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Nanomaterials (Basel, Switzerland) Feb 2021Eu(OH) with various shape-controlled morphologies and size, such as plate, rod, tube, prism and nanoparticles was successfully synthesized through simple hydrothermal...
Eu(OH) with various shape-controlled morphologies and size, such as plate, rod, tube, prism and nanoparticles was successfully synthesized through simple hydrothermal reactions. The products were characterized by XRD (X-Ray Powder Diffraction), FE-SEM (Field Emission- Scanning Electron Microscopy) and TG (Thermogravimetry). The influence of the initial pH value of the starting solution and reaction temperature on the crystalline phase and morphology of the hydrothermal products was investigated. A possible formation process to control morphologies and size of europium products by changing the hydrothermal temperature and initial pH value of the starting solution was proposed.
PubMed: 33669535
DOI: 10.3390/nano11020529 -
Acta Crystallographica. Section E,... Oct 2020Polycrystalline potassium nickel(II) hafnium(IV) tris-(orthophosphate), a langbeinite-type phosphate, was synthesized by a solid-state method. The three-dimensional...
Polycrystalline potassium nickel(II) hafnium(IV) tris-(orthophosphate), a langbeinite-type phosphate, was synthesized by a solid-state method. The three-dimensional framework of the title compound is built up from two types of [O] octa-hedra [the sites are occupied by Hf:Ni in ratios of 0.754 (8):0.246 (8) and 0.746 (8):0.254 (8), respectively] and [PO] tetra-hedra are connected O vertices. The K cations are located in two positions within large cavities of the framework, having coordination numbers of 9 and 12. The Hf, Ni and K sites lie on threefold rotation axes, while the P and O atoms are situated in general positions.
PubMed: 33117578
DOI: 10.1107/S2056989020012062 -
Acta Crystallographica. Section C,... Feb 2022The crystal structure of cynarine monohydrate (systematic name: 1,3-bis{[(E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy}-4,5-dihydroxycyclohexane-1-carboxylic acid...
The crystal structure of cynarine monohydrate (systematic name: 1,3-bis{[(E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy}-4,5-dihydroxycyclohexane-1-carboxylic acid monohydrate), CHO·HO, has been solved and refined using synchrotron powder X-ray diffraction data, and optimized using density functional techniques. Despite being purchased as anhydrous, cynarine crystallizes as a monohydrate and the crystal structure is characterized by alternating layers of hydrocarbon and hydrogen-bonding interactions parallel to the bc plane. Hydrogen bonds are significant in the crystal structure. The carboxylic acid group forms a strong intermolecular hydrogen bond to a hydroxy group of the quinic acid ring. Most of the hydroxy groups act as donors in O-H...O hydrogen bonding to carbonyl O atoms. One hydroxy group participates in bifurcated hydrogen bonds, one to a hydroxy group on the quinic acid ring and the other, an intramolecular interaction, to another hydroxy group. The powder pattern has been submitted to the International Centre for Diffraction Data (ICDD) for inclusion in the Powder Diffraction File (PDF-4).
Topics: Cinnamates; Crystallography, X-Ray; Hydrogen Bonding; Powder Diffraction; Powders; Synchrotrons; X-Ray Diffraction
PubMed: 35119388
DOI: 10.1107/S2053229622000687 -
RSC Advances Aug 2019A comparative X-ray powder diffraction study on poly(-vinyl pyrrolidone) (PVP)-stabilized palladium and gold nanoparticles and bimetallic Pd-Au nanoparticles (both types...
A comparative X-ray powder diffraction study on poly(-vinyl pyrrolidone) (PVP)-stabilized palladium and gold nanoparticles and bimetallic Pd-Au nanoparticles (both types of core-shell nanostructures) was performed. The average diameter of Au and Pd nanoparticles was 5 to 6 nm. The two types of core-shell particles had a core diameter of 5 to 6 nm and an overall diameter of 7 to 8 nm, a shell thickness of 1 to 2 nm. X-ray powder diffraction on a laboratory instrument was able to distinguish between a physical mixture of gold and palladium nanoparticles and bimetallic core-shell nanoparticles. It was also possible to separate the core from the shell in both kinds of bimetallic core-shell nanoparticles due to the different domain size and because it was known which metal was in the core and which was in the shell. The spherical particles were synthesized by reduction with glucose in aqueous media. After purification by multiple centrifugation steps, the particles were characterized with respect to their structural, colloid-chemical, and spectroscopic properties, particle size, morphology, and internal elemental distribution. Dynamic light scattering (DLS), differential centrifugal sedimentation (DCS), atomic absorption spectroscopy (AAS), ultraviolet-visible spectroscopy (UV-vis), high-angle annular dark field imaging (HAADF), and energy-dispersed X-ray spectroscopy (EDX) were applied for particle characterization.
PubMed: 35528588
DOI: 10.1039/c9ra05117a -
Molecules (Basel, Switzerland) Dec 2021X-ray powder diffraction (XRPD) and thermal analysis (differential scanning calorimetry/derivative of thermogravimetry (DSC/DTG)) are solid-state techniques that can be...
X-ray powder diffraction (XRPD) and thermal analysis (differential scanning calorimetry/derivative of thermogravimetry (DSC/DTG)) are solid-state techniques that can be successfully used to identify and quantify various chemical compounds in polycrystalline mixtures, such as dietary supplements or drugs. In this work, 31 dietary supplements available on the Polish market that contain iron compounds, namely iron gluconate, fumarate, bisglycinate, citrate and pyrophosphate, were evaluated. The aim of the work was to identify iron compounds declared by the manufacturer as food supplements and to try to verify compliance with the manufacturer's claims. Studies performed by X-ray and thermal analysis confirmed that crystalline iron compounds (iron (II) gluconate, iron (II) fumarate), declared by the manufacturers, were present in the investigated dietary supplements. Iron (II) bisglycinate proved to be semi-crystalline. However, depending on the composition of the formulation, it was possible to identify this compound in the tested supplements. For amorphous iron compounds (iron (III) citrate and iron (III) pyrophosphate), the diffraction pattern does not have characteristic diffraction lines. Food supplements containing crystalline iron compounds have a melting point close to the melting point of pure iron compounds. The presence of excipients was found to affect the shapes and positions of the endothermic peaks significantly. Widening of endothermic peaks and changes in their position were observed, as well as exothermic peaks indicating crystallization of amorphous compounds. Weight loss was determined for all dietary supplements tested. Analysis of the DTG curves showed that the thermal decomposition of most food supplements takes place in several steps. The results obtained by a combination of both simple, relatively fast and reliable XRPD and DSC/DTG methods are helpful in determining phase composition, pharmaceutical abnormalities or by detecting the presence of the correct polymorphic form.
Topics: Calorimetry, Differential Scanning; Dietary Supplements; Diphosphates; Fumarates; Gluconates; Iron; Thermogravimetry; X-Ray Diffraction
PubMed: 35011434
DOI: 10.3390/molecules27010197 -
Acta Crystallographica. Section A,... Sep 2023The local structural characterization of iron oxide nanoparticles is explored using a total scattering analysis method known as pair distribution function (PDF) (also...
The local structural characterization of iron oxide nanoparticles is explored using a total scattering analysis method known as pair distribution function (PDF) (also known as reduced density function) analysis. The PDF profiles are derived from background-corrected powder electron diffraction patterns (the e-PDF technique). Due to the strong Coulombic interaction between the electron beam and the sample, electron diffraction generally leads to multiple scattering, causing redistribution of intensities towards higher scattering angles and an increased background in the diffraction profile. In addition to this, the electron-specimen interaction gives rise to an undesirable inelastic scattering signal that contributes primarily to the background. The present work demonstrates the efficacy of a pre-treatment of the underlying complex background function, which is a combination of both incoherent multiple and inelastic scatterings that cannot be identical for different electron beam energies. Therefore, two different background subtraction approaches are proposed for the electron diffraction patterns acquired at 80 kV and 300 kV beam energies. From the least-square refinement (small-box modelling), both approaches are found to be very promising, leading to a successful implementation of the e-PDF technique to study the local structure of the considered nanomaterial.
PubMed: 37490406
DOI: 10.1107/S2053273323005107 -
Chemistry (Weinheim An Der Bergstrasse,... Nov 2023A Mn(II) salt and A CN under anaerobic conditions react to form 2-D and 3-D extended structured compounds of A Mn (CN) stoichiometry. Here, the creation and... (Review)
Review
Cation Adaptive Structures Based on Manganese Cyanide Prussian Blue Analogues: Application of Powder Diffraction Data to Solve Complex, Unprecedented Stoichiometries and New Structure Types.
A Mn(II) salt and A CN under anaerobic conditions react to form 2-D and 3-D extended structured compounds of A Mn (CN) stoichiometry. Here, the creation and characterization of this large family of compounds, for example AMn (CN) , A Mn (CN) , A Mn (CN) , A Mn (CN) , and A Mn [Mn (CN) ], where A represents alkali and tetraalkylammonium cations, is reviewed. Cs Mn [Mn (CN) ] has the typical Prussian blue face centered cubic unit cell. However, the other alkali salts are monoclinic or rhombohedral. This is in accord with smaller alkali cation radii creating void space that is minimized by increasing the van der Waals stabilization energy by reducing ∠Mn-N≡C, which, strengthens the magnetic coupling and increases the magnetic ordering temperatures. This is attributed to the non-rigidity of the framework structure due the significant ionic character associated with the high-spin Mn sites. For larger tetraalkylammonium cations, the high-spin Mn sites lack sufficient electrostatic A ⋅⋅⋅NC stabilization and form unexpected 4- and 5-coordinated Mn sites within a flexible, extended framework around the cation; hence, the size, shape, and charge of the cation dictate the unprecedented stoichio-metry and unpredictable cation adaptive structures. Antiferromagnetic coupling between adjacent Mn sites leads to ferrimagnetic ordering, but in some cases antiferromagnetic coupling of ferrimagnetic layers are compensated and synthetic antiferromagnets are observed. The magnetic ordering temperatures for ferrimagnetic A Mn [Mn (CN) ] with both octahedral high- and low-spin Mn sites increase with decreasing ∠Mn-N≡C. The crystal structures for all of the extended structured materials were obtained by powder diffraction.
PubMed: 37572364
DOI: 10.1002/chem.202302136 -
Materials (Basel, Switzerland) Nov 2021Cement hydration is a very complex set of processes. The evolution of the crystalline phases during hydration can be accurately followed by X-ray powder diffraction data...
Cement hydration is a very complex set of processes. The evolution of the crystalline phases during hydration can be accurately followed by X-ray powder diffraction data evaluated by the Rietveld method. However, accurate measurements of some microstructural features, including porosity and amorphous content developments, are more challenging. Here, we combine laboratory X-ray powder diffraction and computed microtomography (μCT) to better understand the results of the μCT analyses. Two pastes with different water-cement ratios, 0.45 and 0.65, filled within capillaries of two sizes, ϕ = 0.5 and 1.0 mm, were analysed at 50 days of hydration. It was shown that within the spatial resolution of the measured μCTs, ~2 μm, the water capillary porosity was segmented within the hydrated component fraction. The unhydrated part could be accurately quantified within 2 vol% error. This work is a first step to accurately determining selected hydration features like the hydration degree of amorphous phases of supplementary cementitious materials within cement blends.
PubMed: 34832365
DOI: 10.3390/ma14226953 -
ACS Applied Materials & Interfaces Jul 2022To explore an effective route of customizing the superelasticity (SE) of NiTi shape memory alloys via modifying the grain structure, binary NiTi (wt) alloys were...
To explore an effective route of customizing the superelasticity (SE) of NiTi shape memory alloys via modifying the grain structure, binary NiTi (wt) alloys were fabricated in as-cast, hot swaged, and hot-rolled conditions, presenting contrasting grain sizes and grain boundary types. synchrotron X-ray Laue microdiffraction and synchrotron X-ray powder diffraction techniques were employed to unravel the underlying grain structure mechanisms that cause the diversity of SE performance among the three materials. The evolution of lattice rotation, strain field, and phase transformation has been revealed at the micro- and mesoscale, and the effect of grain structure on SE performance has been quantified. It was found that (i) the NiTi and NiTi precipitates are similar among the three materials in terms of morphology, size, and orientation distribution; (ii) phase transformation happens preferentially near high-angle grain boundary (HAGB) yet randomly in low-angle grain boundary (LAGB) structures; (iii) the smaller the grain size, the higher the phase transformation nucleation kinetics, and the lower the propagation kinetics; (iv) stress concentration happens near HAGBs, while no obvious stress concentration can be observed in the LAGB grain structure during loading; (v) the statistical distribution of strain in the three materials becomes asymmetric during loading; (vi) three grain lattice rotation modes are identified and termed for the first time, namely, multi-extension rotation, rigid rotation, and nondispersive rotation; and (vii) the texture evolution of B2 austenite and B19' martensite is not strongly dependent on the grain structure.
PubMed: 35759353
DOI: 10.1021/acsami.2c05939 -
Journal of the American Chemical Society Jul 2022The development of materials showing rapid proton conduction with a low activation energy and stable performance over a wide temperature range is an important and...
The development of materials showing rapid proton conduction with a low activation energy and stable performance over a wide temperature range is an important and challenging line of research. Here, we report confinement of sulfuric acid within porous MFM-300(Cr) to give MFM-300(Cr)·SO(HO), which exhibits a record-low activation energy of 0.04 eV, resulting in stable proton conductivity between 25 and 80 °C of >10 S cm. synchrotron X-ray powder diffraction (SXPD), neutron powder diffraction (NPD), quasielastic neutron scattering (QENS), and molecular dynamics (MD) simulation reveal the pathways of proton transport and the molecular mechanism of proton diffusion within the pores. Confined sulfuric acid species together with adsorbed water molecules play a critical role in promoting the proton transfer through this robust network to afford a material in which proton conductivity is almost temperature-independent.
PubMed: 35775201
DOI: 10.1021/jacs.2c04900