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[Display omitted] Enveloped viruses are pivotal in causing various illnesses, including influenza and COVID-19. The antimicrobial peptide LL-37, a critical part of the human innate immune system, exhibits potential as an antiviral agent capable of thwarting these viral threats. Its mode of action involves versatile and non-specific interactions that culminate in dismantling the viral envelope, ultimately rendering the viruses inert. However, the exact mechanism of action is not yet understood. Here, the mechanism of LL-37 triggered changes in the structure and function of an enveloped virus is investigated. The bacteriophage "Phi6" is used as a surrogate for pathogenic enveloped viruses. Small angle X-ray and neutron scattering combined with light scattering techniques demonstrate that LL-37 actively integrates into the virus's lipid envelope. LL-37 addition to Phi6 leads to curvature modification in the lipid bilayer, ultimately separating the envelope from the nucleocapsid. Additional biological assays confirm the loss of virus infectivity in the presence of LL-37, which coincides with the structural transformations. The results provide a fundamental understanding of the structure-activity relationship related to enveloped viruses. The knowledge of peptide-virus interactions can guide the design of future peptide-based antiviral drugs and therapies. [ABSTRACT FROM AUTHOR]

The structure–property studies in unpolymerized and polymerized tannic acid incorporated hydrogels exhibited the presence of micron sized aggregates. The hydrogen bonded aggregates breaks at high temperatures for the unpolymerized and polymerized cases as evident from the scattering studies. The structural changes is clearly reflected in rheological properties for the unpolymerized case as a clear elastic to dissipative transition while the polymerized case exhibited dissipation even at higher temperatures. [Display omitted] Hydrogels made with semi-interpenetrating networks of the oligomerized polyphenol tannic acid, and poly(acrylamide), exhibit high stiffness and toughness. However, the structure property relationships that give rise to enhanced mechanical properties is not well understood. Herein, we systematically investigate the hydrogels using small angle X-ray scattering and small and Ultra-small angle neutron scattering within a wide length scale range (1 nm to 20 µm), polarized optical microscopy, and rheology. Small angle X-ray and neutron scattering reveal the presence of micron sized hydrogen bonded clusters in the hydrogels. Breaking of hydrogen bonded clusters above a critical solution temperature was clearly observed in the small angle neutron scattering data. Polarized optical microscopy show enhanced anisotropy for the gels with oligomerized tannic acid incorporated - when compared to gels with monomeric tannic acid. Rheological studies at varying temperatures nicely corroborate the structural changes observed at high temperatures and reveal a self-healing behavior of the gels. The knowledge gained from this study will aid in rational design of hydrogels for biomedical applications. [ABSTRACT FROM AUTHOR]

This structural study exploits the possibility to use modular protein deuteration to facilitate the study of ubiquitin signalling, transfer, and modification. A protein conjugation reaction is used to combine protonated E2 enzyme with deuterated ubiquitin for small angle X-ray and neutron scattering with neutron contrast variation. The combined biomolecules stay as a monodisperse system during data collection in both protonated and deuterated buffers indicating long stability of the E2–Ub conjugate. With multiphase ab initio shape restoration and rigid body modelling, we reconstructed the shape of a E2–Ub-conjugated complex of UBE2D1 linked to ubiquitin via an isopeptide bond. Solution X-ray and neutron scattering data for this E2–Ub conjugate in the absence of E3 jointly indicate an ensemble of open and backbent states, with a preference for the latter in solution. The approach of combining protonated and labelled proteins can be used for solution studies to assess localization and movement of ubiquitin and could be widely applied to modular Ub systems in general. [ABSTRACT FROM AUTHOR]

Magnesium doped Amorphous Calcium Carbonate was synthesised from precursor solutions containing varying amounts of calcium, magnesium, H2O and D2O. The Mg/Ca ratio in the resultant Amorphous Calcium Carbonate was found to vary linearly with the Mg/Ca ratio in the precursor solution. All samples crystallised as aragonite. No Mg was found in the final aragonite crystals. Changes in the Mg to Ca ratio were found to only marginally effect nucleation rates but strongly effect crystal growth rates. These results are consistent with a dissolution-reprecipitation model for aragonite formation via an Amorphous Calcium Carbonate intermediate. [ABSTRACT FROM AUTHOR]

Studies in spin dynamics of disordered media and multiple ultra-small angle neutron scattering are considered. The experiments were carried out on unique installations designed in ITEP laboratory of neutron physics: beta-NMR spectrometer and universal neutron diffractometer. The main attention is paid to random walks in disordered systems and ultra-small angle neutron scattering (USANS) on objects with space correlations in positions of scatterers. Synthesis of concentration expansion, semi-phenomenological theory and numerical simulations produced satisfactory description of the nuclear polarization transfer within disordered 8Li–6Li spin subsystem in LiF single crystal. The theory of USANS starts from eikonal approximation for the scattering amplitude, which (a) reproduces the phenomenological Moliere–Bethe theory for the observable neutron angular distributions for uncorrelated random positions of scatterers, and (b) gives a possibility to take into account their spatial correlations. [ABSTRACT FROM AUTHOR]

In high resolution neutron scattering experimental work the use of significantly longer incoming neutron wavelengths compared to the currently widely used cold neutron range can be of significant advantage. Such advantages are to obtain higher data rates at equal resolution conditions, for example in small angle neutron scattering, and to obtain far better resolution, e.g., in neutron spin echo and time-of-flight spectroscopy or both. [ABSTRACT FROM AUTHOR]

Abstract HKUST-1 is a strictly microporous crystalline metal organic framework with pore sizes of 5, 11, and 13.5 Å. Detailed gas adsorption measurements show that its adsorption capacity for water at 20 °C is higher than that for nitrogen at −196 °C, and far exceeds that for methane at 0 °C. Extended exposure to water vapour at high relative humidity, or consecutive adsorption-desorption cycling of water vapour, destroys both the MOF crystal structure and its adsorption capacity, after a reduced number (<5) of cycles. Destruction proceeds through mesoporous defects that open within the crystal structure, as attested both by the development of hysteresis in the adsorption isotherms and by changes in the small angle X-ray scattering pattern. In the pristine crystal, the structure of the water in the micropores closely resembles that of bulk liquid water. Small angle neutron scattering demonstrates that water is adsorbed preferentially over methane, and that the size of the spherical cavities occupied by the adsorbed water molecules in the intact crystal is consistent with the known pore size structure in this system. Graphical abstract Unlabelled Image Highlights • In pores of fully hydrated HKUST-1, water molecules are in an amorphous state. • Structural damage occurs through dehydration/rehydration cycles. • Five cycles suffice to destroy crystal structure completely. • Damage starts at crystallite surfaces and results in mesoporosity. • Water is preferentially adsorbed over methane (0 °C, 1 bar). [ABSTRACT FROM AUTHOR]

Abstract We have introduced a 7 T dynamic nuclear polarization apparatus for contrast variation neutron scattering experiments on iMATERIA spectrometer at the Materials and Life Science Facility at the J-PARC spallation neutron source. At 1.2 K and 6.7 T, we have achieved high proton spin polarizations (76%/ − 84%) and short buildup time constants (3.2 min/4.1 min) for a polystyrene cast film doped with 50 mM 2,2,6,6-tetramethylpiperidine 4-oxy (TEMPO), after applying microwave frequency modulation. The instrument realizes easy sample exchange and significant contrast variation beyond what is available by deuterium substitution. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Hypothesis The solvation characteristics of poly(ethylene oxide) (PEO) in nanostructured protic ionic liquids (PILs) are driven by polymer-solvent interactions in the polar domains of the PIL. This work hypothesises that the nanostructure of a PIL can be altered via halide addition, directly affecting the solvation of PEO. Experiments Small angle neutron scattering (SANS) is used to explore the conformation of 38 kDa PEO dissolved in the PIL propylammonium nitrate (PAN), a mol fraction of 10% propylammonium chloride (PACl) in PAN, and a mole fraction of 10% propylammonium bromide (PABr) in PAN. Findings Each of these solutions are shown to behave as a good solvent for PEO, as determined by their Flory exponents and Zimm plot analysis. The quality of solvation is reduced by the addition of the halide salt, with the order of solvation as follows: PAN > Br− addition > Cl− addition. Our experimental observations are consistent with the recently reported solvation structure of PEO in these solutions (Stefanovic et al., 2018). The increased charge density from NO 3 − to Br− to Cl− results in greater net ionic interaction between the ionic charge centres. As PEO interacts with PAN primarily through the ammonium hydrogens of the cation, this increased ionic interaction effectively displaces the PEO, resulting in poorer solvation. [ABSTRACT FROM AUTHOR]

Abstract The response to pH variation of polymeric cyclodextrin-based hydrogels has been investigated by a multi-technique approach based on UV Raman and Brillouin light scattering (BLS) together with Small Angle Neutron Scattering (SANS). By exploiting the complementary information of these three investigation methods, the structural, viscoelastic and molecular modifications of the polymer brought about by the pH changes have been examined, over a spatial range going from mesoscopic to nanoscopic length-scale. The data provide a picture where an increase of pH promotes the change of the characteristic size of the hydrophilic pores when the cross-linker has the suitable structural and acid-base properties, and leads to the reinforcement of the polymer domains interconnections, providing a stiffer gel network on the length-scale probed by BLS. Raman signals are sensitive both to structural changes of the polymer network and to changes of the intermolecular ordering of water due to solvent-polymer interactions. The destructuring effect on the tetrahedral ice-like configurations of water is especially evident at high pH, and might be ascribed to an increased exposition to the solvent of the ionic portions of the polymer surface. Highlights • SANS, Brillouin and UV Raman are used to describe pH-dependent changes in hydrogels. • Molecular and acid-base properties of cross-linker are controlling factors of pH-responsivity. • pH increase promotes stronger interconnections among polymeric domains. • Destructuring of tetrahedral ice-like configurations of water is observed at high pH. • Response to pH is tuned by monomer/cross-linker ratio in polymer network. [ABSTRACT FROM AUTHOR]

Abstract: Two amphiphilic random copolymers, PEGMAx‐co‐FAy (x = 90 and 70 mol%), are synthesized by ATRP and their solutions are investigated as a function of solvent, concentration, and temperature by DLS and SANS analyses. Both copolymers self‐assemble in nanostructures by single‐chain folding in water solutions over a wide range of temperatures. The values of the DLS hydrodynamic radius and the SANS radius of gyration are found to be ≈4 nm and ≈3.4–3.7 nm, respectively. Moreover, SANS shows the self‐folded nanoassemblies to be prolated spheroids with a ratio of polar/equatorial axes of ≈5:1 for PEGMA90‐co‐FA10 and ≈2:1 for PEGMA70‐co‐FA30. On heating above a critical temperature Tc, multichain microassemblies are formed that revert back to nanoassemblies on cooling below Tc. This temperature‐responsive transition is fully and sharply reversible. [ABSTRACT FROM AUTHOR]

Small angle neutron scattering (SANS) responses of particulate silica as disordered and ordered porous and non-porous powders were obtained. Each classification provided distinct scattering patterns which were fitted and analysed using Guinier-Porod and mass-surface fractal (msf) models. The resulting particle dimensions showed good agreement with the same from nitrogen gas adsorption analyses. Additionally, the excellent fit of the msf model to the non-porous silica scattering response resulted in an agreement between the mass and surface fractal dimension values for it and similar analyses and results published previously for fumed silica. The msf fitting gave additional insight into particle and cluster scattering dimensions with particle dimensions being consistent with those from the G-P analyses. [ABSTRACT FROM AUTHOR]

In this report, the solubilization behaviour of a hydrophobic drug Clozapine (CLZ) in micellar suspensions of pluronics having different hydrophilic lipophilic balance (HLB) ratios viz. P84, F127 and F108 in the absence and presence of bile salt sodium deoxycholate (SDC) has been studied. UV–Vis spectroscopy has been exploited to determine the solubilization capacity of the investigated micellar systems in terms of drug loading efficiency, average number of drug molecules solubilized per micelle ( n s ), partition coefficient ( P ) and standard free energy of solubilization (∆ G ° ). The morphological and structural changes taking place in pluronics in different concentration regimes of SDC and with the addition of drug CLZ has been explored using dynamic light scattering (DLS) and small angle neutron scattering (SANS) measurements. The SANS results revealed that aggregation behaviour of pluronic-SDC mixed micelles gets improved in the presence of drug. The micropolarity measurements have been performed to shed light on the locus of solubilization of the drug in pure and mixed micellar systems. The compatibility between CLZ and drug carriers (pluronics and SDC) was confirmed using powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR) techniques. Among the investigated systems, P84-SDC mixed system was found to be highly efficient for CLZ loading. The long term stability data indicated that CLZ loaded P84-SDC mixed micellar formulation remained stable for 3 months at room temperature. Further, it was revealed that the CLZ loaded P84-SDC mixed micelles are converted into CLZ loaded pure P84 micelles at 30-fold dilutions which remain stable up to 48-fold dilutions. The results from the present studies suggest that P84-SDC mixed micelles can serve as suitable delivery vehicles for hydrophobic drug CLZ. [ABSTRACT FROM AUTHOR]

We have used small angle neutron scattering (SANS) to investigate the differences in methane and hexane penetration in pores in bituminous coal samples from the U.S., Canada, South Africa, and China, and maceral concentrates from Australian coals. This work is an extension of previous work that showed consistent differences between the extent of penetration by methane into 10–20 nm size pores in inertinite in bituminous coals from Australia, North America and Poland. In this study we have confirmed that there are differences in the response of inertinite to methane and hexane penetration in coals sourced from different coal basins. Inertinite in Permian Australian coals generally has relatively high numbers of pores in the 2.5–250 nm size range and the pores are highly penetrable by methane and hexane; coals sourced from Western Canada had similar penetrability to these Australian coals. However, the penetrability of methane and hexane into inertinite from the Australian Illawarra Coal Measures (also Permian) is substantially less than that of the other Australian coals; there are about 80% fewer 12 nm pores in Illawarra inertinite compared to the other Australian coals examined. The inertinite in coals sourced from South Africa and China had accessibility intermediate between the Illawarra coals and the other Australian coals. The extent of hexane penetration was 10–20% less than CD 4 penetration into the same coal and this difference was most pronounced in the 5–50 nm pore size range. Hexane and methane penetrability into the coals showed similar trends with inertinite content. The observed variations in inertinite porosity between coals from different coal regions and coal basins may explain why previous studies differ in their observations of the relationships between gas sorption behavior, permeability, porosity, and maceral composition. These variations are not simply a demarcation between Northern and Southern Hemisphere coals. [ABSTRACT FROM AUTHOR]

Small angle neutron scattering study reveals that at pD ≈ 7.0, above the isoelectric point of the globular protein Bovine Serum Albumin (BSA), in the presence of different divalent ions (Mg 2+ , Ca 2+ , Sr 2+ and Ba 2+ ), the short-range attractive interaction remains nearly constant and the intermediate-range repulsive interaction decreases with increasing salt concentration up to a certain concentration value but after that remains unchanged. However, for the monovalent ion (Na + ), repulsive interaction decreases gradually up to 1 M salt concentration. Dynamic light scattering study shows that for all ions, diffusion coefficient of BSA decreases with increasing salt concentration and then nearly saturates. [ABSTRACT FROM AUTHOR]

Sophorolipid (SL), a bio-derived surfactant is an excellent gelling agent for natural fibrous protein, silk fibroin (SF) leading to potential biomedical applications. Interaction of SF with SL has been shown to accelerate the formation of hydrogel with the rate being dependent on the form of SL used. Here, we examine the effect of pH on SL-SF interaction and gel formation by employing rheology, fluorescence spectroscopy, SANS and NMR. The results indicate that the size of SL assemblies decrease as pH increases from acidic to alkaline and significantly impacts the association of SL and SF. The association of SF and SL is mainly via hydrophobic interactions, with the SL molecules forming bead like structures along the SF chain. The increased charge on the acidic form of SL at higher pH results in greater repulsion between acidic SL molecules, which are bound to the hydrophobic sites of SF, leading to rapid chain unfolding and subsequent gelation. [ABSTRACT FROM AUTHOR]

The 2nd biennial International Society for Sample Environment (ISSE) School included training on high pressure (HP) cells for Soft Matter studies. Neutron research centers are responding to a growing need for HP experimental data, relevant to a broad range of applications in bioscience, biotechnology and others. The importance of disseminating designs and operating protocols, to support concerted efforts towards the advancement of sample environment instrumentation across research centers, was repeatedly acknowledged at the ISSE school. The liquid insertion HP system for SANS, currently used at the NIST Center for Neutron Research for solutions of biological macromolecules, is described here. Emphasis is placed on the context of subzero temperature studies and the design challenges. The current model of the HP system – HP up to 3.5 kbar and −18°C < T < +80°C – uses sample volumes of 2.7 ml to cover an accessible q-range of 0.001–0.6 Å−1. [ABSTRACT FROM AUTHOR]

We have developed and realised a compact high-pressure clamp cell of the piston-cylinder type for Small Angle Neutron Scattering (SANS) and Neutron Spin Echo (NSE) spectroscopy measurements. The cell can pressurise ⌀5 mm samples up to 1.5 GPa. It is non-magnetic, produces a sufficiently low and flat SANS background with a relatively good neutron transmission and can be used in combination with polarised neutrons. The cell accommodates samples of up to 55 mm3 in volume and adopts a two-layer geometry: a TiZr body (outer layer) and a CuBe2 insert (inner layer). Its design is very compact and can be employed inside cryomagnets featuring a sample bore greater than ⌀30 mm. We present the cell and illustrate its performances with a series of neutron scattering experiments performed on single-crystalline MnSi. [ABSTRACT FROM AUTHOR]

Diffusion, rheology, and small angle neutron scattering (SANS) data for organic phase 30 v/v % tributyl phosphate (TBP) samples containing varying amounts of water, nitric acid, and uranium or zirconium nitrate were interpreted from a colloidal perspective to give information on the types of structures formed by TBP under different conditions. Taken as a whole, the results of the different analyses were contradictory, suggesting that these samples should be treated as molecular solutions rather than colloids. This conclusion is supported by molecular dynamics (MD) simulations showing the existence of small, molecular aggregates in TBP samples containing water and nitric acid. Interpretation of TBP and nitric acid diffusion measurements from a molecular perspective suggest that nitric acid and metal species formed are consistent with the stoichiometric solvates that have traditionally been considered to exist in solution. [ABSTRACT FROM AUTHOR]

Hypothesis The conformation of poly(ethylene oxide) (PEO) in deep eutectic solvents (DESs) is determined by the polymer–solvent interactions, especially hydrogen bonding interactions. The hypothesis for this work is that the hydrogen bonding environment of a DES can be varied via changing the cation or hydrogen bond donor (HBD), and therefore the solvent quality for PEO; the anion species will also effect hydrogen bonding, but this is not examined here. Experiments Small angle neutron scattering (SANS) is used to probe the concentration dependent conformation of 36 kDa PEO dissolved in DESs formed by mixing ethyl or butyl ammonium bromide with a molecular HBD (glycerol or ethylene glycol) in a 1:2 molar ratio. Findings The radius of gyration ( R g ), Flory exponent and crossover concentration ( c * ) from the dilute to the semi-dilute regime of PEO in the DESs revealed by SANS and Zimm plot analysis show that these DESs are moderately good solvents for PEO. When the ammonium alkyl chain length is increased, the hydrogen bond density per unit volume decreases, and with it the solvent quality for PEO. The solvent quality is improved when the HBD is changed from glycerol to ethylene glycol due to differences in the hydrogen bonding environment for PEO. [ABSTRACT FROM AUTHOR]

The main objective of this work was to study the electric response of the carbon nanotubes/epoxy composites upon varying the concentrations of the nanotubes, in order to obtain a comprehensive understanding of the influence of filler’s percentage and temperature on the impedance parameters. Dielectric spectra of the carbon nanotubes–epoxy resin composites were recorded in the frequency range of 1 Hz–10 MHz and over the temperature range of 25°C–105°C. In a first part, the thermal properties of the composites were analyzed by differential scanning calorimetry, which reveals a decrease in the glass transition temperatures with the concentration of the nanotubes. The phenomenon of the positive temperature coefficient in resistivity that is recognizable for the carbon nanotube concentrations above the percolation threshold has been the interest of the second part of the work. The results reveal that gradually, as the filler concentration approaches the percolation threshold of the composite, the positive temperature coefficient in the resistivity effect becomes even more pronounced. Finally, the structure of the filled polymer samples is characterized using a small angle neutron scattering technique. [ABSTRACT FROM PUBLISHER]

The structure of phycobiliproteins of the cyanobacterium Acaryochloris marina was investigated in buffer solution at physiological temperatures, i.e. under the same conditions applied in spectroscopic experiments, using small angle neutron scattering. The scattering data of intact phycobiliproteins in buffer solution containing phosphate can be well described using a cylindrical shape with a length of about 225 Å and a diameter of approximately 100 Å. This finding is qualitatively consistent with earlier electron microscopy studies reporting a rod-like shape of the phycobiliproteins with a length of about 250 (M. Chen et al., FEBS Letters 583, 2009, 2535) or 300 Å (J. Marquart et al., FEBS Letters 410, 1997, 428). In contrast, phycobiliproteins dissolved in buffer lacking phosphate revealed a splitting of the rods into cylindrical subunits with a height of 28 Å only, but also a pronounced sample aggregation. Complementary small angle neutron and X-ray scattering experiments on phycocyanin suggest that the cylindrical subunits may represent either trimeric phycocyanin or trimeric allophycocyanin. Our findings are in agreement with the assumption that a phycobiliprotein rod with a total height of about 225 Å can accommodate seven trimeric phycocyanin subunits and one trimeric allophycocyanin subunit, each of which having a height of about 28 Å. The structural information obtained by small angle neutron and X-ray scattering can be used to interpret variations in the low-energy region of the 4.5 K absorption spectra of phycobiliproteins dissolved in buffer solutions containing and lacking phosphate, respectively. [ABSTRACT FROM AUTHOR]

We have assessed the impact of the welding parameters on the nano-sized oxide dispersion and the grain size in the matrix of an ODS steel after friction stir welding. Our results, based on combined small angle neutron scattering and electron microscopy, reveal a decrease in the volume fraction of the particles smaller than 80 nm in the welds, mainly due to particle agglomeration. The increase in tool rotation speed or decrease in transverse speed leads to a higher reduction in nano-sized particle fraction, and additionally to the occurrence of particle melting. The dependence of the average grain size in the matrix on the particle volume fraction follows a Zener pinning-type relationship. This result points to the principal role that the particles have in pinning grain boundary movement, and consequently in controlling the grain size during welding. [ABSTRACT FROM AUTHOR]

Objective To characterize the microstructure of two zinc phosphate cement formulations in order to investigate the role of liquid/solid ratio and composition of powder component, on the developed porosity and, consequently, on compressive strength. Methods X-ray powder diffraction with the Rietveld method was used to study the phase composition of zinc oxide powder and cements. Powder component and cement microstructure were investigated with scanning electron microscopy. Small angle neutron scattering (SANS) and microfocus X-ray computed tomography (XmCT) were together employed to characterize porosity and microstructure of dental cements. Compressive strength tests were performed to evaluate their mechanical performance. Results The beneficial effects obtained by the addition of Al, Mg and B to modulate powder reactivity were mitigated by the crystallization of a Zn aluminate phase not involved in the cement setting reaction. Both cements showed spherical pores with a bimodal distribution at the micro/nano-scale. Pores, containing a low density gel-like phase, developed through segregation of liquid during setting. Increasing liquid/solid ratio from 0.378 to 0.571, increased both SANS and XmCT-derived specific surface area (by 56% and 22%, respectively), porosity (XmCT-derived porosity increased from 3.8% to 5.2%), the relative fraction of large pores ≥50 μm, decreased compressive strength from 50 ± 3 MPa to 39 ± 3 MPa, and favored microstructural and compositional inhomogeneities. Significance Explain aspects of powder design affecting the setting reaction and, in turn, cement performance, to help in optimizing cement formulation. The mechanism behind development of porosity and specific surface area explains mechanical performance, and processes such as erosion and fluoride release/uptake. [ABSTRACT FROM AUTHOR]

ABSTRACT The purpose of this study is to identify the relationship between the electrical and structural characteristics of multiwalled carbon nanotubes dispersed into the polymer matrix of a resin. In a first step, the composites were characterized by small-angle neutron scattering, which provide information about the bulk dispersion of nanotubes in the matrix and form three-dimensional networks with a surface fractal behavior. In the second step, a dielectric and electrical study was carried out in the frequency range between 1 Hz and 10 MHz at room temperature. We have found that the electric and dielectric behavior of these composites can be described by Jonscher's universal dielectric response. We show that the critical exponents describing the concentration dependence of the conductivity and the dielectric constant, obtained in the vicinity of the percolation threshold, are in good agreement with the theoretical values. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44514. [ABSTRACT FROM AUTHOR]

Structures and interactions among globular proteins BSA and lysozyme are explored by small angle neutron scattering (SANS) technique at pD ≈ 7.0 by varying ethanol concentration. Interaction behaviours are also obtained in presence of monovalent salt (NaCl). SANS analysis shows that for both lower and higher BSA concentrations and in presence of NaCl, combination of intermediate-range repulsion and weak long-range attraction is responsible for the effective interaction behaviours with the variation of ethanol concentration. For lysozyme, interaction nature is same as BSA in absence of NaCl but in presence of NaCl, fractal structure factor explains the interaction behaviours. [ABSTRACT FROM AUTHOR]

Lipids membranes, the primary component of the living cell, involve collective behaviour of numerous interacting molecules. The rich morphology and complex phase diagram of the lipid systems require different strategies in describing bio-membranes in order to capture the essential properties of self-assembly processes as well as the underling molecular collective phenomena involved in biological functions. Among the experimental methods used, the scattering techniques such as small angle neutrons and X-rays scattering (SANS and SAXS) are probably the most important experimental approaches for the structural investigation of bio-membranes and mixed lipids complex systems. In this tutorial review we describe the main approaches employed in the investigation of lipid bio-membranes by means of the neutron and x-ray scattering techniques. While introducing the main structural properties of lipid bio-membranes we highlight the important role of lipid components in different biological functions of living organisms. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo. [ABSTRACT FROM AUTHOR]

We review some of our latest contributions in the field of neutron scattering of polymers with linear and non-linear architecture. On the one hand, the reviewed Small Angle Neutron Scattering investigations cover dilute mixtures of dendritic polymers and linear polymers that were investigated during relaxation after a fast step strain or in situ during a strain ramping. The focus was on the otherwise not accessible long time dynamics of the inner branches. The parameters of the model are those of the tube model and include the evolution of liberated chain ends, the size and time dependence of the confining tube diameter and branch-point related dynamics. The case of deformed tube diameters could be obtained from a permanently-linked network state as the limiting case of a deformed melt. On the other hand, recently, cyclic polymers as a special class of branched architectures showed to be of high significance to detect similar features directly from equilibrium measurements by means of quasi-elastic Neutron Spin Echo spectroscopy. We show that by means of polymer rings as a probe different aspects of the tube concept can be distinguished in a unique way. [ABSTRACT FROM AUTHOR]

The hierarchical morphology of xanthan solutions is analyzed by light and neutron scattering in a broad range of concentrations in order to connect their morphology to their well-documented dynamic properties. Static light scattering inside the semidilute regime is dominated by the form factor of individual xanthan chains while at higher concentrations chain interconnections appear to modify the low wave vector scattering. Dynamic light scattering reveals the self-similar nature of the solutions caused by interchain associations as intensity autocorrelation functions present power-law behaviour. Small angle neutron scattering is dominated by the fractal scattering from the formed network at intermediate length scales. At small length scales the rigid structure of xanthan is revealed and the molecular weight per unit length is extracted. No detectable morphological alterations for shear rates up to 1000 rad/s are observed revealing that the shear thinning behaviour of xanthan is related to the disruption of chain-chain associations. [ABSTRACT FROM AUTHOR]

Distribution ratios for the extraction of Zr(IV) and Hf(IV) as well as third phase formation limits for the extraction of Zr(IV) by solutions of tri- iso-amyl phosphate (T iAP) and tri- n-butyl phosphate (TBP) in n-dodecane have been measured as a function of equilibrium aqueous phase nitric acid concentration at 303 K. The concentrations of the constituents of the organic phases at different equilibrium aqueous phase Zr(IV) concentrations were determined and correlated with the third phase formation tendency of T iAP and TBP. The aggregation behaviour of T iAP and TBP in the extraction of Zr(IV) from its solution in nitric acid media (4.06-4.41 M HNO) has been compared using small angle neutron scattering technique. Studies indicate the higher third phase formation tendency of TBP as compared to T iAP in the extraction of Zr(IV) from nitric acid media. [ABSTRACT FROM AUTHOR]

Investigation of the process of structure formation of samples of hydrated cement compositions on the nano level is conducted with the help of the method of small angle neutron scattering (neutron wavelength is λ=0.3 nm) both on the basis of Portland cement without additives and that modified by various nanoadditives and nanomodifiers of artificial (alpha aluminium oxide, gamma aluminium oxide) and technogenic (sludge) origin, as well as by complex additives containing surfactants. Dynamics of changes of structural parameters of samples of cement compositions depending on time is analyzed. Changes of correlation functions of scattering objects and fractal dimensions are observed. It is substantiated that Portland cement compositions are fractal clusters. [ABSTRACT FROM AUTHOR]

Synergistic effect of temperature, protein and salt concentration on structures and interactions among lysozyme proteins in solution has been studied using small angle neutron scattering technique. Scattering study shows that for a particular protein concentration, with increasing temperature, short-range attraction decreases but long-range repulsion becomes system specific. In absence of salt, lower value of attractive interaction is obtained, however, in presence of salt it becomes higher and decreases with increasing temperature. For specific condition, weak long range attraction and intermediate range repulsion exists. At higher temperature (90 °C), fractal structure develops and the corresponding fractal dimension depends upon the experimental conditions. [ABSTRACT FROM AUTHOR]

Full characterization of fired-clay bricks is crucial for the improvement of process variables in manufacturing and, in case of old bricks, for restoration/replacement purposes. To this aim, five bricks produced in a plant in Czech Republic in the past have been investigated with a combination of analytical techniques in order to derive information on the firing process. An additional old brick from another brickyard was also used to study the influence of different raw materials on sample microstructure. The potential of X-ray diffraction with the Rietveld method and small angle neutron scattering technique has been exploited to describe the phase transformations taking place during firing and characterize the brick microstructure. Unit-cell parameter of spinel and amount of hematite are proposed as indicators of the maximum firing temperature, although for the latter, limited to bricks produced from the same raw material. The fractal quality of the surface area of pores obtained from small angle neutron scattering is also suggested as a method to distinguish between bricks produced from different raw clays. [ABSTRACT FROM AUTHOR]

Phenol-functionalized MWCNTs were prepared by specially synthesized “wet chemistry” process. TEM images revealed that the produced carbon nanotubes are of high purity having diameter from 20 to 45 nm and length 2–3 μm. In order to optimize the utilization of MWCNTs for the preparation of mixed matrix composite materials a thorough characterization of their dispersions in various solvents was of key importance. Small-angle neutron scattering (SANS) measurements were performed for the investigation of the nanotube dispersion grade into NMP and DMSO solvents. The results suggest that NMP, even in the highest concentration (1.2% wt), is a good solvent for dispersing phenol-functionalized MWCNTs. [ABSTRACT FROM AUTHOR]

The correlation between the morphology of catalyst supports and their effect on catalyst dispersion was investigated. The structure of two types of γ-alumina (γ-Al 2 O 3 ) crystallite particles, rod-like and platelet-like alumina, were measured in 4 orders of length scales, from nanometer to micrometer, using ultra small angle neutron scattering (USANS) and SANS and quantitatively characterized with Hammouda's Generalized Guinier–Porod model. Pt nanoparticles tended to deposit in finer particles and had narrower particle size distribution on the rod-like alumina supports compared to the plate-like alumina supports due to geometrically restricted deposition areas and higher surface curvatures of the rod-like supports. The high diffusion barrier for Pt particles on the highly curved surfaces of the rod-like supports was attributed to be the reason why Pt particles were prevented from diffusing and clustering. While aggregates of the rod-like alumina supports were randomly dispersed without any specific orientation, resulting in high surface area, aggregates of the plate-like alumina supports consisted of a stack of 2–3 layers due to the high van der Waals forces between planar layers, resulting in low surface area. Pt/rod-like alumina supports showed more than 100% higher catalytic activities than Pt/platelet-like alumina supports in model three-way-catalyst (TWC) reactions of CO, NO, and C 3 H 6 conversions at 200–250 °C. Control of shape and aggregation of catalytic support materials in nano–micrometer scale can be an important parameter to improve catalytic performance. [ABSTRACT FROM AUTHOR]

Bainite transformation behavior was monitored using simultaneous measurements of dilatometry and small angle neutron scattering (SANS). The volume fraction of bainitic ferrite was estimated from the SANS intensity, showing good agreement with the results of the dilatometry measurements. We propose a more advanced monitoring technique combining dilatometry, SANS and neutron diffraction. [ABSTRACT FROM AUTHOR]

Three oxide dispersion-strengthened (ODS) steels are produced in order to investigate the effect of the mechanical alloying (MA) temperature on the microstructural evolution and high temperature mechanical properties. The microstructural evolution with different MA conditions is examined using small angle neutron scattering. As the MA temperature decreases, the density of the nanoclusters below 10 nm increases and their mean diameter decreases. A low temperature during MA leads to a high strength in the compression tests performed at 500 °C; however, this effect disappears in testing at 900 °C. The milling process at −70 °C exhibits excellent high fracture toughness, which is better than the benchmark material 14YWT-SM10. However, the −150 °C milling process results in significantly worse fracture toughness properties. The reasons for this strong temperature dependency are discussed. [ABSTRACT FROM AUTHOR]

This investigation is based on the results of the experiments on small angle neutron scattering (neutron wavelength is λ=0.3 nm) and goes into patterning trans-atomic-level structure of hydrated portland cement compositions. The following structural parameters are determined: particle size distribution, porosity, fractal dimensionality. The paper stresses the effect of both artificial (γAl2O3, carbon materials) and technogenic (slurry) nanoagents and nanomodifiers on these structural parameters as well as the effect of complex additives with surface-active agents. [ABSTRACT FROM AUTHOR]

The solution properties of the multiresponsive polymer P1 (poly(2-((3-(1-(2-(dimethylamino)ethyl)-1H-1,2,3-triazol-4-yl)propanoyl)oxy)ethyl methacrylate) are studied by small angle neutron scattering (SANS) and dynamic light scattering (DLS). The P1 solution exhibits a phase transition above certain temperatures and cloud points following dissolution through the incubation at room temperature. SANS and DLS studies show that P1 forms clusters via hydrophobic interactions, which are weakened by continued incubation. The temperature dependent cluster formation is explained by hydrophobic adsorption and shrinking behavior as a function of hydrodynamic radius, correlation lengths, and Porod exponents. The weak clustering and solution property are discussed on the basis of Flory theory. Taken together, the results here indicate that time-dependent dissolution of P1 leads to a weakly hydrophobic structure. [ABSTRACT FROM AUTHOR]

We report a simultaneous study in self-seeding and isothermal crystallization of polyethylene (PE) in the solution using time resolved small angle neutron scattering (SANS). We observe that the SANS spectra obtained from self-seeding technique are significantly different from isothermal crystallization technique of PE crystallization in solution. The first correlation peak from structure factor for self-seeding crystallization is not clear compare to isothermal crystallization spectra, indicating that crystals are dominantly in single or few lamellae forms. Structural information, such as the lamellar long period, lamellar crystal thickness, amorphous layers between lamellae, invariant and crystallinity has been quantitatively determined based on model fitting. Avrami analysis depicts 2D lamellar structure formation. [ABSTRACT FROM AUTHOR]