Structure Of Materials Research Articles

Review of: "structure of nanomaterials, one of the thermal phenomena caused by the shrinking of the material structure is the thermal instability of nanoparticles"

Review of: "structure of nanomaterials, one of the thermal phenomena caused by the shrinking of the material structure is the thermal instability of nanoparticles"

Universal power-law scaling in the packing structure of frictional granular materials

Universal power-law scaling in the packing structure of frictional granular materials

A Design Study on Polarized Beam Splitter for Visible Light

This study employs the thin film design software TFCale to successfully design and realize a high-efficiency polarization beam splitter suitable for the visible light wavelength range of 400-700 nm, with incident angles between 40 and 50. The design objective was to achieve near 100% reflectance for S-polarized light and near 100% transmittance for P-polarized light. By optimizing the refractive index, thickness, and multilayer structure of the thin film materials, we achieved high-performance optical characteristics. During the design process, we conducted an in-depth investigation of the optical constants of various materials and combined the interference effects of multilayer films to ensure the desired polarization splitting effect within the specified range of incident angles. Simulation results indicate that the film exhibits high-efficiency polarization separation across the entire visible spectrum: the reflectance of S-polarized light remains above 80% within a certain angular range, and the transmittance of P-polarized light also remains above 80%. This high-efficiency polarization beam splitter has broad application prospects in optical instruments, laser systems, display technologies, and other fields requiring precise polarization control. Its superior performance not only enhances the efficiency and accuracy of optical systems but also provides valuable references for future optical thin film design. The study demonstrates that using TFCale for thin film design is an effective method to meet complex optical performance requirements and offers reliable solutions for practical applications

The Most Promising Alternative to Mercury-containing Dental Restorations

The European Union Environmental Commission report and the United Nation Minamata Convention have legislated for phasing-out of mercury-containing dental materials use (dental amalgams) by 2030.1, 2 Several Scandinavian countries have already banned the use of dental amalgams, and this ban is expected to grow to other countries worldwide.2, 3 This creates a market gap for materials which can be used as an alternative to dental amalgams.4 Varieties of mercury-free dental materials have been clinically approved as posterior restorations; such as (1) resin-based composite materials, and (2) glass-based materials, including glass ionomers and glass hybrids. Using these types of dental materials will decrease the mercury’s risks on human’s health and also contribute significantly in the reduction of the environmental mercury pollution.5, 6 Recently, several clinical approaches to treat dental caries lesions have shifted the focus to preserving tooth structure and use of adhesive materials. Considering this, Minimally Intervention Dentistry (MID) has become a crucial concept which includes three aspects to fulfil the requirement of preventive and restorative dentistry; these are early caries diagnosis, enhance remineralisation and minimal cutting of tooth surfaces.7, 8 This approach is identified as an Atraumatic Restorative Treatment (ART). The ART technique was adopted in 1994 by the World Health Organisation (WHO) as an alternative technique for dental caries management in the developed countries either for treating deciduous and/or permanent dentitions.9 The high viscous glass ionomer cement (GIC) is approved as an ideal candidate material to be used with ART technique; such as GC Fuji IX®, KetacTM Molar and Glass Carbomer®.10, 11 One of the main advances in dental materials field is based on the modifications of the GIC chemical compositions, by introducing a bioactive glass in different particle sizes (for promoting remineralising ability) and/or using a highly molecular weight of poly- acrylic acid (for enhancing matrix strength).12 When bioactive glass-containing dental materials come into contact with body fluid, will undergo to a sequence of bioactivity reactions; which is summarised into (1) ion exchange, (2) dissolution and (3) precipitation stages, leading to formation of apatite crystals in fractions identical to those of the natural bone and tooth components.13 Formation of apatite crystals [hydroxyapatite-Ca10(PO4)6OH2 or fluorapatite-Ca10(PO4)6F2] in the bioactive glass-containing GICs occurs via delivering of calcium (Ca2+), phosphate (PO43), hydroxyl (OH-) and/or fluoride (F-) species at the interfaces between the GIC/tooth surfaces and/or the GIC/oral environment.14 For this reason, the bioactive glass-containing GICs are considered as the most promising alternative restorative materials for posterior cavities.

Electronic and optical properties of computationally predicted Na-K-Sb crystals

Abstract Thanks to their favorable electronic and optical properties, sodium-potassium-antimonides are an emerging class of crystals used as photocathodes in particle accelerators. The persisting challenges related to the synthesis and characterization of these materials demand support from theory and make the study of computationally predicted polymorphs particularly relevant to identifying the structure, composition, and properties of the samples. Using first-principles methods based on density functional theory and many-body perturbation theory, the electronic and optical properties of cubic NaK2Sb and hexagonal Na2KSb are studied. Both systems, experimentally reported in the hexagonal and cubic phase, respectively, exhibit an indirect fundamental gap that is energetically very close to the direct band gap at Γ of magnitude 0.81 eV for NaK2Sb and 0.70 eV for Na2KSb. In the band structure of both materials, Sb p-states dominate the valence region with minor contributions from the alkali p-states, while the alkali s-states mainly contribute at lower energies. The optical spectra of both crystals are not subject to sizeable excitonic effects, except for a redshift of the excitation energies of 50-100 meV and some redistribution of the oscillator strength beyond the lowest-energy peak in the near-infrared region. Our results indicate that computationally predicted cubic NaK2Sb and hexagonal Na2KSb have favorable characteristics as photocathodes and, as such, their presence in polycrystalline samples is not detrimental for this application.

Rare Earth Selectivity and Electric Potentials at Mica Interfaces.

Controlling materials' composition and structure to selectively adsorb rare earth elements (REE) is critical for better separations. Understanding how local electric potentials affect REE adsorption and how they can be modified via chemical substitution is of fundamental importance. We present calculated mean inner potentials for muscovite and phlogopite micas in excellent agreement with measured values of +10.6 V. Natural substituents for aluminum significantly influence the electric potentials at the basal surface, altering the REE adsorption energies (Ead). Nd3+ adsorption is generally favored over that of Yb3+ on both micas. Substituents with lower charge than aluminum increase the Lewis basicity of adjacent oxygen atom lone electron pairs, enhancing Ead by 20 to 30 kcal/mol. These substitutions modify the electric potential's magnitude and spatial extent, highlighting the role of high-resolution electron holography/tomography and the importance of understanding atomic-scale variations in electric potentials for improving REE cation adsorption and selectivity on micas. In summary, the adsorption energies of REE cations are correlated with the substituent charge and local electrostatic potential variations because these factors dictate the electrostatic interactions between the cations and the interface.

White light-emitting electrochemical cells based on metal-free TADF emitters

The attainment of white emission from a light-emitting electrochemical cell (LEC) is important, since it enables illumination and facile color conversion from devices that can be cost-efficient and sustainable. However, a drawback with current white LECs is that they either employ non-sustainable metals as an emitter constituent or are intrinsically efficiency limited by that the emitter only converts singlet excitons to photons. Organic compounds that emit by thermally activated delayed fluorescence (TADF) can address these issues since they can harvest all excitons for light emission while being metal free. Here, we report on the first white LEC based on solely metal-free TADF emitters, as accomplished through careful tuning of the energy-transfer processes and the electrochemically formed doping structure in the single-layer active material. The designed TADF-LEC emits angle-invariant white light (color rendering index = 88) with an external quantum efficiency of 2.1 % at a luminance of 350 cd/m2.

Investigating the Effects of Copper Impurity Deposition on the Structure and Electrochemical Behavior of Hydrogen Evolution Electrocatalyst Materials

Investigating the Effects of Copper Impurity Deposition on the Structure and Electrochemical Behavior of Hydrogen Evolution Electrocatalyst Materials

Universal Bench for Full-scale Tests of FOPS® Filters and Modeling of Suspended Solids Pollution

The problems related to the treatment of surface runoff polluted by suspended solids are evaluated. The peculiarities of morphology and composition of suspended solids particles contained in surface runoff are considered. The design and the principle of operation of the developed experimental testing bench for tests to determine the efficiency of retention of solid particles by different filtering materials and life-size FOPS® filters are presented. It is shown that narrow particle size distribution fractions of natural zeolite can be used to evaluate both the retention of suspended solids by filter materials (or FOPS® filters) and the porous structure of fiber filter materials.

Electrospinning vs Fluorescent Organic Nano-Dots: A Comparative Review of Nanotechnologies in Organoluminophores Utilization

Abstract This review explores the pivotal roles of two advanced nanotechnologies—electrospinning (ES) and fluorescent organic nano-dots (FONs) in the development and application of organoluminophores (OLs). As demand intensifies for innovative OL-based systems in fields such as biomedical imaging, drug delivery, materials engineering, sensing, and energy, ES and FONs present complementary yet distinct technological pathways. Each method offers unique advantages in optimizing material properties, compatibility, and optical performance, positioning them at the forefront of OL-based research. ES enables precise control over material structure, enhancing performance for scalable industrial applications. FONs deliver superior optical properties, particularly for bio-imaging, through environmentally friendly synthesis. This comparative analysis critically examines the strengths and limitations of both techniques, including aspects of synthesis complexity, material adaptability, functional enhancement, and industrial utilization. Furthermore, recent advancements, ongoing challenges, and future prospects within this rapidly evolving field are discussed, providing a comprehensive perspective on the potential of these luminescent technologies to drive next-generation OL applications. Graphical Abstract

Research on the Application of Flexible Pressure Sensors in Wearable Devices

The potential applications of transparent, adaptable electronic devices in the human body are driving up demand for them. For flexible and wearable electronics, such as medical surveillance devices and artificial skin, pressure sensing is mandatory. The flexibility and sensitivity of pressure sensors have advanced recently owing to developments in material and device structure. Moreover, their low manufacturing costs enable widespread implementation, leading to promising application prospects. The sensors utilize different materials and structures, including capacitive pressure sensors with ionically charged CFMs, magnetic particle-infused carbon sponges, CNT-PDMS composites, and MoSe2/MWNT combinations. These sensors offer advantages such as high sensitivity, wide pressure-detecting ranges, optical transparency, and energy efficiency. They can detect both large and subtle human movements, from walking and finger bending to breathing and eye blinking. The fabrication methods range from simple and cost-effective processes to more complex techniques like photolithography. Many of the sensors incorporate carbon nanotubes (CNTs) in various forms, exploiting their excellent electrical properties. The review highlights the potential of these sensors for healthcare monitoring, clinical diagnosis, and integration into wearable electronics, emphasizing their flexibility, biocompatibility, and ability to provide real-time, non-invasive measurements of physiological signals. Moreover, their low manufacturing costs enable widespread implementation, leading to promising application prospects.

Skin-Inspired and Self-Powered Piezoionic Sensors for Smart Wearable Applications.

Bio-inspired by tactile function of human skin, piezoionic skin sensors recognize strain and stress through converting mechanical stimulus into electrical signals based on ion transfer. However, ion transfer inside sensors is significantly restricted by the lack of hierarchical structure of electrode materials, and then impedes practical application. Here, a durable nanocomposite electrode is developed based on carbon nanotubes and graphene, and integrated into piezoionic sensors for smart wearable applications, such as facial expression and exercise posture recognitions. The nanocomposite electrode provides abundant channels for ion transfer because of its hierarchically porous structure. Carbon nanotubes not only prevent restacking of graphene nanolayers, but also connect them across out-plane dimension. The piezoionic skin sensors present a high degree of linearity in a wide strain range with high sensitivity, and long cycling life with bending strains beyond 20000 s. Further, a smart bracelet based on flexible sensors is fabricated for accurate posture recognition of badminton exercise, valuable to athlete training.

Catalytic Assembly of Peptides Mediated by Complex Coacervates.

The assembly of peptides is generally mediated by liquid-liquid phase separation, which enables control over assembly kinetics, final structure, and functions of peptide-based supramolecular materials. Modulating phase separation can alter the assembly kinetics of peptides by changing solvents or introducing external fields. Herein, we demonstrate that the assembly of peptides can be effectively catalyzed by complex coacervates. The negatively charged sodium alginate (SA) can form complex coacervates with the positively charged KLVFFAE (Aβ16-22, abbreviated as KE) peptide, thereby lowering the nucleation barrier and promoting the assembly of the peptide. As the binding affinity of SA-KE and the dosage of SA decrease, the system shifts from a relatively inefficient template-induced assembly to a highly efficient catalytic assembly before ultimately reverting to slow spontaneous assembly. Therefore, both the affinity as well as the stoichiometry do not follow the intuitive rule that "more is better", but rather there exists an optimal value that maximizes the rate of assembly.

Effect of changing the internal structure on the mechanical properties of three-dimensional-printed custom tray material: An in vitro study.

The main challenges to the widespread clinical application of three-dimensional (3D)-printed customized trays include cost and time limitations. This study examined how changing the internal structure of 3D-printed materials used for customized trays affects flexural strength (FS), flexural modulus (FM), manufacturing time, and material weight. Specimens (64×10×3.3mm) were printed using a light-sensitive liquid resin. The internal structures of control specimens were completely filled, whereas the internal structures of test groups comprised vertical bars spaced 1 mm (Test 1) or 2 mm (Test 2) apart. Specimens were weighed and then subjected to a three-point bending test to evaluate their FS and FM. Data were analyzed using one-way ANOVA and Tukey's test, with Weibull analysis applied to FS values. Control specimens had the highestFS (106±4 MPa), while Test 2 specimens demonstrated the highest FM (6101±1407 MPa). No significant differences were found between Test 1 and Test 2 specimens in FS or FM. Test 2 specimens had the lowest mean weight (1440±42 mg). Manufacturing times were 80min for control and Test 1 specimens and 60min for Test 2 specimens. Including spaces in the internal structure of 3D-printed customtray material saves material and manufacturing time while maintaining mechanical properties.

Efficient construction of high-quality sulfonated porous aromatic frameworks by optimizing the swelling state of porous structures.

Conventional post-modification methods usually face the fundamental challenge of balancing the high content of functional groups and large surface area for porous organic polymers (POPs). The reason, presumably, stems from ineffective and insufficient swelling of the porous structure of POP materials, which is detrimental to mass transfer and modification of functional groups, especially with large-sized ones. It is important to note that significant differences exist in the porous structures of POP materials in a solvent-free state after thermal activation and solvent swelling state. Herein, we propose that the improvement of the swelling state of the porous structure of POP materials is more conducive to obtaining high-quality sulfonated POP materials, and employ a one-pot modification strategy for preparing sulfonated porous aromatic frameworks (PAFs) to prove the proposal. These results show that the specific surface area of the resulting polymer is 580 m2 g-1 with a sulfur content of up to 13.2 wt%, which is superior to most sulfonated porous materials and the control sample. More importantly, we have also shown that the same conclusion is reached by performing similar treatments on hyper-crosslinked polymers (HCPs) and conjugated microporous polymers (CMPs), proving that our hypothesis is effective and feasible when compared to the conventional post-sulfonation method. The excellent hydrophilicity, rich content of sulfonic acid groups, high specific surface area and hierarchical pore structure make the resulting polymer an ideal adsorbent for micro-pollutants in water. The maximum adsorption capacities for Rhodamine B (RhB), Methylene Blue (MB), Tetracycline (TC) and Ciprofloxacin (CIP) are 1075 mg g-1, 1020 mg g-1, 826 mg g-1 and 1134 mg g-1, respectively. This study not only demonstrates the preparation of efficient sulfonated porous adsorbents for the efficient removal of cationic dyes and antibiotics but also illustrates an effective method for constructing high-quality functional POP materials by optimizing the swelling state of the porous structure.

Stable structure and oxygen-rich vacancy assist NH4V4O10 to become a high-performance aqueous zinc-ion battery cathode material

Ammonium vanadate (NH4V4O10) is an emerging cathode material for aqueous zinc-ion batteries (AZIBs), gaining recognition for V element multivalent and budget. However, Zn2+ exhibit robust coulombic bonds with the lattice structure, poor ion transport and cycling stability, and narrow layer spacing limit its further application. In this study, we prepared an efficient cathode designed for AZIBs by inserting ascorbic acid (AA) into the interlayer of NH4V4O10 (AANVO). The insertion of AA increases the distance between layers and enhances the stability of the material's structure, provided a large interlayer channel for the diffusion of Zn2+ and successfully partially replaced NH4+ in NH4V4O10, alleviating the irreversible deamination reaction. Furthermore, the doping of AA reduces the crystallinity of NVO, increases the oxygen vacancies, and accelerates the ion and charge transfer kinetics, resulting in excellent electrochemical properties. The findings reveal that AANVO exhibits a remarkable charge capacity of 638 mAh g-1 at 0.1Ag-1, and it maintains 86.6% of this capacity after 1000 cycles when subjected to 10Ag-1.

The EFG Rosetta Stone: translating between DFT calculations and solid state NMR experiments.

We present a comprehensive study on the best practices for integrating first principles simulations in experimental quadrupolar solid-state nuclear magnetic resonance (SS-NMR), exploiting the synergies between theory and experiment for achieving the optimal interpretation of both. Most high performance materials (HPMs), such as battery electrodes, exhibit complex SS-NMR spectra due to dynamic effects or amorphous phases. NMR crystallography for such challenging materials requires reliable, accurate, efficient computational methods for calculating NMR observables from first principles for the transfer between theoretical material structure models and the interpretation of their experimental SS-NMR spectra. NMR-active nuclei within HPMs are routinely probed by their chemical shielding anisotropy (CSA). However, several nuclear isotopes of interest, e.g.7Li and 27Al, have a nuclear quadrupole and experience additional interactions with the surrounding electric field gradient (EFG). The quadrupolar interaction is a valuable source of information about atomistic structure, and in particular, local symmetry, complementing the CSA. As such, there is a range of different methods and codes to choose from for calculating EFGs, from all-electron to plane wave methods. We benchmark the accuracy of different simulation strategies for computing the EFG tensor of quadrupolar nuclei with plane wave density functional theory (DFT) and study the impact of the material structure as well as the details of the simulation strategy. Especially for small nuclei with few electrons, such as 7Li, we show that the choice of physical approximations and simulation parameters has a large effect on the transferability of the simulation results. To the best of our knowledge, we present the first comprehensive reference scale and literature survey for 7Li quadrupolar couplings. The results allow us to establish practical guidelines for developing the best simulation strategy for correlating DFT to experimental data extracting the maximum benefit and information from both, thereby advancing further research into HPMs.

The Synergistic Effect of MOF and Biomass Achieving Dual Breakthroughs in Material Structure and Performance

In order to cope with the environmental crisis and the depletion of non-renewable resources, the combination of metal-organic framework (MOFs) and biomass materials has become an important breakthrough in sustainable...

ANÁLISIS DE MODELOS DE INTELIGENCIA ARTIFICIAL PARA PREDECIR LA TEMPERATURA VICAT DE DIVERSOS COMPUESTOS BASADO EN BIOHDPE COMPARANDO DIVERSAS TÉCNICAS DE MACHINE LEARNING

Materials science is an interdisciplinary field that studies the structure, properties, behavior, and performance of materials. This work focuses on polyethylene polymers, the most widely used in the industry, with a particular emphasis on bio-polyethylenes, which align with sustainability goals by being derived from renewable materials such as biomass and agricultural crops, reducing dependence on fossil resources and minimizing the carbon footprint. The VICAT temperature is a key measure for evaluating the thermal resistance of thermoplastic materials, indicating the temperature at which they begin to soften under load. A higher VICAT temperature suggests better resistance to thermal deformation. A BioHDPE matrix, known for its high impact and tensile strength, suitable for demanding applications, was used. To improve mechanical and thermal properties, hemp fibers, almond powder, argan powder, and Halloysite nanotubes (HNT) were incorporated into the matrix, using organic waste to reduce costs. These components, available in the Mediterranean region, affect the VICAT temperature differently: hemp fiber and HNT enhance mechanical strength, while almond and argan powders may reduce it due to their tendency to decompose. Machine learning (ML) techniques were applied to predict the VICAT temperature, aiming to reduce time and costs in the development of new materials. Regression models, including Multiple Linear Regression (MLR), Neural Networks (NN), Decision Trees (DT), and k-Nearest Neighbors (kNN), were compared, evaluated using the Mean Absolute Percentage Error (MAPE) and the coefficient of determination (R²). The best ML model was identified by a low MAPE and high R², ensuring high prediction accuracy. This study demonstrates the potential of ML in predicting material properties, contributing to the efficient and sustainable design of new polymers. Keywords: BioHDPE, Machine Learning, VICAT Temperature, Neural Networks, Prediction

Influence of Cu2Se doping on the morphology, structure and synthesis reactions in MgB2 material

Influence of Cu2Se doping on the morphology, structure and synthesis reactions in MgB2 material