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Guerinoni, E.*; 上田 祐生; 元川 竜平; Zemb, T.*; Pellet-Rostaing, S.*; Dourdain, S.*
Langmuir, 42(12), p.8313 - 8321, 2026/03
被引用回数：1 パーセンタイル：0.00(Chemistry, Multidisciplinary)Third phase formation in liquid-liquid extraction poses operational challenges by inducing organic phase separation, limiting extraction efficiency and process safety. Here, we employ combined ultra-small-angle X-ray (USAXS) and neutron scattering (USANS) to elucidate pre-transitional structures occurring during uranium extraction by tri-octylamine (TOA) in octane as diluent. SAXS highlights uranium-filled aggregates, while SANS captures all aggregates, regardless of uranium content. Extending the q-range from 0.004 to 3 
reveals two distinct populations: small spherical reverse micelle-like aggregates (radius 11 AA) and larger fluctuating domains exceeding 150 nm, consistent with Ornstein-Zernike critical fluctuations. Increasing TOA concentration amplifies these superstructures until divergence, the formation of a third phase. This study demonstrates that phase instability originates from the hierarchical condensation of water-filled aggregates around uranium-filled aggregates, rather than from simple micelle growth. Predicting such instability therefore requires accounting for the complete distribution of species, including water. The U-U distance in neighboring aggregate forming a supercluster is evidenced without ambiguity. Understanding such multiscale pre-transitional phenomena offers new routes to predict and mitigate phase separation in solvent extraction processes critical for nuclear fuel recycling.
Noh, S.*; 菅原 章秀*; 石原 尚昌*; 小西 隆士*; 上田 祐生; 元川 竜平; 高島 義徳*; 宇山 浩*
Advanced Science (Internet), p.e76110_1 - e76110_15, 2026/00
被引用回数：0 パーセンタイル：0.00(Chemistry, Multidisciplinary)Visualizing mechanical stress in soft materials is highly desirable, yet real-time optical readouts remain difficult using conventional sensing approaches, as mechanophore-based systems typically require large-force, threshold-type activation with slow recovery. Herein, we report supramolecular hydrogels that enable continuous and reversible visualization of mechanical stress in real time via stretch-induced phase separation. Mechanical stimuli are converted into a distinct network state transition by exploiting host-guest complexes between 
-cyclodextrin (-CD) and adamantane (Ad) as supramolecular switches. In this design, guest-functionalized polymers undergo an on-off transition between hydrated and dehydrated states via host-guest complexation and decomplexation. The responsive polymers were incorporated into the hydrogel network via supramolecular bonds that function as reversible cross-links and molecular switches, enabling the formation of phase-separation domains. Upon stretching, the hydrogels exhibited macroscopic transition from transparent to opaque owing to phase separation of the responsive domains. The opacity changed linearly and reversibly with applied stress, attributable to the sacrificial and reversible supramolecular switches, enabling visualization of stress distributions. This design principle offers a direction to spatiotemporally resolved mapping of mechanical states in hydrogels with an intuitive, instrument-free readout, providing a foundation for safer operation, condition monitoring, and timely intervention in soft material systems.
柴田 基樹*; 竹中 幹人*; 元川 竜平; 熊田 高之; 上田 祐生; 宮崎 司*; 中西 洋平*; 阿部 淳*; 岩瀬 裕希*; 柴山 充弘*; et al.
Polymer, 340, p.129203_1 - 129203_7, 2025/12
被引用回数：0 パーセンタイル：0.00(Polymer Science)The development of effective plastic degradation methods is crucial to address environmental pollution. Hydrothermal liquefaction using near-critical water is a promising technology, but the fundamental dissolution and decomposition mechanisms remain poorly understood. This study investigates the thermodynamics of a polystyrene (PS)/water system under near-critical conditions to elucidate this mechanism. We performed in situ small-angle neutron scattering (SANS) to observe the swelling of PS particles in deuterated water (D
O) at various temperatures under pressures of 10 MPa and 25 MPa. By applying the 
(FHS) theory to the swelling data, We quantitatively determined the Flory-Huggins interaction parameter as a function of temperature and pressure by applying the FHS theory to the swelling data. Based on these results, we constructed a phase diagram of the PS/DO system. The diagram reveals that miscibility increases with increasing pressure. This work provides a thermodynamical properties of water solutions of polymers under near-critical conditions for optimizing industrial hydrothermal recycling processes.
吉田 美里*; 新井 健悟*; 中川 大輝*; 堀川 喜樹*; 岩瀬 裕希*; 熊田 高之; 元川 竜平; 四方 俊之*
Biomacromolecules, 26(11), p.8332 - 8342, 2025/11
被引用回数：1 パーセンタイル：35.01(Biochemistry & Molecular Biology)Structure and conformation of hydroxypropylmethyl cellulose (HpMC) samples (DS = 1.8 and MS = 0.15) with narrow molar mass distributions of Mw/Mn 
1.3 at Mw of 210, 310 and 440 kg/mol dissolved in aqueous solution were investigated using static light scattering (SLS) and small angle neutron scattering (SANS) techniques to cover a wide scattering vector (q) range. The q dependencies of the concentration-reduced excess Rayleigh ratios via SLS at the extrapolated zero-concentration were smoothly linked with those of the concentration reduced excess scattering intensities via SANS using the same factor for all the HpMC samples. The linked scattering intensity curves were reasonably described with the form factor of monodisperse rod particles. Moreover, broad interference scattering peaks possibly exist at q= 0.042 nm
in the linked scattering curves, suggesting the presence of a periodicity of ~150 nm in the rod-like particles formed by HpMC molecules.
戸田 賀奈子*; 元川 竜平; 斉藤 拓巳*
Journal of Physical Chemistry C, 129(36), p.16261 - 16271, 2025/09
被引用回数：2 パーセンタイル：23.54(Chemistry, Physical)The development of the nano-scale pore size distribution of metakaolin-based geopolymers (MKGPs) was evaluated by the application of the small-angle neutron scattering (SANS), followed by the polydisperse spherical (PDSP) model application, where the modelled outputs were then deconvoluted by bimodal log-normal distribution fitting. Small pores, with a log-normal distribution modal value of 2.5 nm, immediately formed after mixing, with a decrement in the pore volume as a function of time. Larger pore size distribution with log-normal distribution modal values larger than 4nm, required an induction period, indicating the larger pore size distribution evolution corresponds to the pores as aluminosilicate cluster gel interstices. The nano-scale pore size distribution development varied by the curing temperature and the type of activators, which were evaluated in this study. The initial pore evolution of the MKGPs may be the critical step in determining the nano-sized porosity of the MKGPs, which characterizes the diffusive property of the material, such as the De of HDO.
熊田 高之; 元川 竜平; 大場 洋次郎; 中川 洋
no journal, ,
JRR-3の運転再開にあわせて中性子小角散乱装置(SANS-J)の更新および高度化を行った。更新作業においてもっとも重視したのが信頼性とユーザビリティの向上である。我々は以前に故障が頻発していた駆動軸の一部廃止や簡素化を行った。また、エンコーダー付きモーターやGUIを導入して異常個所の早期発見・復旧を可能にするとともにユーザビリティを向上させて操作ミスを低減した。その結果、令和3年度は100日のマシンタイムのうち3日を除きほぼ順調に稼働した。令和4年度は、マシンタイム競争率の高い同装置のスループットの拡大および性能向上を主眼に改良を行った。特に、フライトチューブの手前に前面検出器を導入して測定効率を引き上げるとともに、以前から要望が高かった1nm Q 5nmの散乱を小角散乱との同時測定できるようにした点が大きな改良である。また、既存の中性子レンズをうまく用いることで、小角領域の測定効率を3倍に引き上げることにも成功している。
