Anion Exchange Membranes Based on Chemical Modification of Recycled PET Bottles.

This study presents an innovative and effective solution for recycling PET bottles as raw for producing anion exchange membranes (AEMs) for electrochemical applications. This approach reduces the demand for pristine materials, a key principle of the circular economy and sustainability. PET was subjected to chemical modification by introducing cationic functional groups followed by methylation and OH exchange process.

X-ray powder diffraction in education. Part II. Intensity of a powder pattern.

This article is the second part of a series dealing with the description and visualization of mathematical functions used to describe a powder diffraction pattern for teaching and education purposes. The first part dealt with the instrumental and sample contributions to the profile of a Bragg peak [Dinnebier & Scardi (2021 ▸). , 1811-1831].

Water Uptake in an Anion Exchange Membrane Based on Polyamine: A First-Principles Study.

An atomistic level study of a single monomer of polyamine interacting with water molecules and hydroxide anions (OH) was carried out to investigate the role of the polyamine structure in the hydrated morphology of anion exchange membranes (AEMs) for alkaline fuel cells and its influence on ionic conductivity and chemical stability. DFT calculations were performed to find the ground state of the system, studying the interactions of the solvent species with three different regions of the polymer─the amine functional group, the backbone, and the carbonyl group. The hydrophilic/hydrophobic behavior of each segment was determined, with calculated binding energies and Bader charge analysis providing a more quantitative analysis of the interactions and activation and reaction energies computed to investigate the chemical degradation mechanism.

First principles study of SnX(X = S, Se) and Janus SnSSe monolayer for thermoelectric applications.

Tin-based chalcogenides are of increasing interest for thermoelectric applications owing to their low-cost, earth-abundant, and environmentally friendly nature. This is especially true for 2D materials, in which breaking of the structural symmetry plays a crucial role in tuning the electronic properties. 2D materials present a unique opportunity to manipulate the electronic and thermal properties by transforming a monolayer into a Janus monolayer.

Static and dynamic components of Debye-Waller coefficients in the novel cubic polymorph of low-temperature disordered CuZnSnS.

CuZnSnS (CZTS) is an attractive material for sustainable photovoltaics and thermoelectrics, and several properties originate from its marked polymorphism. High-energy mechanical alloying is found to lead to a disordered phase that possesses a sphalerite-like cubic structure. This is investigated in detail with the aid of laboratory and synchrotron radiation X-ray diffraction, Raman spectroscopy, electron microscopy and molecular dynamics.

Effects of Preparation Procedures and Porosity on Thermoelectric Bulk Samples of CuSnS (CTS).

The thermoelectric behavior and stability of CuSnS (CTS) has been investigated in relation to different preparations and sintering conditions, leading to different microstructures and porosities. The studied system is CTS in its cubic polymorph, produced in powder form via a bottom-up approach based on high-energy reactive milling. The as-milled powder was sintered in two batches with different synthesis conditions to produce bulk CTS samples: manual cold pressing followed by traditional sintering (TS), or open die pressing (ODP).

X-ray powder diffraction in education. Part I. Bragg peak profiles.

A collection of scholarly scripts dealing with the mathematics and physics of peak profile functions in X-ray powder diffraction has been written using the Wolfram language in . Common distribution functions, the concept of convolution in real and Fourier space, instrumental aberrations, and microstructural effects are visualized in an interactive manner and explained in detail. This paper is the first part of a series dealing with the mathematical description of powder diffraction patterns for teaching and education purposes.

Topological Anderson Insulator in Cation-Disordered CuZnSnS.

We present the first candidate for the realization of a disorder-induced Topological Anderson Insulator in a real material system. High-energy reactive mechanical alloying produces a polymorph of CuZnSnS with high cation disorder. Density functional theory calculations show an inverted ordering of bands at the Brillouin zone center for this polymorph, which is in contrast to its ordered phase.

Effect of High-Energy Milling on the Dissolution of Anti-HIV Drug Efavirenz in Different Solvents.

The anti-HIV drug efavirenz (EFV) displays low and variable bioavailability because of its poor aqueous solubility. Ball milling is a simple and cost-effective alternative to traditional micronization to improve the solubility and dissolution rate of EFV. A multibody dynamics model was employed to optimize the milling process parameters, while the motion of the balls in the mill jar was monitored .

Diffraction line profiles from polydisperse crystalline systems. Corrigenda.

Equation (16) and some entries in Table 1 in the article by Scardi & Leoni [(2001), Acta Cryst. A57, 604-613] are corrected.

Large-Area Nanocrystalline Caesium Lead Chloride Thin Films: A Focus on the Exciton Recombination Dynamics.

Caesium lead halide perovskites were recently demonstrated to be a relevant class of semiconductors for photonics and optoelectronics. Unlike CsPbBr and CsPbI, the realization of high-quality thin films of CsPbCl, particularly interesting for highly efficient white LEDs when coupled to converting phosphors, is still a very demanding task. In this work we report the first successful deposition of nanocrystalline CsPbCl thin films (70-150 nm) by radio frequency magnetron sputtering on large-area substrates.

Surface softening in palladium nanoparticles: effects of a capping agent on vibrational properties.

The presence of a capping agent (CTAB) on Pd nanoparticles produces a strong static disorder in the surface region. This results in a surface softening, which contributes to an overall increase in the Debye-Waller coefficient measured by X-ray powder diffraction. Molecular dynamics and density functional theory simulations show that the adsorption-induced surface disorder is strong enough to overcome the effects of nanoparticle size and shape.

Synthesis and Post-Annealing of CuZnSnS Absorber Layers Based on Oleylamine/1-dodecanethiol.

CuZnSnS (CZTS) nanocrystals in oleylamine (OLA) and 1-dodecanethiol (1-DDT) solvents were successfully prepared via hot-injection method, to produce inks for the deposition of absorber layers in photovoltaic cells. In this process, 1-DDT acts as a coordinating ligand to control the nucleation and growth of CZTS nanocrystals, whereas lower amounts of OLA promote a homogeneous growth of the grains in the absorber layer. X-Ray Diffraction (XRD) revealed both tetragonal and hexagonal phases of CTZS in films obtained after soft thermal treatments (labeled TT0).

Solution-Based Synthesis and Characterization of CuZnSnS (CZTS) Thin Films.

CuZnSnS (CZTS) ink was synthesized from metal chloride precursors, sulfur, and oleylamine (OLA), as a ligand by a simple and low-cost hot-injection method. Thin films of CZTS were then prepared by spin coating, followed by thermal annealing. The effects of the fabrication parameters, such as ink concentration, spinning rate, and thermal treatment temperatures on the morphology and structural, optical, and electrical properties of the films were investigated.

The Impact of Shear and Elongational Forces on Structural Formation of Polyacrylonitrile/Carbon Nanotubes Composite Fibers during Wet Spinning Process.

Wet spinning of polyacrylonitrile/carbon nanotubes (PAN/CNT) composite fibers was studied and the effect of spinning conditions on structure and properties of as-spun fibers influenced by the presence of CNTs investigated. Unlike PAN fibers, shear force had a larger effect on crystalline structure and physical and mechanical properties of PAN/CNT composite fibers compared to the elongational force inside a coagulation bath. Under shear force CNTs induced nucleation of new crystals, whereas under elongational force nucleation of new crystals were hindered but the already formed crystals grew bigger.

A comparative study of the mechanical properties of a dinosaur and crocodile fossil teeth.

Vertebrate teeth are complex structures adapted in terms of shape and structure to serve a variety of functions like biting and grinding. Thus, examining the morphology, composition and mechanical properties of the teeth can aid in providing insights into the feeding behaviour of extinct species. We here provide the first mechanical characterisation of teeth in a spinosaurid dinosaur, Suchomimus tenerensis, and a pholidosaurid crocodylomorph, Sarcosuchus imperator.

Effect of the Order-Disorder Transition on the Seebeck Coefficient of Nanostructured Thermoelectric CuZnSnS.

Bulk samples of kesterite (CuZnSnS, CZTS) were produced by cold-pressing and sintering of CZTS powders obtained via reactive ball-milling. An increase in the Seebeck coefficient of more than 100 μV/K, almost doubling the expected value, is noticed around a temperature of 260 °C. As pointed out by thermal analyses, this is due to a second order transition of kesterite from an ordered I-4 to a disordered I-42m crystal structure.

Vibrational Properties of Pd Nanocubes.

The atomic disorder and the vibrational properties of Pd nanocubes have been studied through a combined use of X-ray diffraction and molecular dynamics simulations. The latter show that the trend of the mean square relative displacement as a function of the radius of the coordination shells is characteristic of the nanoparticle shape and can be described by a combined model: A correlated Debye model for the thermal displacement and a parametric expression for the static disorder. This combined model, supplemented by results of line profile analysis of the diffraction patterns collected at different temperatures (100, 200, and 300 K) can explain the observed increase in the Debye-Waller coefficient, and shed light on the effect of the finite domain size and of the atomic disorder on the vibrational properties of metal nanocrystals.

Understanding the instrumental profile of synchrotron radiation X-ray powder diffraction beamlines.

A Monte Carlo algorithm has been developed to calculate the instrumental profile function of a powder diffraction synchrotron beamline. Realistic models of all optical elements are implemented in a ray-tracing software. The proposed approach and the emerging paradigm have been investigated and verified for several existing X-ray powder diffraction beamlines.

100 years of Debye's scattering equation.

Debye's scattering equation (DSE) has spanned a century of scientific development, from the dawn of quantum mechanics and the investigation of the structure of atoms and molecules to the era of nanotechnology, paving the way to total scattering methods. The formulation offers the most accurate representation of the intensity scattered by randomly oriented atomic aggregates, constructed by superimposing the signal from each atomic distance in the molecule. The present paper reviews some of the milestone applications, from the interpretation of the intensity curves from gases and vapours, to aggregates of increasing size and more extended order.

Celebrating 100 years of the Debye scattering equation.

One hundred years of the Debye scattering equation are celebrated with a series of articles arising from the DSE 2015 conference.

On the reliability of powder diffraction Line Profile Analysis of plastically deformed nanocrystalline systems.

An iron-molybdenum alloy powder was extensively deformed by high energy milling, so to refine the bcc iron domain size to nanometer scale (~10 nm) and introduce a strong inhomogeneous strain. Both features contribute to comparable degree to the diffraction peak profile broadening, so that size and strain contributions can be easily separated by exploiting their different dependence on the diffraction angle. To assess the reliability of Line Profile Analysis, results were compared with evidence from other techniques, including scanning and transmission electron microscopy and X-ray small angle scattering.