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Biocomposite materials made of natural plant fibers are becoming a viable alternative to the use of synthetic ones such as glass fibers, thanks to many economic, ecological, and technical benefits. However, their massive use in the industry requires optimal control of their mechanical performances, which constitutes a real scientific issue to be overcome. Indeed, biocomposites suffer from an important variability in their mechanical properties because of their multiscale structure, natural growth conditions, and various processing parameters, in addition to eventual chemical treatments. Biocomposites are also highly sensitive to the surrounding environment in terms of humidity and temperature because of the hydrophilic properties of natural plant fibers. In this context, this Perspective aims to provide a critical look at the influence of the main factors that affect the mechanical properties of biocomposites in order to suggest some possible research outlooks that could contribute to optimizing the control of these mechanical properties and expanding the use of biocomposites in industry. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effects of post length, post material, and substance loss on the fracture resistance of endodontically treated mandibular premolars. Materials and Methods: A total of 96 extracted human mandibular first premolars were endodontically treated and divided into 12 test groups (n = 8 each) based on the number of residual walls (one/two), post material (glass-fiber/titanium), and post length (5 mm, 7.5 mm, and 10 mm). After luting the posts, specimens received a composite resin core and a crown preparation with a 1.5-mm ferrule. Cast cobalt-chromium crowns were cemented using glass-ionomer cement. After 1,200,000 chewing cycles with a load of 49 N and simultaneous thermocycling (5°C to 55°C), specimens were quasi-statically loaded at 30 degrees to the longitudinal axis of the tooth until fracture. Fracture loads were analyzed using three-way, two-way, and one-way ANOVA (a = .05). Fracture modes were examined under a stereomicroscope (×25 magnification) and recorded. Results: The mean ± SD fracture loads ranged from 642 ± 190 N (one wall, glass fiber, 5 mm) to 1,170 ± 130 N (two walls, titanium, 7.5 mm). The mean fracture load of titanium posts was significantly higher than that of glass-fiber posts (P < .001), and the 7.5-mm post length exhibited significantly higher fracture loads than groups with 5-mm and 10-mm post length (P = .008). Conclusions: Teeth restored with titanium posts revealed considerably higher fracture resistance than teeth restored with glass-fiber posts, especially if 7.5-mm-length posts were used. [ABSTRACT FROM AUTHOR]

The dissolution behavior of calcium aluminosilicate based glass fibers, such as stone wool fibers, is an important consideration in mineral wool applications for both the longevity of the mineral wool products in humid environments and limiting the health impacts of released and inhaled fibers from the mineral wool product. Balancing these factors requires a molecular-level understanding of calcium aluminosilicate glass dissolution mechanisms, details that are challenging to resolve with experiment alone. Molecular dynamics simulations are a powerful tool capable of providing complementary atomistic insights regarding dissolution; however, they require force fields capable of describing not-only the calcium aluminosilicate surface structure but also the interactions relevant to dissolution phenomena. Here, a new force field capable of describing amorphous calcium aluminosilicate surfaces interfaced with liquid water is developed by fitting parameters to experimental and first principles simulation data of the relevant oxide-water interfaces, including ab initio molecular dynamics simulations performed for this work for the wüstite and periclase interfaces. Simulations of a calcium aluminosilicate surface interfaced with liquid water were used to test this new force field, suggesting moderate ingress of water into the porous glass interface. This design of the force field opens a new avenue for the further study of calcium and network-modifier dissolution phenomena in calcium aluminosilicate glasses and stone wool fibers at liquid water interfaces. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate different protocols for recementation of dislodged glass fiber posts (GFPs).Materials and Methods: The root canals of 50 bovine incisors were prepared to receive GFPs, which were conditioned with 24% hydrogen peroxide, silanized, and cemented with a self-adhesive resin cement. After light curing, the specimens were submitted to a pullout test. The dislodged GPFs were distributed into five experimental groups (n = 10 each) according to surface treatment for recementation: NT = no treatment; SI = silane; ET = 92.8% ethanol/silane; HP = 24% hydrogen peroxide/silane; AL = airborne-particle abrasion (50-μm alumina)/silane. The GFPs were recemented with the same self-adhesive resin cement, and specimens were submitted to a second pullout test. Data were analyzed by Student t test and one-way ANOVA (α = .05).Results: For all groups, the recementation bond strength was higher than the strength obtained after the first cementation (P < .05). There were no statistical differences among the experimental recementation protocols (P = .096).Conclusion: All recementation protocols might be reliably applied since they led to higher bond strength than the first cementation. [ABSTRACT FROM AUTHOR]

Laser glass deposition is an additive manufacturing method to produce individualized glass components. This process uses a CO2 laser with a defocused beam as a heat source to additively melt-fused silica filaments. The fiber filament is fed laterally in the process zone and is deposited layer-by-layer to form 3D structures. The formation of boundary layers in conventional 3D-printing methods is a usual byproduct of the process. In this paper, the boundary layer formation of deposited fused silica filaments is investigated in detail by means of varying different process parameters such as, laser power, feed rate, laser spot diameter, and printing strategy. This involves examining both thin-walled and thick-walled test specimens. Quality characteristics like the surface roughness and the optical transmission are analyzed for the printed specimen. Finally, fully transparent structures with surface roughness below 100 nm and a transparency of 90% could be printed boundary layer-free and without post-processing. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM), also recognized as 3D printing, has gained significant attention in various industries for its potential to revolutionize production processes. One critical aspect of AM is ensuring the quality and performance of printed parts, particularly concerning mechanical properties like tensile stress. In the present work, the effect of process variables on 3D‐printed acrylonitrile butadiene styrene (ABS)/Glass fiber composite materials was explored. The machine learning approach, classification and regression trees (CART) algorithm, was used to predict tensile stress in ABS/Glass fiber composite materials based on predictor variables such as layer thickness, nozzle temperature, bed temperature, and infill density. The objective is to develop an accurate and interpretable model that captures the relationships between these variables and tensile stress. The model is evaluated using performance metrics such as R‐squared, mean absolute deviation (MAD), and root mean squared error (RMSE) on both training and test datasets. From results the highest tensile stress of 39 MPa was achieved at nozzle temperature of 250°C, bed temperature of 80°C and infill density at 60%. The CART model predicts the most influencing parameter as infill density followed by nozzle temperature and bed temperature. Highlights: Novel material is manufactured by sandwiching glass fiber in ABS layers.FDM process for novel material is optimized based upon process parameters.SEM analysis reported good interlayer adhesion with few micro‐porosities.Modeling of tensile stress by classification and regression tree algorithm.CART model predicts significant impact of infill density on tensile stress. [ABSTRACT FROM AUTHOR]

Polyamide 6 (PA6) thermoplastic‐based composites are often used in automobile, aerospace, marine, and biomedical applications. Here, PA6 and its composites with varied chopped glass fiber (GF) concentrations of 5, 10, and 20 mass% were fabricated by injection molding. The specimens were characterized by structural, thermal kinetic, mechanical, as well as tribological analyses. Tribological performance was evaluated in dry pin‐on‐disc test apparatus with three different levels of time, speed, and load factors. The PA6/GF composites showed high decomposition activation energy compared to pure PA6. Thermal activation, Ea increased to 46.16% with increasing of GF content up to 10 mass% in the composites compared to PA6. PA6/5GF exhibited best mechanical properties (e.g., strength = 44.46 MPa and Hardness = 45.2). Addition of GF in PA6 significantly improved tribological properties, coefficient of friction (COF) and specific wear rate (WR) besides thermal stability and mechanical properties of the composites. Especially, COF and WR of PA6/5GF composite decreased by 17%–65% and 68%–92%, respectively, compared to PA6. ANOVA statistical results determined the significant contribution of the tribological factors to the performance metrics of the composites for COF and WR. Therefore, the PA6/5GF composite would highly be useful for tie‐rod gears and bearings as a crucial structural component in automotive bodywork. [ABSTRACT FROM AUTHOR]

Polymer composites with continuous fibers are expected to exhibit good mechanical performance due to orientation and high aspect ratio of fillers. Fused filament fabrication (FFF) provides an affordable method for processing these materials as products with tunable architecture. By incorporating continuous bioactive fibers coated with biodegradable polymer, the degradation rate of printed scaffolds may vary over time. As proof of concept, macroporous composites were 3D printed using continuous glass fiber‐reinforced polycaprolactone filament. Parametrization and challenges associated with printing on non‐dedicated equipment are discussed. A model describing the melt flow was employed to evaluate the velocity and shear rate profiles. Although the maximum velocity is approximately 18 mm s−1 for both neat and reinforced polymer, the obstruction caused by fibers results in higher shear rate, up to 481 s−1, higher pressure gradient, 1.95 MPa mm−1, and higher velocity gradient, conditions that limit print quality. Additionally, it was also possible to determine the shear stress experienced by the fiber bundle, 300 KPa, and the influence of different processing conditions. This investigation advances the development and understanding of manufacturing of continuous fiber‐reinforced polymers via FFF. [ABSTRACT FROM AUTHOR]

Highlights The bio‐sandwich composites are lightweight, economical, recyclable, and easily obtainable. Sandwich panels comprising glass fiber/epoxy face sheets and hemp fiber/epoxy core with varying fiber orientations, thickness, and montmorillonite nanoclay are prepared by stirring the epoxy/clay mixture to have uniform dispersion followed by compression molding. The sandwich and monolithic composites are loaded under quasi‐static punch shear. The sandwich panel with 3 wt.% nanoclay shows optimum quasi‐static tensile modulus and strength than the neat panel. Energy absorption, and specific energy absorption of sandwich panels G0/H(0)5/G0‐0%, G0/H(0)10/G0‐0%, G0/H(0)15/G0‐0% are 2%, 76%, 111%, and 28%, 132%, 183% higher than same weight glass/epoxy composites G(0)5‐0%, G(0)8‐0%, G(0)10‐0%. Energy absorption and specific energy absorption of panels G0/H(0)3/G0‐3%, G0/H(0)7/G0‐3%, G0/H(0)9/G0‐3% are similar, 25%, 24%, and 18%, 55%, 57% higher than same thickness composites G(0)5‐0%, G(0)8‐0%, G(0)10‐0%. The energy absorption of sandwich panel G0/90/H(0)15/G90/0‐0% is 49% lower than same weight composite G0/90/(0)9/90/0‐0%. Similar behavior is observed for panels with ±45° face sheets, 0° core, and 0°/90° face sheets, ±45° core compared to composites. Therefore, sandwich panels with 0° face sheets and core outperform composites and can replace them in structural applications in automotive. Particularly, panels show greater improvement over same‐weight composites than same‐thickness ones. Energy absorption of sandwich panels having 0° and ±45° cores is comparable while it is higher than a panel with 0°/90° core, each of 0°/90° face sheets. This is observed for monolithic composites as well. The quasi‐static indentation response of bio‐sandwich composites is examined. Bio‐sandwich composites outperform synthetic composites, each of the same weight. Bio‐sandwich panels with 3 wt. % nanoclay perform better than the same thickness synthetic composites. The behavior of sandwich and monolithic composites varies with fiber orientations. [ABSTRACT FROM AUTHOR]

In the field of composite materials, many reports have shown that catastrophic structural damage is caused by lightning strikes. In this study, new design concepts were proposed for the lightning-strike protection of nickel-coated glass/epoxy foam-core composites. Instead of using a neat metal mesh, glass fibers were modified with nickel particles via a plating technique to improve their thermal and electrical conductivities. In addition, a thin Invar plate was inserted at the middle of the structure and a foam core was introduced to reduce damage to the structure. Three models with different materials and stacking sequences were used in this study. Severe damage was experimentally observed following artificial lightning at a peak current of approximately 150 kA when considering a waveform A. Furthermore, numerical prediction was performed to identify the damage mechanisms of the structures. Besides the heat flux source, a mechanical source known as the shock wave overpressure was investigated separately as a new factor for dielectric materials. These two sources of lightning were determined as minor reasons for the structural damage. The failure modes were analyzed for further discussion about the failure mechanism in this study. [ABSTRACT FROM AUTHOR]

Advanced engineering materials like glass fabric-reinforced composites (GFRC) are frequently utilized in automotive components, civil structures, aviation sectors, etc. Contrary to metals, the anisotropic nature of composites makes it difficult to forecast damage and failure under real-time loads. GFRC is employed in this work to demonstrate structural health monitoring (SHM) using a reduced graphene oxide (rGO) coated glass fabric piezo-resistive sensor. The sensor was embedded in the GFRC composite to detect changes in the fractional electrical resistance under flexural strain. The developed composite specimens were subjected to three-point bending to examine the piezo-resistive performance. Throughout testing, the effect of sensor width and relative positions in the thickness direction within the composite specimen on strain and damage detection was assessed. The results of the tests revealed that these parameters were responsively associated with the piezo-resistance of the developed sensor. This study concluded that the developed piezo-resistive sensor has the potential to be used as a strain and damage detection mechanism for glass fabric-reinforced composite structures for disparate applications. [ABSTRACT FROM AUTHOR]

Environmental awareness has driven a crucial search for biodegradable materials. Over the past few decades, the machining of these materials, particularly through drilling, has garnered significant research interest. This study presents an evaluation of the drilling performance of a hybrid composite (jute/glass), considering factors such as the concentration of chemical treatment with sodium bicarbonate, the type of glass fiber (random or woven), the degree of hybridization between the jute and glass fibers, and cutting parameters like rotation speed, feed rate, and drill diameter. Drilling operations were conducted to determine the maximum temperature in the cutting zone, the surface roughness of the drilled holes, and the maximum delamination factor. A Sobol sensitivity analysis was performed to identify the input parameters influencing these responses studied. Predictive modeling of the results based on the input factors was then conducted using the deep neural network (DNN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) approaches. The results show that the type of glass fiber significantly affects surface roughness, while rotation speed primarily influences cutting temperature. Similarly, the drill diameter directly impacts the maximum delamination factor. Finally, the predictive modeling demonstrates that the ANN-IGWO models provide the best predictions of drilling parameters compared to the ANN-GA and ANFIS models, with mean absolute errors ranging from 1.22 to 12%. [ABSTRACT FROM AUTHOR]

In this paper, the friction properties of the port pair with non‐smooth surface in the pump were studied. The lubrication film was modelled and simulated to analyse dynamic pressure, velocity vector and friction coefficient. Tests were made for studying the effects of pit shape and revolution speed on friction properties of glass fibre epoxy resin (GFER) samples under seawater lubrication, with the wear of the surface and friction coefficient discussed. The results show that GFER is mainly manifested as adhesive and abrasive wear during the tests. The simulations and tests suggest that the hydrodynamic lubrication effect is improved by increasing revolution speed and using non‐smooth surfaces, with the friction coefficient being decreased. Moreover, a roughness test was conducted, and it was found that the Ra value of the 316L sample decreased, whereas the Ra value of the GFER sample increased. [ABSTRACT FROM AUTHOR]

Polyamide (PA) composites exhibit excellent properties such as stiffness, impact resistance, chemical resistance, and thermal stability, making them widely used in automotive interiors, engine parts, and bodywork. To leverage these advantages, high-content composite materials that enhance the wettability and interfacial adhesion between polyamide 66 (PA66) and glass fiber are essential. In this study, we synthesized linear and hyperbranched amide-based flow modifiers to improve the flowability of PA66 composites. H-NMR and FT-IR analyses confirmed the successful preparation of these structures. FT-IR analysis confirmed the successful synthesis of flow modifiers, showing characteristic amide peaks at 1650 cm−1 and the absence of -NH2 peaks at 3300 cm−1. Five flow modifiers were mixed with PA66 in various ratios using a micro-compounder, and viscosity reduction was confirmed by rotational rheometer measurements. Tensile strength and DMA indicated that PA66 composites with flow modifiers showed improved mechanical properties without significant reduction. Notably, PA66 composites with ACDA exhibited a superior viscosity reduction effect while maintaining mechanical strength. The DMA results indicated that the mechanical properties of PA66 composites with flow modifiers showed no significant reduction. The tensile strength of samples with flow modifiers ranged from 208 to 212 MPa, and the elongation at break was between 8.94 and 9.18%. These findings demonstrate that the synthesized flow modifiers improve the viscosity of PA66 composites while maintaining or enhancing mechanical properties. [ABSTRACT FROM AUTHOR]

Glass fiber reinforced phenolic composites (GFRP) are an advanced composite material with good processability, fatigue resistance, corrosion resistance and stability, and are widely used in the production of structural parts for aircraft and ships. Our research described in this article explores the performance changes of GFRP in different aging media with prolonged aging time using GFRP with different fiber/matrix ratios. The research results indicated that aging time had the most significant impact on the various properties of the composite materials among all variables. With the extension of aging time, the bending strength of our composite materials decreased significantly, with a maximum decrease of 33%. The water absorption rate gradually increased and tended to stabilize, but the thermal decomposition temperature remained at 300 °C, and the mass residual rate remained stable at around 61% with little change. As the content of GF was increased, the aging of the composite gradually slowed down, and the rate of decline in its bending strength gradually decreased. In addition, the influence of different aging media on the performance was also studied, and it was found that the presence of NaCl in artificial seawater could cause changes in the osmotic pressure at the interface of the composite materials and the sea water, thus exacerbating interface damage and affecting the material's performance. [ABSTRACT FROM AUTHOR]

Er3+‐doped fluoride glass and fiber have been widely used in multiple fields such as mid‐infrared laser, visible laser, and amplifier. However, there is no unified conclusion on the thermal and optical properties with respect to varying concentrations of Er3+ doping. Furthermore, this is a paucity of systematic guidance on the preparation of Er3+‐doped fluoride glass and fiber. In this study, fluorozirconate fiberglass with Er3+ doping is systematically examined. Additionally, a preliminary explanation of the evolutionary behavior of glass devitrification, thermal properties, and fluorescence properties is provided. Energy transition models were built for 1.5 and 2.7 µm emissions in Er3+‐doped fluorozirconate at room temperature. Moreover, a suitable doping concentration is proposed based on the evolutionary behavior of thermal and optical properties. In this study, guidance on appropriate Er3+ doping concentration levels in fluorozirconate glass is provided and potential applications are explored. [ABSTRACT FROM AUTHOR]

The design and development of efficient microwave-absorbing and electromagnetic interference (EMI) shielding materials and structures to conceal electromagnetic (EM) waves remains a consistent and challenging task. Despite advancements in materials science and microwave engineering, there is a need for optimized materials that offer both effective microwave absorption and EMI shielding while minimizing material layer thickness. This research aims to address this gap by utilizing the firefly algorithm (FFA) to predict the optimal medium properties and thickness of microwave-absorbing and EMI shielding materials under specific constraints. In this context, a comprehensive investigation was carried out at the X-band involving numerical and experimental EM characterization of novel lightweight fiber-based samples. Additionally, the FFA has been applied to optimize these fiber-based microwave structures within the given constraints. Two separate objective functions (OBF) targeting minimum sample thickness, maximum microwave absorption, and shielding effectiveness (SE) bandwidth have been integrated into the FFA to address the thickness–bandwidth trade-off issue. Subsequently, resistive ink-coated glass fiber (IGF) and ink-coated mesh fiber (IMF) were developed and characterized based on the optimal solutions provided by the FFA. Consequently, an optimized IMF sample provides a minimum reflection coefficient (RC) of −19.0 dB at 10.7 GHz with a bandwidth of 2.8 GHz (9.6 to 12.4 GHz) below the −10 dB threshold. Besides, the optimal IGF sample achieves maximum SE of 11 dB at thickness of only 0.8 mm and covers the entire operating band. Furthermore, the response of the proposed structure was assessed for various oblique angles of incidence, revealing significant potential for various practical applications. A strong correlation between measured and theoretical findings underscores the potential of the proposed approach in realizing efficient microwave stealth and EMI shielding materials. [ABSTRACT FROM AUTHOR]

Highlights This study examines the mechanical properties of open‐hole unidirectional laminates by hybridizing jute and glass fabrics. Characterization involved microscopy, thickness variation, density measurements, tensile, and flexural tests. Numerical models were developed for each configuration, validated by experimental data, with a VUMAT subroutine implemented in ABAQUS/Explicit™ to simulate progressive damage using the 3D Hashin criteria. Results showed voids in the interphase regions of both jute‐based and hybrid laminates, indicating that jute fibers contribute to void formation. Thickness varied with the number of hybrid interfaces, with the glass laminate (G5) being thinnest, while jute and hybrid laminates (JGJGJ, JGGGJ and J5) were thicker. Density variation was influenced by the fiber types and their respective densities. Tensile tests revealed lower strength and modulus in jute laminates compared to glass. Open holes reduced tensile properties across laminates, except for G5. Numerical‐experimental tensile strength differences ranged from 0.5% to 6.1% (without hole) and 3.7% to 64.0% (with hole). Open‐hole laminates also showed reduced flexural strength but maintained a consistent flexural modulus. Numerical and experimental results for jute and hybrid laminates matched closely, with differences from 0.02% to 19.5%. Failure modes during tensile and flexural tests provided important insights into laminate behavior. Hybridization of jute and glass fibers led to void formation in interphase regions. Thickness variation in laminates influenced by the number of hybrid interfaces. Density variation primarily influenced by fiber types and their densities. Bi‐component jute laminates showed lower tensile properties compared to glass laminates. Open holes resulted in decreased tensile properties, except for G5‐H laminate. Failure modes during tensile testing provided valuable insights into laminate behavior. Open‐hole laminates exhibited reduced flexural strength with similar flexural modulus. [ABSTRACT FROM AUTHOR]

Highlights Fiber hybrid with bundle‐by‐bundle dispersion can achieve the high performance of composites, fully understand the hybrothermal resistance of hybrid composites is the key to prove the applications in engineering structures. In the present paper, the hygrothermal resistance performances of new type carbon and glass fiber reinforced epoxy based hybrid rod with bundle‐by‐bundle dispersion produced by pultrusion technology is investigated experimentally. The tests of water absorption and desorption, thermal and mechanical performances are performed to obtain the evolution rules of hygrothermal aging. As a result, the water absorption of hybrid rod confirms to the Fick's diffusion behavior, the serious relaxation of resin matrix and the interfacial debonding of fiber‐resin exposed at high temperature provide more diffusion space for water molecules. Long‐term hydrothermal aging results in the recoverable plasticization of resin matrix and irrecoverable interfacial debonding of fiber‐resin, which brings about the degradation of 6.7%–15.0% for short beam shear strength (SBSS) retention. In addition, the plasticization effect reduces the cross‐linking density of resin matrix, which leads to the degradation of 3.3%–15.6% for glass transition temperature (Tg) retention. The life prediction results show that degradation rate of SBSS is gradually slow down and reached to a stable retention of 85.5%. Relaxation of resin matrix and interfacial debonding accelerate the diffusion of water molecules. Plasticization and interfacial debonding lead to the degradation of short beam shear strength retention and glass transition temperature. Long‐term life prediction shows that short beam shear strength e retention is 85.5%. [ABSTRACT FROM AUTHOR]

This study investigates the residual tensile behaviour of hybrid Carbon Glass fibers reinforced thermoplastic PEEK laminates after they were exposed for 5 min to a hydrogen/oxygen flame. This flame results in a severe thermal aggression characterized by a wall temperature ranging from 900 to 1270 °C and with different heat fluxes (from 200 to 800 kW/m2). The thermally-induced damages were examined by means of microscopic observations and micro CT analyses. The results show that the mass loss linearly depends on the measured heat flux for a 5 min exposure. Depending on the fire testing conditions, the mechanical properties in tension (stiffness and strength) are totally degraded after exposure to the highest heat fluxes (600 and 800 kW/m2) but the retention of the tensile properties is moderate (about −35 to −60% decrease in strength and stiffness, respectively) after exposure to a 200 kW/m2 heat flux. The residual tensile properties of CG/PEEK laminates follow master curves representing the correlations between the mass loss and the changes in the tensile properties regardless the heat flux. These master curves provide a relevant design rule for composite parts to be used under critical service conditions (H 2 /O 2 flame exposure). • The influence of a H 2 /O 2 flame on the behaviour of composite materials was studied. • Wall temperature ranges from 900 to 1270 °C for heat fluxes from 200 to 800 kW/m2. • The mechanical properties are totally degraded after exposure to 600–800 kW/m2. • The changes in the tensile properties are correlated to the mass loss. • Master curves provide a criterion to design composite parts under H 2 /O 2 flame. [ABSTRACT FROM AUTHOR]

Sandwich panels with trapezoidal metal/glass fiber cores are increasingly popular due to their lightweight and energy-absorption properties. This study employs response surface methodology (RSM) and Box-Behnken design to investigate the effects of core angle, fiber orientation, and MCM-48 nanoparticles on the panels' energy absorption and peak force, developing regression models with high R2 values of 0.9027 and 0.9228, respectively. Experimental tests were conducted to validate these models, showing minimal deviation from predicted values. Results indicate that increasing the fiber orientation angle from 30° to 90° enhances energy absorption and peak force by 72.18 and 46.9%, respectively, and adding MCM-48 nanoparticles up to 0.25% weight improves energy absorption by 60.8%. A core angle of 52° balances energy absorption and peak force, while integrating a metal wire mesh within the panels significantly enhances energy absorption and reduces core brittleness. The optimal parameters for maximum energy absorption and minimum peak force include a core angle of 58°, fiber orientation of 73.5°, and no nanoparticles. These findings provide valuable insights into the design and optimization of sandwich panels for various applications. [ABSTRACT FROM AUTHOR]

In this study, a novel bionic periosteum (BP)‐bioactive glass fiber membrane (BGFM) is designed. The introduction of magnesium ion (Mg2+) and zinc ion (Zn2+) change the phase separation during the electrospinning (ES) jet stretching process. The fiber's pore structure transitions from connected to closed pores, resulting in a decrease in the rapid release of metal ions while also improving degradation via reducing filling quality. Additionally, the introduction of magnesium (Mg) and zinc (Zn) lead to the formation of negative charged tetrahedral units (MgO42− and ZnO42−) in the glass network. These units effectively trap positive charged metal ions, further inhibiting ion release. In vitro experiments reveal that the deigned bionic periosteum regulates the polarization of macrophages toward M2 type, thereby establishing a conducive immune environment for osteogenic differentiation. Bioinformatics analysis indicate that BP enhanced bone repair via the JAK‐STAT signaling pathway. The slow release of metal ions from the bionic periosteum can directly enhance osteogenic differentiation and vascularization, thereby accelerating bone regeneration. Finally, the bionic periosteum exhibits remarkable capabilities in angiogenesis and osteogenesis, demonstrating its potential for bone repair in a rat calvarial defect model. [ABSTRACT FROM AUTHOR]

Finfish aquaculture is one of the fastest-growing food production sectors in the world, and numerous infectious diseases are a constant challenge to the fish farming industry, causing decreased fish health and, consequently, economic losses. Specific and sensitive tools for pathogen detection are crucial for the surveillance of environmental samples to prevent the spread of fish pathogens in farms. Monitoring of waterborne pathogens through filtration of water and subsequent molecular detection of target-specific DNA or RNA sequence motifs is an animal-friendly method. This approach could reduce or even replace the sacrifice of fish for monitoring purposes in aquaculture and allow earlier implementation of disease control measures. Sampling methods might be a bottleneck, and there is a need for simple sampling methods that still ensure the best detection probability. In this study, we tested different filtration methods with spiked freshwater and seawater for a panel of fish pathogens to discern a suitable procedure that can be easily applied on-site by farm personnel without compromising detection probability. Specifically, we tested combinations of different filtration flow rates, lysis buffers, and filters for the detection of some of the pathogens relevant to the aquaculture industry. The results showed that a "sandwich" filtration method using two different filters and a flow rate of up to 4.0 L/min ensured good pathogen detection. The filters, consisting of a hydrophilic glass fibre filter with binder resin on the top and a hydrophilic mixed cellulose esters membrane at the bottom, achieved the best concentration and qPCR detection of both viral and bacterial fish pathogens. This up-and-coming tool allows the detection of very different fish pathogens during a single filtration step, and it can be combined with one single automated total nucleic acid extraction step for all the investigated pathogens, reducing both analysis costs and time. [ABSTRACT FROM AUTHOR]

In this semi‐quantitative study, laser crystal microparticles which are potentially capable of generating mid‐infrared (MIR) light are incorporated into MIR transmitting optical fibers using a volumetric interface doping technique that combines interface doping with volumetric doping. Using confocal microscopy with a refractive index matching fluid, the Er:YAP microcrystals (MCs) inside the tellurite glass fiber are observed based on the detection of the green upconversion fluorescence emission of Er3+ ions, produced under excitation at 976 nm and localized at the central region within the fiber. The key outcome from this proof‐of‐concept study is that MC particles that are fused with the glass during the fiber drawing process survived heat treatment because the MC particles are exposed for a short time to a glass fluid with high viscosity of ≈105 Pa.s, which prevented the glass from exerting a dissolution effect. The survival of the MCs demonstrated the viability of the doping technique for fabricating fibers with exotic crystal‐glass combinations for applications including good refractive index matching across the pump and lasing bands of rare earth ions. This latter parameter provides significant particle size flexibility whilst minimizing additional loss from scattering especially at MIR wavelengths where the MC diameter‐to‐wavelength ratio becomes smaller. [ABSTRACT FROM AUTHOR]

Metallic glass fibers have high strength, poor plasticity and low Young's modulus. In this study, it was used as a reinforcement to prepare metallic glass fiber reinforced epoxy composites with different fiber volume contents (20%, 30%, 40%, and 50%). The effect of fiber volume contents on the tensile properties of the metallic glass fiber reinforced epoxy composites was studied by experiment and the finite element analysis method. The experiment and simulation results are in good agreement. The tensile strength and plasticity of the metallic glass fiber reinforced epoxy composites increase with the increase of fiber volume contents. When the fiber volume content is 40% or 50%, a sharply necking feature appeared on the fibers and exhibited improved plasticity, due to the formation of interacting and arresting events of shear bands occurring at the interface between the metallic glass fibers and the epoxy. In addition, the strain hardening due to plastic deformation of the metallic glass fibers further enhanced the tensile strength of the metallic glass fiber reinforced epoxy composites. This is a first step toward toughening the inherently brittle metallic glass fibers under tensile conditions. Highlights: A novel CoFeSiB metallic glass fiber reinforced epoxy resin compositeThe increase of fiber volume fraction improves the tensile strength and plasticity of fiber reinforced composites.The strain hardening due to plastic deformation of the metallic glass fibers further enhanced the tensile strength of the metallic glass fiber reinforced epoxy composites. [ABSTRACT FROM AUTHOR]

In this study, we investigate the relationship between structure and properties of fiber–matrix adhesion for material extrusion–based 3‐dimensional (3D) printed composites. We examine the influence of fiber length and fiber content on the tensile properties of glass, basalt, and carbon fiber–reinforced polylactic acid (PLA) composites. Short fiber–reinforced filaments were produced, then, simple micromechanical models were used to predict the in‐plane tensile properties. We found that interlayer tensile properties are strongly influenced by fiber–matrix adhesion. If adhesion is sufficient, the fibers and matrix deform together under tensile load. A second‐order relationship describes interlayer tensile strength in relation to fiber content between 5 and 25 w%, with a maximum at 15 w%, for carbon and basalt fiber–reinforced composites. If adhesion is weak, the crack propagates along the fiber–matrix interface, causing brittle fracture and low strength. This behavior was noted for the glass fiber composite, for which the calculated interface shear strength was the lowest (1.4 MPa). In this case, fiber content is inversely proportional to interlayer tensile strength. Our results show the role of fiber–matrix adhesion quality on tensile properties, which has a major impact on both the accuracy of predictions and the damage processes. Highlights: Critical fiber length determines accuracy of tensile property estimatesQuality of fiber–matrix adhesion governs interlayer damage processPoor adhesion causes brittle fracture and low strengthSecond‐order relationship of interlayer tensile strength and fiber contentLoss of interlayer tensile strength in composite due to fiber–matrix interface [ABSTRACT FROM AUTHOR]

This article aims to investigate the mechanical properties and substrate adhesion of the pull-off method in polymer mortars modified with styrene-butadiene resin polymer (SBR) containing glass powder and composite fiber-reinforced slag. Different mix designs were investigated with and without SBR, taking into account different amounts of glass powder and slag separately and in combination, along with the effect of glass, polypropylene, and steel fibers alone and in combination. The flexural performance and energy absorption of beams retrieved with these layers were also assessed. The results revealed significant differences and increases in the substrate adhesion of the restored modified polymer layers containing SBR compared to the polymer-free repair overlays. Furthermore, an improvement was observed in the adhesion performance of the repair overlay using a combination of slag and glass powder and the glass and polypropylene fiber composite. The highest adhesion was related to the modified polymer mortar design containing composite fibers of glass, polypropylene, and steel with 25% replacement of SBR polymer for 10% glass powder, 10% slag, and 5% slag with 5% glass powder. The adhesion was increased by about 3.74, 3.72, and 3.78 times compared to the repair overlay of the control design. Modified polymer mortars had a higher T 150 D toughness. Moreover, the energy absorption was significantly improved by the presence of SBR polymer. The highest toughness values were found in the beams restored with modified polymer mortars containing polypropylene, glass, and steel composite fibers with an increase of 48.51%-66.42% compared to the samples without polymer as a result of the pozzolans used in this mix. [ABSTRACT FROM AUTHOR]

The rampant dendrites growth caused by uncontrolled deposition of Zn2+ ions at Zn metal anode poses a significant obstacle to the practical applications of aqueous zinc‐ion batteries (ZIBs). Herein, an ultrathin (5 µm) aramid nanofiber (ANF) separator is reported to enhance the Zn anode stability and the ZIB energy density. Through systematic experimental studies and DFT simulations, it is demonstrated that the ANF separator with unique surface polarity can modify the solvation configuration, facilitate desolvation, and regulate the deposition orientation of Zn2+ ions. Consequently, the Zn anode with the ANF separator demonstrates an 85‐fold increase in running time beyond 850 h compared with the conventional glass fiber separator at 5 mA cm−2/2.5 mAh cm−2. Even under the harsh depth of discharge conditions of 50% and 80%, the Zn anodes still sustain extended cycling periods of over 475 and 200 h, respectively. As pairing this ANF separator with thin Zn anode and high‐areal‐capacity Mn2.5V10O24∙5.9H2O cathode in a low negative capacity/positive capacity ratio (2.64) full cell, superior gravimetric/volumetric energy density (129.2 Wh kg−1/142.5 Wh L−1) is achieved, far surpassing majority of the ZIB counterparts reported in the literature. This work offers a promising ultrathin separator for promoting the utilization of energy‐dense aqueous ZIBs. [ABSTRACT FROM AUTHOR]

Highlights Recently, thermosetting epoxy resin is expected to be substituted by thermoplastic featured from green circular economy. Poly(methyl methacrylate) (PMMA) has been well known as one promising thermoplastic resin, although its mechanical property needs to be further investigated. In this paper, the free radical polymerization of methyl methacrylate (MMA) was initiated by lauroyl peroxide/N,N‐dimethylaniline (LPO/DMA) and lauroyl peroxide/N,N‐dimethyl‐p‐toluidine (LPO/DMT) redox system at room temperature, respectively. The PMMA (n(MMA:LPO:DMA) = 200:1.2:1) exhibited excellent mechanical properties, and the tensile strength was 66.5 MPa, the bending strength was 118.0 MPa. The tensile strength increased to 78.9 MPa at −40°C, which suggested a promising application at low temperature. The resin was applied to fabricate continuous glass fiber reinforced PMMA (GF/PMMA) composites by vacuum‐assisted resin infusion. The 0° tensile strength and modulus were 1.17 and 43.7 GPa and 90° tensile strength and modulus were 48.3 MPa and 13.2 GPa, respectively. The mechanical properties of GF/PMMA composites are higher than GF/epoxy. Moreover, PMMA resin and glass fiber can be recycled from GF/PMMA composites by MMA as solvent, which is more energy‐efficient and environment‐friendly. This work is of great significance for preparing sustainable resin and composites. GF/PMMA composites were fabricated by vacuum perfusion. GF/PMMA composites showed higher mechanical properties than GF/epoxy. GF/PMMA composite was recycled with MMA and closed‐loop recovery was achieved. [ABSTRACT FROM AUTHOR]

Highlights Two‐phase hybrid modification has been used as an advanced method to improve the strength and toughness of composite. An interfacial modification strategy for simultaneous strengthening, toughening, and damage monitoring of glass fiber (GF)/epoxy composite is proposed by coating rigid multi‐walled carbon nanotubes (MWCNT) and flexible thermoplastic polyurethane (TPU) on the glass fiber surface. The fiber pull‐out and out‐of‐plane experiments were performed to investigate the interfacial modification effect of rigid/flexible hybrid modifier. The results show that the hybrid modifier with a MWCNT/TPU mass ratio of 3:1 (MT@GF‐3/epoxy composite) realizes the most significant enhancement. Specifically, in comparison to GF/epoxy composites, MT@GF‐3/epoxy composite has an increment of 36.52%, 60.96%, 29.56%, and 80.36% in interfacial shear strength (IFSS), transverse fiber bundle test (TFBT) strength, interlaminar shear strength (ILSS) and interlaminar fracture toughness (GIC), respectively, and a significant enhancement in impact resistance. The enhanced interfacial strength and toughness are attributed to the mechanical interlocking, deflection of cracks, and plastic stretching generated by MWCNT and TPU. Results show that the two modifiers interact in a mutually reinforcing way with regard to the strengthening/toughening effects. In addition, multiple mechanical tests confirm the MT@GF/epoxy composites have an excellent damage monitoring ability by recording the resistance change based on the MWCNT's conductive characteristics. This strategy for interfacial modification coating a rigid‐flexible MWCNT/TPU hybrid modifier would offer valuable guidance for improving the strength and toughness of glass fiber/epoxy composites, as well as monitoring and locating the damage. A rigid/flexible hybrid modifier is proposed for modifying the GF/EP composites. The modifier achieves the greatest enhancement at a 3:1 mass ratio of MWCNT/TPU. The mutual reinforcing mechanism between the rigid/flexible phases is analyzed. Damage monitoring is realized for the modified GF/EP composites. [ABSTRACT FROM AUTHOR]

Highlights A detailed investigation was employed on the manufacturing process of Glass Fiber (GF) reinforced poly‐L‐lactide (PLLA) composites (GFRP) during in‐situ PLLA polymerization using Resin Transfer Molding (RTM). The lower viscosity of lactide, in comparison to PLLA, led to a strong interaction between PLLA and GF as a result of improved penetration into the fiber matrix, resulting in a high conversion rate of 100% for GFRP and 91.9% for PLLA. GF incorporation into the composite material resulted in an improved crystallinity of 55.65% for GFRP, where PLLA showed crystallinity of 36.5%. A GFRP composite with exceptional mechanical properties, including 122.3 MPa tensile strength and 4.485 GPa modulus, was achieved. Both surface and bulk erosion were seen during the breakdown of these composites. These composites seem to be a viable substitute for metallic implants in biological applications. In situ, resin transfer molding of poly‐l‐lactide and GF composite. Higher volume fraction such as 40% w/v loading of GF into composites. 1% conversion of GFRP is achieved. GFRP shows the machinal strength of 122 MPa and harness of 4.2 GPa. Biocompatibility of GFRP composites in body stimulated conditions. [ABSTRACT FROM AUTHOR]

The commercialization of sodium batteries faces many challenges, one of which is the lack of suitable high-quality separators. Herein, we presented a novel natural silkworm cocoon-derived separator (SCS) obtained from the cocoon inner membrane after a simple degumming process. A Na||Na symmetric cell assembled with this separator can be stably cycled for over 400 h under test conditions of 0.5 mA cm−2–0.5 mAh cm−2. Moreover, the Na||SCS||Na3V2(PO4)3 full cell exhibits an initial capacity of 79.3 mAh g−1 at 10 C and a capacity retention of 93.6% after 1000 cycles, which far exceeded the 57.5 mAh g−1 and 42.1% of the full cell using a commercial glass fiber separator (GFS). The structural origin of this excellent electrochemical performance lies in the fact that cationic functional groups (such as amino groups) on silkworm proteins can de-solvate Na-ions by anchoring the ClO4− solvent sheath, thereby enhancing the transference number, transport kinetics and deposition/dissolution properties of Na-ions. In addition, the SCS has significantly better mechanical properties and thinness indexes than the commercial GFS, and, coupled with the advantages of being natural, cheap, non-polluting and degradable, it is expected to be used as a commercialized sodium battery separator material. [ABSTRACT FROM AUTHOR]

The injection molding process is one of the most widely used methods for polymer processing in mass production. Three critical factors in this process include the type of polymer, injection molding machines, and processing molds. Polypropylene (PP) is a widely used semi-crystalline polymer due to its favorable flow characteristics, including a high melt flow index and the absence of a need for a mold temperature controller. Additionally, PP exhibits good elongation and toughness, making it suitable for applications such as box hinges. However, its tensile strength is a limitation; thus, glass fiber is added to enhance this property. It is important to note that the incorporation of glass fiber increases the viscosity of PP. Multi-cavity molds are commonly employed to achieve cost-effective and efficient mass production. The filling challenges associated with geometrically balanced layouts are well documented in the literature. These issues arise due to the varying shear rates of the melt in the runner. High shear rate melts lead to high melt temperatures, which decrease melt viscosity and facilitate easier flow. Consequently, this results in an imbalanced filling phenomenon. This study examines the impact of runner size, gate size, polymer viscosity, and molding process on the filling imbalanced problem in multi-cavity injection molds. Tensile bar injection molding was performed using conventional injection molding (CIM) and microcellular injection molding (MIM) techniques. The tensile properties of the imbalanced multi-cavity molds were analyzed. Flow length within the cavity served as an indicator of the filling imbalance. Additionally, computer simulations were conducted to assess the shear rate's effect on the runner's melt temperature. The results indicated that small runner and gate sizes exacerbate the filling imbalance. Conversely, glass fiber-filled polymer composites also contribute to increased filling imbalance. However, foamed polymers can mitigate the filling imbalance phenomenon. [ABSTRACT FROM AUTHOR]

Bismuth (Bi) and Germanium (Ge) co‐doped silica glass and fiber, as advanced gain media with broadband near‐infrared (NIR) emission and amplification, have promise for extending communication bandwidth. However, efficiently modulating the NIR emissions of bismuth to cover the C+L communication bands remain a significant challenge. In the study, a high‐temperature and high‐pressure reduction treatment on Bi/Ge co‐doped silica glass is employed to tailor the coordination environment around bismuth active center. This method facilitated the creation of new bismuth NIR luminescence centers, resulting in the luminescence spectrum with a peak position at 1550 nm and a FWHM exceeding 350 nm. The changes in the bismuth coordination environment are elucidated using HRTEM, photoluminescence decay, temperature‐dependent emission, EXAFS and CW‐EPR. Furthermore, the feasibility of this method in Bi/Ge co‐doped silica fiber is validated, and obtained >5 dB amplification in the range of 1400–1700 nm. This coordination engineering method holds significant potential for widespread application in Bi/Ge co‐doped silica glass and optical fiber is believed. It presents a promising prospect for expanding communication bandwidth by effectively modulating the NIR emissions of bismuth to cover the S to U communication band. [ABSTRACT FROM AUTHOR]

Titanium dioxide-enriched phosphate glasses are esteemed for their applicability in the biomaterial area, yet the investigation into the influence of TiO 2 on the crystallization dynamics of glass melts and the spinnability of sodium-calcium-magnesium phosphate glasses remains unclear. To elucidate these effects, sodium-calcium-magnesium phosphate glasses with 0, 5, and 10 mol% of TiO 2 have been prepared using the melt-quenching method, and glass fibers were drawn from the correspondent glass melts. FTIR and Raman spectroscopy have disclosed that the introduction of TiO 2 induces a depolymerization in phosphate network, causing a transition from Q2 species to Q1 units, and reduction in both the theoretical network connectivity (NC theor) and the average chain length (n theor). Meanwhile, the interposition of TiO 2 also gives rise to the replacement of P–O–P linkages with P–O–Ti bonds, along with the formation of [TiO 5 ] groups. This structural transformation resulted in the increase in molar volume and the coefficient of thermal expansion (CTE), concurrently lowering the glass transition and softening points. Evidently, the TiO 2 -free glass exhibited crystallization across a temperature range spanning from its transition to the liquidus temperature. However, the introduction of TiO 2 and the subsequent formation of P–O–Ti bonds effectively inhibited crystallization, which is favorable for drawing glass fibers. Analyses of viscosity-temperature relationships using various rheological models suggested that TiO 2 raises fragility for all glasses, suggesting a more "open" structure in the glass melts, which can be supported by the increment in free volume. The m-D diagram failed to describe the enhancement in spinnability imparted from TiO 2. While, the quantitative fiber spinnability index (K fib) increases with higher TiO 2 content, as a successful indicative of an improved ability to form fibers. [ABSTRACT FROM AUTHOR]

Glass-based sealing materials exhibit significant potential for utilization in solid oxide fuel cells (SOFCs). We conducted a study on the impact of mullite fibers with varying particle sizes on glass composite sealing materials. We evaluated and discussed properties such as coefficient of thermal expansion (CTE), softening temperature (Ts), gastightness, interfacial compatibility, and flexural strength of the sealing materials with different ranges of fiber particle sizes. Our findings indicate that the three different particle sizes of mullite fiber-glass composite sealing materials met the required coefficients of thermal expansion, displayed good interfacial compatibility, and exhibited gastightness lower than 0.0016 sccm cm−1. Notably, the mullite fiber-reinforced sealing material that underwent ball-milling for 1 h outperformed the other two variants. It demonstrated fewer defects, a 57.1 % increase in flexural strength, and a 117.4 % higher maximum strain value. [ABSTRACT FROM AUTHOR]

Highlights In this study, the axial crushing response and energy‐absorbing mechanisms of circular composite tubes, which were reinforced by carbon fiber (C10) and carbon/glass hybrids (C3G4C3), were investigated experimentally and numerically. Both samples exhibited similar crushing responses comprising delamination and intralayer shear failure. The impact kinetic energy is primarily converted into frictional and composite damage energies. C3G4C3 had poorer crashworthiness with a mean crushing force and specific energy absorption of 313.3 kN and 58.0 kJ/kg, which are by 39.3% and 30.8% less, respectively, than those of C10. The influence of glass fiber reinforced polymers (GFRP) content (hybrid ratio) and stacking sequence on tubal crashworthiness was investigated numerically. For composite tubes with a hybrid ratio of 40%, the central distribution of GFRP (C3G4C3) achieved optimal energy absorption performance. Additionally, when GFRP layers were centralized stacked, a reduction of the hybrid ratio from 60% (G3C4G3) to 20% (GC8G) helped improve the crashworthiness of the hybrid tubes, where the mean crushing force increased by 23%. Impact responses of composite tubes reinforced by carbon fiber and carbon/glass hybrids were investigated experimentally and numerically. Carbon/glass hybrid tubes exhibited lower crashworthiness. The effects of stacking sequence and hybrid ratio on the energy absorption performance were studied. [ABSTRACT FROM AUTHOR]

Highlights Present study comprehensively explores the phenomenon of in‐plane fiber waviness in glass/epoxy fiber reinforced polymer (GFRP) composites. Utilizing a pioneering technique that employs a semi‐circular bar to induce controlled fiber waviness, coupled with image processing using OpenCV library in Python coding for precise measurement and analysis of in‐plane fiber waviness. This defect is commonly found in components fabricated with fiber‐reinforced composites. During the process of manufacturing fibers may deviate from their intended orientation due to process variables or resin flow dynamics. Understanding in‐plane fiber waviness is crucial due to its impact on mechanical properties of composites. It is essential for optimizing manufacturing processes and ensuring enhanced structural performance in diverse engineering applications through analysis of strength and failure mechanism. A novel study was conducted by introducing a circular cutout within the fiber waviness region to investigate the combined effect of multiple defects. The experimental tensile test reveals that as waviness ratio (WR) increases a significant decrease in its tensile strength and vice versa. The study incorporates scanning electron microscopy (SEM) image analysis to examine composite failure. By advancing the understanding of in‐plane fiber waviness and its implications, this research significantly contributes to ongoing efforts in composite design and optimization. Adopting a cutting‐edge method to create controlled fiber waviness that makes use of a semi‐circular bar. Image processing with Python code that makes use of the OpenCV package to precisely measure and analyze in‐plane fiber waviness. A new investigation was carried out to examine the combined effect of multiple flaws by creating a circular cutout within the fiber waviness zone. [ABSTRACT FROM AUTHOR]

(1) Background: The main aim of this study was to investigate the effects of different cements (Panavia V5, RelyX U200) and placement techniques (indirect ultrasonic vibration and manual method) on the bond strength of glass fiber posts in teeth with different post space preparation methods and to evaluate the failure types. (2) Methods: A total of 120 human upper central teeth were collected for the study. One week after root canal treatment, 10 mm long post space preparation was performed using post drills. Post spaces were irrigated in three different ways, namely NaOCl, NaOCl + EDTA solutions, and passive ultrasonic irrigation of NaOCl and EDTA solutions. Glass fiber posts were divided into two groups for resin cement systems, namely RelyX U200 (3M ESPE) or Panavia V5 (Kuraray Medical). Two different methods, namely the indirect ultrasonic vibration and the manual method, were applied for post placement. Then, 1.2 mm sections were taken from the middle and coronal regions of the inserted fiber posts for a push-out test. (3) Results: the Irrigation × Cement (p = 0.002), Cement × Section (p = 0.043) and Placement × Section (p = 0.049) pairwise interactions were statistically significant. (4) Conclusions: in our study, the effects of different post cavity preparations, different cement types, and different placement techniques on the bond strength of the fiber post were observed. [ABSTRACT FROM AUTHOR]

Although numerous investigations study the improvement of flame retardancy of epoxy resins using additives, maintaining the flame retardant (FRs) modes of action present in the resins upon transfer to composites is challenging. In this study, ammonium polyphosphate (APP) and inorganic silicate (InSi) are loaded at 10%, 30%, and 50% by weight, in a diglycidyl ether of bisphenol A (DGEBA) resin cured with dicyandiamide and transferred to bidirectional (BD) glass fiber (GF) composites. Although a 50% loading of the FRs impacts the curing kinetics of the resin system, the effect on the glass transition temperature of the resin system remains negligible compared to reactive FRs in the state of the art integrated into the resin's chemical structure. Increasing the FR content improved the heat release characteristics in both the resins and composites. However, the charring mode of action is completely suppressed in the formulation with 10% APP + InSi. A 30% concentration of the FRs restored the charring action in the composite and the GFs provide increased protective layer action upon transfer to the composites. This study highlights the importance of accounting for the changing dynamics related to processing and flame retardancy upon transferring FRs from resins to composites. [ABSTRACT FROM AUTHOR]

In this study, the post‐buckling damage behavior of cylindrical composite tubes was examined experimentally. The samples were reinforced with glass, carbon, and kevlar fibers to obtain glass‐reinforced fiber polymer (GRFP), carbon‐reinforced fiber polymer (CRFP), and Kevlar‐reinforced fiber polymer (KRFP) cylindrical tubes. The samples were produced using 4 stacking layers with filament winding technology. In producing all composite tubes, the outer diameter was kept constant at 17 mm, and two inner diameters of 12 and 13 mm, two wall thicknesses, 5 winding angles, and two lengths were used as parameters. The load was applied to the samples until completely damaged, and the maximum post‐buckling load values obtained were measured on the testing device. The effect of different reinforcement materials, winding angle, wall thickness, and length on the load‐carrying capacity was analyzed and it was understood that they had a significant effect. It was observed that the load‐carrying capacity of GFRP samples was the highest compared to the others, followed by CFRP and KFRP samples, respectively. In all samples, it was observed that a 0.5 mm wall thickness increase increased the load‐carrying capacity, while a 50 mm length increase decreased it. The energy absorption (EA) values of GFRP, CFRP, and KFRP samples were 46.99, 25.22, and 15.48 Joules, respectively. It was understood that the energy absorption of GFRP samples was 1.86 times better than CFRP and 3 times better than KFRP. Highlights: The samples were produced using the fiber winding method, which is one of the most common production methods in the manufacture of tubes.Three different polymer reinforcement materials were used in the production of the samples.The effects of polymer reinforcement material, winding angle, length, and wall thickness on the maximum post‐buckling load were investigated.Wall thickness was found to have a significant effect on the maximum post‐buckling load.It was observed that GFRP samples had the highest energy absorption feature. [ABSTRACT FROM AUTHOR]

This research aimed to understand how the incorporation of nanocarbon powder (NCP) influences the crashworthiness performance of glass fiber‐reinforced epoxy (GFRE) tubular components, potentially offering insights into improving the safety and resilience of structures or vehicles. Consequently, the crashworthiness behaviors of circular tubes made of GFRE with varying amounts of NCP was studied. Utilizing wet‐wrapping through hand lay‐up technique, GFRE tubes were fabricated with various weight percentages of NCP, that is, 0, 0.25, 0.50, 1, 2, 3, and 4 wt.%. Following that, the crashing load, total absorbed energy against displacement responses, and deformation histories of these tubes under quasi‐static axial loading conditions were calculated and tracked. As part of the crashworthiness analysis, critical indicators were evaluated, including initial peak load (Fip), total absorbed energy (U), mean crash force (Fm), crash force efficiency (CFE), and specific energy absorption (SEA). The findings reveal that the maximum Fip, U, Fm, and SEA were noted at 0.5 wt.% of NCP, with increasing percent's of 30.80, 12.17, 12.16, and 7.50, respectively, compared to the unfilled tube. While, the CFE was recorded by 3 wt.% of NCP with an enhancement of 16.67%. It is worth to note that, the findings reveal that the inclusion of NCP increases crashworthiness metrics up, that is, Fip, U, Fm, and SEA to a concentration of 0.50 wt.% NCP. However, beyond this point, there's a notable decline in performance. Highlights: The GFRE tubes were filled with various wt.% of NCP.The planned tubes were made using hand lay‐up methods.The tubes were subjected to axial compression loads to examine their crashing behavior.The crashing load and absorbed energy versus displacement responses for tubes were exposed.The experimental results were analyzed and discussed. [ABSTRACT FROM AUTHOR]

This study introduces an innovative approach to enhance the absorption capabilities of skin‐core dual‐domain structure radar‐absorbing materials (SDSRAM) composed of thin‐ply laminates and honeycomb. The upper skin laminates consist of transmissive skin and impedance matching layer. The impedance matching layer was hot‐pressed using functionalized absorbed thin‐ply glass fibers prepregs, flaked carbonyl iron powder (FCIP) and multi‐walled carbon nanotubes (MWCNTs) as the absorber. The lower skin was manufactured using carbon fiber‐plated nickel. The core is prepared by honeycomb modified (HCM). The permittivity and permeability of the skin laminates and the HCM were measured by wave‐guide method. The impact of FCIP/MWCNT on the electromagnetic (EM) parameters of the thin‐ply laminates and the influence of MWCNTs on the permittivity of the honeycomb were investigated. Microwave absorption properties of SDSRAM were assessed through the measurement of reflection loss (RL) using the arch method and simulated using the microwave simulation software CST studio suite 2020. Experimental verification was conducted to confirm the absorbing performance. The results show that the effective absorption bandwidth (RL < 10 dB) of SDSRAM covers the frequency range of 2.2–18 GHz, with a maximum absorption intensity of −42.5 dB. The introduction of the thin‐ply laminates caused a shift in the peak of the reflectance curve toward lower frequencies. Highlights: Functionalized absorbed glass fibers were prepared using fiber spreading functional sizing integrated process.A new skin‐core dual‐domain synergistic modulation absorbed structure was developed with thin‐ply laminates and modified honeycomb. Its broadband absorption mechanism was discussed.Desired broadband absorption performance was acquired with thin thickness. [ABSTRACT FROM AUTHOR]

Biological structures achieve remarkable material performance owing to naturally assembled structures that extend from the molecular to macro‐scale. Synergy among constituents of various length scales yields lightweight, hierarchically structured materials with properties superior to those of individual components. To replicate nature's ingenuity, this work emulates the cylindrical core‐shell structure found in osteons and bamboo, utilizing Halloysite Nanotubes (HNTs) and Glass Fibers (GFs) in a semi‐crystalline polymer matrix. HNTs are environmentally friendly, naturally occurring tubular aluminosilicates with high aspect ratios, large lumen volumes, and low cost, and are readily dispersible in polymer matrices. Here, hierarchical reinforcement is achieved through controlled electrostatic assembly of HNTs onto GFs and subsequent trans‐crystallization‐encapsulation. This cylindrical core‐shell architecture yields composites with exceptional mechanical performance, superior thermal management (insulation/stability), improved industrial processability, and reduced flame propagation speed. Compared to the current industrial composite substitute for metallic structural components, the hybrid composites exhibit a remarkable 84% increase in impact strength, 27% increase in specific tensile strength, 56% increase in tensile toughness, and 30% in specific flexural strength, accompanied by a 20% weight reduction and a 255% increase in processability (melt‐flow index). This scalable assembly strategy marks a cornerstone in lightweight multifunctional materials development, to conquer future sustainability targets. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Material and Methods Results Conclusion To evaluate the plant‐derived compound lignin (LIG) as a pretreatment of intraradicular dentin in combination with EDTA on push‐out bond strength (PBS) and nanoleakage of the glass fiber posts (GFPs) cemented using adhesive resin cement.Twenty‐eight human incisor roots were prepared for GFP cementation and divided based on dentin pretreatment: (1) CONTROL: no pretreatment, (2) EDTA: 17% EDTA for 3 min, (3) EDTA‐LIG: 17% EDTA and 2% lignin for 3 min, (4) EDTA‐PAC: 17% EDTA and 2% lignin for 3 min. The GFPs were cemented using the self‐adhesive resin cement Multilink Speed. The roots (n = 7) were sectioned into 1 mm‐thick discs and subjected to PBS testing after 1 week or 6 months. Nanoleakage was analyzed by SEM. Statistical analysis was performed using two‐factor ANOVA and Tukey's test (p < 0.05).Higher PBS was identified for the CONTROL group (p < 0.001). After 6 months, the EDTA‐LIG maintained the bond strength with a predominance of mixed failures, while the EDTA‐PAC, EDTA, and CONTROL groups showed reduction of bond strength, with a predominance of adhesive failures along with severe silver infiltration in the interface.LIG associated with EDTA as a pretreatment for intraradicular dentin shows significant potential for attaining stable bond strength and interfacial integrity of self‐adhesive resin cement to intraradicular dentin. [ABSTRACT FROM AUTHOR]

This study investigated the influence of moisture absorption on the electromagnetic (EM) wave absorption performance and mechanical strength of a radar-absorbing structure (RAS) with nickel-coated pristine glass fibers and polyamide 6. To construct the RAS, nickel was deposited on pristine glass fibers via electroless plating, and the RAS was fabricated using a hot-press process. An environmental test was conducted under a high humidity of 85%, and the EM wave absorption capacity of the RAS was measured at 2-week intervals. Moreover, compressive and interlaminar shear tests were conducted to verify the degradation of mechanical strength and the effect of the nickel coating on moisture absorption resistance. The test results revealed that immersion in moisture degraded the EM absorption capacity of the RAS. Nevertheless, an improvement in the mechanical strength of the RAS after saturation was observed due to the nickel coating. [ABSTRACT FROM AUTHOR]

In this study, high loadings of boron nitride (BN) nanoplatelets were added to silica fiber-reinforced phenolic composites to study the multifunctional impact of BN loading and manufacturing processing on the subsequent mechanical, thermal, and thermomechanical properties. A series of high-quality laminates were made with various loadings of BN using compression-molded out-of-autoclave processing. Three-point bend and short beam shear testing determined the relationship between BN loading and mechanical performance. The fracture properties were analyzed using optical and scanning electron microscopy. The thermal conductivity performance was increased up to a 93% improvement, indicating the thermal management multifunctionality of the modified composites without changing the crosslinking ability or glass transition temperature significantly. The modified performance of hybrid silica/phenolic/BN composites is demonstrated through micromechanical multiscale modeling, where BN loading and particle stress concentrations impact the modulus and strength of the composite. [ABSTRACT FROM AUTHOR]

This paper proposes a multi-objective optimization method for injection molding, combining the random forest (RF) model optimized using the light spectrum optimizer (LSO) with the non-dominated sorting whale optimization algorithm (NSWOA), to tackle the quality defects of warpage deformation and volume shrinkage commonly observed for the glass fiber injection molded product. Based on the simulation results of central composite face centered design (CCF), the model for control of injection molding quality defects using LSO-RF is constructed. NSWOA is used for multi-objective optimization to obtain the Pareto solutions, and the critic method is employed to determine the optimal process parameter scheme. Then, the optimal process parameter scheme is inputted to Moldflow for simulation verification. The validation results demonstrate that the LSO-RF model achieves prediction errors within 3 % for warpage deformation and volume shrinkage, indicating good predictive accuracy. The optimized warpage deformation and volume shrinkage are 0.3519 mm and 7.0930 %, respectively. Compared to the pre-optimized state, the warpage deformation decreased by 32.57 % and the volume shrinkage decreased by 15.93 %, indicating a significant improvement in molding quality for the glass fiber injection molded product. [ABSTRACT FROM AUTHOR]

Short-fiber reinforcement is a potent approach to improving the material properties of injection-molded parts. The main consideration in such reinforced materials is to preserve the fiber length, as this is the major influence on the properties of a given composite. The aim of this work was to investigate the different influencing parameters in injection molding processing on the properties of short carbon and glass fiber-reinforced polypropylene. We investigated parameters like melt temperature and back pressure, but also machine size and pre-heating regarding their influence on the tensile properties. We found that adjustments of melt temperature and back pressure only yield small improvements in the fiber length and the tensile properties, also depending on machine size, but a pre-heating step of the granules can significantly improve the properties. [ABSTRACT FROM AUTHOR]