Search Results (2,566)

The development of cost-effective and resource-rich materials is crucial for the practical application of microwave absorbers. This study demonstrates the successful fabrication of core-shell Fe and TiC nanoparticles encapsulated within carbon shells using the arc discharge method. The samples are designated as Fe3Ti1 and Fe1Ti3, where the numbers indicate the Fe-to-Ti mass ratio in the precursor (e.g., Fe1Ti3 = 1:3 by mass). In the arc discharge synthesis mechanism, the mass ratio of Fe to Ti in the raw material was adjusted from 3:1 to 1:3 to optimize the Fe/TiC/C interfaces under a CH₄ forming gas atmosphere. TEM analysis reveals spherical and polyhedral nanoparticles with diameters of 30–50 nm and a uniform carbon shell thickness of 3–4 nm. Raman spectroscopy shows that the Fe1Ti3 sample has a higher defect density (I_D/I_G = 1.13) compared to Fe3Ti1 (0.87), indicating a more disordered carbon structure. Magnetic measurements yield saturation magnetization values of 87 emu/g for Fe3Ti1 and 50 emu/g for Fe1Ti3, with coercivities of 190.72 Oe and 203.65 Oe, respectively. When composited with paraffin at 50 wt% loading, the Fe1Ti3 sample exhibits superior microwave absorption performance, achieving a minimum reflection loss (RL) of −25.22 dB at 8.23 GHz and an effective absorption bandwidth (RL ≤ −10 dB) of 4 GHz (6.5–10.5 GHz) at a thickness of 2.5 mm. This enhanced performance is attributed to the synergistic effect of multiple loss mechanisms, including conduction loss within the three-dimensional core-shell architecture, interfacial polarization at the heterojunctions between the core and the carbon shell, and magnetic loss induced by ferromagnetic behavior associated with defects in both the shell and carbon atomic layers. The magnetic loss in the (Fe/TiC)@C nanocomposites primarily arises from the natural resonance (at ~6.5 GHz) and exchange resonance (at ~12 GHz) of the Fe cores. The dielectric loss is primarily attributed to dipole, interfacial, and space charge polarization from TiC and the carbon shell, as well as multiple scattering effects between nanoparticles. Furthermore, far-field radar cross-section simulations substantiate that the Fe/TiC@C nanocomposite demonstrates excellent radar wave attenuation capability. Further, first principles simulations reveal that introducing Fe at the C/TiC interface induces strong charge redistribution and orbital hybridization, transforming a localized dielectric interface into a highly conductive and electronically coupled C/Fe/TiC system. This interfacial modulation enhances both dielectric loss (via charge transport and polarization) and magnetic loss (via Fe-induced magnetic interactions), thereby enabling optimized dielectric-magnetic synergy for broadband microwave absorption in (Fe/TiC)@C nanocomposites. Full article

Owing to its inherent electrical conductivity, reversible redox activity, and structural versatility, polypyrrole (PPy) has become an important material for advanced functional coatings. This review summarizes recent advances in PPy-based coatings, systematically exploring the correlation between fundamental material design and macroscopic multifunctional applications. First, the core structural characteristics of PPy and its primary fabrication strategies, including electrochemical deposition, chemical oxidative polymerization, solution processing, and hybrid composite engineering, are delineated. Subsequently, the role of PPy in surface protection is analyzed, with an emphasis on the synergistic mechanisms underlying corrosion mitigation, mechanical durability, and environmental barriers (e.g., anti-fouling and solar-driven desalination). In addition, the application expansion of PPy in emerging fields, such as electromagnetic interference (EMI) shielding, highly sensitive smart sensing, electroactive energy interfaces, and advanced biomedical electrodes, is summarized. Finally, current challenges—particularly the physicochemical trade-offs among conductivity, interfacial adhesion, and long-term stability—are discussed, and future development directions are prospected. By integrating green processing technologies and data-driven smart system integration, next-generation PPy coatings are expected to meet the demands of flexible electronics, sustainable energy, and precision medicine. Full article

The rapid expansion of artificial intelligence has intensified the demand for hardware systems capable of emulating brain-like information processing with high accuracy, energy efficiency, and reliability. Neuromorphic computing based on memristive artificial synapses has emerged as a promising approach to overcome the limitations of conventional von Neumann architectures. Although inorganic and oxide-based synaptic memristors have been widely explored for neuromorphic systems, they often suffer from poor linearity, asymmetric potentiation/depression behavior, limited conductance states, and device variability, which restrict learning accuracy and scalability. In contrast, polymer-based memristors have gained significant attention owing to their intrinsic advantages, including mechanical flexibility, molecular tunability, controllable electronic/ionic transport, low-temperature processability, and compatibility with large-area fabrication. This review critically examines recent advances in polymer—based memristive materials and devices for achieving linear and symmetric artificial synaptic behavior. Polymer synapses are classified into pure polymer, polymer composite, and polymer-hybrid systems through a mechanism to function framework. Rather than providing a general compilation of organic memristor studies, this review analyzes how polymer chemistry, ion-migration control, trap state distribution, redox activity, electrode selection, active layer thickness, and interface engineering govern conductance update linearity, symmetry, and uniformity. Fundamental switching mechanisms, material classifications, device architectures, key synaptic characteristics, and system-level neuromorphic performance, including pattern-recognition applications, are critically discussed. By explicitly linking material and device design to conductance update fidelity, learning accuracy, training convergence, and pattern-recognition reliability, this review provides practical design guidelines and future perspectives for next-generation polymer-based neuromorphic hardware with improved linearity, symmetry, reliability, and scalability. Full article

Hybrid materials, combining synthetic and biological components, leverage the biocompatibility of biological tissues—even after decellularization—alongside the mechanical strength, durability, and impermeability of synthetic polymers. This study presents the functional assessment of two hybrid conduits developed by coupling decellularized porcine pericardium and decellularized swine intestinal submucosa with a commercial polycarbonate urethane, intended for use as vascular and urinary substitutes, respectively. The response of the hybrid conduits to pulsatile flow was evaluated under physiologically relevant conditions in terms of pressure and flow rate. Their ability to withstand cyclic dilations was assessed using a dedicated image processing method that integrates classical approaches with AI-based segmentation techniques. Mechanical tests were also performed before and after hydrodynamic testing to investigate the potential effects of two different fluids—distilled water and simulated body fluid—on the hybrid materials following cyclic hydrodynamic stimulation. The results demonstrate that hybrid conduits deserve to be subjected to further evaluations to prove their potential use as substitutes in vascular and urological surgical applications. Full article

The Judd–Ofelt (J–O) intensity parameters and oscillator strengths are key to understanding the optical transition properties of rare-earth-doped glasses. However, the scarcity of experimental samples and the complex nonlinear relationship between composition and spectral properties pose significant challenges to accurate predictions. To address this, we propose a generalizable framework that integrates conditional generative adversarial network (cGAN)-based data augmentation with an attention-embedded artificial neural network (ANN)–support vector regression (SVR) hybrid model. The cGAN generates physically plausible virtual samples to enrich data distribution and enhance generalization in sparse compositional regions. The attention mechanism in the ANN identifies critical compositional features, which are then leveraged by SVR for robust regression of parameter trends. The framework demonstrates high predictive accuracy for Er³⁺-doped glasses, achieving R² values above 0.93 for Ω₂, Ω₄, and Ω₆, and exhibits strong generalization performance on independent Dy³⁺- and Nd³⁺-doped datasets without task-specific retraining, confirming its practical applicability across multiple rare-earth ions. The model maintains consistency across diverse glass host systems (tellurite, borate, phosphate, silicate/germanate, heavy-metal oxide), and the attention analysis reveals feature importance aligned with established glass chemistry principles. Demonstrated on Er³⁺, Dy³⁺, and Nd³⁺, with potential for a broader range of rare-earth ions through transfer learning and future dataset extensions, this approach offers a data-driven, physics-informed tool for the targeted design of rare-earth optical materials in next-generation optical sensors. Full article

A novel macromolecular photoinitiator (MPI) was synthesized from a copolymer of maleic anhydride and methyl methacrylate and subsequently functionalized with 3-hydroxy-2-methoxy-1,2-diphenylpropan-1-one moieties via a polymer-analogous acylation reaction. The structure and physicochemical properties of the MPI were characterized by IR, UV–Vis, NMR, DSC, and TGA analyses. TiO₂ nanoparticles were successfully functionalized with the MPI, yielding materials with enhanced surface activity and photoinitiating efficiency. The MPI-modified TiO₂ facilitated efficient UV-induced polymerization of methyl methacrylate, as confirmed by DLS and SEM analyses. Compared with unmodified fillers, the resulting composites exhibited improved dispersion, accelerated polymerization rates, and enhanced mechanical properties. This hybrid strategy offers a promising approach for the development of high-performance polymer nanocomposites through the integration of surface-engineered inorganic fillers and photoreactive polymers. Full article

The development of biodegradable scaffolds for load-bearing bone tissue engineering (BTE) presents a fundamental multi-criteria optimization challenge, requiring a simultaneous balance among mechanical performance, biological integration, and degradation kinetics. These criteria are inherently conflicting: composite formulations with the highest compressive strength frequently exhibit suboptimal porosity, while those with superior osteoconductivity often lack sufficient load-bearing capacity. To address this challenge rigorously, this study establishes a hybrid Fuzzy Analytic Hierarchy Process–Technique for Order of Preference by Similarity to Ideal Solution (Fuzzy AHP-TOPSIS) framework to evaluate and rank five clinically relevant biodegradable polymer–ceramic composite candidates: PLA/Hydroxyapatite (PLA/HA), PCL/Hydroxyapatite (PCL/HA), PLGA/Bioactive Glass (PLGA/BG), PLA/Carbon Nanotubes (PLA/CNT), and PLA/Magnesium (PLA/Mg). Quantitative property data were systematically extracted from ten peer-reviewed experimental studies published between 2021 and 2025, and converted into Triangular Fuzzy Numbers (TFNs) to explicitly model inter-study variability arising from differences in fabrication methods, filler loading, and testing conditions. Fuzzy AHP analysis identified Compressive Strength (w = 25.2%) and Cell Viability (w = 21.5%) as the dominant decision criteria for load-bearing cortical bone repair. The Fuzzy TOPSIS ranking identified PLA/HA as the optimal composite candidate (Closeness Coefficient, CCᵢ = 0.677), demonstrating the superior multi-criteria balance required for cortical bone repair applications. Although PLA/CNT achieved the highest mechanical strength, it was outranked due to lower osteoconductivity and elevated cytotoxicity uncertainty at high nanotube concentrations (CCᵢ = 0.544). Sensitivity analysis across five distinct weighting scenarios confirmed the robustness of PLA/HA as the primary candidate. These findings provide a validated, replicable computational blueprint for evidence-based scaffold material selection, with direct implications for reducing the burden of costly trial-and-error experimentation in BTE research. Full article

Glass fiber-reinforced polymer (GFRP) composites offer a compelling solution to the durability degradation of reinforced concrete (RC) structures in harsh marine and de-icing environments. Hybridizing fiber-reinforced polymer (FRP) with conventional steel reinforcement synergizes the superior corrosion resistance of FRP with the high ductility of steel. However, the synergistic mechanisms of GFRP–steel hybrid reinforced columns confined by either GFRP or steel spiral stirrups under axial compression remain insufficiently quantified. This study systematically investigates the axial compressive performance of such structures through material testing, static axial compression tests on seven short column specimens, and advanced finite element (FE) modeling. The investigation focuses on the effects of the steel-to-GFRP area ratio and the spiral stirrup type. Experimental results reveal that spirally confined hybrid columns exhibit failure modes remarkably similar to conventional RC columns. The incorporation of GFRP bars significantly enhanced the ultimate load-bearing capacity, while the steel bars ensured the requisite ductility. Notably, a higher ultimate capacity was achieved at a steel-to-GFRP area ratio of 1:1 under steel spiral confinement, retaining a ductility index equivalent to 83.6% of a pure RC column. Furthermore, an ABAQUS-based FE model was developed and rigorously validated against experimental data, successfully capturing the failure progression and ultimate capacities across diverse parameters. Ultimately, based on the superposition principle, by quantifying the independent load-bearing contributions and synergistic interactions of the spalled concrete cover, confined core, and hybrid bars, this study derives a theoretical formula. The proposed model accurately predicts the axial compressive capacity of spirally confined hybrid columns, providing an analytical tool for resilient structural design. Full article

Electrochemical sensors have emerged as promising tools for rapid pesticide screening in food and environmental samples because they combine simple instrumentation, fast response, portability, and compatibility with disposable electrodes. This review organizes recent progress through a cross-system framework linking pesticide class, interfacial electrochemical process, and material design. Carbon materials, metal–organic frameworks and their derivatives, metal nanoparticles, metal compounds, conducting polymers, MXene-based composites, and selected emerging materials are compared in terms of enrichment capability, charge-transfer regulation, catalytic amplification, recognition-layer integration, and suitability for real-sample analysis. Emphasis is placed on issues that are often under-discussed in performance-centered surveys, including matrix interference, electrode fouling, batch-to-batch reproducibility, storage stability, scalability, and cost-effectiveness. Representative examples show that the most useful advances arise not simply from lowering the limit of detection but from improving structure–function understanding and translating interfacial design into robust analytical performance. Future work should prioritize standardized fabrication and benchmarking protocols, in situ and operando identification of active sites and interface evolution, matrix-specific antifouling validation, multiresidue and metabolite analysis, and hybrid portable devices coupled with intelligent readout. Full article

Ultra-high molecular weight polyethylene (UHMWPE) fibers have recently emerged as a promising reinforcement material in fiber-reinforced concrete (FRC). To investigate the synergistic effects and reinforcing mechanisms of fibers with different elastic moduli within the concrete matrix, a series of hybrid fiber-reinforced concrete (HFRC) specimens were prepared by incorporating 0.25 vol%, 0.5 vol%, and 0.75 vol% carbon fibers (CFs) or polypropylene (PP) fibers into concrete containing 1 vol% UHMWPE fibers. The mechanical performance of the prepared composites was systematically evaluated through compressive, splitting tensile, flexural, and drop-weight impact tests. The experimental results indicate that concrete reinforced solely with UHMWPE fibers exhibits higher compressive strength but lower tensile strength, flexural strength, ductility, and impact toughness than the hybrid fiber systems. For both UHMWPE-CF and UHMWPE-PP hybrid concretes, the initial cracking impact resistance and failure impact resistance increased progressively with increasing CF or PP content. At equivalent fiber volume fractions, UHMWPE-PP hybrid concrete demonstrated superior resistance to initial cracking, whereas UHMWPE-CF hybrid concrete exhibited better post-failure impact resistance. Furthermore, fractal theory was employed to quantitatively characterize the impact damage behavior of HFRC specimens. The impact damage evolution equation is established by using the two-parameter Weibull distribution model. The findings provide theoretical and experimental support for the design and optimization of hybrid fiber-reinforced concrete subjected to impact loading. Full article

Tropical lignocellulosic residues are increasingly relevant feedstocks for lignin-containing nanocellulose composites, but their performance cannot be predicted from botanical origin or bulk lignin percentage alone. This review defines the interface as the geometrical boundary between phases and the interphase as the finite, compositionally graded region in which lignin distribution, nanocellulose morphology, adsorbed water, and the surrounding matrix jointly govern stress transfer and mass transport. Using an evidence-weighted framework, the literature is organized into the following categories: residual-lignin nanofibrils, redeposited-lignin systems, lignin nanoparticle assemblies, compatibilized thermoplastic hybrids, and all-lignocellulosic sheets. Representative quantitative observations show that controlled residual lignin can the increase water contact angle from approximately 35 degrees to 78 degrees and reduce oxygen permeability by up to 200-fold in nanopapers, while selected PLA/LCNF systems show tensile-strength and modulus increases of 37% and 61%, respectively; however, high or poorly distributed lignin can suppress fibrillation, lower viscosity, weaken gel networks, and reduce reproducibility. The most defensible near-term product windows are packaging layers, grease/oil barrier papers, coatings, paper-like multilayers, and selected porous media. Thermoplastic matrices remain process-sensitive, and biomedical, additive-manufacturing, nano-reactor, and energy-material claims require stronger validation of the extractables, rheology, humidity history, TEA/LCA metrics, and end-of-life behavior. This review, therefore, provides a critical, application-backward roadmap for tropical biorefineries in which interfacial function, wet handling, drying energy, and process integration are assessed together rather than treated as independent variables. The abbreviations used in the abstract are defined as follows: CNFs, cellulose nanofibrils; CNC, cellulose nanocrystals; LCNF, lignin-containing cellulose nanofibrils; LCNCs, lignin-containing cellulose nanocrystals; PLA, poly(lactic acid); PHB, polyhydroxybutyrate; PHAs, polyhydroxyalkanoates; PVA, poly(vinyl alcohol); DESs, deep eutectic solvents; TEA, techno-economic analysis; LCA, life-cycle assessment; ML, machine learning. Full article

3D concrete printing (3DP) enables automated construction with reduced material waste and enhanced geometric flexibility. However, its structural performance remains sensitive to anisotropy, mix design, and printing parameters, thereby complicating quality control. Self-sensing cementitious materials provide a promising approach by enabling intrinsic strain monitoring during fabrication and service. In this study, a hybrid multi-material printing strategy was developed using a conductive cement-based mix incorporating graphite (G), milled carbon microfibers (MCMF), and chopped carbon microfibers (CCMF), alongside a plain cement-based matrix. Based on percolation analysis, an optimal composition of 2 wt.% G, 0.25 wt.% MCMF, and 0.0625 wt.% CCMF was selected. Reinforced beam specimens were fabricated with the conductive material embedded in either the tensile (bottom) or compressive (top) region, combined with two internal architectures: diagonal infill and solid-base configuration. Four configurations were defined: Pattern 1 (bottom/diagonal), Pattern 2 (bottom/solid-base), Pattern 3 (top/diagonal), and Pattern 4 (top/solid-base). Cyclic three-point bending tests with spatially distributed electrical measurements were conducted to evaluate the electromechanical response in the elastic range. Specimens with the conductive layer located in the tensile region (Patterns 1 and 2) consistently exhibited higher gauge factors than those in the compressive region (Patterns 3 and 4). Pattern 2 exhibited the best sensing performance, with an average gauge factor of 556 and SNR of 31. Across all configurations, SNR decreased with increasing electrode spacing, with reductions of up to 31.0%, demonstrating the effect of current path length on sensing performance. Full article

Carbon/polymer composites are increasingly designed as microstructure-engineered multifunctional materials that combine mechanical reinforcement with electrical/thermal transport, electromagnetic interference (EMI) shielding, and sensing. Performance is governed less by filler fraction than by the coupled control of network topology, junction resistance, and interfacial thermal boundary resistance under processing-induced shear and thermal histories. Electrical response follows percolation combined with tunneling/contact-controlled junctions, producing nonlinear σ(φ) behavior and high piezoresistive sensitivity near the percolation threshold. In contrast, thermal transport is commonly limited by Kapitza resistance and filler–filler junction resistance, restricting exploitation of the intrinsic conductivity of CNTs and graphene. Recent advances emphasize hybrid and 3D carbon architectures that densify connectivity, reduce junction losses, and enable programmable anisotropy via scalable routes such as masterbatch extrusion and additive manufacturing. However, translation remains constrained by dispersion-driven variability, transport–toughness trade-offs, and incomplete durability assessment under cycling, humidity, and reprocessing. This review consolidates mechanistic structure–processing–property relationships and provides application-driven design rules for sensors, EMI shielding, and thermal management. Full article

Cancer continues to present a profound challenge due to high mortality and the inherent limitations of conventional treatments, including suboptimal targeting, systemic toxicity, and difficulty in overcoming physiological barriers. Micro/nanorobots (MNRs) offer a promising enhanced precision and efficacy in cancer therapy. This review systematically analyzes recent advancements in MNR applications, establishing a consistent framework that interlinks their diverse material compositions, propulsion strategies, and therapeutic functions. We critically compare various materials (inorganic, organic/polymeric, and biological/hybrid materials), elucidating their respective trade-offs in biocompatibility, biodegradability, and stimulus responsiveness. This paper further examines both internal (chemical and biological) and external (magnetic, light, and ultrasound) propulsion mechanisms, highlighting their strengths in overcoming biological barriers and enabling complex in vivo navigation, while also discussing their inherent limitations in control, fuel dependency, and tissue penetration. We then synthesize the therapeutic capabilities of MNRs across targeted drug delivery, phototherapy, radiotherapy, and immunotherapy, emphasizing common advantages like enhanced tumor specificity and reduced systemic side effects. A forward-looking perspective was also provided on the remaining challenges, particularly focusing on in vivo controllability, long-term biosafety, manufacturing scalability, and the significant hurdles in clinical translation. By offering a more critical and integrated analysis, this review underscores the immense potential of MNRs to revolutionize personalized precision cancer treatment, while candidly addressing the complex obstacles that must be surmounted for their successful clinical adoption. Full article

The twist angle serves as a geometric tuning parameter in two-dimensional layered materials, enabling modulation of interlayer coupling and band structures without altering the chemical composition. In this work, six commensurate twisted bilayer WSe₂ configurations with rotation angles of 0°, 9.4°, 13.14°, 21.9°, 27.8°, and 60° were systematically investigated using first-principles density functional theory. Structural optimization, together with calculations of electronic structures, density of states, charge redistribution, effective masses, and optical properties, was performed. The results show that AA (0°) and 2H (60°) stackings exhibit the largest and smallest interlayer separations, respectively, whereas intermediate twist angles yield similar average spacings but distinct local stacking registries. All configurations remain indirect-gap semiconductors, with the valence band maximum located at K and the conduction band minimum near the Q point along the K–Γ path. The band gap increases from 1.450 eV at 0° to 1.579 eV at 27.8°, before decreasing to 1.333 eV at 60°, indicating strong twist-angle modulation of interlayer coupling. Density-of-states analysis shows that the valence-band edge mainly originates from Se-p and W-d hybridized states, whereas the conduction-band edge is dominated by W-d states, with intermediate angles exhibiting enhanced band folding and localization features. Charge-density analyses further reveal notable interfacial charge redistribution, which is most pronounced at 9.4°. Optical responses in the in-plane directions are nearly identical and significantly stronger than those along the out-of-plane direction. Optical absorption mainly occurs in the ultraviolet region, with band-edge features appearing in the near-infrared range. Intermediate twist angles exhibit broader dielectric responses in the visible region and extended long-wavelength tails, indicating enhanced interband transition channels. These results demonstrate that twist-angle engineering enables effective tuning of electronic and optical properties in bilayer WSe₂, providing theoretical guidance for the design of tunable optoelectronic devices. Full article