Materials Science Research Articles

Boosting Electrocatalytic Performance of Sulfide Oxidation on Polyoxomolybdates with Synergistic Effects of CNT‐Doped Aerogel Foams

AbstractThe meticulous design of highly efficient indirect electrocatalysts with value‐added conversion properties remains a substantial challenge within the realm of organic catalysis. While polyoxometalates (POMs) serve as crucial active centers in catalytic modeling systems for chemical materials, their exploration in electrocatalytic organic molecular transformations is hindered by kinetic barriers. Therefore, an efficient protocol is established for the synthesis of electrocatalysts utilizing polyoxomolybdates (CuMo6) immobilized on aerogel foams (CMC). The electrical conductivity and electrocatalytic activities of the electrocatalyst (CuMo6/CNT@CMC) can be readily enhanced by adjusting the microenvironment between the CuMo6 and CMC using carbon nanotubes (CNT). Controlled experiments demonstrate that the CuMo6/CNT@CMC electrocatalyst for the oxidation of sulfide achieves an impressive Faradaic Efficiency (FE) exceeding 95% under ambient conditions, while the working potential is markedly lower than that of reported heterogeneous electrocatalysts. Combined experimental and theoretical analyses suggest that the modulated electronic synergistic interaction between the Cu‐assisted Mo sites and CNT within foam favors the appropriate binding of PhCH3S+• intermediates, thereby promoting the selective oxidation of sulfides. This study paves the way for the utilization of polyoxometalate‐based materials with simple synthesis methods for various electrocatalytic applications.

XElemNet: towards explainable AI for deep neural networks in materials science

Recent progress in deep learning has significantly impacted materials science, leading to accelerated material discovery and innovation. ElemNet, a deep neural network model that predicts formation energy from elemental compositions, exemplifies the application of deep learning techniques in this field. However, the “black-box” nature of deep learning models often raises concerns about their interpretability and reliability. In this study, we propose XElemNet to explore the interpretability of ElemNet by applying a series of explainable artificial intelligence (XAI) techniques, focusing on post-hoc analysis and model transparency. The experiments with artificial binary datasets reveal ElemNet’s effectiveness in predicting convex hulls of element-pair systems across periodic table groups, indicating its capability to effectively discern elemental interactions in most cases. Additionally, feature importance analysis within ElemNet highlights alignment with chemical properties of elements such as reactivity and electronegativity. XElemNet provides insights into the strengths and limitations of ElemNet and offers a potential pathway for explaining other deep learning models in materials science.

PENGEMBANGAN LEMBAR KERJA PESERTA DIDIK BERBASIS DISCOVERY LEARNING PADA MATERI SISTEM PENCERNAAN MANUSIA

The background to this research is the development of student worksheets based on Discovery Learning. This research aims to produce interactive learning media products on the human digestive system that are valid, practical and effective. This type of research is the development of the PLOMP model. The research method used in this research is research and development. This research was tested on 20 class VIII students at SMP Negeri 1 O'o'u. To standardize products, three test stages are carried out, namely: validity test, practicality test, effectiveness test. The instruments used are assessment questionnaires using a Likert scale and evaluation test questions to determine student learning outcomes. The research results show that the Discovery Learning-based LKPD is very valid with a presentation of 85% and is suitable for use. The average value of practicality assessed by teachers is 3.48 and students are 3.64 in the very practical category. Student motivation results are at 86% with a cognitive average of 88.7. The suggestion given by the researcher is that science-biology subject teachers should use LKPD as teaching materials in the teaching and learning process because it can increase students' interest and motivation to learn. Through this teaching material, students can broaden their horizons regarding science-biology learning on the subject of the human digestive system. For future researchers, this student worksheet can be used as reference material in research

Buckybowl-Based Fullerene Receptors.

Buckybowls, bowl-shaped polyaromatic hydrocarbons, have received intensive interest owing to their multifaceted potentials in supramolecular chemistry and materials science. Buckybowls possess unique chemical and physical properties associated with their concave and convex faces. In view of the shape complementarity, which is one of the key factors for host-guest assembly, buckybowls are ideal receptors for fullerenes. In fact, the host-guest assembly between buckybowls and fullerenes is one of the most active topics in buckybowls chemistry, and the resulting supramolecular materials show promising applications in optoelectronics, biomaterials, and so forth. In this tutorial review, we present an overview for the progress on fullerene receptors based on buckybowls over the last decade.

Facilitating Absorption Spectroscopy of Strongly Absorbing Fluids: A High-Throughput Approach.

Measuring absorption spectra of strongly absorbing solutions is usually only possible by diluting the solution. However, the absorption spectra can be heavily influenced by concentration-dependent interactions, so dilution leads to misleading results. To enable reliable absorption measurements of concentrated solutions, we introduce in this work thinning fluid film spectroscopy (TFFS), a simple and highly automatable method. We present three exemplary measurement modes of TFFS suitable for many different applications and validate the TFFS measurements with control data obtained in specialized, low optical path length cuvettes. Additionally, we compare the suitability of the different measurement modes over a broad concentration range and demonstrate the automation possibilities with a spectroscopy robot. Beyond this automated approach for highly efficient and high-throughput lab work, we also show the possibility of direct integration into production systems with an in-line setup, which can be incorporated into a variety of pipe systems. The TFFS method is not limited to samples from material science but can be transferred to a broad variety of research and industry fields, including proteins, food, and pharmaceuticals or also agriculture and forensics.

Enhanced Singlet Oxygen Generation in Aggregates of Naphthalene-Fused BODIPY and Its Application in Photodynamic Therapy.

Several reports are available on aggregation-induced emission and its applications in biomedical imaging and other material sciences. However, enhancement of singlet oxygen generation in nanoaggregates is rarely reported. Here, we report the synthesis of Naph-BODIPY Br2, which absorbs at 661 nm (monomer) with a high molar absorption coefficient. The presence of bromine promotes intersystem crossing, thereby enhancing the singlet oxygen quantum yield (ΦΔ ∼ 0.50 in methanol). In order to increase hydrophilicity, we developed Naph-BODIPY Br2 nanoaggregates (∼100 nm), which demonstrated aggregation-induced properties and exhibited a bathochromic shift with an absorption maximum at 757 nm. The bathochromic shift in the UV-vis spectra due to aggregation is corroborated by TD-DFT analysis. The computational data also confirm the presence of a low-lying triplet state, which enhances the generation of singlet oxygen, making it effective for photodynamic therapy. These aggregates showed excellent singlet oxygen generation in aqueous media, compared to their monomeric form and standard methylene blue. Their hydrophilic nature and high singlet oxygen generation enabled significant phototoxicity against human carcinoma cells with IC50 values of 4.06 ± 0.01 and 4.09 ± 0.1 μM, respectively, for MCF-7 and A549 cells upon 5 min exposure to light. Moreover, their phototoxicity further increases with an increasing exposure time of light for both cell lines. Notably, Naph-BODIPY Br2 nanoaggregates exhibited nearly zero dark cell toxicity and effectively induced apoptosis in cancer cells upon light activation, highlighting their potential as powerful photosensitizers for photodynamic cancer therapy.

Genetically Engineered Filamentous Bacteriophages Displaying TGF-β1 Promote Angiogenesis in 3D Microenvironments

Combined 3D cell culture in vitro assays with microenvironment-mimicking systems are effective for cell-based screening tests of drug and chemical toxicity. Filamentous bacteriophages have diverse applications in material science, drug delivery, tissue engineering, energy, and biosensor development. Specifically, genetically modified bacteriophages have the potential to deliver therapeutic molecules or genes to targeted tumor tissues. The engineered bacteriophages in this study significantly enhanced endothelial cell migration and tube formation within the extracellular matrix (ECM). Compared to TGF-β1 alone and non-modified phages, the presence of TGF-β1 on the bacteriophages demonstrated superior performance as a continuous stimulant in the microenvironment, effectively promoting these angiogenic processes. Assays, including RT-qPCR, ELISA, and fluorescence microscopy, confirmed the expression of angiogenic markers such as CD31, validating the formation of 3D angiogenic structures. Our findings indicate that the TGF-β1 displayed by bacteriophages likely acted as a chemotactic factor, promoting the migration, proliferation, and tube formation of endothelial cells (ECs) within the ECM. Although direct contact between ECs and bacteriophages was not explicitly confirmed, the observed effects strongly suggest that TGF-β1-RGD bacteriophages contributed to the stimulation of angiogenic processes. The formation of angiogenic structures by ECs in the ECM was confirmed as three-dimensional and regulated by the surface treatment of microfluidic channels. These results suggest that biocompatible TGF-β1-displaying bacteriophages could continuously stimulate the microenvironment in vitro for angiogenesis models. Furthermore, we demonstrated that these functionalized bacteriophages have the potential to be utilized as versatile biomaterials in the field of biomedical engineering. Similar strategies could be applied to develop angiogenic matrices for tissue engineering in in vitro assays.

Advancing quinoxaline chemistry: Sustainable and green synthesis using L-arabinose as a catalyst

In the present study, an innovative and eco-friendly methodology for synthesizing quinoxaline derivatives has been introduced, leveraging L-arabinose as a novel catalyst. This approach not only underscores the feasibility of green chemistry in synthesizing high-purity quinoxaline derivatives but also highlights the enhanced sustainability of the process. Detailed mechanistic investigations revealed the synergistic interactions between L-arabinose and the reactants, providing a deeper understanding of the catalytic process. The synthesized compounds, due to their unique structural and electronic properties, may find promising applications in life and material sciences such as optoelectronics. Furthermore, our environmental impact assessment demonstrated significant reduction in generated waste, solvent use, and overall carbon footprint, aligning with the global agenda for sustainable development. This research marks a significant step forward in quinoxaline chemistry, promoting the adoption of green synthesis pathways while reinforcing the principles of sustainable and environment-friendly chemical practices.

Aza‐Diarylethenes Undergoing Both Photochemically and Thermally Reversible Electrocyclic Reactions

AbstractExploring novel molecular photoswitches plays a crucial role in the field of photo‐functional materials chemistry. In this study, we synthesized aza‐diarylethenes with benzothiophene‐S,S‐dioxide as a part of the hexatriene structure and investigated their photochromic properties. Unlike previously reported aza‐diarylethenes, which exhibit fast thermally reversible photochromism, the compounds synthesized here exhibited pseudo‐photochemically reversible photochromism. Due to their thermal stability, we successfully isolated the colored isomer. X‐ray crystallographic analysis revealed for the first time that the colored isomer adopts a closed‐ring structure with a bond between carbon and nitrogen atoms. Remarkably, these aza‐diarylethenes exhibited not only photochemical ring‐closing and ring‐opening reactions but also thermal ring‐closing and ring‐opening reactions, driven by a thermal equilibrium between the open‐ and closed‐ring isomers. This behavior, unprecedented for common diarylethenes, was elucidated through kinetic analysis, revealing an energy‐level diagram for the thermal equilibrium between these isomers. Furthermore, 1H NMR spectroscopy revealed that both photochemically and thermally generated closed‐ring isomers adopt the same molecular structure, which was well explained based on the reaction mechanism of photochemical and thermal ring‐closing reactions. These findings not only advance the field of aza‐diarylethenes but also inspire future research in the development of new photoswitches.

Visible Light-Sensitive Sustainable Quantum Dot Crystals of Co/Mg Doped Natural Hydroxyapatite Possessing Antimicrobial Activity and Biocompatibility.

Cutting-edge research in advanced materials is increasingly turning toward the development of novel multifunctional nanomaterials for use in high-tech applications. This research uses the solid-state method as a solvent-free technique to create multifunctional quantum dot (QD) hydroxyapatite (HA) crystals from bovine bone waste. By incorporating cobalt (Co) and magnesium (Mg) into the HA structure, the crystallinity of the hexagonal HA nanoparticles (99.7%), showing QD crystals is enhanced. Oxygen vacancies on the surfaces of the HA nanoparticles contributed to their bandgap falling within the visible light range. In addition, the dopants substituted calcium in the HA crystal structure and generated a divalent oxidation state, shifting the bandgap of natural HA toward red wavelengths (3.26 to 1.94eV). Moreover, the incorporation of Co led to magnetization within the HA structure through spin polarization. Additionally, the doped QD crystals of HA nanoparticles showed significant antimicrobial activity against Escherichia coli, Staphylococcus aureus, and bacteriophages MS2, particularly under visible light exposure. In short, the Co/Mg co-doped HA nanoparticles exhibited ferromagnetic properties, sensitivity to visible light, biocompatibility, and considerable antimicrobial effects, establishing their potential as sustainable multifunctional materials for biomedical applications, especially in anti-infection treatments.

Breaking Symmetry for SHG Response: Lanthanide Acetate Crystals via Water Molecule Regulation Strategy.

In the field of nonlinear optical (NLO) materials research, the design and synthesis of novel materials are crucial for advancing modern scientific and technological development. This study employs an innovative coordination strategy, building upon the existing structure of [Ln2(CH3COO)6(H2O)4]·4H2O (Ln = Tb, Sm), to successfully synthesize a series of acetate rare-earth metal compounds [Ln2(CH3COO)6(H2O)]n [Ln = Tb(1), Er(2), Y(3)] by regulating the number of water molecules. This approach achieved a structural transition from centrosymmetric (CS) to noncentrosymmetric (NCS), endowing these compounds with significant nonlinear optical responses. We discovered that reducing the coordinated water molecules and introducing acetate as a bidentate ligand is an effective method for modulating crystal structure and realizing NLO performance. This finding not only deepens the understanding of the structure of acetate salts but also provides important theoretical and experimental support for the development of materials with potential NLO propeties.

Electrospinning Aligned SF/Magnetic Nanoparticles-Blend Nanofiber Scaffolds for Inducing Skeletal Myoblast Alignment and Differentiation.

In the realm of skeletal muscle tissue engineering, anisotropic materials that emulate natural tissues show substantial promise. Electrospun scaffolds, mimicking the fibrillar structure of the extracellular matrix, are commonly employed but often fall short in achieving optimal alignment and mechanical strength. Silk fibroin has emerged as a versatile material in tissue engineering, valued for its biocompatibility, mechanical robustness, and biodegradability. However, conventional electrospinning methods of SF result in randomly oriented fibers, limiting their efficacy. In this work, we developed a straightforward method to fabricate directional tissue scaffolds using silk fibroin. By integrating a magnetic field collecting device and incorporating Fe3O4 nanoparticles into the spinning solution, we successfully produced well-aligned silk nanofiber scaffolds. These aligned fibers not only improved scaffold orientation and mechanical properties but also exhibited magnetic responsiveness. The aligned SF scaffolds effectively guided the adhesion, proliferation, and differentiation of mesenchymal stem cells along the fiber direction. Cultured on these scaffolds, myoblast C2C12 cells demonstrated oriented growth, highlighting the potential of aligned SF fibers in advancing skeletal muscle engineering for biomedical applications.

Numerical Optimization of Functionally Graded Ti-HAP Material for Tibial Bone Fixation System

Functionally graded materials (FGMs) are heterogeneous composites characterized by outstanding properties. They are built from two or more components with a gradient distribution of chemical composition along a given direction. A promising graded material for biomedical engineering as an implant could be a FGM made of titanium (Ti) and hydroxyapatite (HAP). It would allow us to counteract the difference between the stiffness modulus of pure titanium and bone tissue. Moreover, it can be a good solution to the problem of stress shielding for bone fixation plates made of conventional titanium or steel. The presented paper aims to perform micromechanical modeling and optimization of a functionally Ti-HAP graded plate, followed by numerical analysis of a fractured tibia stabilization system under specific boundary conditions. Finite element analysis was performed using ANSYS Workbench 2021 software. The models of the FGM plate and tibial fixation system were made using the Space Claim tool. The ANSYS software allowed the optimization of the model considered and the selection of the appropriate structural parameters of the FGM Ti-HAP material. In general, the results proved that the osteosynthesis plate built of graded Ti-HAP material resulted in lower bone stress compared to titanium and steel plates. The results obtained confirmed the validity of the design and the possibility to use functionally graded Ti-HAP bone fixation plates.

Analytical modeling and computational optimization for a 1-DOF compliant mechanism

The first natural frequency directly affects the operational conditions of compliant mechanisms in precision engineering systems. To address this challenge, a computational method based on the surface response method is proposed to optimize the frequency of a new one degree of freedom (DOF) compliant mechanism. Initially, a 1-DOF 3D model of a compliant mechanism is built. The dynamic equation and the frequency response are formulated via equivalent stiffness and the Lagrange method. Subsequently, a series of numerical simulations are conducted to find the fundamental frequency of the mechanism. The initial dimensions of the flexible joints are determined, and the initial frequency is analyzed by using finite element analysis. Next, the flexible joints in the designed mechanism are optimized by a variant of the genetic algorithm. The optimized dimensions of the mechanism are found with the thickness of the circular joint of 1.10 mm, the thickness of the leaf joint of 1.19 mm, and the length of the leaf joint of 54.50 mm. The optimized result showed that there is a significant improvement in the frequency of the mechanism, increasing from an initial design of 53.218 Hz to an optimal design of 75.927 Hz with an improvement of 42.6%. This study provides important reference materials for future research on compliant mechanisms.

Dual‐Modal Sensing Skin Adaptive to Daylight, Darkness, and Ultraviolet Light for Simultaneous Full‐Field Deformation Measurement and Mechanoluminescence Responses

AbstractMechanoluminescence (ML) and digital image correlation (DIC) have emerged as promising optical methods to visualize and measure deformation fields. In this study, a dual‐modal sensing skin, called the ML‐DIC skin is introduced, that is capable of emitting ML and facilitating DIC measurements under various lighting conditions, including daylight, night or darkness, and UV irradiation. Four ML‐DIC skins are fabricated with or without carbon nanotubes (CNTs) using a composite powder consisting of SrAl2O4: Eu,Dy (SAO), and acrylic resin, with CNT milling times of 48, 72, and 96 h for three of four skins, respectively. DIC measurements are performed under multiple lighting conditions for measuring photoluminescence, persistence luminescence, and reflection. Uniaxial tension tests demonstrate the superior performance of ML‐DIC skins with CNTs compared with pristine SAO skins, with the skin subjected to 48 h of CNT dispersion exhibiting optimal performance. Further investigations focus on ML emission and DIC measurements near the crack‐tip vicinity of static and propagating cracks as well as on surfaces above subsurface cracks. The integration of ML and DIC techniques offers a versatile approach for comprehensive deformation analysis applicable to diverse environments, with implications for materials science, engineering, and structural health monitoring.

Antagonistic-contracting high-power photo-oscillators for multifunctional actuations.

High-power autonomous soft actuators are in high demand yet face challenges related to tethered power and dedicated control. Light-driven oscillation by stimuli-responsive polymers allows for remote energy input and control autonomy, but generating high output power density is a daunting challenge requiring an advanced material design principle. Here, inspired by the flight muscle structure of insects, we develop a self-oscillator based on two antagonistically contracting photo-active layers sandwiching an inactive layer. The actuator produces an output power density of 33 W kg-1, 275-fold higher than other configurations and comparable to that of insects. Such oscillators allow for broad-wavelength operation and multifunction integration, including proprioceptive actuation and energy harvesting. We demonstrate high-performance flapping motion enabling various locomotion modes, including a wing with a thrust-to-weight ratio of 0.32. This work advances autonomous, sustained and untethered actuators for powerful robotics.

Green Synthesis and Enhanced Photocatalytic Performance of rGO/ZnO/Fe3O4 Nanocomposites: A Sustainable Approach to Environmental Remediation.

The fast industrialization and mounting pollution have necessitated the need for advanced materials in order to degrade pollutants efficiently. Metal oxide-based and graphene-derivative photocatalytic nanocomposites are excellent for harnessing light energy in environmental remediation. Among them, ZnO-based nanocomposites have drawn considerable attention because of their high photocatalytic activity and stability. However, improving the performance of these nanocomposites is still necessary for their wide applications. This study explores the green synthesis, detailed characterization, and enhanced photocatalytic efficiency of reduced graphene oxide rGO/ZnO/Fe3O4 nanocomposites. The nanocomposites were synthesized via a hydrothermal method, utilizing milk thistle extract as a natural reducing agent, representing a novel and sustainable approach to fabricating magnetic rGO/Fe3O4 nanocomposites. These composites were further integrated with zinc oxide to produce a multifunctional material, exhibiting high surface area, superior electrical and thermal conductivity, and robust mechanical strength. The photocatalytic performance was significantly enhanced due to the synergistic interaction between graphene and metal oxide nanoparticles, leading to efficient degradation of environmental pollutants. Electrochemical analysis via cyclic voltammetry revealed distinctive redox peaks, demonstrating efficient electron transfer processes essential for applications in energy conversion and storage. This green synthesis not only provides a sustainable pathway for the development of advanced nanocomposites but also underscores their potential in a wide range of applications, including environmental remediation, sensing, energy storage, and optoelectronics.

Integrating an antimicrobial nanocomposite to bioactive electrospun fibers for improved wound dressing materials

This study investigates the fabrication and characterization of electrospun poly (ε-caprolactone)/poly (vinyl pyrrolidone) (PCL/PVP) fibers integrated with a nanocomposite of chitosan, silver nanocrystals, and graphene oxide (ChAgG), aimed at developing advanced wound dressing materials. The ChAgG nanocomposite, recognized for its antimicrobial and biocompatible properties, was incorporated into PCL/PVP fibers through electrospinning techniques. We assessed the resultant fibers’ morphological, physicochemical, and mechanical properties, which exhibited significant enhancements in mechanical strength and demonstrated effective antimicrobial activity against common bacterial pathogens. The findings suggest that the PCL/PVP-ChAgG fibers maintain biocompatibility and facilitate controlled therapeutic delivery, positioning them as a promising solution for managing chronic and burn-related wounds. This study underscores the potential of these advanced materials to improve healing outcomes cost-effectively, particularly in settings plagued by high incidences of burn injuries. Further clinical investigations are recommended to explore these innovative fibers’ full potential and real-world applicability.

Photothermally‐Induced Reversible Rigidity of Nacre‐Mimetic Composites Toward Semi‐Active Personal Safeguard

AbstractThe capacity to withstand challenges posed by complex environments is crucial for developing advanced high‐performance protective materials with mechanically adjustable nature. By constructing long‐range hierarchical network of shear‐stiffening gel‐carbon nanotube‐cellulose nanofiber (SCC) embedded within epoxy resin (ER), this work engineers a nacre‐inspired variable‐stiffness SCC‐ER composite (SCCE). Lightweight SCC scaffold attenuates falling impact force from 2.23 to 0.46 kN, and reaches 60 °C within 20 s under 1 sun exposure. Additionally, owing to the rigid ER matrix, SCCE exhibits 4.03 GPa elastic modulus, outperforming numerous conventional engineering materials in puncture resistance. Specific energy absorption of nacre‐mimetic SCCE presents 1.91 MJ m−3 while that of random structural SCCE is only 0.50 MJ m−3. More importantly, SCCE features representative photothermal‐induced reversible rigidity whose storage modulus varies from 9.85 MPa at 30 °C to 11.61 kPa at 116 °C under light stimulation. It also presents shape‐programmability, capable of adhering complex structural surfaces for protection. Eventually, SCCE‐based semi‐active adjustable protectors are constructed that leverage contactless photothermal effect to modulate rigidity. 5 mm‐thick smart SCCE‐protectors resist 163.93 m s−1 ballistic impact while 15‐mm commercial kneepads are penetrated at lower speed of 136.98 m s−1. This bio‐inspired semi‐active strategy proposes a promising avenue for enhancing personal protective equipment.

Exploring European Parents’ Attitudes Towards the Age Appropriateness of Digital Sexuality Education for Adolescents

We conducted a multinational cross-sectional survey in Europe to explore parental attitudes toward the appropriate age for adolescents to receive sexuality education through an app interface. This was delivered via an online survey across Belgium (n = 479), the United Kingdom (n = 445), and Italy (n = 454). Parents from Belgium consistently accepted their children accessing digital material at the youngest ages, whereas Italian participants selected the oldest age groups. Most parents, however,endorsed a spiral curriculum, whereby topics are introduced sequentially throughout adolescents’ school careers. Thus, whilst on average participants were comfortable with adolescents having access to content on body anatomy younger ages (from 9–12 years to 12–15 years), they approved virtual content on relationships and sex at older school ages (from 12–15 years to 15–18 years). European ethnicity, liberal sociosexual attitudes, lower religiosity, and higher educational attainment were associated with parents approving adolescent exposure to digital sex education at younger ages. To our knowledge, this exploratory study is the first to quantitatively examine parental attitudes toward digital sex education curricula, as well as explore the parental characteristics that relate to these attitudes. This work should inform educators internationally on their future efforts to deploy virtual sexuality learning.