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We investigate the phase behavior of model ternary triacylglycerol blends, comprising triolein (C57H104O6, OOO), tripalmitin (C51H98O6, PPP) and tristearin (C57H110O6, SSS), building upon extensive characterisation of single and binary mixtures, in order to rigorously map the thermal transitions of model natural ‘fats’. A combination of calorimetry, X-ray diffraction, and FTIR spectroscopy is employed to determine crystallisation and melting temperatures and identify the corresponding phases in the complex ternary system. We recover the eutectic behaviour of SSS-PPP blends and the invariability of OOO neat transitions, and resolve the complex β′ + β ternary surface, reflecting the roles of unsaturation and polymorphism of its constituents. Our results provide a representation of the OOO:PPP:SSS:temperature phase behaviour into a triangular prism, consistent with binary pair-wise data, which can inform a range of food science, cosmetic, pharmaceutical and cleaning applications that depend strongly on the physical-chemistry of such multicomponent ‘triglycerides’.

We report for the first time that pectin-degrading enzymes could be tailored for wood bark based on the chemical features of pectin. Besides wood, stems of trees contain 10-20% bark that remains one of the largest underutilized biomasses on the planet. Unique extractive compounds, suberin, pectin, sclerenchyma fibres, etc. form a major part of the bark that is today mainly combusted for energy production. In certain trees, such as willow, lignified sclerenchyma fibres organize in continuous, thin bundles or bast fibres which are surrounded by the non-lignified ground tissue. Random screening of lignocellulose-degrading enzymes is the mainstream, suitable for uniform and simple substrates like cellulose, but the pectin chemistry is more complex. The structure of pectin was first elucidated after which pectin-degrading enzymes were tailored. Surprisingly, the applied pectinases alone were able to fully liberate the fibre bundles from the bark under mild conditions. When the pectinases were used together with hemicellulases, fibre bundles with an abnormally low surface lignin content of 10% were obtained. Overall, the novel findings of this study give promise for commercial valorisation of the underappreciated bark biomass in the future without the need to build huge plants with their expensive chemical recovery systems. Most importantly, the "tailor-made enzyme consortium based on the structural features of the substrate" concept may be a revolutionary breakthrough in precisely designing biochemical degradation strategies particularly for the recalcitrant macromolecule component (such as pectin) of lignocellulosic biomass.

Non-destructive characterization methods to observe phase transformations and thus, gain insights to transformation mechanisms in representative volumes are key for the development of advanced materials and manufacturing. Conventional methods are constrained to the surface and small sizes, thus, access to the bulk often implies tedious destructive approaches and hinders in-situ observations of phase evolution. In this work, we introduce a non-destructive technique that overcomes key limitations prevailing today for mapping the spatial distribution of magnetic phases in bulk materials. The use of polarized neutrons, being sensitive to sub-percent fractions of ferromagnetic phases and able to penetrate centimeter sized samples, enables micrometer-scale spatial and second-scale time resolutions. We demonstrate ex-situ and in-situ quantitative mapping of magnetic phases, in particular the evolution of martensite induced by uniaxial- and biaxial deformation in metastable 304 steel. The quantitative results obtained during in-situ deformation testing prove polarization contrast neutron imaging to be particularly effective in detecting small fractions of martensite. Especially during early stages of deformation where neutron diffraction, which in contrast does not provide full field spatial resolution, fails. The short exposure times and high sensitivity renders the method well suited for rapid 3D tomographic mapping and/or operando investigations of phase distributions. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

RSC Advances 12(52), 33469 - 33478 (2022). doi:10.1039/D2RA05269E, Despite the importance of layered double hydroxides (LDHs) in catalysis, medicine and water treatment, the crystallisation process of these materials is seldom investigated. In this study, in situ characterisation techniques granted unprecedented experimental access to the formation dynamics of carbonate-intercalated Mg$^{2+}$/Al$^{3+}$ LDHs as model system when applying the most relevant co-precipitation approaches by exploring the effects of temperature and concentration of reactants. For this purpose, a combinatorial multi-modal characterisation approach was applied involving in situ measurements of pH, ion conductivity and light scattering, as well as synchrotron-based in situ X-ray diffraction (XRD). Shortly after beginning the addition of basic solutions (i.e., sodium carbonate and sodium hydroxide) to the solutions of magnesium nitrate hexahydrate and aluminium nitrate nonahydrate, a stable pH was reached due to the uptake of hydroxyl ions for nuclei formation. Shortly after, crystal growth phase was detected by an increase in the light scattering signal and confirmed via in situ XRD. Increasing the concentration of reactants accelerated the onset of crystal growth by 70% without significantly changing the crystallite size. On the other hand, increasing the temperature up to 65 °C showed a smaller influence on the reaction kinetics but resulted in a two-fold increase in crystallite size. Adding the solution of metal precursors to the basic solution, saturation was rapidly reached, without an induction period, favouring the formation of very small crystallites of approximately 10 nm., Published by RSC Publishing, London

A crystal structure of a photolyase at room temperature confirms the structural information obtained from cryogenic crystallography and paves the way for time-resolved studies of the photolyase at an X-ray free-electron laser., (6–4) photolyases are flavoproteins that belong to the photolyase/cryptochrome family. Their function is to repair DNA lesions using visible light. Here, crystal structures of Drosophila melanogaster (6–4) photolyase [Dm(6–4)photolyase] at room and cryogenic temperatures are reported. The room-temperature structure was solved to 2.27 Å resolution and was obtained by serial femtosecond crystallography (SFX) using an X-ray free-electron laser. The crystallization and preparation conditions are also reported. The cryogenic structure was solved to 1.79 Å resolution using conventional X-ray crystallo­graphy. The structures agree with each other, indicating that the structural information obtained from crystallography at cryogenic temperature also applies at room temperature. Furthermore, UV–Vis absorption spectroscopy confirms that Dm(6–4)photolyase is photoactive in the crystals, giving a green light to time-resolved SFX studies on the protein, which can reveal the structural mechanism of the photoactivated protein in DNA repair.

Hafnia, HfO2, which is a wide band gap semiconducting oxide, is much less studied than the chemically similar zirconia (ZrO2). Here, we study the formation of hafnia nanocrystals from hafnium tetrachloride in methanol under solvothermal conditions (248 bar, 225-450 °C) using complementary in situ powder X-ray diffraction (PXRD) and Pair Distribution Function (PDF) analysis. The main structural motif of the precursor solution (HfCl4 dissolved in methanol) is a Hf oxide trimer with very similar local structure to that of m-HfO2. Different measurements on precursor solutions show large intensity variation for the Hf-Cl correlations signifying different extents of HCl elimation. A few seconds of heating lead to a correlation appearing at 3.9 Å corresponding to corner-sharing Hf-polyhedra in a disordered solid matrix. During the next minutes (depending on temperature) the disordered structure rearranges and the nearest neighbour Hf-Hf distance contracts while the Hf-O coordination number increases. After approximately 90 seconds (at T = 250 °C) the structural rearrangement terminates and 1-2 nm nanocrystals of m-HfO2 nucleate. Initially the m-HfO2 nanocrystals have significant disorder as reflected in large Hf atomic displacement parameter (ADP) values, but as the nanocrystals grow to 5-6 nm in size during extended heating, the Hf ADPs decrease toward the values obtained for ordered bulk structures. The nanocrystal growth is not well modelled by the Johnson-Mehl-Avrami expression reflecting that multiple complex chemical processes occur during this highly nonclassical nanocrystal formation under solvothermal conditions.

FeSb 2 exhibits a colossal Seebeck coefficient ((Formula presented.)) and a record-breaking high thermoelectric power factor. It also has an atypical shift from diamagnetism to paramagnetism with increasing temperature, and the fine details of its electron correlation effects have been widely discussed. The extraordinary physical properties must be rooted in the nature of the chemical bonding, and indeed, the chemical bonding in this archetypical marcasite structure has been heavily debated on a theoretical basis since the 1960s. The two prevalent models for describing the bonding interactions in FeSb 2 are based on either ligand-field stabilization of Fe or a network structure of Sb hosting Fe ions. However, neither model can account for the observed properties of FeSb 2. Herein, an experimental electron density study is reported, which is based on analysis of synchrotron X-ray diffraction data measured at 15 K on a minute single crystal to limit systematic errors. The analysis is supplemented with density functional theory calculations in the experimental geometry. The experimental data are at variance with both the additional single-electron Sb−Sb bond implied by the covalent model, and the large formal charge and expected d-orbital splitting advocated by the ionic model. The structure is best described as an extended covalent network in agreement with expectations based on electronegativity differences.

Graphite as a positive electrode material of dual ion batteries (DIBs) has attracted tremendous attentions for its advantages including low lost, high working voltage and high energy density. However, very few literatures regarding to the real-time observation of anion intercalation behavior and surface evolution of graphite in DIBs have been reported. Herein, we use in situ atomic force microscope (AFM) to directly observe the intercalation/de-intercalation processes of PF6− in graphite in real time. First, by measuring the change in the distance between graphene layers during intercalation, we found that PF6− intercalates in one of every three graphite layers and the intercalation speed is measured to be 2 µm·min−1. Second, graphite will wrinkle and suffer structural damages at high voltages, along with severe electrolyte decomposition on the surface. These findings provide useful information for further optimizing the capacity and the stability of graphite anode in DIBs.

For polycrystalline materials, key material properties, such as mechanical anisotropy or transformation behavior, and magnetic properties strongly depend on the crystallographic texture of the crystalline material. Assessment of texture is generally destructive and highly local. Only high energy X-ray diffraction at synchrotron sources and neutrons enable to study, non-destructively, the microstructure in the bulk of materials. Here, we report how progress in Laue three-dimensional neutron diffraction tomography enables to index the crystallographic orientation of several hundred grains and, thus, enables grain-resolved characterization of texture in the volume of centimeter-sized coarse-grained samples with statistical significance. To demonstrate the neutron technique for characterizing the crystallographic microstructure, we investigate a Fe-Ni-Mn austenitic alloy. A total number of 481 grains within a 1 cm(3) of material is indexed and the results in assessing the crystallographic texture are compared with electron backscatter diffraction measurements. The short exposure times and non-destructive nature of the Laue three-dimensional neutron diffraction render it a novel promising method for corresponding characterization. (C) 2022 The Author(s). Published by Elsevier Ltd.

The processing of belite cement clinker in a rotary kiln at about 1000oC is a new recycling option for autoclaved aerated concrete (AAC) waste that otherwise must be landfilled. The clinker produced can partially substitute ordinary portland cement (OPC) in AAC production. Waste quantities and landfill costs are minimized, while at the same time CO2 emissions and the primary resource consumption of AAC production are reduced. The technology is currently under development. New analytical possibilities and modeling have made it possible to optimize the process conditions to such an extent that the use of belite cement clinker in aerated concrete production has already been technically tested. Particularly large effects on CO2 emissions can be achieved through the electrical heating of the rotary kiln and the coupled sequestration of the released CO2 in other secondary products such as recycled aggregate for concrete production from waste concrete. Comparable concepts for the AAC cycle are currently being worked on together with the industry partner Xella. Although decentralized plant concepts would be useful in order to minimize transportation, small plants are currently not economical according to initial estimates. In the long term, emission-free product cycles are aimed at.

Variant reorientation is a ubiquitous phenomenon in shape memory alloys and has a great influence on their texture and mechanical response. In the present study, a martensitic NiTi rolled sheet is investigated by the electron backscattering diffraction (EBSD) technique; the variant reorientation and texture evolution are followed during bending. The initial weak texture components of martensite evolve by reorientation toward a strong texture around [104]M and a weak one around [112]M. The initial laths are transformed into blocks made of one or two variants. The EBSD maps were analyzed with the Interaction Work (IW) criterion associated with (a) the individual variant and (b) habit plane variants (a combination of two distortion variants). Compared with the experimental results, the prediction given with individual variant fits better than with the habit plane variants. An empirical quantification of the threshold on interaction work (IW) permits to rationalize and predict the variant pairs formed by the reorientation and their numbers in the blocks. A critical influence of the pre-texture of the parent B2 grains on the final texture and on the number of variants per block was revealed. This study could give insights into the mechanical response of the NiTi alloys with various textures during tensile and fatigue tests.

As a promising alternative to the market-leading lithiumion batteries, low-cost sodium-ion batteries (SIBs) are attractive for applications such as large-scale electrical energy storage systems. The energy density, cycling life, and rate performance of SIBs are fundamentally dependent on dynamic physiochemical reactions, structural change, and morphological evolution. Therefore, it is essential to holistically understand SIBs reaction processes, degradation mechanisms, and thermal/mechanical behaviors in complex working environments. The recent developments of advanced in situ and operando characterization enable the establishment of the structure-processing-property- performance relationship in SIBs under operating conditions. This Review summarizes significant recent progress in SIBs exploiting in situ and operando techniques based on X-ray and electron analyses at different time and length scales. Through the combination of spectroscopy, imaging, and diffraction, local and global changes in SIBs can be elucidated for improving materials design. The fundamental principles and state-of-the-art capabilities of different techniques are presented, followed by elaborative discussions of major challenges and perspectives. U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences program [DE-SC0019121]; National Science Foundation [CBET 1912885]; USDA AFRI Foundational and Applied Program [2020-67021-31139]; U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-06CH11357]; U.S. DOE [DE-AC02-06CH11357]; Canadian Light Source Published version D.H., E.G., J.R., K.G., Y.L., and H.X. acknowledge the funding support by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences program under Award Number DE-SC0019121. The work at Virginia Tech was supported by the National Science Foundation under no. CBET 1912885 and the USDA AFRI Foundational and Applied Program (grant number 2020-67021-31139). Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. This research used resources of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, and was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357, and the Canadian Light Source, and its funding partners.

Biobased and biodegradable polyhydroxyalkanoates (PHAs) have great potential as sustainable packaging materials. However, improvements in their processing and mechanical properties are necessary. In this work, the influence of melt processing conditions on the mechanical properties and microstructure of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is examined using a full factorial design of experiments (DoE) approach. We have found that strict control over processing temperature, mold temperature, screw speed, and cooling time leads to highly increased elongation at break values, mainly under influence of higher mold temperatures at 80 °C. Increased elongation of the moldings is attributed to relaxation and decreased orientation of the polymer chains together with a homogeneous microstructure at slower cooling rates. Based on the statistically substantiated models to determine the optimal processing conditions and their effects on microstructure variation and mechanical properties of PHBHHx samples, we conclude that optimizing the processing of this biopolymer can improve the applicability of the material and extend its scope in the realm of flexible packaging applications. ispartof: POLYMERS vol:13 issue:22 ispartof: location:Switzerland status: published

Polyproline II (pPII) is a left-handed 31-helix conformation, which has been observed to be the most abundant secondary structure in unfolded peptides and proteins compared to α-helix and β-sheet. Although pPII has been reported as the most stable conformation for several unfolded short chain peptides in aqueous solution, it is rarely observed in their solid state. Here, we show for the first time a glycine homopeptide (gly-gly-gly) adopting the pPII conformation in its crystalline dihydrate structure. The single crystal X-ray structure with molecular dynamic simulation suggests that a network of water and the charged carboxylate group is critical in stabilizing the pPII conformation in solid state, offering an insight into the structures of unfolded regions of proteins and the role of water in peptide crystallization.

Molecular dynamics (MD) simulations were performed to determine thermal expansion, thermal conductivity and diffusional properties of Th1-xNpxO2 and U1-xNpxO2 mixed oxides (MOX). The linear thermal expansion coefficient (LTEC) of Th1-xNpxO2 MOX increases with NpO2 concentration, while that of U1-xNpxO2 MOX decreases. The degradation of thermal conductivity in U1-xNpxO2 is predicted to be far less significant compared to Th1-xNpxO2 because defect-phonon scattering is less pronounced in U1-xNpxO2. Addition of 6.25 atom% NpO2 in ThO2 degrades the thermal-conductivity of ThO2 by 24.0–12.5% in the 750–1000 K temperature range whereas up to 50 atom% NpO2 doping in UO2 degrades the thermal-conductivity only by 13–2.3%. Analytical expressions have been derived that describe the predicted lattice parameters and thermal conductivities over the full temperature and compositional ranges. Oxygen diffusivity is higher in UO2 and NpO2 compared to ThO2. With the addition of Th4+ or U4+ to NpO2, the diffusivity decreases due to the increase in the migration barriers caused by the larger ionic radius of Th4+ or U4+. The addition of Np4+ to ThO2 or UO2 decreases oxygen diffusion due to the preference for the oxygen vacancy to be adjacent to Np4+, even though the migration barriers decrease due to the smaller size of Np4+. Our MD calculated binding energies of the oxygen vacancy can be correlated with the isolated oxygen Frenkel pair defect energies (O-FPisolated) of individual actinide oxides calculated using same interatomic potential set. Moreover, MD calculated oxygen vacancy binding energy is consistent with that calculated using density functional theory.

The covalent nature of the low-barrier N−H−N hydrogen bonds in the negative thermal expansion material H 3[Co(CN) 6] has been established by using a combination of X-ray and neutron diffraction electron density analysis and theoretical calculations. This finding explains why negative thermal expansion can occur in a material not commonly considered to be built from rigid linkers. The pertinent hydrogen atom is located symmetrically between two nitrogen atoms in a double-well potential with hydrogen above the barrier for proton transfer, thus forming a low-barrier hydrogen bond. Hydrogen is covalently bonded to the two nitrogen atoms, which is the first experimentally confirmed covalent hydrogen bond in a network structure. Source function calculations established that the present N−H−N hydrogen bond follows the trends observed for negatively charge-assisted hydrogen bonds and low-barrier hydrogen bonds previously established for O−H−O hydrogen bonds. The bonding between the cobalt and cyanide ligands was found to be a typical donor–acceptor bond involving a high-field ligand and a transition metal in a low-spin configuration.

Designing environmentally friendly materials from natural resources represents a great challenge in the last decade. However, the lack of fundamental knowledge in the processing of the raw materials to fabricate the composites structure is still a major challenge for potential applications. Natural fibers extracted from plants are receiving more attention from researchers, scientists and academics due to their use in polymer composites and also their environmentally friendly nature and sustainability. The natural fiber features depend on the preparation and processing of the fibers. Natural plant fibers are extracted either by mechanical retting, dew retting and/or water retting processes. The natural fibers characteristics could be improved by suitable chemicals and surface treatments. This survey proposes a detailed review of the different types of retting processes, chemical and surface treatments and characterization techniques for natural fibers. We summarize major findings from the literature and the treatment effects on the properties of the natural fibers are being highlighted.

The safety, durability and power density of lithium-ion batteries (LIBs) are currently inadequate to satisfy the continuously growing demand of the emerging battery markets. Rapid progress has been made from material engineering to system design, combining experimental results and simulations to enhance LIB performance. Limited by spatial and temporal resolution, state-of-the-art advanced characterization techniques fail to fully reveal the complex multi-scale degradation mechanism in LIBs. Strengthening interaction and iteration between characterization and modeling improves the understanding of reaction mechanisms as well as design and management of LIBs. Herein, a seed cyber hierarchy and interactional network framework is demonstrated to evaluate the overall lifecycle of LIBs. The typical examples of bridging the characterization techniques and modeling are discussed. The critical parameters extracted from multi-scale characterization can serve as digital inputs for modeling. Furthermore, advanced computational techniques including cloud computing, big data, machine learning, and artificial intelligence can also promote the comprehensive understanding and precise control of the whole battery lifecycle. Digital twins techniques will be introduced enabling the real-time monitoring and control of LIBs, autonomous computer-assisted characterizations and intelligent manufacturing. It is anticipated that this work will provide a roadmap for further intensive research on developing high-performance LIBs and intelligent battery management.

The tear film lipid layer (TFLL) is important to the maintenance of ocular surface health. Surprisingly, information on the individual roles of the myriad of unique lipids found therein is limited. The most abundant lipid species are the wax esters (WE) and cholesteryl esters (CE), and, especially their branched analogs. The isolation of these lipid species from the TFLL has proved to be tedious, and as a result, insights on their biophysical profiles and role in the TFLL is currently lacking. Herein, we circumvent these issues by a total synthesis of the most abundant iso-methyl branched WEs and CEs found in the TFLL. Through a detailed characterization of the biophysical properties, by the use of Langmuir monolayer and wide-angle X-ray scattering techniques, we demonstrate that chain branching alters the behavior of these lipid species on multiple levels. Taken together, our results fill an important knowledge gap concerning the structure and function of the TFLL on the whole.

(KxNa1-x)NbO3 (KNN) and its solid solutions are considered as potential alternatives to traditional Pb-based piezoelectric materials. Recent investigations indicated that the local structure in KNN is much more complex than its long-range average structure. Here, we have undertaken a systematic investigation of the temperature-dependent evolution of local and average structures of KNN5 [(KxNa1-x)NbO3,x=0.5] using time of flight neutron scattering. Rietveld analysis of neutron diffraction patterns indicated that the average structure of KNN5 changes from monoclinic to tetragonal to cubic upon heating from 100 to 773 K. In contrast, analysis of neutron pair distribution function (PDF) indicated that the local structure stays monoclinic within the above temperature range. Based on comparative analysis of local and average structures, it is proposed that the average structural phase transitions in KNN5 are partly derived from a local ordering of the polar units, which are correlated over a length of 10 15 Å. A clear indication of order-disorder type transition at 473 K is evident from the temperature-dependent PDF patterns. Additionally, based on local structural analysis, it is shown that large electrical polarization in KNN5 can be attributed to displacements of both A-site and B-site atoms. These structural insights may help in further optimization of electrical properties of Pb-free KNN piezoceramics.

The indium oxides, c-In2O3, h-In2O3, InOOH and In(OH)3, constitute an important class of wide band gap semiconductors. Synthesis of any indium oxide phase involves manoeuvring in a complex matrix of process parameters, and some phases are only obtained through controlled phase transformations. Considering the widespread use of indium oxide semiconductors it is restrictive that no coherent picture exists of the formation mechanisms of individual phases and phase transformations between them. Here we access the indium oxide system through solvothermal synthesis and/or powder calcinations, and we use in situ X-ray scattering in combination with thermal analysis to investigate the complex phase relations. This allows us to unravel synthesis pathways for the different indium oxide phases, and the insight is used to develop procedures for scalable continuous flow solvothermal synthesis. Direct formation of crystalline nanomaterials from precursor solutions was observed for In(OH)3, InOOH and cubic c-In2O3, while formation of hexagonal h-In2O3 requires thermal decomposition of InOOH. The in situ X-ray scattering data reveal new phase transformations from In(OH)3 to InOOH, and from InOOH to c-In2O3. Interestingly, solvothermal synthesis conditions facilitate different reactions mechanisms than dry powder calcinations, and both In(OH)3 and InOOH have different transformations under dry and wet conditions. This journal is.