Amorphous Crystalline Research Articles

Antibacterial Amorphous–Crystalline Coatings Based on Wollastonite and ZnO Particles

Antibacterial Amorphous–Crystalline Coatings Based on Wollastonite and ZnO Particles

B-281 Performance Characteristics Evaluation of the ARK Diagnostics Immunoassay for Xylazine/4-HydroxyXylazine in Urine

Abstract Background Xylazine exposure is currently common in some US cities, but routine laboratory testing is not available. We evaluated the ARK Diagnostics immunoassay for qualitative detection of xylazine/4-hydroxy Xylazine in urine, prior to its anticipated release as a Forensic Use Only assay. Evaluation of performance characteristics of the ARK assay were conducted at two university hospitals, using either the semi-quantitative application of the assay, as performed on the Roche Cobas 503 analyzer (Institution A), or the qualitative application of the assay, as performed on the Beckman Coulter AU480 analyzer (Institution B). Methods Xylazine (X) and 4-hydroxy Xylazine (4-OHX) were obtained from Cayman Chemical (Ann Arbor, MI). Pooled xylazine-free urine was spiked either with X or 4-OHX in the range of 0-2000 ng/mL. De-identified, to-be-discarded patient urine samples were obtained from among those submitted for routine drugs-of-abuse panel testing. X measurements on all samples were performed by LC-MS/MS; samples were segregated into X-NEGATIVE (X<10 ng/mL) and X-POSITIVE (X>=10 ng/mL). The ARK assay was conducted according to manufacturer’s instructions, either as a semi-quantitative assay (Institution A, Roche analyzer) or as a qualitative assay (Institution B, Beckman Coulter analyzer), with 10 ng/mL as the manufacturer-specified cutoff for ARK POSITIVE, using manufacturer-supplied calibration standards ranging from 0-500 ng/mL X. Results The ARK semi-quantitative analysis (Roche analyzer) showed essentially equivalent curvilinear response curves for either X or 4-OHX at concentrations below 1000 ng/mL; for the semi-quantitative ARK assay, we use “>1200 ng/mL” for X-ARK >1200 ng/mL. By mixing studies (Roche), there were neither positive nor negative interferences observed as assessed for common drugs of abuse or for common therapeutic drugs. The presence of hemoglobin, bilirubin or moderate lipemia were devoid of assay interference. Precision studies for manufacturer-supplied controls were as follows: intra-assay CVs were 6.9% for the NEGATIVE control (5.1±0.35 ng/mL) and 5.9% for the POSITIVE control (15.7±0.53 ng/mL) (n=20); interassay CVs were 7.8% for the NEGATIVE control (5.1±0.40 ng/mL) and 5.7% for the POSITIVE control (15.9±0.90 ng/mL) (n=20). For the qualitative ARK assay as performed on the Beckman analyzer, POSITIVE and NEGATIVE controls ran invariably according to their designations. For the semi-quantitative assay application (Roche analyzer): among 78 X-NEGATIVE samples by LC-MS/MS, there were 0% ARK-POSITIVE results (false-positive rate=0%); among 74 X-POSITIVE samples by LC-MS/MS, there was one ARK-NEGATIVE result (false-negative rate=1.4%); this sample (X=65 ng/mL) was found to have a high amorphous crystalline content, and was unable to be reanalyzed. For the qualitative assay application (Beckman Coulter analyzer): among 78 X-NEGATIVE samples there was one ARK-POSITIVE sample (false-positive rate=1.3%) for a sample with xylazine=8.8 ng/mL by LC-MS/MS, with undetectable 4-OHX (<10 ng/mL); among 74 X-POSITIVE samples, there were no ARK-NEGATIVE results (false-negative rate=0%). Conclusions The ARK xylazine immunoassay demonstrated acceptable analytical performance with respect to detection of xylazine in urine at 10 ng/mL. With additional consideration of the assay’s cross reactivity with the major xylazine metabolite, 4-OH-xylazine, the assay was judged to be highly suitable for routine use as a screening test for detection of xylazine exposure via urine testing.

Crystallization Kinetics of Crystalline–Crystalline and Crystalline–Amorphous Block Copolymers of Linear Polyethylene and Isotactic Polypropylene

Crystallization Kinetics of Crystalline–Crystalline and Crystalline–Amorphous Block Copolymers of Linear Polyethylene and Isotactic Polypropylene

Dual Polarization of Ni Sites at VOx-Ni3N Interface Boosts Ethanol Oxidation Reaction.

Substituting thermodynamically favorable ethanol oxidation reaction (EOR) for oxygen evolution reaction (OER) engenders high-efficiency hydrogen production and generates high value-added products as well. However, the main obstacles have been the low activity and the absence of an explicit catalytic mechanism. Herein, a heterostructure composed of amorphous vanadium oxide and crystalline nickel nitride (VOx-Ni3N) is developed. The heterostructure immensely boosts the EOR process, achieving the current density of 50mA cm-2 at the low potential of 1.38V versus reversible hydrogen electrode (RHE), far surpassing the sluggish OER (1.65V vs RHE). Electrochemical impedance spectroscopy indicates that the as-fabricated heterostructure can promote the adsorption of OH- and the generation of the reactive species (O*). Theoretical calculations further outline the dual polarization of the Ni site at the interface, specifically the asymmetric charge redistribution (interfacial polarization) and in-plane polarization. Consequently, the dual polarization modulates the d-band center, which in turn regulates the adsorption/desorption strength of key reaction intermediates, thereby facilitating the entire EOR process. Moreover, a VOx-Ni3N-based electrolyzer, coupling hydrogen evolution reaction (HER) and EOR, attains 50mA cm-2 at a low cell voltage of ≈1.5V. This work thus paves the way for creating dual polarization through interface engineering toward broad catalysis.

Mechanochemical Synthesis of Sodium-Ion Conducting Chloride NaTaCl6

All-solid-state sodium batteries have been attracting attentions owing to their high energy density and safety. Solid electrolytes play a significant role in the electrochemical performances of all-solid-state batteries. Chloride-based solid electrolytes are particularly important for achieving high energy densities because of their high oxidation stability, ionic conductivity, and formability. Fewer sodium-ion conducting chlorides have been developed compared to lithium-ion conducting materials. It is necessary to discover the chlorides as the end-member of sodium-ion conductors. In this study, we report the development of a new NaTaCl6 chloride as an end-member sodium-ion conductor with high ionic conductivity. NaTaCl6 sample was mechanically prepared using a planetary ball mill apparatus. The X-ray diffraction patterns of the obtained sample displayed a broad pattern similar to the reported NaTaCl6 (ICSD#36519), suggesting that the sample contains both amorphous and crystalline phases. The reference intensity ratio method was used to investigate the weight ratios of the amorphous phases in the sample. The ratio was approximately 45 %. Transmission electron microscopy observations suggested that the sample consisted of the amorphous matrix and crystalline with the crystallite size of approximately 20 nm. The electrical conductivities of the pelletized samples were measured using two-terminal AC electrochemical impedance spectroscopy. The sample pellets were prepared by uniaxial pressing at 360 MPa without heat treatment. The pellet sample had the relative density of 85 % (powder density: 3.32 g cm–3, pellet density: 2.83 g cm–3). The sample shows σ 25ºC of 6.2×10–5 S cm–1, and the activation energy of 0.37 eV. To determine the NaTaCl6 onset oxidation voltage (OOV), linear sweep voltammetry measurement was carried out. The OOV of the sample at 60 ºC was 3.8 V vs. Na15Sn4. To demonstrate the high oxidation stability of NaTaCl6 in all-solid-state sodium batteries, it was used in a positive electrode by mixing Na3V2(PO4)3 as the active material and the buffer layer. The cell exhibited an initial reversible capacity of 96 mAh g–1 and stable cycling after 40 cycles with the capacity retention of 99.5 %. A 3.3 V all-solid-state sodium battery without oxide solid electrolytes was successfully operated. In this study, the NaTaCl6 electrolyte was developed with a high ionic conductivity and oxidation stability.Acknowledgement: This work was partly supported by JSPS KAKENHI (Grant Numbers: JP21H04701 and JP19H05816) and MEXT Program: Data Creation and Utilization-Type Material Research and Development Project Grant Number JPMXP1122712807.

Enhancing Charge Storage of Anatase Nanoparticles through Pseudocapacitance in Amorphous–Crystalline–Amorphous Architectures

Enhancing Charge Storage of Anatase Nanoparticles through Pseudocapacitance in Amorphous–Crystalline–Amorphous Architectures

Influence of the Content of Ni as Minority Alloying Element on the Microstructure and Mechanical Properties of Amorphous and Ultrafine Crystalline Al-Cu-Mg-Ni Alloys

Influence of the Content of Ni as Minority Alloying Element on the Microstructure and Mechanical Properties of Amorphous and Ultrafine Crystalline Al-Cu-Mg-Ni Alloys

Polyoxometalate based ionic liquids reinforced on magnetic nanoparticles: A sustainable solution for microplastics and heavy metal ions elimination from water

To purify water from contaminents is essential for life on universe. Here, in this manuscript we introduces an innovative approach to overcome the intricate challenge of eliminating heavy metal ions and microplastics from water. We designed a mesoporous composite materials by synergistically integrating polyoxometalates (POMs) based ionic liquids with silica coated magnetic nanoparticles. The synthesis process initiates with the utilization of highly reduced molybdenum aggregates in polyoxometalate-ionic liquids, reinforced onto magnetic nanoparticles (POM–IL–MNPs). Crafted composites, including Q8[Mo64Ni8La6]@SiO2@Fe3O4, Q10[Mo64Ni8La6]@SiO2@Fe3O4, Q8[Mo176/Mo248]@SiO2@Fe3O4, and Q10[Mo176/Mo248]@SiO2@Fe3O4, are meticulously designed by substituting POM counter cations with long-chain alkyl-based quaternary ammonium salts. The ionic liquids and composites exhibit remarkable hydrophobicity and thermal stability due to large anions and long-chain organic counter cations. Comprehensive characterization, including FT–IR, UV–vis spectroscopy, TGA, DSC, CV, rheological study, elemental analysis, and ICP-AES, ensures a thorough investigation. Additional analyses, such as Powder X-ray diffraction (PXRD), SEM, EDX, DLS, N2 adsorption, and VSM, reveal amorphous crystallinity, distinctive surface morphology, and substantial specific surface area. Core shell structure of POM-IL-MNPs was determined by Transmision electron microscope (TEM), ICP-AES analysis demonstrates metal ion removal efficiencies from 87.35% to 99.98%, with DLS confirming 100% efficiency in PVC beads elimination. This research not only advances water decontamination but also provides valuable insights into designing and characterizing novel materials with promising environmental applications.

Flash viscous flow sintering of nanostructured amorphous ZrO2–Y2O3 composite ceramics starting from a partially amorphous precursor powder

Nanostructured amorphous composites are novel materials comprising nano-sized crystal phases embedded in an amorphous matrix, but often necessitating ultra-high-pressure molding for preparation. In this study, nanostructured amorphous ZrO2–Y2O3 composite ceramics were rapidly prepared for the first time using flash viscous flow sintering without the application of pressure. The relative density of the ZY ceramics increased with increasing current density, and ZY composite ceramics with relative density of 86%–97 % were prepared by FS in a short time of 60 s under 700 V/cm with 0.16–0.56 A/cm2. Furthermore, the sintering activities in FS were compared between partially amorphous powder and crystalline powder. The ceramics prepared by flash sintering of partially amorphous powder show a much higher relative density than that from crystalline powder, suggesting that partially amorphous powder achieves easier densification than crystalline powder in flash sintering under given current density and power dissipation. This phenomenon was attributable to the differing sintering mechanisms between the two materials, i.e., solid-state sintering for crystalline powder and viscous flow sintering for partially amorphous powder.

Investigation of Cu-Sn-Sb Thin Film for Ultra-Speed and Phase High-Reliability Change Memory Applications

SnSb (SS), a vital phase-change thin film, has attracted attention due to its excellent phase-change properties, but the poor amorphous stability and crystalline speed of SS greatly limit its application in rapid phase-transition memories. Here, we propose a copper (Cu)-doped SS phase change films to achieve ultra-speed and high-reliability of SS. Resistance-temperature tests show Cu-Sn-Sb possesses ultra-low crystalline and amorphous resistivity, higher phase transition speed, and lower activation energy. X-ray diffraction measurements illustrate the introduction of Cu ions hinders the growth of grains and reduce grains size. Atomic force microscopy characterizes the surface morphology of as-deposited and annealed Cu-Sn-Sb films, and difference of root-mean-square roughness before and after annealing promote Cu-Sn-Sb film is more reliable to touch electrodes. In addition, the ultra-low resistivity and fast transition speed effectively reduce thermal loss in SET and RESET process. The results reveal that Cu-Sn-Sb is a promising material for ultra-rapid phase change and high-reliability storage applications.

Thermodynamic analysis of cellulose nitration

In this study, the standard formation enthalpies and entropies of cellulose and nitrocellulose samples were determined. These characteristics were used for thermodynamic analysis of bulk nitration of the entire cellulose sample and local nitration only of amorphous domains (ADs) of cellulose. It was found that the reaction of bulk nitration of cellulose up to a substitution degree (DS) of 1.5 is endothermic and determined primarily by the contribution of the temperature-entropy component to the negative Gibbs potential. However, if DS is higher than 1.5, the bulk nitration becomes exothermic and its feasibility is determined by the impact of enthalpy on the Gibbs potential. In the case of local nitration of cellulose ADs, the main contribution to the Gibbs potential is made by the reaction enthalpy that determines the feasibility of this process. It was shown that with the enhancement in DS of nitrocellulose, the negative value of the Gibbs potential of the reaction increases. Thus, the cellulose nitration to higher DS is thermodynamically favorable. Since the locally nitrated samples are copolymers of amorphous nitrocellulose and crystalline cellulose, they should be significantly less hydrophilic than cellulose. Therefore, it can be expected that the local nitration method will find a wide practical application for inexpensive hydrophobization of cellulose materials.

Constructing Amorphous-Crystalline Interfacial Bifunctional Site Island-Sea Synergy by Morphology Engineering Boosts Alkaline Seawater Hydrogen Evolution.

The development of efficient and durable non-precious hydrogen evolution reaction (HER) catalysts for scaling up alkaline water/seawater electrolysis is highly desirable but challenging. Amorphous-crystalline (A-C) heterostructures have garnered attention due to their unusual atomic arrangements at hetero-interfaces, highly exposed active sites, and excellent stability. Here, a heterogeneous synthesis strategy for constructing A-C non-homogeneous interfacial centers of electrocatalysts on nanocages is presented. Isolated PdCo clusters on nanoscale islands in conjunction with Co3S4 A-C, functioning as a bifunctional site "island-sea" synergy, enable the dynamic confinement design of metal active atoms, resulting in excellent HER catalytic activity and durability. The hierarchical structure of hollow porous nanocages and nanoclusters, along with their large surface area and multi-dimensional A-C boundaries and defects, provides the catalyst with abundant active centers. Theoretical calculations demonstrate that the combination of PdCo and Co3S4 regulates the redistribution of interface electrons effectively, promoting the sluggish water-dissociation kinetics at the cluster Co sites. Additionally, PdCo-Co3S4heterostructure nanocages exhibit outstanding HER activity in alkaline seawater and long-term stability for 100h, which can be powered by commercial silicon solar cells. This finding significantly advances the development of alkaline seawater electrolysis for large-scale hydrogen production.

Heterogeneous-Structured Molybdenum Diboride as a Novel and Promising Anode for Lithium-Ion Batteries.

With the development of electric vehicles, exploiting anode materials with high capacity and fast charging capability is an urgent requirement for lithium-ion batteries (LIBs). Borophene, with the merits of high capacity, high electronic conductivity and fast diffusion kinetics, holds great potential as anode for LIBs. However, it is difficult to fabricate for the intrinsic electron-deficiency of boron atom. Herein, heterogeneous-structured MoB2 (h-MoB2) with amorphous shell and crystalline core, is prepared by solid phase molten salt method. As demonstrated, crystalline core can encapsulate the honeycomb borophene within two adjacent Mo atoms, and amorphous shell can accommodate more lithium ions to strengthen the lithium storage capacity and diffusion kinetics. According to theoretical calculations, the lithium adsorption energy in MoB2 is about -2.7 eV, and the lithium diffusion energy barrier in MoB2 is calculated to be 0.199 eV, guaranteeing the enhanced adsorption capability and fast diffusion kinetic behavior of Li+ ions. As a result, h-MoB2 anode presents high capacity of 798 mAh g-1 at 0.1 A g-1, excellent rate performance of 183 mAh g-1 at 5 A g-1 and long-term cyclic stability for 1200 cycles. This work may inspire ideas for the fabrication of borophene analogs and two-dimensional metal borides.

Influence of the substrate conductivity type on the electroluminescence properties of PP+IN and PIN+N diodes based on amorphous silicon carbide (a-Si1-xCx:H) / crystalline silicon (c-Si) heterostructures

The study of the conduction and light emission mechanisms of PIN diodes based on amorphous silicon-carbide (a-Si1-xCx:H) thin film and crystalline silicon (c-Si) substrates is reported in this work. Using the same low-temperature process (200 °C), PP+IN and PIN+N structures were fabricated on p-type and n-type silicon (Si) substrates, respectively. The plasma enhanced chemical vapor deposition (PECVD) technique was employed for the active layers deposition where two different CH4/SiH4 flow rates ratios of 30 sccm/6 sccm and 30 sccm/1 sccm were used. All structures show red-orange light emission in forward bias (FB). The structures with the active layer deposited with a lower SiH4 flow rate, display light emission with a higher intensity at a lower voltage bias.In addition, we related the current-voltage measurements with different conduction models and the dominant charge transport mechanisms in the PIN structures were proposed. The highest Si content structures were related to Fowler-Nordheim (F-N) tunneling, because of its active layer with lower barrier height. On the other hand, the lowest Si content structures were associated with the Poole-Frenkel (P-F) emission, due to a higher density of defects in localized tail states. The results showed the same conduction and emission mechanisms for the PP+IN and PIN+N diodes with the same active layer, regardless of the conduction type of substrate, proving that it is feasible to use the same process for developing light emission devices on p-type and n-type Si substrates.

A Coordination-Derived Cerium-Based Amorphous-Crystalline Heterostructure with High Electrocatalytic Oxygen Evolution Activity.

The rational design of heterogeneous catalysts is crucial for achieving optimal physicochemical properties and high electrochemical activity. However, the development of new amorphous-crystalline heterostructures is significantly more challenging than that of the existing crystalline-crystalline heterostructures. To overcome these issues, a coordination-assisted strategy that can help fabricate an amorphous NiO/crystalline NiCeOx (a-NiO/c-NiCeOx) heterostructure is reported herein. The coordination geometry of the organic ligands plays a pivotal role in permitting the formation of coordination polymers with high Ni contents. This consequently provides an opportunity for enabling the supersaturation of Ni in the NiCeOx structure during annealing, leading to the endogenous spillover of Ni from the depths of NiCeOx to its surface. The resulting heterostructure, featuring strongly coupled amorphous NiO and crystalline NiCeOx, exhibits harmonious interactions in addition to low overpotentials and high catalytic stability in the oxygen evolution reaction (OER). Theoretical calculations prove that the amorphous-crystalline interfaces facilitate charge transfer, which plays a critical role in regulating the local electron density of the Ni sites, thereby promoting the adsorption of oxygen-based intermediates on the Ni sites and lowering the dissociation-related energy barriers. Overall, this study underscores the potential of coordinating different metal ions at the molecular level to advance amorphous-crystalline heterostructure design.

Boosting charge transfer via interface charge reconstruction between amorphous NiFe-LDH and crystalline NiCo2O4 for efficient alkaline water/seawater oxidation

Boosting charge transfer via interface charge reconstruction between amorphous NiFe-LDH and crystalline NiCo2O4 for efficient alkaline water/seawater oxidation

Unsupervised machine learning combined with 4D scanning transmission electron microscopy for bimodal nanostructural analysis

Unsupervised machine learning techniques have been combined with scanning transmission electron microscopy (STEM) to enable comprehensive crystal structure analysis with nanometer spatial resolution. In this study, we investigated large-scale data obtained by four-dimensional (4D) STEM using dimensionality reduction techniques such as non-negative matrix factorization (NMF) and hierarchical clustering with various optimization methods. We developed software scripts incorporating knowledge of electron diffraction and STEM imaging for data preprocessing, NMF, and hierarchical clustering. Hierarchical clustering was performed using cross-correlation instead of conventional Euclidean distances, resulting in rotation-corrected diffractions and shift-corrected maps of major components. An experimental analysis was conducted on a high-pressure-annealed metallic glass, Zr-Cu-Al, revealing an amorphous matrix and crystalline precipitates with an average diameter of approximately 7 nm, which were challenging to detect using conventional STEM techniques. Combining 4D-STEM and optimized unsupervised machine learning enables comprehensive bimodal (i.e., spatial and reciprocal) analyses of material nanostructures.

Properties of an amorphous crystalline nanopowder Si–SiO2 produced by pulsed electron beam evaporation

A mesoporous amorphous crystalline nanopowder (NP) Si–SiO2 with a specific surface area (SSA) of 35 m2/g was produced by pulsed electron beam evaporation (PEBE) of a compact of micron commercial SiO2 powder (0.9 m2/g). Si semimetal nanoparticles (NPles) reduced in for vacuum (≈4 Pa) had a marked effect on the thermal and luminescent properties of the Si–SiO2 nanoparticles compared to the properties of amorphous SiO2 NPles produced earlier by PEBE evaporation of a target compound made from NP Aerosil 90 (Degussa). Photocatalytic capabilities of Si–SiO2 nanoparticles were evaluated. NPles Si–SiO2 showed high antioxidant activity on HELA cancer cells.

Atomic Radius Mismatch: A Key Parameter for Design and Synthesis of High‐Entropy Physical Vapor Deposition Coatings—Review

High‐entropy metal sublattice coatings (HESCs) prepared by physical vapor deposition (PVD) have received attention due to their diverse range of properties and applications. One of the most critical requirements for their synthesis is the prediction and control of their widespread properties, and several efforts have been undertaken using various thermodynamical parameters. The majority of these predictions concentrate on high‐entropy alloys (HEAs) while high‐entropy ceramics receive little attention. One of the most important parameters to control the structure and properties of HEAs is their atomic radius mismatch (δr), which is applied to crystalline, amorphous, and composite (amorphous matrix, crystalline matrix, and multilayer) HESCs. Based on the relationships between δr and structure, mixing enthalpy (ΔHmix), electronegativity difference (Δχ), ion bonding percentage (IBPHE), mechanical properties (including hardness, H, and Young's modulus, E), and wear performance descriptors (H/E and H3/E2 ratios), a δr‐based map to aid the design and selection of elements for HESCs is provided.

Steering surface reconstruction of hybrid metal oxides for efficient oxygen evolution reaction in water splitting and zinc-air batteries

Surface reconstruction yields real active species in electrochemical oxygen evolution reaction (OER) conditions; however, rationally regulating reconstruction in a targeted manner for constructing highly active OER electrocatalysts remains a formidable challenge. Here, an electrochemical activation strategy with selective etching was utilized to guide the reconstruction process of a hybrid cobalt-molybdenum oxide (CoMoO4/Co3O4@CC) in a favorable direction to improve the OER performance. Both in-situ Raman and multiple ex-situ characterization tools demonstrate that controlled surface reconstruction can be easily achieved through Mo etching, with the formation of a dynamically stable amorphous-crystalline heterostructure. Theoretical calculations together with experimental results reveal that the synergistic effects between amorphous CoOOH and crystalline Co3O4 are crucial in enhancing the catalytic performance. Consequently, the reconstructed CoMoO4/Co3O4@CC exhibits a low overpotential of 250 mV to achieve a current density of 10 mA cm−2 in 1 M KOH, and more importantly it can be practiced in electrolytic water splitting and rechargeable zinc-air batteries devices, achieving ultra-long stability for over 500 and 1200 h, respectively. This work provides a promising route for the construction of high-performance electrocatalysts.