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The Aquivion®‐type perfluorinated proton conducting membranes were studied subjected to a specially developed technique of uniaxial orientational stretching. Membranes were prepared from copolymer produced by aqueous‐emulsion copolymerization and by pressing the melt copolymer precursor or by casting a solution of copolymer in sulfonyl alkaline form in dimethylformamide. The possibilities of the regulation of electrochemical and physical–chemical properties of Aquivion®‐type membranes using the method of orientational stretching are demonstrated. Proton conductivity rises in the stretching direction due to the straightening of the pathways for protons in membranes found by small‐angle neutron scattering technique. [ABSTRACT FROM AUTHOR]

Micromagnetic small‐angle neutron scattering theory is well established for analyzing spin‐misalignment scattering data of bulk ferromagnets. Here, this theory is extended to allow for a global uniaxial magnetic anisotropy (texture) of the material, in addition to the already included random zero‐average local anisotropy. Macroscopic cross sections and spin‐misalignment response functions are computed analytically for several practically relevant mutual anisotropy and external magnetic field orientations in both parallel and perpendicular scattering geometries for field magnitudes both above and below the rotational saturation. Some of these expressions are tested on published experimental data of magnetic‐field‐annealed Vitroperm and plastically deformed Ni, allowing determination of the corresponding global uniaxial anisotropy quality factors. [ABSTRACT FROM AUTHOR]

On the basis of Brown's static equations of micromagnetics, the uniaxial polarization of the scattered neutron beam of a bulk magnetic material is computed. The approach considers a Hamiltonian that takes into account the isotropic exchange interaction, the antisymmetric Dzyaloshinskii–Moriya interaction, magnetic anisotropy, the dipole–dipole interaction and the effect of an applied magnetic field. In the high‐field limit, the solutions for the magnetization Fourier components are used to obtain closed‐form results for the spin‐polarized small‐angle neutron scattering (SANS) cross sections and the ensuing polarization. The theoretical expressions are compared with experimental data on a soft magnetic nanocrystalline alloy. The micromagnetic SANS theory provides a general framework for polarized real‐space neutron methods, and it may open up a new avenue for magnetic neutron data analysis on magnetic microstructures. [ABSTRACT FROM AUTHOR]

The small‐angle neutron scattering data of nanostructured magnetic samples contain information regarding their chemical and magnetic properties. Often, the first step to access characteristic magnetic and structural length scales is a model‐free investigation. However, due to measurement uncertainties and a restricted q range, a direct Fourier transform usually fails and results in ambiguous distributions. To circumvent these problems, different methods have been introduced to derive regularized, more stable correlation functions, with the indirect Fourier transform being the most prominent approach. Here, the indirect Fourier transform is compared with the singular value decomposition and an iterative algorithm. These approaches are used to determine the correlation function from magnetic small‐angle neutron scattering data of a powder sample of iron oxide nanoparticles; it is shown that with all three methods, in principle, the same correlation function can be derived. Each method has certain advantages and disadvantages, and thus the recommendation is to combine these three approaches to obtain robust results. [ABSTRACT FROM AUTHOR]

In this study, we used sodium chloride (NaCl) to extensively modulate non-specific protein-protein interactions (PPI) of a humanized anti-streptavidin monoclonal antibody class 2 molecule (ASA-IgG2). The changes in PPI with varying NaCl (CNaCl) and monoclonal antibody (mAb) concentration (CmAb) were assessed using the diffusion interaction parameter kD and second virial coefficient B22 measured from solutions with low to moderate CmAb. The effective structure factor S(q)eff measured from concentrated mAb solutions using small-angle X-ray and neutron scattering (SAXS/SANS) was also used to characterize the PPI. Our results found that the nature of net PPI changed not only with CNaCl, but also with increasing CmAb. As a result, parameters measured from dilute and concentrated mAb samples could lead to different predictions on the stability of mAb formulations. We also compared experimentally determined viscosity results with those predicted from interaction parameters, including kD and S(q)eff. The lack of a clear correlation between interaction parameters and measured viscosity values indicates that the relationship between viscosity and PPI is concentration-dependent. Collectively, the behavior of flexible mAb molecules in concentrated solutions may not be correctly predicted using models where proteins are considered to be uniform colloid particles defined by parameters derived from low CmAb. [ABSTRACT FROM AUTHOR]

Protein–protein interaction in solution strongly depends on dissolved ions and solution pH. Interaction among globular protein (bovine serum albumin, BSA), above and below of its isoelectric point (pI ≈ 4.8), is studied in the presence of anions (Cl–, Br–, I–, F–, SO42–) using small-angle neutron scattering (SANS) technique. The SANS study reveals that the short-range attraction among BSA molecules remains nearly unchanged in the presence of anions, whereas the intermediate-range repulsive interaction increases following the Hofmeister series of anions. Although the interaction strength modifies below and above the pI of BSA, it nearly follows the series. [ABSTRACT FROM AUTHOR]

We introduce a simple method to extract the nuclear coherent and isotope incoherent, spin incoherent, and magnetic neutron scattering cross section components from powder scattering data measured using a single neutron beam polarization direction and a position-sensitive detector with large out-of-plane coverage. The method draws inspiration from polarized small-angle neutron scattering and contrasts with conventional so-called "xyz" polarization analysis on wide-angle instruments, which requires measurements with three orthogonal polarization directions. The viability of the method is demonstrated on both simulated and experimental data for the classical "spin ice" system Ho2Ti2O7, the latter from the LET direct geometry spectrometer at the ISIS facility. The cross section components can be reproduced with good fidelity by either fitting the out-of-plane angle dependence around a Debye–Scherrer cone or grouping the data by angle and performing a matrix inversion. The limitations of the method and its practical uses are discussed. [ABSTRACT FROM AUTHOR]

We demonstrate the first live, autonomous control over neutron diffraction experiments by developing and deploying ANDiE: the autonomous neutron diffraction explorer. Neutron scattering is a unique and versatile characterization technique for probing the magnetic structure and behavior of materials. However, instruments at neutron scattering facilities in the world is limited, and instruments at such facilities are perennially oversubscribed. We demonstrate a significant reduction in experimental time required for neutron diffraction experiments by implementation of autonomous navigation of measurement parameter space through machine learning. Prior scientific knowledge and Bayesian active learning are used to dynamically steer the sequence of measurements. We show that ANDiE can experimentally determine the magnetic ordering transition of both MnO and Fe1.09Te all while providing a fivefold enhancement in measurement efficiency. Furthermore, in a hypothesis testing post-processing step, ANDiE can determine transition behavior from a set of possible physical models. ANDiE's active learning approach is broadly applicable to a variety of neutron-based experiments and can open the door for neutron scattering as a tool of accelerated materials discovery. [ABSTRACT FROM AUTHOR]

In our previous work, a new design for a gaseous neutron detector composed of a boron-lined multilayer converter was proposed to replace the 3He proportional counter, and a prototype detector was constructed to test its performance and characteristics. The neutron detection efficiency varies for different incident angles of neutrons to the converter surface, mainly due to the effective area of the converter and the emitting probability of the alpha and 7Li. Hence, the variation of detection efficiency with the incident angle is analyzed theoretically in this work, and then the GEANT4 simulations and preliminary experimental tests are conducted to verify the calculation results. The highest detection efficiency is obtained at 1.72° (100 mm length, 3 mm gap, and θ = atan (3/100) ≈ 1.72°), the detection efficiency decreases sharply when the angle approaches 0°, and the detection efficiency decreases gradually when the incident angle is larger than 1.72°. The simulation results and experimental results are consistent with the trend of theoretical calculation. Therefore, the proposed detector is suitable for angle-sensitive applications, such as small angle neutron scattering and locating the isotopic neutron sources. [ABSTRACT FROM AUTHOR]

Composite silica xerogels were prepared via acid catalysed sol–gel route using tetraethoxysilan (TEOS) as silica precursor, and 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4] or 1-butyl-3-methylimidazolium chloride [BMIM][Cl] ionic liquids, used simultaneously as co-solvents, catalysts and pore templates, at various IL-to-silica ratios. Morphology of the xerogels prepared using the different IL templating agents were investigated using scanning electron microscopy (SEM), nitrogen sorption and small angle neutron scattering (SANS). The thermal behavior of the composites was analyzed by thermal gravimetry, whereas the compositions were checked by infrared spectroscopy and EDX. The differences in the morphology and thermal behavior of the composites due to the different IL additives were revealed. [ABSTRACT FROM AUTHOR]

The Kitaev spin liquid, a ground state of the bond-dependent Kitaev model in a honeycomb lattice has been a center of attraction, since a microscopic theory to realize such an interaction in solid-state materials was discovered. A challenge in real materials though is the presence of the Heisenberg and another bond-dependent Gamma interactions detrimental to the Kitaev spin liquid, and there have been many debates on their relative strengths. Here we offer a strategy to extract the Kitaev interaction out of a full microscopic model by utilizing the symmetries of the Hamiltonian. Two tilted magnetic field directions related by a two-fold rotational symmetry generate distinct spin excitations originated from a specific combination of the Kitaev and Gamma interactions. Together with the in- and out-of-plane magnetic anisotropy, one can determine the Kitaev and Gamma interactions separately. Dynamic spin structure factors are presented to motivate future experiments. The proposed setups will advance the search for Kitaev materials. The Kitaev model describes bond dependent interactions on a 2D honeycomb lattice and is often associated with experiments to realise a quantum spin liquid state; however, despite many potential candidates, data on such materials are complex to interpret. Here, the authors propose a method to extract and separate exchange parameters in Kitaev materials, which can be applied to techniques such as inelastic neutron scattering and angle-dependent ferromagnetic resonance. [ABSTRACT FROM AUTHOR]

Stray neutrons might cause several negative impacts. However, it is usually difficult to conduct precise stray neutron simulations using the Monte Carlo method. Therefore, in this study, a measurement technique was proposed to study the stray neutrons experimentally inside the neutron scattering instruments at China Spallation Neutron Source (CSNS). The adopted measurement instruments comprise an extended-range Bonner sphere spectrometer and a commercial neutron ambient-dose-equivalent dosimeter, which enables us to directly measure the neutron spectra and ambient-dose equivalent H*(10) values. Verification experiments were performed inside the BL06 beam line experimental area at CSNS at two exposed locations with different sample conditions. Comparison of the experimentally measured neutron spectra, integral neutron fluence, and H*(10) value with the simulations demonstrated the feasibility of using the proposed method for studying stray neutrons for the neutron instruments. [ABSTRACT FROM AUTHOR]

Understanding protein functions requires not only static but also dynamic structural information. Incoherent quasi-elastic neutron scattering (QENS), which utilizes the highly incoherent scattering ability of hydrogen, is a powerful technique for revealing the dynamics of proteins in deuterium oxide (D2O) buffer solutions. The background scattering of sample cells suitable for aqueous protein solution samples, conducted with a neutron backscattering spectrometer, was evaluated. It was found that the scattering intensity of an aluminum sample cell coated with boehmite using D2O was lower than that of a sample cell coated with regular water (H2O). The D2O-Boehmite coated cell was used for the QENS measurement of a 0.8 wt.% aqueous solution of an intrinsically disordered protein in an intrinsically disordered region of a helicase-associated endonuclease for a fork-structured type of DNA. The cell was inert against aqueous samples at 283–363 K. In addition, meticulous attention to cells with small individual weight differences and the positional reproducibility of the sample cell relative to the spectrometer neutron beam position enabled the accurate subtraction of the scattering profiles of the D2O buffer and the sample container. Consequently, high-quality information on protein dynamics could be extracted from dilute protein solutions. [ABSTRACT FROM AUTHOR]

Materials engineering by neutron scattering (MENUS) at the second target station will be a transformational high-flux, versatile, multiscale materials engineering diffraction beamline with unprecedented new capabilities for the study of complex materials and structures. It will support both fundamental and applied materials research in a broad range of fields. MENUS will combine unprecedented long-wavelength neutron flux and unique detector coverage to enable real-time studies of complex structural and functional materials under external stimuli. The incorporated small angle neutron scattering and transmission/imaging capabilities will extend its sensitivity to larger length scales and higher spatial resolution. Multimodal MENUS will provide crystallographic and microstructure data to the materials science and engineering community to understand lattice strain/phase transition/microstructure/texture evolution in three orthogonal directions in complex material systems under combined extreme applied conditions. The capabilities of MENUS will open new scientific opportunities and meet the research needs for science challenges to enable studies of a range of phenomena and answer the key questions in material design/exploration, advanced material processing, transformative manufacturing, and material operations of national impacts in our daily life. [ABSTRACT FROM AUTHOR]

A 9Cr-oxide dispersion strengthened (ODS) steel was thermally aged at 873 K for up to 5000 h. The size distribution and chemical composition of the dispersed oxide nanoparticles were analyzed by small-angle neutron scattering under a magnetic field. Combined with transmission electron microscopy, Vickers micro-hardness tests and electron backscattered diffraction measurements, all the results showed that the thermal treatment had little or no effect on the size distributions and volume fractions of the oxide nanoparticles in the ferromagnetic matrix, which suggested excellent thermal stability of the 9Cr-ODS steel. [ABSTRACT FROM AUTHOR]

Zwitterionic surfactants based on 3‐(1‐alkyl‐3‐imidazolio) propane‐sulfonate ([ImS3‐R] where R is octyl or dodecyl) is an emerging and important class of amphiphile due to their relevance as nano reactors for the synthesis of metallic nanoparticles and accelerated acid hydrolysis. The physicochemical properties of such synthesized imidazolium ring‐containing zwitterionic surfactants have been characterized by surface tension and small‐angle neutron scattering (SANS) techniques. Surface tension measurements were used to calculate several thermodynamic parameters over a range of concentrations and temperatures (298–313 K). The results obtained showed a weak signature representing the critical micelle concentration (CMC) for ImS3‐8, however, by increasing the alkyl length of the hydrophobic group to dodecyl, that is, ImS3‐8 to ImS3‐12, the signature of the CMC was much more evident. As expected, the CMC for ImS3‐12 shifted to a lower concentration. An increase in temperature increased the surface activity and decreased the CMC of both zwitterionic surfactants, although the changes were small. Compared to classical surfactants, that is, sodium dodecyl sulfate and dodecyl trimethylammonium bromide, the CMC of ImS3‐12 is much lower. Modeling of SANS data demonstrated that the morphology of the micelles formed by these amphiphiles may be described by the "classical" model, a central hydrophobic core, with a shell of hydrated headgroups. Due to their widespread applications in colloidal and interfacial science, the present study adds new insight to the fundamental understanding of these interesting imidazolium‐based surface‐active ionic liquids (ImS3‐R). [ABSTRACT FROM AUTHOR]

The effect of cooling rate after solution treatment on the initial structure of super duplex stainless steel 25Cr-7Ni (wt.%), and the effect of the initial structure on phase separation (PS) evolution during subsequent aging were investigated. The nanostructure in the bulk of the steel was studied using small-angle neutron scattering (SANS). Ex situ SANS experiments showed that the rate of PS differs during aging, due to the different initial structures imposed by the difference in cooling rate after solution treatment. In situ SANS experiments revealed that the PS is already pronounced after aging at 475 °C for 180 min and that a slower cooling rate after solution treatment will lead to more significant PS. Hence, PS depends on the plate thickness, imposing different cooling rates in the production of duplex stainless steels. [ABSTRACT FROM AUTHOR]

It has been known for decades that a ferromagnetic sample can depolarize a transmitted neutron beam. This effect was used and developed into the neutron-depolarization technique to investigate the magnetic structure of ferromagnetic materials. Since the polarization evolves continuously as the neutrons move through the sample, the initial spin states on scattering will be different at different depths within the sample. This leads to a contamination of the measured spin-dependent neutron-scattering intensities by the other spin-dependent cross sections. The effect has rarely been considered in polarized neutron-scattering experiments even though it has a crucial impact on the observable signal. A model is proposed to describe the depolarization of a neutron beam traversing a ferromagnetic sample, provide the procedure for data correction and give guidelines to choose the optimum sample thickness. It is experimentally verified for a small-angle neutron-scattering geometry with samples of the nanocristalline soft-magnet Vitroperm (Fe73Si16B7Nb3Cu1). The model is general enough to be adapted to other types of neutron-diffraction experiments and sample geometries.

In this work, we investigate the effect of concentrated alcoholic solutions (up to 40 % w) on extruded 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) liposomes using scattering techniques. Extrusion in alcoholic aqueous solutions (methanol, ethanol, or butanol) reduces liposome size, evidenced from the decrease in hydrodynamic radius (R H) obtained from dynamic light scattering. Short-chain alcohols such as ethanol and butanol soften the lipid membranes, as observed by the decrease of the unrelaxed bending modulus (κ ̃ ) obtained by neutron spin-echo spectroscopy. Thus, softer membranes are easily ruptured during extrusion, leading to a reduction in vesicle radius corroborated by a reduction in both R H and radius of gyration as seen by dynamic and static light scattering. Moreover, model-free analysis of small-angle neutron scattering (SANS) curves suggests that solvent molecules become incorporated into the lipid membrane. Analysing deviations in the scattering invariant from values predicted by mass balance, we find that the volume fraction of liposomes increases, modifying the scattering length density of the assemblies. By quantifying these changes, we estimate that 12% to 18% of the liposome membrane is composed of solvent molecules (alcohol + water), depending on the type of alcohol and its concentration present in solution, with the exception of glycerol where next to no incorporation was observed. Finally, structural parameters obtained through light scattering and changes in contrast profiles calculated from analysis of the invariant were corroborated through modelling of the SANS curves. Modelling suggests that a reduction of bilayer thickness takes place for liposomes dispersed in ethanolic and butanolic solutions, but not in the presence of methanol or glycerol. [Display omitted] • Incorporation of solvent molecules into the lipid bilayer. • Liposomes extruded with alcohols exhibit size reduction. • Reduction of bilayer bending rigidity induced by alcohols. [ABSTRACT FROM AUTHOR]

Data reduction is a critical step in a small-angle neutron scattering experiment. It corrects the data for instrument-specific artefacts, making it ready for analysis, interpretation, as well as for comparison against data collected with different small-angle neutron scattering instruments. Here, the drtsans software package developed at Oak Ridge National Laboratory for data reduction for the EQ-SANS, GP-SANS, and Bio-SANS instruments, which are located at the Spallation Neutron Source and High Flux Isotope Reactor, is described. The software and the rigorous development methods employed have positively impacted the scientific programs on the three SANS instruments.

We have examined the effect of crowder particle charge on macromolecular structure, studied via small-angle neutron scattering, and translational dynamics, studied via pulsed-field gradient NMR, in addition to bulk viscosity measurements, in a polymer macromolecule (polyethylene glycol) --nanoparticle crowder (polysucrose, Ficoll70) model system, in the case where polymer size and crowder size are comparable. While there are modest effects of crowder charge on polymer dynamics at relatively low packing fractions, there is only a tiny effect at the high packing fractions that represent the limit of molecular crowding. We find, via different measures of macromolecular mobility, that the mobility of the flexible polymer in the crowding limit is 10-100 times larger than that of the compact, spherical crowder in spite of their similar size, implying that the flexible polymer chain is able to squeeze through crowder interstices. [ABSTRACT FROM AUTHOR]

The self-assembly of multiblock copolymers in solutions is controlled by a delicate balance between inherent phase segregation due to incompatibility of the blocks and the interaction of the individual blocks with the solvent. The current study elucidates the association of pentablock copolymers in a mixture of selective solvents which are good for the hydrophobic segments and poor for the hydrophilic blocks using small angle neutron scattering (SANS). The pentablock consists of a center block of randomly sulfonated polystyrene, designed for transport, tethered to poly-ethylene-r-propylene and end-capped by poly-t-butyl styrene, for mechanical stability. We find that the pentablock forms ellipsoidal core-shell micelles with the sulfonated polystyrene in the core and Gaussian decaying chains of swollen poly-ethylene-r-propylene and poly-t-butyl styrene tertiary in the corona. With increasing solution concentration, the size of the micelle, the thickness of the corona, and the aggregation number increase, while the solvent fraction in the core decreases. In dilute solution the micelle increases in size as the temperature is increased, however, temperature effects dissipate with increasing solution concentration. [ABSTRACT FROM AUTHOR]

The formation of nanoprecipitates in the Fe 81 Ga 19 alloy doped with Tb (∼0.1 at. %) was studied by small-angle neutron scattering (SANS). Measurements at room temperature for several samples pre-aged at a fixed temperature in the range of (300–700)°C revealed a dilute system of precipitates with a characteristic size at nanoscale (<1000 Å) growing with an increase in ageing temperature. In situ measurements during isothermal ageing at 300 °C for 3 h revealed fast (order of 10 min) formation of precipitates. SANS analysis is consistent with the results of neutron diffraction experiments, which suggest the microstructure of this alloy as a matrix of disordered atomic structure (A2 phase) with embedded precipitates of the structurally and magnetically ordered D0 3 phase. [ABSTRACT FROM AUTHOR]

• Impact of fractal dimension on aggregate scattering cross-section predicted by EMA was assessed. • Condition when EMA is more accurate than RDG-FA was proposed with reference to MSTM. • A critical aggregate size parameter value for which EMA is applicable was suggested. Particles within aggregates are commonly in a status of dependent scattering due to the near-field multiple scattering and far-field interferences from neighboring particles. The integral radiative characteristics of fractal aggregates are consequently not only influenced by the monomer size parameter x s , the refractive index n m , and the monomer number N s , but also tied to the fractal dimension D f. The effective-medium approximation (EMA) simplifies the calculation of aggregate radiative characteristics by treating an aggregate and its surrounding medium as a homogeneous sphere with an effective refractive index, and by applying the Lorenz-Mie theory to this equivalent sphere. The study aims to assess the applicability of EMA to predict the scattering cross-section of fractal aggregates consisting of non-absorbing monomers with x s , varying from 0.001 to 1.25, N s ranging from 10 to 500, under different fractal dimensions D f. The accurate results obtained using the multiple spheres T-matrix were used as a reference. In addition, the RDG-FA (Rayleigh-Deybe-Gans Fractal Aggregates) theory, which is widely used for aggregates with monomer size x s ≪ 1, was also evaluated for comparison. The finding reveals that both EMA and RDG-FA provide accurate predictions for aggregates satisfying the equivalent aggregate size parameter χ m less than D f , where the dependent scattering is limited. As the dependent scattering effect increases, the fractal dimension D f emerges as a critical factor influencing EMA's accuracy, with EMA excelling for aggregates with larger fractal dimensions close to 3. Furthermore, 2.1 is a critical value of D f above which EMA outperforms RDG-FA. [ABSTRACT FROM AUTHOR]

This paper reviews the recent progress of small angle scattering (SAS) techniques, mainly including X-ray small angle scattering technique (SAXS) and neutron small angle scattering (SANS) technique, in the study of metal-organic framework (MOF) colloidal materials (CMOFs). First, we introduce the application research of SAXS technique in pristine MOFs materials, and review the studies on synthesis mechanism of MOF materials, the pore structures and fractal characteristics, as well as the spatial distribution and morphological evolution of foreign molecules in MOF composites and MOF-derived materials. Then, the applications of SANS technique in MOFs are summarized, with emphasis on SANS data processing method, structure modeling and quantitative structural information extraction. Finally, the characteristics and developments of SAS techniques are commented and prospected. It can be found that most studies on MOF materials with SAS techniques focus mainly on nanoporous structure characterization and the evolution of pore structures, or the spatial distribution of other foreign molecules loaded in MOFs. Indeed, SAS techniques take an irreplaceable role in revealing the structure and evolution of nanopores in CMOFs. We expect that this paper will help to understand the research status of SAS techniques on MOF materials and better to apply SAS techniques to conduct further research on MOF and related materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Fractal dimension analysis has become an essential tool to assess the pore structure of various porous geomaterials including shale rock. In this regard, changes of fractal dimension during the thermal maturation of organic rich shale could represent the evolution of its pore structure. To this end, complementary tests were conducted on six organic rich shale samples that are in a wide range of thermal maturity (equivalent R o values of 0.52–3.53 %). Fractal dimensions were obtained from small-angle neutron scattering (SANS), N 2 physisorption, and field emission-scanning electron microscopy (FE-SEM) data. Herein, surface fractal dimensions were calculated from the N 2 adsorption isotherms using the Frenkel–Halsey–Hill method, which was found between 2.46 and 2.71. Power-law exponents (E) of the SANS profiles varied from 2.75 to 3.48, indicating that both surface fractals and mass fractals would characterize the shale samples. As thermal maturity progressed, the fractal dimension shifted from surface to mass fractal while further analyses suggested this was caused by changes in the number density of pores (NDP) of various pore-size ranges. Ultimately, the pore size of the samples during such transition decreased with the increase of R o. [Display omitted] • The evolution of fractal features in the shale with thermal maturation is elucidated. • Fractal dimension shifted from surface fractal to mass fractal of shale and its controlling factors were revealed. • The number density of fractal pores were employed to evaluate the fractal characteristics of overall shale. • Pore size of conversion in shale will influence hydrocarbon preservation and transportation. [ABSTRACT FROM AUTHOR]

In accordance with the second phase construction blueprint for the China Spallation Neutron Source (CSNS-II), the proposal includes the establishment of a single crystal neutron diffractometer. This apparatus necessitates a neutron detector array spanning over 1 m2 and capable of covering neutron diffraction angles from 20° to 160°. Additionally, the detector's position resolution must better than 1 mm × 1 mm. To meet such requirements, a scintillator neutron detector based on the Anger-Camera principle was designed. The detector is composed of a 6LiF/ZnS (Ag) scintillation screen, optical guide, silicon photomultipliers (SiPMs) array and self-design composite compression readout electronic systems. A detector prototype, featuring a detection area of 50 mm × 50 mm, was fabricated and subjected to testing at the BL20 neutron test line in the China Spallation Neutron Source (CSNS). The detector system achieved an optimal position resolution of 0.6 mm, while the maximum count rate was approximately 20 kHz. Moreover, the detector's Bragg edge imaging capability was preliminarily investigated using stainless steel samples, demonstrating its future potential for Bragg edge transmission imaging. The proposed detector demonstrates promising potential as a candidate for the single crystal diffractometer in CSNS-II. • Development of a novel position-sensitive scintillator neutron detector utilizing the Anger-Camera principle. • Composition includes a 300 μm thick 6LiF/ZnS (Ag) scintillation screen, 5 mm air light guide, SiPM array, and advanced compression circuit readout electronics. • Demonstrated performance with a high position resolution of 0.6 mm and maximum counting rate of 20 Kcps in neutron beam experiments. • Successful application in acquiring the Bragg edge transmission spectrum of 316L stainless steel, suggesting potential for preliminary crystal structure identification in metals. • Outperforms traditional 3He PSD tubes in position resolution, enhancing capabilities for neutron scattering applications. • Meets crucial specifications for various diffractometers, poised to facilitate future neutron instrument development and research. [ABSTRACT FROM AUTHOR]

A dual sensitive, simple, and rapid membrane-based potentiometric sensor was developed to determine thorium (Th) ion in nuclear fuel samples which does not require any prior chemical separation of other matrix elements. Sensor was prepared by incorporating N,N,N',N',N",N" -hexa- n -octylnitrilotriacetamide (HONTA) in a polyvinyl chloride (PVC) matrix in presence of 2-nitrophenyl octyl ether (NPOE) and sodium tetraphenyl borate (NaTPB). The optimum membrane composition was found to be 14.1% HONTA, 3.2% NaTPB, 54.9% NPOE, 27.8% PVC, which showed a dual sensitive linear region in the calibration plot with sub-Nernstian and super-Nernstian slopes of 12.1 ± 0.4 mV/decade and 71.7 ± 3.5 mV/decade, respectively, with the corresponding linear dynamic ranges of 2.0 × 10−5 to 5.3 × 10−4 M and 3.8 ×10−3 to 1.4 × 10−2 M, respectively. The super-Nernstian sensitivity exhibited by the sensor increases with Th(IV) as well as HONTA concentrations in the membrane and can be thought to be due to micelle-mediated selective adsorption (MMSA) sensing of the metal ion. Solution speciation of Th(IV) in acetate buffer was determined by laser desorption/ionization mass spectrometry (LDI-MS) and Medusa software. Pristine and used membranes were characterized by Fourier transform infrared (FTIR), scanning electron microscopy–energy dispersive x–rays (SEM-EDS) and small angle neutron scattering (SAXS). Thorium was measured in an actual (Th–U) mixed solution and in a synthetic advance heavy water reactor (AHWR) fuel sample. The present study describes a new approach for the detection of Th(IV) ion through MMSA in an ion selective electrode (ISE). [Display omitted] • A highly sensitive and selective potentiometric sensor for Th estimation was developed. • Sensor exhibited dual sensitivity with sub and super-Nernstian slopes in calibration plot. • Aggregation of the ionophore has been observed from SAXS studies in the membrane. • Micelle mediated selective adsorption (MMSA) mechanism is proposed for sensing. • Sensor can determine thorium in mixed (Th 0.9 –U 0.1)O 2 samples without separation of other elements. [ABSTRACT FROM AUTHOR]

The energy-resolved neutron imaging instrument (ERNI) is built on the number 13 beamline at the China Spallation Neutron Source (CSNS), which is the first instrument dedicated to pulsed neutron imaging in China. ERNI is designed as a multi-scale, multi-dimensional, multi-modality characterization platform. The analytical techniques will include conventional neutron radiography and tomography, Bragg-edge neutron imaging, neutron grating imaging, neutron resonance imaging, neutron diffraction, and complementary X-ray tomography. The spatial resolution for conventional neutron imaging is about 15 μm; the maximum field of view could achieve 200 mm × 200 mm; the spectral resolution is better than 0.5%. ERNI is expected to serve the growing multidisciplinary imaging user community from materials science, engineering, energy, cultural heritage, biology, geosciences, industry, and so on. [ABSTRACT FROM AUTHOR]

Polarized neutron imaging has many applications through characterization of magnetic fields generated from currents or magnetic moments. If local magnetic field directions change slowly relative to its precession frequency, the angle between neutron polarization vector and the local field vector remains constant. Conversely, if the fields change rapidly relative to the precession frequency, this angle may vary. The transition between these scenarios follows the adiabatic condition. In this study, we analyze the effects of the adiabatic condition on a polarized neutron image. Two case studies are used for illustrating possible scenarios. The first case shows how an external field, due to the adiabatic condition, influences the symmetry of a polarized neutron image of a current carrying solenoid. The second case study shows how the adiabatic coupling of the beam polarization could lead to the loss of contrast in a polarized neutron image while studying field penetration in type II superconductors. Both case studies serve to highlight the importance of taking this phenomenon into account while interpreting polarized neutron imaging data given the rising importance of the technique as a characterization method in magnetism and superconductivity research. [ABSTRACT FROM AUTHOR]

Three conjugated copolymers, PDPP-2FTVT, PIID-2FTVT, and PNDI-2FTVT based on the 2,2′-(1E)-1,2-ethenediylbis[3-fluorothiophene] (2FTVT) core with varying acceptor units, diketopyrrolopyrrole (DPP), isoindigo (IID), and naphthalenediimide (NDI) were developed for organic field-effect transistors (OFETs). Combined electron-withdrawing fluorine atoms and vinyl linkage in the 2FTVT unit not only reduce the frontier molecular orbital energies but also extended the absorption profile and planarize the polymer backbone, manifesting synergetic effect on the strengthened molecular interactions and charge-carrier properties. The resulted copolymer, PDPP-2FTVT show highly reliable thin film transistor properties with highest hole mobility of 1.93 cm2 V−1 s−1 compared to PIID-2FTV and PNDI-2FTVT. PIID-2FTV copolymer show ambipolar characteristic with hole and electron mobilities of 0.71 and 0.03 cm2 V−1 s−1 respectively while PNDI-2FTVT exhibited the highest electron mobility of 0.20 cm2 V−1 s−1 among three copolymers. Thin film micro-structure characterization reveal that the three copolymers formed lamellar, edge-on molecular packing (for PDPP-2FTVT and PIID-2FTV), increased crystallinity with smaller π-π stacking distances, and strengthen the planarity after thermal annealing. These results contribute important progresses in solution-processed OFET and could provide a greater possibility of 2FTVT based copolymers for commercial application. [Display omitted] • Three conjugated 2FTVT donor-based copolymers were designed and synthesized. • The impact of various acceptors on their OFET properties was fully discussed. • An excellent hole mobility of 1.93 cm2 V−1 s−1 was achieved for PDPP-2FTVT. • The work promotes future fluorinated 2FTVT-based materials for OFETs. [ABSTRACT FROM AUTHOR]

We present a method, FMAPS(q), for calculating the structure factor, S (q) , of a protein solution, by extending our f ast Fourier transform-based m odeling of a tomistic p rotein-protein interactions (FMAP) approach. The interaction energy consists of steric, nonpolar attractive, and electrostatic terms that are additive among all pairs of atoms between two protein molecules. In the present version, we invoke the free-rotation approximation, such that the structure factor is given by the Fourier transform of the protein center-center distribution function g C (R). At low protein concentrations, g C (R) can be approximated as e − β W (R) , where W (R) is the potential of mean force along the center-center distance R. We calculate W (R) using FMAPB2, a member of the FMAP class of methods that is specialized for the second virial coefficient [Qin and Zhou, J Phys Chem B 123 (2019) 8203–8215]. For higher protein concentrations, we obtain S (q) by a modified random-phase approximation, which is a perturbation around the steric-only energy function. Without adjusting any parameters, the calculated structure factors for lysozyme and bovine serum albumin at various ionic strengths, temperatures, and protein concentrations are all in reasonable agreement with those measured by small-angle X-ray or neutron scattering. This initial success motivates further developments, including removing approximations and parameterizing the interaction energy function. [ABSTRACT FROM AUTHOR]

• Analysis of the pore network in Tamusu mudstone based on PDSM. • A predominant presence of nanoscale pores in mudstone. • The PSD curves exhibit multiple peak distributions. • More than half of the pores within Tamusu mudstone lack connectivity. This study focused on the Tamusu mudstone, a candidate rock for high-level radioactive waste (HLW) disposal in China. Utilizing small-angle neutron scattering (SANS) as our primary tool, we provide a comprehensive geometric analysis of the entire pore network, including both open and closed pores, within this target rock. Our results reveal the substantial presence of nanoscale pores in the Tamusu mudstone. The pore size distribution (PSD) curve exhibits a multimodal distribution, with more than half of the unconnected pores contributing to variations in the distribution of connected and total pores. [ABSTRACT FROM AUTHOR]

[Display omitted] • Complicated phase diagram of ionic liquid-water system was determined. • A bicontinuous cubic phase as a double gyroid was formed at the narrow water-concentration region. • Above 94 mol%, a bicontinuous liquid appeared at room temperature. In this study, phase variations within a hydrophilic ionic liquid (IL)–D 2 O mixture were observed in using small- and wide-angle neutron scattering (SWANS). The specific IL used was 1-dodecyl-3-methylimidazolium iodide ([C 12 mim][I]). Owing to the large neutron scattering length density of deuterium, D 2 O nanostructures appeared to be enhanced in the SWANS profile. Moreover, the complicated phase diagram of [C 12 mim][I]–D 2 O was determined using SWANS. Evidently, the water-rich region featured nanoconfined water (a water pocket), a smectic A phase, a columnar hexagonal phase as a lyotropic mesophase, a bicontinuous cubic phase as a double gyroid, and a layered crystal phase. Additionally, a double gyroid structure appeared in the narrow water-concentration region. [ABSTRACT FROM AUTHOR]

In this study, we investigated polymer chain dimensions in solid polymer electrolytes (SPEs) composed of hydrogenated and deuterated poly(ethylene carbonate/ethylene oxide) (h-/d-P(EC/EO)) copolymers and lithium bis(trifluoromethane)sulfonimide (LiTFSI) at various lithium-ion concentrations. The results were compared with h/d-poly(ethylene oxide) (PEO)/LiTFSI systems, extensively studied for their ionic conduction properties. The scattering intensity I(q) at low scattering vector q (≤ 0.4 Å−1) decreased with increasing lithium-ion concentration. From the low q data, the radius of gyration Rg of the polymer chains in SPE was estimated by the Guinier method. For both PEO and P(EC/EO) systems, with increasing the lithium-ion concentration (i.e., molar ratio of lithium ion to monomer, rs), Rg(rs) first decreased and then increased. Furthermore, the normalized Rg(rs) by Rg(0) exhibited a minimum at rs ≈ 0.15 for the PEO systems, whereas the P(EC/EO) system displayed a decrease in Rg to a higher rs (≈ 0.20) followed by a weak re-increase. Previous MD simulations (Y. Doi, et al., J. Phys. Chem. C2022, 126, 20,284) in the P(EC/EO)/LiTFSI systems have reported preferential coordination of carbonyl oxygens to lithium ions and an increase in the coordination number of oxygen atoms (resulting in the disrupted coordination structure) compared to the corresponding PEO systems, which can well explain the results in this study. The above experimental facts in this study are important findings in that they include data on new polymer systems other than PEO, while the number of reports for polymer conformation studies of SPE systems by SANS is still limited.Graphical abstract: In this study, we investigated polymer chain dimensions in solid polymer electrolytes (SPEs) composed of hydrogenated and deuterated poly(ethylene carbonate/ethylene oxide) (h-/d-P(EC/EO)) copolymers and lithium bis(trifluoromethane)sulfonimide (LiTFSI) at various lithium-ion concentrations. The results were compared with h/d-poly(ethylene oxide) (PEO)/LiTFSI systems, extensively studied for their ionic conduction properties. The scattering intensity I(q) at low scattering vector q (≤ 0.4 Å−1) decreased with increasing lithium-ion concentration. From the low q data, the radius of gyration Rg of the polymer chains in SPE was estimated by the Guinier method. For both PEO and P(EC/EO) systems, with increasing the lithium-ion concentration (i.e., molar ratio of lithium ion to monomer, rs), Rg(rs) first decreased and then increased. Furthermore, the normalized Rg(rs) by Rg(0) exhibited a minimum at rs ≈ 0.15 for the PEO systems, whereas the P(EC/EO) system displayed a decrease in Rg to a higher rs (≈ 0.20) followed by a weak re-increase. Previous MD simulations (Y. Doi, et al., J. Phys. Chem. C2022, 126, 20,284) in the P(EC/EO)/LiTFSI systems have reported preferential coordination of carbonyl oxygens to lithium ions and an increase in the coordination number of oxygen atoms (resulting in the disrupted coordination structure) compared to the corresponding PEO systems, which can well explain the results in this study. The above experimental facts in this study are important findings in that they include data on new polymer systems other than PEO, while the number of reports for polymer conformation studies of SPE systems by SANS is still limited. [ABSTRACT FROM AUTHOR]

Complex fluids encompass a significant proportion of the materials that we use today from feedstocks such as cellulose fibre dispersions, materials undergoing processing or formulation, through to consumer end products such as shampoo. Such systems exhibit intricate behaviour due to their composition and microstructure, particularly when analysing their texture and response to flow (rheology). In particular, these fluids when flowing may undergo transitions in their nano- to microstructure, potentially aligning with flow fields, breaking and reassembling or reforming, or entirely changing phase. This manifests as macroscopic changes in material properties, such as core–annular flow of concentrated emulsions in pipelines or the favourable texture of liquid soaps. Small-angle scattering provides a unique method for probing underlying changes in fluid nano- to microstructure, from a few angströms to several microns, of complex fluids under flow. In particular, the alignment of rigid components or shape changes of soft components can be explored, along with local inter-particle ordering and global alignment with macroscopic flow fields. This review highlights recent important developments in the study of such complex fluid systems that couple flow or shear conditions with small-angle scattering measurements, and highlights the physical insight obtained by these experiments. Recent results from neutron scattering measurements made using a simple flow cell are presented, offering a facile method to explore alignment of complex fluids in an easily accessible geometry, and contextualised within existing and potential future research questions. [Display omitted] [ABSTRACT FROM AUTHOR]

The kinetics of pepsin-induced κ-casein hydrolysis and coagulation in cow, goat, and sheep milk were investigated at 37 °C, pH 6.3 and 6.0. At a 0.1 U mg−1 pepsin-to-κ-casein ratio, sheep milk showed the fastest κ-casein hydrolysis, followed by cow and goat milk as assessed by quantifying the release of para-κ-casein using RP-HPLC. Sheep milk coagulated most rapidly, with κ-casein hydrolysis of 64% and 59% at pH 6.3 and 6.0. Goat milk required higher levels of κ-casein hydrolysis (90% and 86% at pH 6.3 and 6.0), before coagulation could occur. Sheep milk formed denser curds, whereas goat milk curd had a more porous structure. Additionally, small-angle neutron scattering showed differing rates of aggregate size growth among species. These findings indicate κ-casein hydrolysis and coagulation differences are not just due to casein content but also physicochemical characteristics such as casein micelle size. This study deepens our understanding of sheep and goat milk coagulation mechanisms compared to cow milk during the early stages of gastric digestion. [ABSTRACT FROM AUTHOR]

This report presents the physics design and optimization of the neutron chopper and optics systems for the CENTAUR instrument, a multifunctional small-angle and wide-angle neutron scattering diffractometer for the Spallation Neutron Source Second Target Station. This instrument will offer a wide range of capabilities, including small-angle neutron scattering with wide Q coverage (e.g., 0.001–20 Å−1), providing a tool to investigate structures from atomic to mesoscopic scales simultaneously. To efficiently transport desired neutrons from the compact high-brightness cold source, several innovative designs are utilized: a time-zero chopper with a straight guide system for short-wavelength neutrons, octagonal guides for higher flux, and a correlation chopper to reduce inelastic scattering. The optimization process considers factors such as useable time-integrated flux, instrument resolution, brilliance transfer, divergence, and acceptance diagram uniformity. The overall design prioritizes flexibility to accommodate diverse user requirements. [ABSTRACT FROM AUTHOR]

The Snoek anelastic internal friction (IF) peak due to stress-induced dipole ordering associated with interstitial atoms was well observed in IF curves of single-principal element alloys (SPEAs) as early as in the 1950s, however, its behavior remains elusive in multi-principal element alloys (MPEAs) to date. Here the temperature-dependent IF spectra of NbTiV 0.5 Zr refractory MPEAs with varying O contents were presented, and the analysis of these data indicates that for O-doped NbTiV 0.5 Zr MPEAs, the O addition triggers two anelastic IF peaks (the P O1 and P O2), corresponding to the O-Snoek-type relaxation in random solid solution (RSS) and local chemical ordering (LCO) structures, respectively. The half-peak width of the P O1 is 2–3 times broader than that for SPEAs, associated with the wide O migration energy barrier distribution in MPEAs. These phenomena show a striking contrast to the single and narrow Snoek-type peak observed for SPEAs. Our analysis further reveals an approximate linear correlation between the half-peak width of the Snoek-type peak and the mixing entropy. The introduction of O also shifts grain boundary relaxation peaks (P G) towards higher temperatures. Interestingly, high-temperature anomalous modulus changes were observed for the first time in TiV-based lightweight refractory MPEAs, which is suggested to be originated from the order reduction of the body-centered cubic (bcc) structure at elevated temperatures. Moreover, the 1 at.%O doped NbTiV 0.5 Zr MPEA with a favorable balance between the peak heights of the P O2 and P G , exhibits outstanding specific yield stress (SYS) among refractory MPEAs while maintaining an elongation as high as 20 %. This work provides not only a bridge between the anelastic behavior of SPEAs and MPEAs for upcoming studies and theories concerning bcc MPEAs with interstitial atoms, but contributes to the holistic design of bcc MPEAs with high strength and excellent ductility. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Dioctadecyldimethylammonium bromide, taurocholate, and polysorbate 80 were explored for the preparation of self-assembled phospholipid-based cationic, anionic, and non-ionic vesicles (LeciPlex®). • Particle size distribution of vesicles is tunable as a response to material attributes such as type of biocompatible solvent and stabilizer concentrations used in the fabrication process. • Physical characterization studies like small angle neutron scattering and transmission electron microscopy helped in ascertaining the structure and morphology of LeciPlex®. The present study investigated the feasibility of fabricating self-assembled liposomes, LeciPlex®, a phospholipid-based vesicular nanocarrier using cationic, anionic, and nonionic stabilizers. The phospholipid investigated was soy phosphatidylcholine and the nano-precipitation method based on solvent diffusion was applied as the fabrication technique of liposomes in this study. The effects of various formulation variables, such as lipid and stabilizer concentration, total solid concentration, and solvent type on the self-assembly of vesicles were studied for physical characterization including particle size analysis, differential scanning calorimetry, viscosity, optical transmittance, transmission electron microscopy, and small angle neutron scattering. All three LeciPlex® systems exhibited a direct relationship between particle size and phospholipid concentration. The two categoric variables, solvent, and stabilizer used to prepare LeciPlex® demonstrated a significant effect on particle size for all three LeciPlex® systems. Small angle neutron scattering, and optical transmittance confirmed the formation of micellar systems at a phospholipid: stabilizer ratio of 1:2 and vesicular systems at a ratio of 2:1 for the systems stabilized with anionic and nonionic surfactants. In contrast to this, the LeciPlex® formed with the cationic stabilizer Dioctadecyldimethylammonium bromide (DODAB), formed vesicles at both ratios. From these investigations, it was clear that the formulation space for LeciPlex® was diversified by the addition of cationic, anionic, and non-ionic stabilizers. [ABSTRACT FROM AUTHOR]

Thermoresponsive polymers have attracted much scientific attention due to their capacity for temperature-driven hydrogel formation. For biomedical applications, such as drug delivery, this transition should be tuned below body temperature to facilitate controlled and targeted drug release. We have recently developed a thermoresponsive polymer that forms gel at low concentrations (2 w/w%) in aqueous media and offers a cost-effective alternative to thermoresponsive systems currently being applied in clinics. This polymer is an ABC triblock terpolymer, where A, B, and C correspond to oligo(ethylene glycol) methyl ether methacrylate with average M n 300 g mol−1 (OEGMA300), n -butyl methacrylate (BuMA), and di(ethylene glycol) methyl ether methacrylate (DEGMA). To investigate the self-assembly and the gelation mechanism in diluted solutions, we used small-angle neutron scattering (SANS) on 1 w/w% (below the gelation concentration) and 5 w/w% solutions (above the gelation concentration). As a comparison, we also investigated the solutions of the most studied thermoresponsive polymer, namely, Pluronic F127, an ABA triblock bipolymer made of ethylene glycol (A) and propylene glycol (B) blocks. SANS revealed that the in-house synthesised polymer forms elliptical cylinders, whose length increases significantly with temperature. In contrast, Pluronic F127 solutions form core-shell spherical micelles, which slightly elongate with temperature. Transmission electron microscopy images support the SANS findings, with tubular/worm structures being present. Variable-temperature circular dichroism (CD) and proton nuclear magnetic resonance (1H NMR) spectroscopy experiments reveal insights on the tacticity, structural changes, and molecular origin of the self-assembly. [Display omitted] • Worm like micelles versus spherical micelles self-assembly and gelation. • Differences between the thermoresponsive behaviour of an ABC and an ABA triblock copolymer. • Tubular/worm like micelles can induce gelation at lower concentrations than spherical micelles. [ABSTRACT FROM AUTHOR]

This paper reports the use of combined electron microscopy and small-angle neutron scattering (SANS) to probe into the compositional and size evolution of the primary carbides and nanoparticles (defined by a size threshold of 100 nm) in an additively manufactured high-alloy steel before and after heat treatment. The primary carbides exhibit marginal changes in their total volume fraction and size after the austenitising and tempering. However, those carbides located at the prior-austenite boundaries provide a pinning effect to impede grain growth during the austenitising. The grain size increases from 1.7 µm in the as-manufactured to 2.8 µm in the as-tempered conditions, resulting in a limited strength loss of 33–126 MPa as estimated by using the Hall-Petch relationship. Atom probe tomography, which offers atomic spatial resolution examining a sample volume of 6.6 × 105 nm3, reveals the presence of numerous V and Cr-enriched nanoparticles with sizes of 1 to 10 nm within the steel matrix after the tempering. In contrast, the complementary SANS which examines a significantly larger sample volume of 0.9 mm3 but lacking spatial resolution, provides nanoparticle size information. It reveals a radius reduction from 7.6 to 1.0 nm and a volume fraction increase from 1.6 % to 2.3 %, in the as-manufactured and as-tempered conditions, respectively. The nanoparticles induced during tempering can contribute to a strength enhancement of 691 MPa, primarily through the Orowan bypass mechanism. This suggests that the combination of limited prior-austenite grain growth and the presence of nanoparticles is the key factor responsible for the unprecedented material strength. [Display omitted] [ABSTRACT FROM AUTHOR]

Lipid-based nanoparticles (LNPs), ranging from nanovesicles to non-lamellar assemblies, have gained significant attention in recent years, as versatile carriers for delivering drugs, vaccines, and nutrients. Small-angle scattering methods, employing X-rays (SAXS) or neutrons (SANS), represent unique tools to unveil structure, dynamics, and interactions of such particles on different length scales, spanning from the nano to the molecular scale. This review explores the state-of-the-art on scattering methods applied to unveil the structure of lipid-based nanoparticles and their interactions with drugs and bioactive molecules, to inform their rational design and formulation for medical applications. We will focus on complementary information accessible with X-rays or neutrons, ranging from insights on the structure and colloidal processes at a nanoscale level (SAXS) to details on the lipid organization and molecular interactions of LNPs (SANS). In addition, we will review new opportunities offered by Time-resolved (TR)-SAXS and -SANS for the investigation of dynamic processes involving LNPs. These span from real-time monitoring of LNPs structural evolution in response to endogenous or external stimuli (TR-SANS), to the investigation of the kinetics of lipid diffusion and exchange upon interaction with biomolecules (TR-SANS). Finally, we will spotlight novel combinations of SAXS and SANS with complementary on-line techniques, recently enabled at Large Scale Facilities for X-rays and neutrons. This emerging technology enables synchronized multi-method investigation, offering exciting opportunities for the simultaneous characterization of the structure and chemical or mechanical properties of LNPs. [Display omitted] • SAXS and SANS allow investigating LNPs' structure and nanoscale interactions, offering ensemble-averaged information. • SAXS and SANS can inform the rational design of LNPs and analyze their interactions with drugs and biological environments. • Time-resolved-SANS and -SAXS can probe dynamic processes of LNPs, from lipid exchange kinetics to nano structural changes. • SANS or SAXS can be coupled with complementary on-line techniques for simultaneous multi-method LNPs' characterization. [ABSTRACT FROM AUTHOR]

Dense interfacial layer in n -heptane leads to rapid extraction compared to diffuse interfacial layer in toluene. [Display omitted] • Selectivity and kinetics in solvent extraction were explained by supramolecular organization of malonamide extractants. • Supramolecular organization of malonamide extractants is strongly related to diluent polar character. • Extractant dimers are highly selective for Pd(II) over Nd(III) ion in toluene. • Extractant large aggregates do not display specific selectivity for Pd(II) or Nd(III) ions in n -heptane. Supramolecular organization of amphiphilic extractant molecules is involved in metal cation selectivity and separation kinetics during solvent extraction. The relationship between extractant associates/aggregates formed in the organic bulk phase and at the liquid–liquid interface is poorly understood even though it affects the extraction mechanism. The nanoscopic structures of the extraction systems N , N , N′ , N′ -tetrahexylmalonamide (THMA) in toluene and N , N′ -dibutyl- N , N′ -dimethyl-2-tetradecylmalonamide (DBMA) in n -heptane, used for either Pd(II) or Nd(III) selective extraction from an acidic aqueous phase, were examined. These systems present markedly different affinity for Pd(II) and Nd(III), and extraction kinetics. Extractant organization in the organic bulk phase and at the interface were compared by small-angle X-ray scattering, interfacial tension, and neutron reflectivity. THMA in toluene forms small associates in the organic bulk phase and accumulates in a diffuse layer at the interface, decreasing Pd(II) coordination probability and resulting in slow extraction. DBMA in n -heptane forms large aggregates and a compact, dense interfacial layer, resulting in rapid Pd(II) and Nd(III) extraction. Thus, Pd(II) extraction is driven by interfacial coordination alone, whereas the incorporation of Nd(III) into the core of large aggregates governs Nd(III) extraction in the interfacial layer. These results suggest that the interface should be described as a nanoscale interphase containing a high extractant concentration compared with the organic bulk phase. [ABSTRACT FROM AUTHOR]

Scattered-beam collimation is a very useful method to reduce unwanted backgrounds and to boost the desired sample signal instead. This approach is of particular interest for samples contained within a complex environment that gives rise to much unwanted parasitic scatter. As neutron scattering instrument and techniques advances, small samples are becoming of more and more interest, which necessitates optimized collimation. Here, we describe a concept for the design and fabrication of advanced scattered-beam collimation 3D printed from B 4 C specifically tailored for samples contained within acomplex environment. This concept is demonstrated through the use ofa diamond anvil cell for high pressure experimentation, a technique that very typically requires small samples. The collimators here are designed through a modeling procedure via Monte Carlo neutron ray tracing that encompasses the entire system: the instrument, the complex environment and the collimator. Since the first approach of simply scaling up of the print-size was not successful, a novel concept of a multi-part alternate-blade collimator was developed. This approach addresses printing constraints but gives greater flexibility in design. Its performance is computationally compared against an unprintable progressively tighter blade collimator to assess the effect of alternating blades. No strong difference was observed. Its performance was validated through experimentation at the Spallation Neutron Source. The results emphasize the critical importance of ultra-high precision alignment while showing good overall agreement between simulation and experiment and underscore the feasibility of the method and its real-world application. [ABSTRACT FROM AUTHOR]

Lipid membranes are a key component of living systems and have been essential to the origin of life. One hypothesis for the origin of life assumes the existence of protomembranes with ancient lipids formed by Fischer–Tropsch synthesis. We determined the mesophase structure and fluidity of a prototypical decanoic (capric) acid-based system, a fatty acid with a chain length of 10 carbons, and a lipid system consisting of a 1:1 mixture of capric acid with a fatty alcohol of equal chain length (C10 mix). To shed light on the mesophase behavior and fluidity of these prebiotic model membranes, we employed Laurdan fluorescence spectroscopy, which reports on the lipid packing and fluidity of membranes, supplemented by small-angle neutron diffraction data. The data are compared with data of the corresponding phospholipid bilayer systems of the same chain length, 1,2-didecanoyl-sn-glycero-3-phosphocholine (DLPC). We demonstrate that the prebiotic model membranes capric acid and the C10 mix show formation of stable vesicular structures needed for cellular compartmentalization at low temperatures only, typically below 20 °C. They reveal the fluid-like lipid dynamic properties needed for optimal physiological function. High temperatures lead to the destabilization of the lipid vesicles and the formation of micellar structures.