Amorphous Structure Research Articles

Dynamic Spall Failure of Polymers

Abstract The dynamic tensile spall failure strength of polymers subjected to high-pressure shock compression and high-strain-rate deformation is of increasing interest across a wide range of applications in extreme environments. Currently, there is no expansive database of polymeric materials for which spall strength properties are available. Plate-on-plate impact gas gun experiments were performed on 11 commercially available polymers using a multi-sample target configuration. The spall strengths obtained from velocity profiles captured using Photon Doppler Velocimetry interferometry for these polymers range from 25 to 160 MPa, with no direct correlation to their inherent characteristics, including the amorphous/semi-crystalline structure. A database of the spall strengths of 23 unique polymers, experimentally determined in this work and combined with those available in the literature, was created to include readily available mechanical and physical properties of the various polymers. The spall strength of most polymers is found to be typically higher than the corresponding quasi-static compressive and tensile strength values and about 30–50% of their bulk and elastic moduli, with some exceptions. Normalizing the spall strengths of the various polymers with respect to their calculated theoretical strength, and then correlating with their decompression (tensile) strain rate, reveals consistent trends similar to those for metals and alloys. Namely, the normalized spall strengths are nominally within 20% of the theoretical strength, although no obvious distinction between the spall failure response of the various polymer types based on amorphous or semi-crystalline structure is observed.

Stabilizing molecular contacts via amorphous structures

Stabilizing molecular contacts via amorphous structures

Construction of Self-healing Active Centers over Amorphous Ni2Fe(OH)x Nanosheets for Enhanced Oxygen Evolution Performance.

Developing efficient nickel-iron-based electrocatalysts for the oxygen evolution reaction (OER) still remains a challenge for long-term application in water electrolysis. Herein, amorphous Ni2Fe hydroxide nanosheets with self-healing active centers supported on stainless steel mesh (a-Ni2Fe(OH)x/SSM) are fabricated using a simple electrochemical deposition strategy. In situ Raman evidence shows that the amorphous structure of a-Ni2Fe(OH)x/SSM exhibits strong self-healing ability, efficiently promoting the rapid interconversion between the γ-NiOOH intermediate and Ni-based hydroxides during electrocatalysis. As a result, the as-obtained a-Ni2Fe(OH)x/SSM exhibits a low overpotential of 247 mV at 100 mA cm-2 and robust electrochemical stability for 200 h. Moreover, an anion-exchange membrane electrolyzer for water splitting is assembled utilizing a-Ni2Fe(OH)x/SSM as the anode, and current densities of 500 and 1000 mA cm-2 are achieved at 1.62 and 1.72 V, respectively, with stable performance at 500 mA cm-2 over 30 h. This work provides a facile approach for designing amorphous catalysts for various useful reactions.

From Tradition to Innovation: Pinellia ternata Extracts Stabilized Selenium Nanoparticles for Enhanced Bioactivity.

Selenium nanoparticles (SeNPs) are widely used for their effective antioxidative, anti-tumor, and antibacterial properties with minimal toxicity. Developing eco-friendly and simple synthesis methods for SeNPs with improved bioactivity, biocompatibility, and stability is crucial. This study synthesized bioactive SeNPs using extracts from the traditional Chinese medicine Pinellia ternata as a stabilizing agent. SeNPs were characterized to have an amorphous structure, spherical shape, uniform dispersion, and an average diameter of 54.6nm. They had a surface charge of - 28.2mV, enhancing stability through interactions with compounds in Pinellia ternata extracts. The synthesized SeNPs demonstrated strong antioxidant and antibacterial properties in vitro, outperforming Na2SeO3 and Pinellia ternata extracts. Specifically, SeNPs showed bacteriostatic activity against Escherichia coli (E. coli) at 120, 240, and 480µg/mL, with a lasting effect at 480µg/mL after 23h. Staphylococcus aureus (S. aureus) was more sensitive, with significant antimicrobial and bactericidal effects at 15, 30, and 60µg/mL, achieving complete inhibition at 60µg/mL after 20h. In zebrafish exposure experiments, SeNPs at low (0.2mg/L) and medium (0.5mg/L) concentrations enhanced antioxidant enzyme activities in the liver without inducing significant acute toxicity, whereas high concentrations (1mg/L) resulted in oxidative damage to the liver and gills. This study introduces a novel method for synthesizing a stable SeNP-herbal medicine extracts composite with outstanding biological activity and biosafety, potentially expanding the applications of herbal medicine beyond traditional antioxidant and antimicrobial treatments.

Effect of heat treatment on hydrothermal aging of CF/PEEK composites

Carbon-fiber-reinforced PEEK matrix composites are exposed to hydrothermal aging owing to their working areas. Therefore, it is important to understand how the mechanical properties of the material change during hydrothermal aging as a design criterion. Firstly, composite samples were quenched to reset their thermal history. Heat treatment (annealing) was applied to carbon fiber-reinforced polyetheretherketone (CF/PEEK) samples at 305°C for 270 min. After quenching. Subsequently, a hydrothermal aging process was applied at 80°C for 45 and 90 days. It was observed that the matrix crystallinity and fiber/matrix interface properties of the CF/PEEK composites changed significantly with the hydrothermal aging and previous thermal history of the material. There was an increase in the degree of crystallinity with heat treatment and hydrothermal aging. The flexural strength values of all materials decreased after hydrothermal aging. However, the decrease in the flexural strength values of the samples with a more amorphous structure after quenching was significantly greater than that in the heat-treated samples before hydrothermal aging. The DMA results show that hydrothermal aging reduces the fiber–matrix interface bond in both quenched and heat-treated materials. On the other hand, the tanδ values of heat-treated samples are much lower than those of quenched materials, as expected. This indicates that the interfacial adhesion was stronger in the heat-treated samples. The test results were supported by scanning electron microscopy (SEM) images obtained from the fractured surfaces as a result of the flexural test.

Investigating the structural and dielectric properties of electrospun nanofibers based on P(VDF-TrFE)/conjugated polymer for optoelectronic applications

Abstract This study investigates the fabrication of semiconductive nanofiber films created from polyvinylidene fluoride-trifluoro ethylene (P(VDF-TrFE)) and Poly [N-9′-heptadecany l-2, 7-carbazole-alt-5, 5- (4′, 7′-di-2-thieny l-2′, 1′, 3′-benzothiadiazole)] (PCDTBT) using the electrospinning technique. Scanning electron microscopy (SEM) revealed that films ranging from 200 to 400 nm in diameter exhibit a smooth fiber topology. Attenuated total reflectance for Fourier transform infrared (ATR-FTIR) spectra showed symmetric, antisymmetric, and non-significant chemical interactions. X-ray diffraction (XRD) analysis revealed a ferroelectric β phase and amorphous structure, with no distinct Bragg diffraction peak. The UV–vis spectra indicated the presence of semicrystalline P(VDF-TrFE) in the electrospun nanofiber film, where the carbazole units and conjugated main chains resulted in PCDTBT absorption at 415 nm and 589 nm. Blending PCDTBT with P(VDF-TrFE) lowered the band gap and enhanced Urbach energy (EU). Incorporating PCDTBT with P(VDF-TrFE) improved the DC conductivity from 1.42 × 10−4 S cm−1 to 1.07 × 10−3 S cm−1. Polarization at the semiconductor-insulator interface improved the nanofiber blend’s characteristics, including a lower bulk resistance (Rb) and a greater dielectric constant than P(VDF-TrFE). These Nanofibers may be employed in transparent electrodes and coatings for optoelectronic devices that need visible spectrum transparency and UV protection.

Catalyst‐free synthesis, characterization and photoluminescence of main‐chain luminescent polybenzoxazines

AbstractTwo novel luminescent main‐chain polybenzoxazine polymers, (Poly1)main and (Poly2)xmain, were synthesized and characterized to explore their structural, thermal, morphological and photophysical properties. Polymer (Poly1)main was obtained via a Mannich condensation reaction without a catalyst, followed by thermal polymerization to produce the crosslinked polymer (Poly2)xmain. Structural analyses using Fourier transform infrared spectroscopy and X‐ray diffraction confirmed the successful formation of the polymers, with (Poly2)xmain exhibiting a higher degree of crosslinking and partial ordering in an otherwise amorphous structure. Scanning electron microscopy imaging revealed that thermal polymerization significantly altered the morphology, transforming the porous structure of (Poly1)main into a denser, layered morphology in (Poly2)xmain. Thermogravimetric analysis and differential scanning calorimetry highlighted the improved thermal stability of (Poly2)xmain due to extensive crosslinking. Photophysical studies showed that (Poly1)main in solution exhibited yellow‐green luminescence with a broad emission maximum at 522 nm and CIE coordinates (0.39, 0.48). In contrast, the powders of both polymers displayed sharp red luminescence with an emission peak at 658 nm and CIE coordinates (0.72, 0.27), attributed to molecular packing effects and exciton coupling in the solid state. These results underscore the interplay among structural, morphological and photophysical properties, highlighting the potential of these polymers in optoelectronics, sensing and luminescent materials. © 2025 Society of Chemical Industry.

Effect Of Nd3+ Nanoparticles On Physical And Optical Properties Of Glasses

Neodymium nanoparticle (Nd³⁺ NPs) incorporated 40B₂O₃-(30-x)TeO₂-15Y₂O₃-15Na₂O-xNd2O3 glasses via melt quenching technique. The amorphous structure of these glasses was established by X-ray diffraction (XRD) studies. The glasses were explored for density measurements by Archimedes' method using toluene as the immersion liquid and density was found in the range between 2.92 and 3.34 g/cm³. Optical band gaps were studied by UV-visible spectroscopy. Indirect bandgap observed in the range from 3.70 to 4.17 eV. Whereas the refractive index varies from 2.14 to 2.23. the correlation and comparable pattens were seen in the optical bandgap values derived from the ASF and DASF approaches.

Unveiling the mechanism of selective CO₂ hydrogenation to CO on amorphous black TiO X in thermal and photo-assisted thermal catalysis: The role of defects in amorphous structure and light irradiation

Unveiling the mechanism of selective CO₂ hydrogenation to CO on amorphous black TiO _<i>X</i> in thermal and photo-assisted thermal catalysis: The role of defects in amorphous structure and light irradiation

Influence of synthesis temperature on the active performance of doped‑carbon dots embedded in polyvinyl alcohol and their potential for active food packaging.

Influence of synthesis temperature on the active performance of doped‑carbon dots embedded in polyvinyl alcohol and their potential for active food packaging.

Functionality mediated colour shifting gels from cetyltrimethylammonium bromide and 6-amino caproic acid

A charge transfer gel from a cetyltrimethylammonium bromide (CTAB) and an additive 6-aminocaproic acid (6-ACA), in a two-component solvent mixture at a critical solvent composition of 3 : 1 v/v water : toluene is reported. The pale yellow colour of the gel arising from charge transfer interactions between the amine group (–NH 2 ) of hexylamine and the ammonium ion (N + ) of CTAB was confirmed after performing a set of trial experiments with CTAB-heptanoic acid and CTAB-hexylamine systems. The process of gelation, gel phase development and its microstructure were investigated using spectroscopy, microscopy, and small-angle X-ray scattering (SAXS) techniques. The gel formed a lamellar organization while preserving a loose-packed arrangement of a bilayer of CTAB and 6-ACA molecules, maintaining H-bonding along with significant charge transfer interactions. The SAXS pattern revealed a distinct crystalline form of the lamellar gel, indicating a stable phase characterized by alternating layers of crystalline and amorphous structures. This unique gelation nature was inferred from the interplanar spacings, demonstrating its non-conducive properties in highly polar solvents such as methanol and ethanol, as well as in less polar solvents like cyclohexane and carbon tetrachloride, when the organic solvent polarity was altered in the presence of water in the mixed amphiphilic system.

Lanthanum-doped zinc borate glasses: fabrication, structural analysis, thermal properties, and gamma radiation shielding performance

Zinc borate glasses with a composition formula of (60-m)B₂O₃–40ZnO–mLa₂O₃ (m = 0, 3, 6, 9, 12, and 15 mol%) were synthesized via the melt-quenching technique for the purpose of investigating the effects of La₂O₃ incorporation on their structural, thermal, and radiation shielding properties. Amorphous structures for all samples (coded as ZBLa0 to ZBLa15) were confirmed using X-ray diffraction and Differential thermal analysis. Incorporating La₂O₃ significantly influenced the glass matrix, increasing density, molar volume, thermal expansion and the glass transition, while decreasing the crystallization peak temperature and thermal stability. These effects highlight La₂O₃'s role as a network modifier that depolymerizes the glass structure, as indicated by shifts in FT-IR bands and altered vibrational modes. Radiation shielding properties improve markedly with La₂O₃ addition, as evidenced by increased mass attenuation coefficients and effective atomic numbers, making the glass with 15 mol% La₂O₃ (ZBLa15) particularly effective at gamma-ray attenuation across a wide photon energy range. These findings suggest that La₂O₃-doped zinc borate glasses are highly suitable for applications requiring enhanced radiation shielding alongside reliable thermal performance.

Enhancing colonic health with encapsulated grape seed anthocyanins: Oral capsule for Colon-targeted delivery.

Enhancing colonic health with encapsulated grape seed anthocyanins: Oral capsule for Colon-targeted delivery.

Reconstructing Lithium Replenishment Channel by Amorphous Structure to Facilitate the Regeneration of Spent LiCoO2 Cathodes

Reconstructing Lithium Replenishment Channel by Amorphous Structure to Facilitate the Regeneration of Spent LiCoO2 Cathodes

Role of hydrogen bonding and water clusters in deamidation of peptide in glycerol-water solutions.

Role of hydrogen bonding and water clusters in deamidation of peptide in glycerol-water solutions.

Effect of the ratio of water to rice on the molecular dynamics of cooked rice starch during retrogradation: Implications for amorphous structure in gelatinized state.

Effect of the ratio of water to rice on the molecular dynamics of cooked rice starch during retrogradation: Implications for amorphous structure in gelatinized state.

A Generalized Bond Switching Monte Carlo method for amorphous structure generation

A Generalized Bond Switching Monte Carlo method for amorphous structure generation

Advances of Vanadium-based Cathodes forAqueous Zinc Ion Batteries.

Aqueous zinc-ion batteries (AZIBs) are promising for energy storage due to their high safety, low cost, and environmental friendliness. Vanadium-based materials, including vanadium oxides, vanadium sulfides, vanadate, and vanadium carbon composites, have gained attention for their diverse crystal structures, multiple oxidation states, and high theoretical capacities. This review summarizes recent advances in vanadium-based cathodes, focusing on structural design and modification strategies, such as amorphous structures, defect engineering, conductive carbon matrices, and cation pre-intercalation to enhance Zn2+ storage. Vanadium oxides and vanadium sulfides offer unique ion diffusion advantages, while vanadate and vanadium carbon composites improve conductivity and stability. Vanadate is highlighted as a critical approach to reduce electrostatic repulsion and facilitate Zn2+ storage. Vanadium carbon composites (V-MOF derivations, vanadium oxides @ carbon, combined with graphene and conductive polymer) have unique advantages in terms of conductivity, ion diffusion, and structural stability. Emerging materials like VN, VOPO₄ and V2CTx are also discussed. Future directions include multi-guest doping, anion pre-intercalation, and advanced carbon integration. This review aims to guide the development of high-performance AZIBs and inspire future research in this field.

Functionalization of biochar using SDS/SAP nanomicelles enhanced its immobilization capacity for dyes and heavy metals in water

To enhance the adsorption capacity of biochar (BC), herein a novel multifunction modified biochar (SDMBC) was prepared by directly crosslinking of the nanomicelle of sodium dodecyl sulfate/sapindus-saponin (SDS/SAP) composite system onto the BC through a simple, environmental friendly approach. Result showed that the adsorption performance of SDMBC has been greatly improved, compared with BC or using alone SDS and SAP, adsorption ability increased by 48.83%, 29.50%, 36.44%, respectively, the best modified effect was appeared when the concentration of SAP to SDS was 0.8 and 0.8 CMC. SDMBC exhibited high adsorption abilities of 130.23, 108.43, 277.09 125.27, 112.78 mg/g for heavy metal ions lead Pb(II), Cadmium Cd(II) and organic pollutants with different chemical properties bisphenol A(BPA), Methylene blue (MB), P-nitrophenol (PNP), respectively, higher than most previously reported adsorbents, importantly, SDMBC can still efficient removal capabilities even in the binary competition. Subsequently, the SDMBC and BC was characterized by Fourier Transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), Zeta potential (Zeta), it found SDMBC has a more layered structure, richer functional groups and more amorphous structure compared with BC, which are closely related with improving its adsorption capacity. The adsorption behavior of SDMBC for MB show that process was found to be spontaneous, propitious, endothermic, the adsorption isotherms fitted Freundlich models well, pseudo-second-order best describes kinetics adsorption, suggesting that the process is multi-layer chemical adsorption. The little affected by ionic strength and coexisting substances, could remained removal rate over a wide pH range, SDMBC still keep high removal rates even after 5 reuses. Based on FT-IR analysis, plausible adsorption mechanism proposed, including hydrogen bond, electrostatic attraction and π-π bonding. Cost analysis manifests that the SDMBC are high efficiency and cheap eco-adsorbents compared with commercial activated carbon, and the SDMBC dosage required for the removal of 99% of a fixed amount of MB in different volumes of effluent was predicted. Seven machine learning (ML) models were used to predict the MB (60 mg/L) adsorption of the SDMBC, using Shapley Additive Explanations (SHAP) for model interpretation. Finding Extreme Gradient Boosting (XGBoost) exhibited best performance, the order of feature importance as time> Ratio> pH> concentration> temperature. Thus, SDMBC as a new cheap and eco-adsorbents, can be used to effectively remove various types of pollutants, has a great application potential in sewage treatment, while the accurate ML prediction model presented a valuable advice for designing efficient adsorbents and optimization operating conditions in the future.

Infrared spectroscopy of astrophysical ice analogs at oblique angles

Abstract In astrochemical exploration, infrared (IR) spectroscopy is vital for understanding the composition and structure of ice in various space environments. This article explores the impact of incident angles on IR spectroscopy, focusing on molecular components present in interstellar and circumstellar ice mantles such as CO, CO2, H2O, CH3OH, NH3, CH4, H2S. The experiment involves changing the angle at which the infrared beam hits the surface used for ice deposition. It is important to measure the density of the ice layer accurately, especially for experiments that involve using different angles in infrared spectroscopy. Furthermore, the experimental methodology allowed us to derive the effective refraction index values in the infrared range for each ice component. Existing corrections typically consider geometric configurations but overlook the refractive index of the ice (n), a factor dependent on ice composition. The study reveals that the incident angle and the refractive index, determine the pathlength of the IR beam across the ice sample. This insight challenges conventional corrections, impacting the integrated absorption values of the IR bands and column densities. In addition, for certain ice components, variations in the incidence angle affect the longitudinal (LO) and transverse (TO) optical modes of the ice, leading to observable changes in the IR band profiles that provide information on the amorphous or crystalline structure of the ice. The practical implications of this work apply to experimental setups where normal IR measurements are unfeasible. Researchers using, for example, the standard 45○ angle for IR spectroscopy, will benefit from a more accurate estimation of ice column density.