Journal of Composites Science

20 pages, 19306 KiB

Open AccessArticle

Integrated Development of Mechanical Strength and Thermoelectric Properties in Cement Composites Incorporating Graphene Oxide and Manganese Dioxide

by Jude Shalitha Perera, Anuradha Silva, Priyan Mendis, Shanaka Kristombu Baduge, Aathavan Kuhanandha, Lochlan Hau and Philip Trinh

J. Compos. Sci. 2025, 9(4), 196; https://doi.org/10.3390/jcs9040196 - 21 Apr 2025

Abstract

Cement-based thermoelectric materials are gaining popularity among materials scientists due to their robust mechanical characteristics and suitability for thermal energy harvesting in building applications. However, despite advancements in the development of these materials, a significant knowledge gap persists regarding their mechanical characterisation. This [...] Read more.

Cement-based thermoelectric materials are gaining popularity among materials scientists due to their robust mechanical characteristics and suitability for thermal energy harvesting in building applications. However, despite advancements in the development of these materials, a significant knowledge gap persists regarding their mechanical characterisation. This research aimed to enhance the thermoelectric performance of cement composites through the incorporation of graphene oxide (GO) and manganese dioxide (MnO₂), while ensuring adequate compressive strength was maintained. An experimental investigation was conducted to simultaneously assess both properties of cement composites using identical specimens. Additionally, microstructural analysis of the samples was performed to further understand the integrated development of these two properties. To evaluate the integrative properties, a Pareto analysis was performed to identify the Pareto-optimal solutions for specific applications. Additionally, a new index, termed the Thermoelectric Strength Index (TSI), was developed to compare materials in applications where both thermoelectric efficiency and mechanical robustness are important. The findings indicated that while both GO and MnO₂ enhanced the thermoelectric properties of cement, their reactions with the cement phases produced distinct relationships with compressive strength, especially when GO and MnO₂ were added together. The TSI demonstrated that MnO₂ was superior for simultaneously enhancing mechanical strength and thermoelectric performance, with the 7.5 wt.% formulation yielding the best results. This study demonstrates the complex interrelationship between the mechanical strength and thermoelectric properties of the investigated fillers, underscoring the necessity for a holistic approach in the development of thermoelectric cement composites. Full article

(This article belongs to the Special Issue Mechanical Properties of Composite Materials and Joints)

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19 pages, 6866 KiB

Open AccessArticle

Experimental Investigation on Mechanical Properties of Glass Fiber–Nanoclay–Epoxy Composites Under Water-Soaking: A Comparative Study Using RSM and ANN

by Manjunath Shettar, Ashwini Bhat, Nagaraj N. Katagi and Mandya Channegowda Gowrishankar

J. Compos. Sci. 2025, 9(4), 195; https://doi.org/10.3390/jcs9040195 - 21 Apr 2025

Abstract

Fiber-reinforced polymer composites are exposed to severe environmental conditions throughout their intended lifespan. It is essential to investigate how they age when exposed to cold and hot water to increase the durability of fiber-reinforced polymer composites. This work uses a hand lay-up process [...] Read more.

Fiber-reinforced polymer composites are exposed to severe environmental conditions throughout their intended lifespan. It is essential to investigate how they age when exposed to cold and hot water to increase the durability of fiber-reinforced polymer composites. This work uses a hand lay-up process to create composites with different weight percentages of glass fiber, nanoclay, and epoxy. ASTM guidelines are followed for performing tensile and flexural tests. The input parameters, varying wt.% of glass fiber and nanoclay, are continuous, and the aging condition is deemed a categorical factor. The mechanical properties are considered as response variables (output). The mechanical properties are optimized using Response Surface Methodology (RSM), while Artificial Neural Networks (ANNs) provide a reliable predictive model with high correlation coefficients. The findings demonstrate that ANNs outperform RSM in flexural strength prediction, whereas RSM offers greater accuracy for tensile strength modeling. SEM analysis of the fracture surfaces reveals the causes of specimen failure under tensile load, with distinct differences between dry, cold, and boiling water-soaked specimens. Full article

(This article belongs to the Section Composites Modelling and Characterization)

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19 pages, 7457 KiB

Open AccessArticle

Preparation and Photoelectric Properties of Nanostructured Native Oxide of Gallium Monoselenide with Applications in Gas Sensors

by Veaceslav Sprincean, Alexandru Macovei, Liviu Leontie, Aurelian Carlescu, Silviu Gurlui and Mihail Caraman

J. Compos. Sci. 2025, 9(4), 194; https://doi.org/10.3390/jcs9040194 - 19 Apr 2025

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Abstract

Using the Bridgman technique, GaSe single crystals were obtained which were mechanically split into plane-parallel plates with a wide range of thicknesses. By heat treatment in air at 820 °C and 900 °C, for 30 min and 6 h, micro- and nanocomposite layers [...] Read more.

Using the Bridgman technique, GaSe single crystals were obtained which were mechanically split into plane-parallel plates with a wide range of thicknesses. By heat treatment in air at 820 °C and 900 °C, for 30 min and 6 h, micro- and nanocomposite layers of Ga₂Se₃–Ga₂O₃ and β–Ga₂O₃ (native oxide) with surfaces made of nanowires/nanoribbons were obtained. The obtained composite Ga₂Se₃–Ga₂O₃ and nanostructured β–Ga₂O₃ are semiconductor materials with band gaps of 2.21 eV and 4.60 eV (gallium oxide) and photosensitivity bands in the green–red and ultraviolet-C regions that peaked at 590 nm and 262 nm. For an applied voltage of 50 V, the dark current in the photodetector based on the nanostructured β–Ga₂O₃ layer was of 8.0 × 10⁻¹³ A and increased to 9.5 × 10⁻⁸ A upon 200 s excitation with 254 nm-wavelength radiation with a power density of 15 mW/cm². The increase and decrease in the photocurrent are described by an exponential function with time constants of τ_1r = 0.92 s, τ_2r = 14.0 s, τ_1d = 2.18 s, τ_2d = 24 s, τ_1r = 0.88 s, τ_2r = 12.2 s, τ_1d = 1.69 s, and τ_2d = 16.3 s, respectively, for the photodetector based on the Ga₂Se₃–Ga₂S₃–GaSe composite. Photoresistors based on the obtained Ga₂Se₃–Ga₂O₃ composite and nanostructured β–Ga₂O₃ layers show photosensitivity bands in the spectral range of electronic absorption bands of ozone in the same green–red and ultraviolet-C regions, and can serve as ozone sensors (detectors). Full article

(This article belongs to the Special Issue Advanced Composite Materials from Natural and Synthetic Sources: Fabrication, Characterization and Practical Application, Volume II)

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21 pages, 9241 KiB

Open AccessArticle

Theoretical/Experimental Study of the Heavy Metals in Poly(vinylalcohol)/Carboxymethyl Starch-g-Poly(vinyl imidazole)-Based Magnetic Hydrogel Microspheres

by Joaquín Alejandro Hernández Fernández, Jose Alfonso Prieto Palomo and Carlos A. T. Toloza

J. Compos. Sci. 2025, 9(4), 193; https://doi.org/10.3390/jcs9040193 - 18 Apr 2025

Viewed by 128

Abstract

Heavy metal contamination of water is a critical environmental problem due to its toxicity and persistence in ecosystems. In this study, magnetic hydrogel spheres composed of carboxymethylated starch modified with poly(1-vinylimidazole) (CMS-g-PVI) and polyvinyl alcohol (PVA), combined with Fe₃O₄ nanoparticles, [...] Read more.

Heavy metal contamination of water is a critical environmental problem due to its toxicity and persistence in ecosystems. In this study, magnetic hydrogel spheres composed of carboxymethylated starch modified with poly(1-vinylimidazole) (CMS-g-PVI) and polyvinyl alcohol (PVA), combined with Fe₃O₄ nanoparticles, were synthesized and characterized to evaluate their efficiency in adsorbing metal ions such as Cu²⁺, Pb²⁺, and Cd²⁺. Structural characterization by FT-IR spectroscopy confirmed the successful integration of all functional components into the hydrogel matrix. Additionally, scanning electron microscopy (SEM) revealed a rough and porous surface morphology favorable for adsorption and an average bead diameter of 3.2 mm, influenced by the stirring rate during synthesis. Adsorption studies demonstrated maximum capacities of 82.4 mg·g⁻¹ for Cu²⁺, 66.5 mg·g⁻¹ for Pb²⁺, and 51.8 mg·g⁻¹ for Cd²⁺, with optimal removal efficiencies at pH 6.2 and 5.7. From a theoretical perspective, density functional theory (DFT) calculations using the B3LYP/6-311+G(d,p) method allowed the optimization of molecular structures and analysis of electronic properties. The total dipole moment (TDM) of the CMS-g-PVI/PVA system reached 20.81 Debye. A significant reduction in the HOMO-LUMO energy gap was observed upon metal adsorption, with values of 0.0308 eV for Cu²⁺, 0.0175 eV for Pb²⁺, and 0.0235 eV for Cd²⁺, confirming strong interactions between the hydrogel matrix and the metal ions. The combined experimental and computational approach provides a comprehensive understanding of the adsorption mechanisms and supports the development of efficient materials for water decontamination. Full article

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14 pages, 1706 KiB

Open AccessArticle

Thermal Stabilization Activities of Metal Oxide γ-Irradiated Styrene–Isoprene–Styrene Nanocomposites

by Traian Zaharescu, Ademar B. Lugāo, Violeta Mangalagiu and Radu Mirea

J. Compos. Sci. 2025, 9(4), 192; https://doi.org/10.3390/jcs9040192 - 17 Apr 2025

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Abstract

This study provides insights into the stabilization effects of certain oxides (CeO₂, Cr₂O₃, Cd₂O₃, In₂O₃, MnO₂, MgO, Nd₂O₃, and Pr₂O₃ [...] Read more.

This study provides insights into the stabilization effects of certain oxides (CeO₂, Cr₂O₃, Cd₂O₃, In₂O₃, MnO₂, MgO, Nd₂O₃, and Pr₂O₃) in styrene–isoprene–styrene triblock copolymers with respect to neat materials. This study was performed via chemiluminescence (CL), which allowed for the determination of the main parameters characterizing the interphase coexistence: the oxidation induction times, oxidation rates, and onset oxidation temperatures. The improvement in the thermal performances of the pristine and γ-ray-processed samples at a moderate dose was highlighted differently due to the electronic interactions on the particle surface. While the non-isothermal CL measurements pointed to a weaker evolution of oxidation in the studied composites at a higher temperature range over 160 °C, the isothermal CL determinations revealed a delayed start of oxidation, slower oxidation rates, and greater activation energies in the nanocomposite aging patterns. The different individual behaviors of the investigated formulations were ascribed to the dissimilar electronic interactions between the particles and the surrounding matrix, where the oxidation initiators were formed by the molecular fragmentation of the polymer macromolecules. The kinetic features illustrate the influence of the peculiarities due to the electronic interactions. The higher resistance shown by the irradiated samples compared with the non-processed compositions demonstrates the stabilization efficiency of the fillers studied. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

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15 pages, 6304 KiB

Open AccessArticle

Composite Film Based on Polyethylene and Plant Waste

by Natalia Igorevna Cherkashina, Dmitry Sergeevich Romanyuk, Darya Alexandrovna Sinebok, Sergey Ivanovich Gorodov, Artem Yurievich Ruchiy, Roman Alekseevich Barinov and Daria Viktorovna Silchenko

J. Compos. Sci. 2025, 9(4), 191; https://doi.org/10.3390/jcs9040191 - 16 Apr 2025

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Abstract

This study presents the development of a composite film based on low-pressure polyethylene (LPPE) and sunflower husk. The sunflower husk was pretreated with a 4% NaOH solution. Composite films with a thickness of 200 ± 0.20 µm were obtained, containing 40–60 wt.% sunflower [...] Read more.

This study presents the development of a composite film based on low-pressure polyethylene (LPPE) and sunflower husk. The sunflower husk was pretreated with a 4% NaOH solution. Composite films with a thickness of 200 ± 0.20 µm were obtained, containing 40–60 wt.% sunflower husk. The main mechanical properties, water absorption, and surface morphology of the films were analyzed using scanning electron microscopy (SEM). Thermogravimetric (TG) and differential scanning calorimetry (DSC) curves were obtained for sunflower husk, polyethylene, and composite films. The optimal composition of the film components (wt.%) was determined as follows: LPPE—50–55%, sunflower husk—45–50%. The composite film containing 50 wt.% sunflower husk exhibited the following properties: tensile resistance—3.9 ± 0.18 MPa, relative elongation at break—6 ± 0.28%, tensile strain—21 ± 1.02%, modulus of elasticity—108 ± 5.32 MPa, and water absorption over 24 h—2.4%. Full article

(This article belongs to the Section Polymer Composites)

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23 pages, 8743 KiB

Open AccessArticle

Energy-Absorbing Performance of Metallic Thin-Walled Porous Tubes Filled with Liquid Crystal Elastomers Under Dynamic Crush

by Xu’an Hu, Shaohua Niu, Yanxuan Wu, Bingyang Li, Zhen Li and Jun Wang

J. Compos. Sci. 2025, 9(4), 190; https://doi.org/10.3390/jcs9040190 - 16 Apr 2025

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Abstract

Metallic thin-walled porous tubes have been widely applied in energy absorption fields due to their unique mechanical properties. Inspired by foam-filled structures, liquid crystal elastomers as a new category of metamaterials were filled in metallic thin-walled porous tubes to obtain a novel composite [...] Read more.

Metallic thin-walled porous tubes have been widely applied in energy absorption fields due to their unique mechanical properties. Inspired by foam-filled structures, liquid crystal elastomers as a new category of metamaterials were filled in metallic thin-walled porous tubes to obtain a novel composite energy-absorbing structure that can improve energy-absorbing capabilities. By means of experiments and numerical simulations, this paper investigated deformation modes and the energy-absorbing performance of metallic thin-walled porous tubes filled with liquid crystal elastomers under dynamic crush. Moreover, the effects of geometric parameters on deformation modes and the energy-absorbing performance of the metallic thin-walled porous tubes filled with liquid crystal elastomers were analyzed. The results show that liquid crystal elastomers can enhance energy-absorbing capabilities under dynamic crush and geometric parameters can affect deformation modes, further affecting the energy-absorbing performance of metallic thin-walled porous tubes filled with liquid crystal elastomers. Full article

(This article belongs to the Section Composites Applications)

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15 pages, 3551 KiB

Open AccessArticle

Response Surface Methodology-Based Optimization for Enhancing the Viability of Microencapsulated Lactobacillus plantarum in Composite Materials

by Rafael González-Cuello, Joaquín Hernández-Fernández and Rodrigo Ortega-Toro

J. Compos. Sci. 2025, 9(4), 189; https://doi.org/10.3390/jcs9040189 - 15 Apr 2025

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Abstract

Probiotics have gained prominence and consumer appreciation due to their potential health benefits. However, maintaining their viability and stability during gastric transit remains a challenge. This study aims to enhance the viability of microencapsulated Lactobacillus plantarum in composite microcapsules exposed to simulated gastric [...] Read more.

Probiotics have gained prominence and consumer appreciation due to their potential health benefits. However, maintaining their viability and stability during gastric transit remains a challenge. This study aims to enhance the viability of microencapsulated Lactobacillus plantarum in composite microcapsules exposed to simulated gastric juice. The independent variables investigated were low-acyl gellan gum (LAG), bacterial cellulose (BC), and calcium concentrations. The microcapsules were prepared using the internal ionic gelation method. The resulting microcapsules exhibited a uniform size distribution, with a diameter of approximately between 15 to 120 μm, making them suitable for food applications. Response surface methodology (RSM) based on the Box–Behnken design was successfully employed to optimize the concentrations of LAG, BC, and calcium. Under optimal conditions—0.63% w/v LAG, 17.91% w/v BC, and 25.12 mM Ca—the highest L. plantarum viability reached 94.28% after exposure to simulated gastric juice, with an R² value of 99.64%. These findings demonstrate the feasibility of developing multicomponent microcapsules that effectively protect probiotic bacteria against gastric fluids, offering a promising alternative for the food industry in designing probiotic-enriched food systems. Full article

(This article belongs to the Special Issue Advances in Biocomposite Materials for Regenerative Medicine and Biomedical Applications)

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24 pages, 10743 KiB

Open AccessArticle

Investigation of Diffusion of Different Composite Materials on the Damage Caused by Axial Impact Adhesive Joints

by Dudu Mertgenç Yoldaş and Mehmet Fatih Yoldaş

J. Compos. Sci. 2025, 9(4), 188; https://doi.org/10.3390/jcs9040188 - 14 Apr 2025

Viewed by 191

Abstract

In this study, the effects of exposure to seawater on the material properties of glass fiber-reinforced polymer (GFRP) and carbon fiber-reinforced polymer (CFRP) samples were investigated. The samples were stored in seawater with a salinity of 3.3–3.7% and a temperature of 23.5 °C [...] Read more.

In this study, the effects of exposure to seawater on the material properties of glass fiber-reinforced polymer (GFRP) and carbon fiber-reinforced polymer (CFRP) samples were investigated. The samples were stored in seawater with a salinity of 3.3–3.7% and a temperature of 23.5 °C taken from the Aegean Sea in September for different periods (1, 2, 3, 6 and 15 months). The samples prepared in accordance with the ASTM D5868-01 standard were subjected to axial impact testing. In the first stage of this study, moisture retention percentages were determined, and, then, axial impact tests were performed. In the tests, a total of 36 samples bonded with single-lap adhesive were subjected to 30 Joule impact energy, and their mechanical strength was evaluated. In line with the experimental results, moisture absorption and axial impact energy values were compared in order to determine the most durable composite material connection, and the most durable connection was selected by evaluating the mechanical properties. Damage analysis on the samples was performed at the DEU Science and Technology Application and Research Center with ZEISS GEMINI SEM 560. (Oberkochen, Germany). The fracture surfaces of the CFRP and GFRP samples after gold coating were examined in detail with a scanning electron microscope, and their interface properties and internal structures were observed. The fracture toughness of GFRP specimens increased from 4.6% in a dry environment to 27.96% after 15 months in seawater. CFRP specimens increased from 4.2% in a dry environment to 11.96% after 15 months in seawater, but the increase was less pronounced compared to GFRP. According to the experimental results, CFRP samples exhibited superior mechanical performance compared to GFRP samples. Full article

(This article belongs to the Collection Editorial Board Members’ Collection Series: Fibre Composite Materials)

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19 pages, 40454 KiB

Open AccessArticle

Shining a Light on Carbon-Reinforced Polymers: Mg/MgO and TiO₂ Nanomodifications for Enhanced Optical Performance

by Lukas Haiden, Michael Feuchter, Andreas J. Brunner, Michel Barbezat, Amol Pansare, Bharath Ravindran, Velislava Terziyska and Gerald Pinter

J. Compos. Sci. 2025, 9(4), 187; https://doi.org/10.3390/jcs9040187 - 12 Apr 2025

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Abstract

This study examines the intrinsic optical enhancements of carbon fiber-reinforced polymers (CFRPs) achieved through the integration of magnesium oxide (MgO) nanoparticles, as well as Mg/MgO and titanium dioxide (TiO₂) thin films onto carbon fibers. Integration was performed by quasi-continuous electrophoretic deposition [...] Read more.

This study examines the intrinsic optical enhancements of carbon fiber-reinforced polymers (CFRPs) achieved through the integration of magnesium oxide (MgO) nanoparticles, as well as Mg/MgO and titanium dioxide (TiO₂) thin films onto carbon fibers. Integration was performed by quasi-continuous electrophoretic deposition (EPD) and physical vapor deposition (PVD), respectively. Employing a customized electrophoretic cell, EPD facilitated uniform MgO nanoparticle deposition onto unsized carbon fibers, ensuring stable nanoparticle dispersion and precise fiber coating. As a result, the fibers exhibited increased ultraviolet (UV) reflectance, largely attributed to the optical properties of the protective MgO layer. In parallel, PVD enabled the deposition of Mg/MgO and TiO₂ thin films with tailored thicknesses, providing precise control over key optical parameters such as reflectivity and interference effects. Mg/MgO coatings demonstrated high UV reflectivity, while TiO₂ layers, with their varying refractive indices, generated vibrant colors in the visible (Vis) range through thickness-dependent light interference. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) assessed the quality, thickness, and uniformity of these thin films, and UV/Vis spectroscopy confirmed the influence of deposition parameters on the resulting optical performance. Post-lamination analyses revealed that both EPD and PVD modifications significantly enhanced UV reflectivity and allowed for customizable color effects. This dual strategy underscores the potential of combining EPD and PVD to develop advanced CFRPs with superior UV resistance, decorative optical features, and improved environmental stability. Full article

(This article belongs to the Special Issue Carbon Fiber Composites, 4th Edition)

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17 pages, 5233 KiB

Open AccessArticle

Anisotropy and Strain Rate Sensitivity of Additively Manufactured Polymer Composites in Tension and Compression: Effects of Type and Orientation of Fibres

by Md Niamul Islam, Konstantinos P. Baxevanakis and Vadim V. Silberschmidt

J. Compos. Sci. 2025, 9(4), 186; https://doi.org/10.3390/jcs9040186 - 11 Apr 2025

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Abstract

Comprehensive analysis of the anisotropic nature of additively manufactured (AM) parts caused by their fabrication method requires attention, as current quasi-static experiments on AM specimens are used to determine strength and stiffness. This study investigates the anisotropic mechanical behaviour of AM polymer composites [...] Read more.

Comprehensive analysis of the anisotropic nature of additively manufactured (AM) parts caused by their fabrication method requires attention, as current quasi-static experiments on AM specimens are used to determine strength and stiffness. This study investigates the anisotropic mechanical behaviour of AM polymer composites reinforced with short and continuous carbon fibres, examining various filament orientations, loading directions and strain rates. Utilising the fused deposition modelling (FDM) technique, nylon and carbon fibres were fabricated into composites with controlled orientations. Mechanical tests were conducted in different directions to assess the tensile and compressive properties of these composites, with results showing enhanced tensile strength and stiffness in continuous-fibre (CF) composites compared to short-fibre (SF) ones, particularly in longitudinal orientations. The compressive behaviour revealed complex effects of type and orientation of reinforcing fibres, with CF composites demonstrating superior stiffness but lower strength than SF composites in specific orientations. Strain rate sensitivity analysis for the least anisotropic (quasi-isotropic) cases indicated that tensile strength decreased slightly with the increased strain rate while compressive strength increased. These findings underline the critical effect of fibre orientation and type on mechanical properties and suggest potential applications of AM composites in scenarios demanding tailored anisotropic behaviours, including structural optimisation and numerical modelling for various loading conditions. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

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13 pages, 9205 KiB

Open AccessArticle

Fracture Behavior of Additively Manufactured Carbon Fiber Reinforced Acrylonitrile-Styrene-Acrylate Containing Cracks and Notches

by Sergio Cicero, Sergio Arrieta, Fabrizia Devito, Borja Arroyo and Fulvio Lavecchia

J. Compos. Sci. 2025, 9(4), 185; https://doi.org/10.3390/jcs9040185 - 11 Apr 2025

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Abstract

Within the context of the increasing use of additive manufacturing techniques and the corresponding need to understand the behavior of 3D-printed materials, this paper analyzes the fracture behavior of additively manufactured carbon fiber reinforced (10 wt.%) acrylonitrile-styrene-acrylate (ASA) with three different raster orientations [...] Read more.

Within the context of the increasing use of additive manufacturing techniques and the corresponding need to understand the behavior of 3D-printed materials, this paper analyzes the fracture behavior of additively manufactured carbon fiber reinforced (10 wt.%) acrylonitrile-styrene-acrylate (ASA) with three different raster orientations (90/0, 45/−45, 30/−60). The analyzed material (ASA-CF10) combines the remarkable resistance to weathering agents typical of ASA with the enhanced mechanical properties resulting from the inclusion of carbon fiber reinforcement. The analysis is performed on single-edge-notched bending (SENB) specimens containing different types of defects, from cracks to U-notches with notch radii of 0.5 mm, 1 mm and 2 mm. When compared to non-reinforced ASA, the fracture resistance is noticeably higher (nearly double) for the reinforced material in all raster orientations. The notch effect, defined as the increase in the fracture resistance when the notch radius increases, is analyzed through the Theory of Critical Distances (TCD), and it is mostly higher in the reinforced material than in the pristine polymer. These observations are supported by Scanning Electron Microscopy analyses. Full article

(This article belongs to the Special Issue Editorial Board Members' Collection Series: Mechanical Analysis of Composite Materials)

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22 pages, 7094 KiB

Open AccessArticle

Development of Cement-Free Binder Systems Based on Metallurgical Waste: Hardening by Forced Carbonation

by Nikolay Lyubomirskiy, Tamara Bakhtina, Alexey Gusev, Aleksandr Bakhtin, German Bilenko and Wolfgang Linert

J. Compos. Sci. 2025, 9(4), 184; https://doi.org/10.3390/jcs9040184 - 11 Apr 2025

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Abstract

This article explores the possibility of using metallurgical waste slags formed during the smelting of cast iron and steel as cementless binders that harden due to forced carbonization and the subsequent hydration processes of some minerals that form the basis of these slags. [...] Read more.

This article explores the possibility of using metallurgical waste slags formed during the smelting of cast iron and steel as cementless binders that harden due to forced carbonization and the subsequent hydration processes of some minerals that form the basis of these slags. This study presents the results of multi-objective optimization using statistical methods of mathematical experimental design, with the purpose of obtaining a carbonized material with good mechanical and physical properties. As a result of the research, carbonized stone with compressive strength up to 116.5 MPa was obtained. Water absorption by weight is within the range of 6.0–17.0%, and quantitative CO₂ binding was 6–11.9%, depending on the type of slag. A pilot batch of wall product samples (hollow bricks and paving elements of various territories) was manufactured under production conditions. During the tests, we found that the compressive strengths of products based on BOF and EAF slags were 96.3 and 81.1 MPa, respectively, and that of bricks based on BS slag was 37.1 MPa. A comprehensive analysis of the performance properties of products from the pilot batch showed that these samples meet the requirements of national standards. Full article

(This article belongs to the Section Composites Applications)

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28 pages, 16181 KiB

Open AccessArticle

Investigating the Potential of Using Walnut Shell Particles for Manufacturing Cement-Bonded Particle Boards

by Anas El Hamri, Yassine Mouhib, Hassan Chkala, Oussama Oulhakem, Mohammed Chigr and Nour-Eddine El Mansouri

J. Compos. Sci. 2025, 9(4), 183; https://doi.org/10.3390/jcs9040183 - 10 Apr 2025

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Abstract

In the search for eco-friendly and resource-efficient alternatives to conventional building materials, agricultural residues are gaining increasing attention as reinforcements in cement-based composites. This study investigates the potential of walnut shell particles (WSPs), a lignocellulosic bio-product, as a sustainable reinforcing agent in walnut [...] Read more.

In the search for eco-friendly and resource-efficient alternatives to conventional building materials, agricultural residues are gaining increasing attention as reinforcements in cement-based composites. This study investigates the potential of walnut shell particles (WSPs), a lignocellulosic bio-product, as a sustainable reinforcing agent in walnut shell cement boards (WSCBs). Using super white cement (SWC) as a binder, boards were manufactured with WSP content ranging from 10% to 50% by weight, targeting a density of 1300 kg/m³, a 10 mm thickness, and a water-to-cement ratio of 0.6:1. The mixtures were cold-pressed at ambient temperature using a hydraulic press at 3 MPa for 24 h, followed by curing for 28 days under ambient conditions. Physical properties such as density, water absorption, and thickness swelling were assessed, along with mechanical performance, through flexural testing. Fracture surfaces and internal microstructures were examined using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Functional groups and chemical reactions were monitored using FTIR, while thermal analysis (TGA and DSC), as well as measurements of thermal conductivity and resistance, provided comprehensive insights into the thermal behavior, insulating performance, and energy efficiency potential of the boards. Results demonstrate that the board with 30% WSP exhibited an optimal balance of physical and mechanical properties, achieving a 24 h water absorption of 14.05% and a modulus of rupture (MOR) of 6.53 MPa, making it suitable for non-structural applications. The board with 50% WSP exhibited the best thermal insulation performance, with a low thermal conductivity of 0.079 W/m·K. These findings highlight the potential of recycled agricultural materials in enhancing building materials’ performance, contributing to sustainable, eco-friendly construction practices. Full article

(This article belongs to the Special Issue Advancements in Sustainable Cement-Based Composites: Innovations in Performance, Durability, and Environmental Impact)

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24 pages, 3714 KiB

Open AccessArticle

Comparison of Bending Properties of Sandwich Structures Using Conventional and 3D-Printed Core with Flax Fiber Reinforcement

by Viktor Brejcha, Martin Böhm, Tomáš Holeček, Miloš Jerman, Klára Kobetičová, Ivana Burianová, Robert Černý and Zbyšek Pavlík

J. Compos. Sci. 2025, 9(4), 182; https://doi.org/10.3390/jcs9040182 - 9 Apr 2025

Viewed by 464

Abstract

The growing demand for sustainable composites has increased interest in natural fiber reinforcements as alternatives to synthetic materials. This study evaluates the bending properties of sandwich structures with flax fibers and 3D-printed lightweight foaming PLA cores compared to conventional designs using glass fibers [...] Read more.

The growing demand for sustainable composites has increased interest in natural fiber reinforcements as alternatives to synthetic materials. This study evaluates the bending properties of sandwich structures with flax fibers and 3D-printed lightweight foaming PLA cores compared to conventional designs using glass fibers and traditional cores. Three-point bending tests (EN 310) and density profile analysis showed that, despite its lower density, the 3D-printed foaming PLA core achieved a modulus of elasticity of 2269.19 MPa and a bending strength of 31.46 MPa, demonstrating its potential for lightweight applications. However, natural fibers influenced resin absorption, affecting core saturation compared to glass fibers. The use of bio-based epoxy and foaming PLA contributes to a lower environmental footprint, while 3D printing enables precise material optimization. These findings confirm that 3D-printed cores offer a competitive and sustainable alternative, with future research focusing on further optimization of internal structure to enhance mechanical performance. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2024)

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14 pages, 2615 KiB

Open AccessArticle

Rheological Behavior of Ion-Doped Hydroxyapatite Slurries

by Zahid Abbas, Massimiliano Dapporto, Andreana Piancastelli, Davide Gardini, Anna Tampieri and Simone Sprio

J. Compos. Sci. 2025, 9(4), 181; https://doi.org/10.3390/jcs9040181 - 9 Apr 2025

Viewed by 296

Abstract

The present work investigates the rheological behavior of ceramic slurries made of hydroxyapatite powders doped with magnesium and strontium ions and selected as particularly relevant for biomedical applications. The incorporation of doping ions into the apatite crystal structure is a well-known way to [...] Read more.

The present work investigates the rheological behavior of ceramic slurries made of hydroxyapatite powders doped with magnesium and strontium ions and selected as particularly relevant for biomedical applications. The incorporation of doping ions into the apatite crystal structure is a well-known way to enhance the bioactivity of hydroxyapatite through compositional and structural changes, however, this also affects the rheological properties relevant to the fabrication of ceramic devices by forming techniques based on the manipulation of aqueous slurries. We analyzed the effect of different apatitic chemical compositions, powder content, and dispersant amount on the shear behavior and flowability of slurries, thus finding that the structural changes in hydroxyapatite induced by ion doping significantly affected the colloidal stability of the apatite powders and the viscoelasticity of the slurries. This leads to improved rheological behavior in the hydroxyapatite suspensions, which is suitable for the future development of ceramic slurries, particularly for achieving novel ceramic devices by extrusion-based techniques. Full article

(This article belongs to the Special Issue Advancements in Sustainable Cement-Based Composites: Innovations in Performance, Durability, and Environmental Impact)

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26 pages, 25600 KiB

Open AccessArticle

Enhancing Mechanical Properties of 3D-Printed PLA Composites Reinforced with Natural Fibers: A Comparative Study

by Nisakorn Somsuk, Supaaek Pramoonmak, Boonsong Chongkolnee, Ponlapath Tipboonsri and Anin Memon

J. Compos. Sci. 2025, 9(4), 180; https://doi.org/10.3390/jcs9040180 - 8 Apr 2025

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Abstract

Polylactic acid (PLA) is widely used in 3D printing for its biodegradability and ease of processing, but its brittleness and low impact strength often restrict its suitability for more demanding applications. The novelty of this work lies in its direct comparative approach: we [...] Read more.

Polylactic acid (PLA) is widely used in 3D printing for its biodegradability and ease of processing, but its brittleness and low impact strength often restrict its suitability for more demanding applications. The novelty of this work lies in its direct comparative approach: we systematically reinforce PLA with two distinct agricultural residues—rice husk and rice straw—under identical conditions to clarify how particle size (100 vs. 200 mesh) and NaOH surface treatment affect mechanical performance. Composite filaments containing 5–20 wt% of each fiber were produced and 3D-printed into standard tensile and flexural specimens. The results show that, although tensile strength declines at higher fiber loadings, tensile modulus, flexural strength, and impact resistance can improve significantly—particularly with 200-mesh and NaOH-treated fibers. Fourier transform infrared (FTIR) spectroscopy confirms partial lignin removal and enhanced cellulose exposure, improving fiber–matrix adhesion, which is corroborated by scanning electron microscopy (SEM) observations of reduced voids. This comparative study demonstrates that surface-treated, finely milled rice husk and rice straw significantly enhance PLA’s stiffness and toughness, offering a sustainable alternative to conventional polymeric additives. The insights gained here on fiber content, chemical treatment, and 3D printing parameters can guide the broader industrial adoption of these natural fiber-reinforced PLA composites, particularly in automotive and construction applications that require lightweight, durable materials. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

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27 pages, 8076 KiB

Open AccessArticle

Micro-Modeling of Polymer–Masonry Wall Composites Under In-Plane Loading

by Houria Hernoune, Younes Ouldkhaoua, Benchaa Benabed, Rajab Abousnina, Vanissorn Vimonsatit, Ali Mohammed and Allan Manalo

J. Compos. Sci. 2025, 9(4), 179; https://doi.org/10.3390/jcs9040179 - 7 Apr 2025

Viewed by 269

Abstract

Fiber-reinforced polymers (FRPs) are effective for strengthening masonry walls. Debonding at the polymer–masonry interface is a major concern, requiring further investigation into interface behavior. This study utilizes detailed micro-modeling finite element (FE) analysis to predict failure mechanisms and analyze the behavior of brick [...] Read more.

Fiber-reinforced polymers (FRPs) are effective for strengthening masonry walls. Debonding at the polymer–masonry interface is a major concern, requiring further investigation into interface behavior. This study utilizes detailed micro-modeling finite element (FE) analysis to predict failure mechanisms and analyze the behavior of brick masonry walls strengthened with externally bonded carbon fiber-reinforced polymer (CFRP) under in-plane loading. The research investigates three CFRP strengthening configurations (X, I, and H). The FE model incorporates the nonlinear behavior of brick masonry components using the Concrete Damage Plasticity (CDP) model and uses a cohesive interface approach to model unit–mortar interfaces and the bond joints between masonry and CFRPs. The results demonstrate that diagonal CFRP reinforcement enhances the ductility and capacity of masonry wall systems. The FE model accurately captures the crack propagation, fracture mechanisms, and shear strength of both unreinforced and reinforced walls. The study confirms that the model can reliably predict the structural behavior of these composite systems. Furthermore, the study compares predicted shear strengths with established design equations, highlighting the ACI 440.7R-10 and CNR-DT 200/2013 models as providing the most accurate predictions when compared to experimental results. Full article

(This article belongs to the Special Issue Characterization and Modeling of Composites, 4th Edition)

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17 pages, 7218 KiB

Open AccessArticle

Optimizing Conductive Polymer Composites: The Role of Graphite Particle Size and Concentration in PVDF, PP, and PET Matrices

by Sarra Khairi, Ehsan Rostami-Tapeh-Esmaeil, Frej Mighri, Saïd Elkoun, Martin Brassard, Elaheh Oliaii, Philippe Pelletier, Guy Jourdain and Yves Bonnefoy

J. Compos. Sci. 2025, 9(4), 178; https://doi.org/10.3390/jcs9040178 - 7 Apr 2025

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Abstract

This study investigates the impact of graphite (GR) concentration and particle size on the performance of conductive polymer composites (CPCs) using polyvinylidene fluoride (PVDF), polypropylene (PP), and polyethylene terephthalate (PET) as matrix materials. Composites were prepared with GR concentrations ranging from 20 to [...] Read more.

This study investigates the impact of graphite (GR) concentration and particle size on the performance of conductive polymer composites (CPCs) using polyvinylidene fluoride (PVDF), polypropylene (PP), and polyethylene terephthalate (PET) as matrix materials. Composites were prepared with GR concentrations ranging from 20 to 60 wt. % and particle sizes categorized as G1 (5.9 µm), G2 (17.8 µm), and G3 (561 µm), and evaluated for their electrical, thermal, and mechanical properties. The investigation of the effect of graphite particle size on composite properties represents the main originality of this work. Among all composites, PVDF containing 60 wt. % of medium-sized G2 particles exhibited the lowest electrical resistivity (0.77 ohm·cm through-plane and 0.69 ohm·cm in-plane), along with the highest residual ash content (72%). In PP and PET matrices, incorporating 60 wt. % G2 particles resulted in through-plane resistivities of 11.3 ohm·cm and 1.6 ohm·cm, and in-plane resistivities of 5 ohm·cm and 1.2 ohm·cm, respectively, with thermal decomposition temperatures of 374 °C and 401 °C. Regarding mechanical performance and thermal stability, composites with small-sized G1 particles demonstrated superior performance due to their larger surface area and stronger matrix interactions. The PVDF/G1 (40/60 wt. %) composite achieved the highest flexural modulus (6.8 GPa), flexural strength (38.6 MPa), compressive modulus (0.28 GPa), and decomposition temperature (445 °C), highlighting its exceptional properties. These CPCs show significant promise for energy and electronic applications, particularly in the fabrication of bipolar plates for proton exchange membrane fuel cells, as well as in shielding materials and thermoelectric devices. Full article

(This article belongs to the Special Issue Composite Materials Containing Conjugated and Conductive Polymers)

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15 pages, 3434 KiB

Open AccessArticle

Underwater Explosion Analysis on Composite Marine Structures: A Comparison Between CEL and UEL Methods

by Jacopo Bardiani, Giada Kyaw Oo D’Amore, Claudio Sbarufatti and Andrea Manes

J. Compos. Sci. 2025, 9(4), 177; https://doi.org/10.3390/jcs9040177 - 5 Apr 2025

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Abstract

Underwater explosion (UNDEX) problems are typically simulated using numerical coupled techniques, such as the Coupled Eulerian–Lagrangian (CEL) method, to accurately capture fluid–structure interaction (FSI) effects, which are non-negligible in such scenarios. While highly accurate, coupled methods are computationally expensive. Alternatively, uncoupled (or decoupled) [...] Read more.

Underwater explosion (UNDEX) problems are typically simulated using numerical coupled techniques, such as the Coupled Eulerian–Lagrangian (CEL) method, to accurately capture fluid–structure interaction (FSI) effects, which are non-negligible in such scenarios. While highly accurate, coupled methods are computationally expensive. Alternatively, uncoupled (or decoupled) techniques, like the Uncoupled Eulerian–Lagrangian (UEL) approach, offer greater computational efficiency by neglecting FSI effects, but at the cost of reduced predictive accuracy. This study provides a qualitative and quantitative evaluation of how far UEL results deviate from the more realistic CEL solutions in UNDEX scenarios. The comparison focuses on the structural response of a floating double-bottom fiber-reinforced composite structure subject to a near-field UNDEX. The numerical results indicate that the UEL approach overestimates structural response by up to 190% compared to CEL when added mass effects are considered, and up to 400% when they are not. However, a correction strategy based on modifying the Hull Shock Factor (HSF) is proposed to bridge the gap between UEL and CEL predictions. This study demonstrates that, with proper calibration, UEL simulations can serve as a computationally efficient alternative for preliminary UNDEX assessments in naval engineering. Full article

(This article belongs to the Special Issue Advanced Composite Materials from Natural and Synthetic Sources: Fabrication, Characterization and Practical Application, Volume II)

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30 pages, 7078 KiB

Open AccessArticle

Enhancement of Mechanical and Tribological Properties of MWCNT-Reinforced Bio-Based Epoxy Composites Through Optimization and Molecular Dynamics Simulation

by Pavan Hiremath, Y. M. Shivaprakash, Kiran Keshyagol, Suhas Kowshik, B. M. Gurumurthy, D. V. Ghewade, Shivashankarayya Hiremath and Nithesh Naik

J. Compos. Sci. 2025, 9(4), 176; https://doi.org/10.3390/jcs9040176 - 5 Apr 2025

Viewed by 254

Abstract

This study investigated the enhancement of the mechanical and tribological properties of MWCNT-reinforced bio-based epoxy composites through systematic experiments and analysis. Composites incorporating MWCNTs at varying weight percentages were evaluated for hardness, wear rate, interfacial shear strength, and friction coefficient under diverse load, [...] Read more.

This study investigated the enhancement of the mechanical and tribological properties of MWCNT-reinforced bio-based epoxy composites through systematic experiments and analysis. Composites incorporating MWCNTs at varying weight percentages were evaluated for hardness, wear rate, interfacial shear strength, and friction coefficient under diverse load, sliding speed, and distance conditions. An optimal MWCNT content of 0.3–0.4% resulted in a maximum hardness of 4 GPa and a minimum wear rate of 0.0058 mm³/N·m, demonstrating a substantial improvement over the non-reinforced system. FTIR and XRD analyses confirmed robust interfacial bonding between the MWCNTs and epoxy matrix, while molecular dynamics simulations revealed cohesive energy density and stress distribution profiles. The Taguchi optimization identified the MWCNT weight percentage as the most influential parameter, contributing over 85% to wear rate reduction. Contour plots and correlograms further illustrate the parameter interdependencies, emphasizing the role of MWCNT dispersion in enhancing the composite properties. These findings establish that MWCNT-reinforced bio-based epoxy composites are promising candidates for high-performance and sustainable tribological applications. Full article

(This article belongs to the Special Issue Characterization and Modeling of Composites, 4th Edition)

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20 pages, 24517 KiB

Open AccessArticle

Investigations of Thin-Walled Glass Fiber Reinforced Plastic Laminates with Sealing Function for Electric Motors

by Jan David Hübsch, Nils Meyer, Daniela Feldten, Christian Mittelstedt and Philipp Berendes

J. Compos. Sci. 2025, 9(4), 175; https://doi.org/10.3390/jcs9040175 - 3 Apr 2025

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Abstract

This article presents, in detail, design considerations for a thin-walled glass fiber reinforced plastic (GFRP) liner on a fluid-cooled stator lamination of an electric motor. In addition to structural requirements due to the cooling fluid pressure, the GFRP liner needs to guarantee impermeability. [...] Read more.

This article presents, in detail, design considerations for a thin-walled glass fiber reinforced plastic (GFRP) liner on a fluid-cooled stator lamination of an electric motor. In addition to structural requirements due to the cooling fluid pressure, the GFRP liner needs to guarantee impermeability. Analytical considerations deriving from different coefficients of thermal expansion (CTEs) determine the two-layered laminate design. Empirical investigations show two innovative, simple, and, therefore, efficient test setups for the leakage of liquid media through a GFRP liner. The weeping investigations employ two different GFRP systems with four different configurations of interfiber failure (IFF) and, therefore, crack densities. The weeping investigations show that at least one ply in the laminate needs to be flawless regarding IFF cracks in order to guarantee the sealing function. Alternatively, a third sealing layer can be used. Full article

(This article belongs to the Section Composites Applications)

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18 pages, 6813 KiB

Open AccessArticle

Effects of Matrix Properties on the Interfacial Shear Strength Between Carbon Fiber and Various Thermoplastic Polymers, and Their Influence on the Mechanical Properties of Composites

by Kazuto Tanaka and Ryota Sakakibara

J. Compos. Sci. 2025, 9(4), 174; https://doi.org/10.3390/jcs9040174 - 2 Apr 2025

Viewed by 268

Abstract

Although fiber–matrix interfacial strengths, which affect the mechanical properties of fiber-reinforced plastics (FRPs), are considered to be determined by complex factors, few studies have systematically evaluated the relationship between the matrix properties and the fiber–matrix interfacial shear strength. In this study, the properties [...] Read more.

Although fiber–matrix interfacial strengths, which affect the mechanical properties of fiber-reinforced plastics (FRPs), are considered to be determined by complex factors, few studies have systematically evaluated the relationship between the matrix properties and the fiber–matrix interfacial shear strength. In this study, the properties of various thermoplastics were measured, and the matrix tightening stress that constricts the fiber was simulated using finite element method (FEM) analysis. The relationships between the fiber–matrix interfacial shear strength and the matrix properties were clarified. The mechanical properties of carbon fiber reinforced thermoplastic (CFRTP) laminates were also evaluated, and the relationships between the fiber–matrix interfacial shear strength and the mechanical properties of CFRTP laminates were examined. The fiber–matrix interfacial shear strength showed a positive correlation with the matrix tightening stress tightening the fiber in the radial direction, as well as with matrix density, tensile strength, modulus, and melting temperature, while a negative correlation was found with the coefficient of linear expansion of the matrix. A higher fiber–matrix interfacial shear strength can be achieved by using a matrix with higher density, even without direct evaluation of the fiber–matrix interfacial strength, as the fiber–matrix interfacial shear strength showed a strong positive correlation with matrix density. Furthermore, the mechanical properties of CFRTP laminates were enhanced when matrices with higher fiber–matrix interfacial shear strength were used. Full article

(This article belongs to the Special Issue Carbon Fiber Composites, 4th Edition)

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17 pages, 14026 KiB

Open AccessArticle

Analysis of the Deformation Mechanisms of Fabrics Based on rCF Staple Fiber Yarns for Thermoset Composite Applications

by Tobias Georg Lang, Mir Mohammad Badrul Hasan, Anwar Abdkader, Chokri Cherif and Thomas Gereke

J. Compos. Sci. 2025, 9(4), 173; https://doi.org/10.3390/jcs9040173 - 2 Apr 2025

Viewed by 287

Abstract

The draping of textile semi-finished products for complex geometries is still prone to errors, e.g., wrinkles, gaps, and fiber undulations, leading to reduced mechanical properties of the composite. Reinforcing textiles made from carbon fiber (CF) rovings (i.e., endless continuous fibers) can be draped [...] Read more.

The draping of textile semi-finished products for complex geometries is still prone to errors, e.g., wrinkles, gaps, and fiber undulations, leading to reduced mechanical properties of the composite. Reinforcing textiles made from carbon fiber (CF) rovings (i.e., endless continuous fibers) can be draped mainly based on their ability to deform under in-plane shearing. However, CF rovings are hardly stretchable in the fiber direction. These limited degrees of freedom make the production of complex shell-shaped geometries from standard CF-roving fabrics challenging. Contrary to continuous rovings, this paper investigates the processing of spun yarns made of recycled carbon fibers (rCFs), which are discontinuous staple fibers with defined lengths. rCFs are obtained from end-of-life composites or production waste, making them a sustainable alternative to virgin carbon fibers in the high-performance components of, e.g., automobiles, boats, or sporting goods. These staple fiber-spun yarns are considerably more stretchable, which is due to the ability of the individual fibers to slide against each other when deformed, resulting in improved formability of fabrics made from rCF yarns, enabling the draping of much more complex structures. This study aims to develop and characterize woven fabrics based on previous studies of rCF yarns for thermoset composites. In order to investigate staple fiber-spun yarns, a previous micro-scale modeling approach is extended. The formability of fabrics made from those rCF yarns is investigated through experimental forming tests and meso-scale simulations. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

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15 pages, 4473 KiB

Open AccessArticle

Composite Films Based on Poly(3-hexylthiophene):Perylene Diimide Derivative:Copper Sulfide Nanoparticles Deposited by Matrix Assisted Pulsed Laser Evaporation on Flexible Substrates for Photovoltaic Applications

by Marcela Socol, Nicoleta Preda, Andreea Costas, Gabriela Petre, Andrei Stochioiu, Gianina Popescu-Pelin, Sorina Iftimie, Ana Maria Catargiu, Gabriel Socol and Anca Stanculescu

J. Compos. Sci. 2025, 9(4), 172; https://doi.org/10.3390/jcs9040172 - 1 Apr 2025

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Abstract

Today, flexible and lightweight electronics are regarded as a viable alternative to conventional rigid and heavy devices in various application fields. In the optoelectronic area, organic semiconductors offer advantages such as high absorption coefficients, low processing temperatures, mechanical flexibility and compatibility with plastic [...] Read more.

Today, flexible and lightweight electronics are regarded as a viable alternative to conventional rigid and heavy devices in various application fields. In the optoelectronic area, organic semiconductors offer advantages such as high absorption coefficients, low processing temperatures, mechanical flexibility and compatibility with plastic substrates, while inorganic nanostructures provide good electronic properties and high thermal stability. Thus, composite films with enhanced properties can be achieved by inserting inorganic nanostructures within organic layers. In this research work, CuS nanoparticles were prepared by wet chemical precipitation and then added to an organic mixture containing poly(3-hexylthiophene) (P3HT) and N,N-bis-(1-dodecyl)perylene-3,4,9,10 tetracarboxylic diimide (AMC14), a chemically synthesized semiconductor, for fabricating hybrid composite films by matrix assisted pulsed laser evaporation (MAPLE) on indium tin oxide/poly(ethylene terephthalate) (ITO/PET) flexible substrates. A comparative assessment of the morphological, compositional, optical and electrical properties of the composite (P3HT:AMC14:CuS) and organic (P3HT:AMC14) layers was performed to evaluate their applicability in the photovoltaic cells. The transmission and emission spectra of the composite films are dominated by the optical features of AMC14, a perylene diimide derivative compound used as acceptor. In the case of devices based on MAPLE deposited composite layer fabricated on ITO/PET substrates, the electrical measurements carried under illumination revealed an improvement in the open circuit voltage parameter emphasizing their potential applications in the flexible device area. Full article

(This article belongs to the Section Polymer Composites)

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16 pages, 8016 KiB

Open AccessArticle

Structural Insights: In Situ Synthesis of Titanium Carbide by Magnesiothermic Method Using Carbon Nanotubes and Turbostratic Carbon as Carbon Sources

by María Luisa Camacho-Ríos, Guillermo Herrera-Pérez, Luis Carlos Rodriguez-Pacheco, Mariana Lizbeth Luján-Aguilar, Antonio Ramírez-de la Cruz, Nathaly Withney Aguilar-Cisneros, Marco Antonio Ruiz Esparza-Rodriguez, Daniel Lardizabal-Gutierrez, Raúl Pérez-Bustamante and José Antonio Betancourt-Cantera

J. Compos. Sci. 2025, 9(4), 171; https://doi.org/10.3390/jcs9040171 - 31 Mar 2025

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Abstract

The current work presents the influence of the magnesiothermic synthesis method on titanium carbide (TiC). In this method, powdered titanium precursors and two carbon sources—turbostratic carbon and carbon nanotubes—were employed in proportions of 10 wt.% and 20 wt.%. The refinement of the X-ray [...] Read more.

The current work presents the influence of the magnesiothermic synthesis method on titanium carbide (TiC). In this method, powdered titanium precursors and two carbon sources—turbostratic carbon and carbon nanotubes—were employed in proportions of 10 wt.% and 20 wt.%. The refinement of the X-ray diffraction (XRD) patterns using the Rietveld method for TiC suggests suggested coexistence of two phases, cubic with Fm-3m space group and hexagonal with P3₁21 space group. In particular, for the sample with 20 wt.% of carbon sources, the XRD refinement revealed that the cubic phase accounted for 94% of the composition, in contrast to a secondary hexagonal phase, Ti₆C_3.75, which comprised 6%. The influence of carbon on the morphology (particle size and shape) and crystallite size was monitored through bright-field transmission electron microscopy (BF-TEM) imaging and XRD. In samples containing 20 wt.% carbon, a homogeneous morphology in both size (around 11 microns) and shape was observed, along with a reduction in crystallite size (from 22.7 to 17.8 nm). Raman band analysis further revealed vibrational modes indicating that carbon induced disorder in the TiC structure. The magnesiothermic synthesis method developed in this work offers a low-cost approach of interest in the aerospace and automotive industries. Additionally, the study provides significant insights for particles used as additives or reinforcing agents to enhance the mechanical properties of metal matrix composites (MMCs). Full article

(This article belongs to the Section Carbon Composites)

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14 pages, 4439 KiB

Open AccessArticle

Dual Influence of Li Concentration and Nanoparticle Size in LiCoO₂ on the Conductivity and Storage Capacity of Lithium Batteries

by Obaidallah A. Algethami

J. Compos. Sci. 2025, 9(4), 170; https://doi.org/10.3390/jcs9040170 - 31 Mar 2025

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Abstract

Li_xCo_1−xO₂ nanocomposites with molar concentrations x (0.1, 0.3, 0.5, 0.7, 0.9) were prepared using the sol–gel method. The optical and electrical properties were determined using UV-Vis spectrometer. The results obtained indicate that the absorption coefficient increases upon increase [...] Read more.

Li_xCo_1−xO₂ nanocomposites with molar concentrations x (0.1, 0.3, 0.5, 0.7, 0.9) were prepared using the sol–gel method. The optical and electrical properties were determined using UV-Vis spectrometer. The results obtained indicate that the absorption coefficient increases upon increase of nanoparticle size, while the energy gap decreases when nanoparticle size increases. The storage capacity reaches its maximum value near resonance at minimum nanoparticle size. This is attributed to the fact that the optical properties, electrical conductivity, and actual electrical permittivity reach their maximum values near the resonance region and increase as the nanoparticle size decreases. The operating voltages at which the storage capacity attains maximum value in the range from 2.3 to 3.5 volts. These operating voltages can be adjusted to achieve the required range by controlling the Li concentrations and the crystallite size of Li_xCo_1−xO₂ NPs which directly affect the energy gap and, in turn, influence the operating voltage. The operating voltage can thus be increased by increasing the energy gap, which requires decreasing the nano size and the Li concentration. Full article

(This article belongs to the Section Nanocomposites)

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43 pages, 7222 KiB

Open AccessFeature PaperReview

Materials and Energy-Centric Life Cycle Assessment for Drones: A Review

by Ajitanshu Vedrtnam, Harsha Negi and Kishor Kalauni

J. Compos. Sci. 2025, 9(4), 169; https://doi.org/10.3390/jcs9040169 - 30 Mar 2025

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Abstract

The rapid expansion of drone applications across industries such as defense, healthcare, construction, agriculture, and surveillance has intensified the need for advanced materials that enhance performance while minimizing environmental impact. This review provides a comprehensive analysis of materials used in drone construction, categorizing [...] Read more.

The rapid expansion of drone applications across industries such as defense, healthcare, construction, agriculture, and surveillance has intensified the need for advanced materials that enhance performance while minimizing environmental impact. This review provides a comprehensive analysis of materials used in drone construction, categorizing them based on their application in key components such as frames, propellers, wings, and structural supports. An energy-centric life cycle assessment (LCA) examines the environmental footprint of drone materials, emphasizing energy use, emissions, and recyclability. The review highlights the trade-offs between mechanical performance and environmental impact, identifying materials that optimize structural efficiency while reducing environmental impact. Additionally, emerging sustainable alternatives such as bio-based composites and recycled carbon fibers are explored as potential solutions for next-generation UAV design. By addressing existing research gaps, this study aims to guide the development of environmentally responsible drone manufacturing technologies. The findings offer valuable insights into optimizing drone materials for enhanced environmental efficiency, supporting the transition toward more energy-efficient and eco-friendly UAVs. Full article

(This article belongs to the Section Composites Applications)

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25 pages, 2459 KiB

Open AccessArticle

Implementation of Composite Materials for an Industrial Vehicle Component: A Design Approach

by Ivan Tomasi, Stefano Grandi and Luigi Solazzi

J. Compos. Sci. 2025, 9(4), 168; https://doi.org/10.3390/jcs9040168 - 29 Mar 2025

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Abstract

The aim of this research is to define a design approach for implementing composite materials in a component of an industrial vehicle, having weight reduction as the primary goal. Through the schematisation of the problem and analytical analysis, the definition of a new [...] Read more.

The aim of this research is to define a design approach for implementing composite materials in a component of an industrial vehicle, having weight reduction as the primary goal. Through the schematisation of the problem and analytical analysis, the definition of a new geometry, a material and production process, and numerical simulations and experimental studies to test the new solution, an optimization process of the chosen geometry is proposed. After the definition of the process, an applicative example is presented, analysing a front underrun protection device in two different solutions: one made of glass-fibre-reinforced polymer and the other of carbon-fibre-reinforced polymer. An economic comparison has also been conducted between the new configurations and the traditional steel version, showing a weight reduction of approximately 55% for the carbon-fibre-reinforced polymer solution and around 18% for the glass-fibre-reinforced polymer solution. These weight reductions are achievable through a reinvestment that can be amortized in less than five years, thanks to fuel consumption savings. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Modeling and Simulation of Composite Materials)

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23 pages, 3897 KiB

Open AccessArticle

Enhancing Polylactic Acid/Carbon Fiber-Reinforced Biomedical Composites (PLA/CFRCs) with Multi-Walled Carbon Nanotube (MWCNT) Fillers: A Comparative Study on Reinforcing Techniques

by Juan Antonio Paz-González, Yadira Gochi-Ponce, Carlos Velasco-Santos, Enrique Alcudia-Zacarias, Arturo Zizumbo-López, Balter Trujillo-Navarrete, Oscar Adrián Morales-Contreras and Luis Jesús Villarreal-Gómez

J. Compos. Sci. 2025, 9(4), 167; https://doi.org/10.3390/jcs9040167 - 29 Mar 2025

Viewed by 232

Abstract

The limited mechanical properties of composite materials, including stiffness, strength, and biocompatibility, restrict their effectiveness in biomedical applications. This research enhanced the mechanical properties and biocompatibility of polylactic acid and carbon fiber-reinforced composites (PLA/CFRCs) by incorporating multi-walled carbon nanotube (MWCNT) fillers. The methodology [...] Read more.

The limited mechanical properties of composite materials, including stiffness, strength, and biocompatibility, restrict their effectiveness in biomedical applications. This research enhanced the mechanical properties and biocompatibility of polylactic acid and carbon fiber-reinforced composites (PLA/CFRCs) by incorporating multi-walled carbon nanotube (MWCNT) fillers. The methodology involved synthesizing MWCNTs and integrating them into PLA/CFRC laminates using fusion-blending, dispersion, and interlaminar spray-coating. Raman spectroscopy confirmed the presence of MWCNTs, with characteristic D and G band peaks and an I_D/I_G of 1.44 ± 0.089. SEM revealed MWCNTs in the PLA/CFRC matrix and allowed size determination, with an outer diameter range of 125–150 nm and a length of 14,407 ± 2869 nm. FTIR identified interactions between the matrix and the MWCNTs, evidenced by band shifts. TGA/DSC analysis showed thermal stability above 338 °C for all composites. The tensile tests revealed that all composites had values greater than 19 GPa for the elastic modulus and 232 MPa for the ultimate strength. Cytotoxicity assays confirmed biocompatibility, and all samples maintained a cell growth rate greater than 80%. This study highlighted the potential of nanotechnology to optimize the mechanical behavior of polymer-based composites, expanding their applicability in biomedical fields. Full article

(This article belongs to the Special Issue Advances in Carbon Bionanocomposites: Recent Innovations and Applications)

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J. Compos. Sci., Volume 9, Issue 4 (April 2025) – 53 articles

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