures. These results are compared with those obtained from four other TBP models, previously described in the literature. We conclude that our refined TBP model appears to be the only TBP model from this set that, with reasonable accuracy, can simultaneously predict the properties of TBP in bulk TBP, in organic diluents, and in aqueous solution. The other models only work well for two of the three systems mentioned above. This new TBP model is thus appropriate for the simulation of liquid-liquid extraction systems in the nuclear extraction process, where one needs to simultaneously model TBP in both aqueous and organic phases. It is also promising for the investigation of the microscopic structure of the organic phase in these processes and for the characterization of third-phase formation, where TBP again interacts simultaneously with both polar and nonpolar molecules. Because the proposed TBP model uses OPLS-2005 Lennard-Jones parameters, it may be used with confidence to model mixtures of TBP with other species whose parameters are given by the OPLS-2005 force field.

The extractability and complexation properties of lanthanides with N-alkyl-N-phenyl-1,10-phenanthroline-2-carboxamide were investigated. These ligands, which contain two aza-aromatic donors and an oxygen donor in a molecule, are newly developed extractants for actinides and lanthanides. N-Octyl-N-tolyl-1,10-phenanthroline-2-carboxamide exhibited high extractability of Eu3+ even under acidic conditions. In addition, strong complexation in acidic media was confirmed by spectroscopic titration experiments. Investigation of the complexation equilibrium revealed that the presence of an oxygen donor promotes ligand coordination with lanthanides over the competing protonation reaction in acidic solution.

In recent times, ionic liquids (IL) have been studied as a new solvent because of their unique features, in particular, tunability and designability. The electrochemical window, viscosity, conductivity, and hydrophobicity of ILs can be tuned by altering their molecular structures. One of the applications of ILs is an electrolyte solution for electrochemical devices. In the last two decades, many researchers have investigated the IL/electrode interfaces, where the electrochemical reactions exactly occur. It has been well known that both the electrode surface and the electrical double layer (EDL) structure affect the kinetics of electrochemical reactions. However, the IL/electrode interface, especially, the EDL structure has not been well understood. The EDL formed in ILs is assumed to have different structure from that formed in aqueous electrolytes due to IL's high ionic strength. In this study, the EDL structure formed in the deuterated 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([BMIM-d15]TFSA) was elucidated using neutron reflectivity (NR) technique. To analyze the EDL structure, it is important that the technique must not the disturb the EDL structure during measurements and the measurement should be carried out under the ideal electrochemical condition. The NR technique satisfies the both conditions. Further, neutron does not decompose organic compounds, including ILs. Therefore, the NR is suitable for the analysis of EDL structure. [BMIM-d15]TFSA was synthesized at the National Deuteration Facility (NDF), Australian Nuclear Science and Technology Organization (ANSTO). Before use, [BMIM-d15]TFSA was dehydrated at 80°C under vacuum for 24 h. Si(100) electrode was used as the working electrode. The working electrode was cleaned with acetone, ethanol, and Milli-Q. Pt wires were used as the reference and counter electrodes. The electrode potential was controlled by IviumStat. The specially designed electrochemical cell for NR measurements made from Kel-F was used and it was assembled in a glove box filled with Ar gas. NR measurements were carried out at BL-17 SHARAKU, Materials and Life Science Experimental Facility (MLF), Japan Proton Accelerator Research Complex (J-PARC). NR profiles were analyzed using Motofit. Firstly, an impedance measurement was carried out to elucidate the flat band potential of Si electrode in [BMIM]TFSA. The flat band potential was estimated at –0.88 V vs Pt. In NR measurements, NR profiles were taken at open circuit voltage (OCV), –1.1 V (negative than the flat band potential) and +0.5 V (positive than the flat band potential). The analysis reveal that at any electrode potential, where we measured in this study, the EDL consists of IL molecule layers and a bulk IL layer. At the electrode potential, E = –1.1 V, [BMIM]+ molecules adsorb on the electrode surface and a TFSA– molecules adsorb on the [BMIM]+ layer. On the other hand, at E = +0.5 V, the stacking order was opposite, i.e., the first and second layer consist of TFSA– and [BMIM]+ molecules, respectively. The electrode surface is negatively charged when the electrode potential is negative than the flat band potential and vice versa. Therefore, these results show that the EDL structure reflects the charge of electrode surface. The detail measurements and analysis are under way.

By combined use of time-of-flight small-angle neutron scattering (SANS) and synchrotron radiation small-angle X-ray scattering (SAXS), we investigated aggregation behaviors of gemini-type amphiphilic dendrimers (2C12-2denGn, where n denotes the generation number) in an aqueous solution with varying generation (n). 2C12-2denGn consists of two poly(amidoamine) (PAMAM) dendrons and C12 hydrocarbon chains connected by spacer chains. We found that the radius of gyration (Rg) evaluated from the SANS profiles for the 2C12-2denGn solution was nearly constant with n, which was remarkably different from that of dendrimer particles. In addition, model-fitting analysis for the SANS and the SAXS results was carried out using a theoretical scattering function of the polydisperse core-shell sphere model. With increasing n, the core radius gradually decreased, whereas the shell thickness increased. Although the hydrophilic dendron portion was much balky, the results suggested that 2C12-2denGn formed small spherical micelles with an overall radius of about 31 A. This is due to efficient arrangements of both dendrons and hydrocarbon chains in an aqueous solution.

High magnetic anisotropy is one of the requirements for the permanent magnet material. L10-ordered FeNi, which exhibits large magnetocrystalline anisotropy, is a possible candidate for rare-earth-free permanent magnet material. Because of the difficulty in producing bulk amount of L10 FeNi, alternate monolayer stacking of Fe and Ni by molecular beam epitaxy was developed [1]. In order to enhance the degree of crystalline order of the L10 structure and the magnetocrystalline anisotropy, several kinds of buffer layer have been adopted so far [2,3]. Therefore the structural and magnetic depth profile of the multilayer stacking needs to be analyzed to optimize the fabrication procedures. In this study, we performed a polarized neutron reflectometry (PNR) experiment on multilayer samples including L10-ordered FeNi

2-(2'-Hydroxyphenyl)benzimidazole derivatives (X-HBIs), modified by various substituents X (X=H, CH3, OH, OCH3, NO2, NHCOCH3, NH2, N(CH3)2), were synthesized and their fluorescent behaviors and equilibriums in aqueous solution were studied. Strong fluorescence attributed to the tautomer emission was observed in aqueous solution at pH 7.4. The fluorescence intensities of the X-HBIs were enhanced selectively by addition of Zn(2+) but not by addition of Na(+), K(+), Mg(2+), Ca(2+), Mn(2+), Fe(2+), Co(2+), Ni(2+), and Cu(2+). Additionally, the effective ratiometric fluorescence response to Zn(2+) addition was observed in 5-NH2-HBI and 5-N(Me)2-HBI. The pH-titration and speciation studies proved that the X-HBIs have two or three protonation equilibriums and one complexation equilibrium corresponding to the formation of the [Zn(X-HBI)](+) complex. Further structural studies using extended X-ray absorption fine structure analyses and density functional theory calculations identified the dominant Zn(2+) species as the [Zn(HBI)(H2O)3](+) complex in aqueous solution. Based on the substituent effect on the fluorescence properties of X-HBIs and their Zn(2+) complexes in aqueous solution, the maximum fluorescence excitation and fluorescence wavelengths of both the tautomeric form and the Zn(2+) complexes were dependent on the Hammett substituent constants of X, which was attributed to the change of the π-π* energy gap of HBI by introduction of the substituent.

We have been developing a 3He neutron spin filter (NSF) using the spin exchange optical pumping (SEOP) technique. The 3He NSF provides a high-energy polarized neutron beam with large beam size. Moreover the 3He NSF can work as a π-flipper for a polarized neutron beam by flipping the 3He nuclear spin using a nuclear magnetic resonance (NMR) technique. For NMR with the in-situ SEOP technique, the polarization of the laser must be reversed simultaneously because a non-reversed laser reduces the polarization of the spin-flipped 3He. To change the polarity of the laser, a half-wavelength plate was installed. The rotation angle of the half-wavelength plate was optimized, and a polarization of 97% was obtained for the circularly polarized laser. The 3He polarization reached 70% and was stable over one week. A demonstration of the 3He nuclear spin flip system was performed at the polarized neutron reflectometer SHARAKU (BL17) and NOBORU (BL10) at J-PARC. Off-specular measurement from a magnetic Fe/Cr thin film and magnetic imaging of a magnetic steel sheet were performed at BL17 and BL10, respectively.