Authors:Helena Khoury Moussa, Philippe Lestriez, He Thong Bui, Pham The Nhan Nguyen, Philippe Michaud, Romain Lucas-Roper, Guy Antou, Viet Dung Luong, Pham Tuong Minh Duong, Fazilay Abbès, Boussad Abbès First page: 333 Abstract: In the context of global sustainable development, using natural fibers as reinforcement for composites have become increasingly attractive due to their lightweight, abundant availability, renewability, and comparable specific properties to conventional fibers. This paper investigates the tensile properties of a sycamore bark fiber-reinforced composite. The tensile tests using digital image correlation showed that, by adding 18% by volume of sycamore bark for the polyester matrix, the tensile modulus achieves 4788.4 ± 940.1 MPa. Moreover, the tensile strength of the polyester resin increased by approximately 90% when reinforced with sycamore bark fiber, achieving a tensile strength of 64.5 ± 13.4 MPa. These mechanical properties are determined by the way loads are transferred between the polyester matrix and fibers and by the strength of the bond between the fiber-matrix interfaces. Since it is difficult and time consuming to characterize the mechanical properties of natural fibers, an alternative approach was proposed in this study. The method consists of the identification of the fiber elastic modulus using a finite element analysis approach, based on tensile tests conducted on the sycamore bark fiber-reinforced composites. The model correctly describes the overall composite behavior, a good agreement is found between the experimental, and the finite element predicted stress–strain curves. The identified sycamore bark fiber elastic modulus is 17,763 ± 6051 MPa. These results show that sycamore bark fibers can be used as reinforcements to produce composite materials. Citation: Journal of Composites Science PubDate: 2024-08-23 DOI: 10.3390/jcs8090333 Issue No:Vol. 8, No. 9 (2024)
Authors:Mengyuan Li, Chris Stokes-Griffin, Paul Compston First page: 335 Abstract: This paper presents a post-forming technique utilising both induction heating and rotary draw bending (RDB) for carbon fibre-reinforced polyetherentherketone (CF/PEEK) tubular structures. Existing post-forming techniques are unable to form CF/PEEK tubes due to the lack of a suitable mandrel material to provide internal support to the tube while withstanding high heat from melting the PEEK matrix during forming. This is addressed by using a steel spring mandrel in the tube induction heating process. In this study, four sets of [±60°]4 CF/PEEK tubes were formed using an induction heater-incorporated RDB setup into 45°, 90°, 135°, and 180° bends with a bending ratio of 2. Optical characterisation was performed to analyse tube fibre angle changes. A post-forming fibre angle prediction model previously derived for CF/polyamide 6 tubes was validated for its application in predicting fibre angle changes for CF/PEEK tubes by comparing the prediction with the characterised results. Citation: Journal of Composites Science PubDate: 2024-08-23 DOI: 10.3390/jcs8090335 Issue No:Vol. 8, No. 9 (2024)
Authors:László Kótai, Márk Windisch, Kende Attila Béres First page: 336 Abstract: We have developed a convenient route to transform biomass power plant ashes (BPPA) into porous sponge-like fertilizer composites. The absence of water prevents the chemical reaction and carbon dioxide formation when concentrated sulfuric acid is mixed with BPPA and CaCO3. Adding water, however, initiates the protonation reaction of carbonate ion content and starts CO2 evolution. The key element of the method was that the BPPA and, optionally, CaCO3 and/or CaSO4·0.5H2O were mixed with concentrated sulfuric acid to make a paste-like consistency. No gas evolution occurred at this stage; however, with the subsequent and controlled addition of water, CO2 gas evolved and was released through the channels developed in the pastry-like material due to the internal gas pressure, but without foaming. Using a screw-containing tube reactor, the water can be introduced under pressure. Due to the pressure, the pores in the pastry-like material became smaller, and consequently, the mechanical strength of the granulated and solidified mixture became higher than that of the reaction products prepared under atmospheric pressure. The main reaction products were syngenite (K2Ca(SO4)2·H2O) and polyhalite (K2Ca2Mg(SO4)4·2H2O). These compounds are valuable fertilizer components in themselves, but the material’s porous nature helps absorb solutions of microelement fertilizers. Surprisingly, concentrated ammonium nitrate solutions transform the syngenite content of the porous fertilizer into ammonium calcium sulfate ((NH4)2Ca(SO4)2·2H2O, koktaite). Koktaite is slightly soluble in water, thus the amount of ammonium ion released on the dissolution of koktaite depends on the amount of available water. Accordingly, ammonium ion release for plants can be increased with rain or irrigation, and koktaite is undissolved and does not decompose in drought situations. The pores (holes) of this sponge-like fertilizer product can be filled with different solutions containing other fertilizer components (phosphates, zinc, etc.) to adjust the composition of the requested fertilizer compositions for particular soils and plant production. The method allows the preparation of ammonium nitrate composite fertilizers containing metallic microelements, and various solid sponge-like composite materials with adjusted amounts of slowly releasing fertilizer components like syngenite and koktaite. Citation: Journal of Composites Science PubDate: 2024-08-24 DOI: 10.3390/jcs8090336 Issue No:Vol. 8, No. 9 (2024)
Authors:Andrey Evgenevich Akimov, Valentina Vasilevna Yadykina, Mikhail Sergeevich Lebedev, Vasilij Petrovich Denisov, Sergei Sergeevich Inozemtcev, Aleksandr Sergeevich Inozemtcev, Andrey Vladimirovich Korshunov, Anton Sergeevich Pilipenko First page: 337 Abstract: New requirements for the operational reliability of roads make the utilization of polymer-modified bitumen (PMB) more common in road construction. The application of polymer-modified bitumen based on traditional technology for the production of asphalt mixtures is associated with technological and economic difficulties and does not provide proper adhesion to the mixture’s mineral components. In addition, the method of producing a binder over a long time at high process temperatures leads to increased aging, which significantly reduces the service life of the material in the pavement. This paper presents the results of studies on the effect of polymer–bitumen concentrate (PBC) consisting of styrene–butadiene–styrene, plasticizer, and surfactant on the bitumen characteristics. It has been established that the use of PBC in the bitumen binder leads to an increase in the temperature range of plasticity, softening temperature, elasticity, and cohesive strength with a decrease in the viscosity of the modified bitumen. With a complex modifier rational content of 8% by weight of bitumen, the temperature range of plasticity is 79 °C, and elasticity is 82%, which exceeds the parameters of the factory PMB-60 based on SBS polymer. Tests of binders using the Superpave method allow classifying the modified binder to the PG 64-28, which shows an increase in the temperature range of viscoelastic properties by 6 °C compared with the binder produced by traditional methods. Thus, the expediency of using a complex additive containing a polymer and surface-active substances (surfactants) that can be distributed in bitumen without the use of a colloid agitator and plasticizer has been proven to improve the quality of an organic binder. Citation: Journal of Composites Science PubDate: 2024-08-27 DOI: 10.3390/jcs8090337 Issue No:Vol. 8, No. 9 (2024)
Authors:Betul Ari, Erk Inger, Aydin K. Sunol, Nurettin Sahiner First page: 338 Abstract: Carbon dioxide (CO2), one of the primary greenhouse gases, plays a key role in global warming and is one of the culprits in the climate change crisis. Therefore, the use of appropriate CO2 capture and storage technologies is of significant importance for the future of planet Earth due to atmospheric, climate, and environmental concerns. A cleaner and more sustainable approach to CO2 capture and storage using porous materials, membranes, and amine-based sorbents could offer excellent possibilities. Here, sucrose-derived porous carbon particles (PCPs) were synthesized as adsorbents for CO2 capture. Next, these PCPs were modified with branched- and linear-polyethyleneimine (B-PEI and L-PEI) as B-PEI-PCP and L-PEI-PCP, respectively. These PCPs and their PEI-modified forms were then used to prepare metal nanoparticles such as Co, Cu, and Ni in situ as M@PCP and M@L/B-PEI-PCP (M: Ni, Co, and Cu). The presence of PEI on the PCP surface enables new amine functional groups, known for high CO2 capture ability. The presence of metal nanoparticles in the structure may be used as a catalyst to convert the captured CO2 into useful products, e.g., fuels or other chemical compounds, at high temperatures. It was found that B-PEI-PCP has a larger surface area and higher CO2 capture capacity with a surface area of 32.84 m2/g and a CO2 capture capacity of 1.05 mmol CO2/g adsorbent compared to L-PEI-PCP. Amongst metal-nanoparticle-embedded PEI-PCPs (M@PEI-PCPs, M: Ni, Co, Cu), Ni@L-PEI-PCP was found to have higher CO2 capture capacity, 0.81 mmol CO2/g adsorbent, and a surface area of 225 m2/g. These data are significant as they will steer future studies for the conversion of captured CO2 into useful fuels/chemicals. Citation: Journal of Composites Science PubDate: 2024-08-27 DOI: 10.3390/jcs8090338 Issue No:Vol. 8, No. 9 (2024)
Authors:Dorota Dukarska, Radosław Mirski First page: 286 Abstract: This paper discusses methods of using biomass from the agriculture, forestry, food and aquaculture industries as potential raw materials for bio-polyols and as fillers in the production of rigid polyurethane (RPUR) foams. Various aspects of obtaining bio-polyols are discussed, as well as the impact of replacing petrochemical polyols with bio-polyols on the properties of foams. Special attention is paid to the conversion of vegetable oils and lignin. Another important aspect of the research is the use of biomass as foam fillers. Chemical and physical modifications are discussed, and important factors, such as the type and origin of biomass, particle size and amount, affecting the foaming process, microstructure and properties of RPUR foams are identified. The advantages and disadvantages of using biomass in foam production are described. It is found that bio-polyols can replace (at least partially) petrochemical polyols while maintaining the high insulation and strength of foams. In the case of the use of biomass as fillers, it is found that the shaping of their properties is largely dependent on the specific characteristics of the filler particles. This requires further research into process optimization but allows for the fine-tuning of RPUR foam properties to meet specific requirements. Citation: Journal of Composites Science PubDate: 2024-07-23 DOI: 10.3390/jcs8080286 Issue No:Vol. 8, No. 8 (2024)
Authors:Mohammad Hematibahar, Makhmud Kharun, Alexey N. Beskopylny, Sergey A. Stel’makh, Evgenii M. Shcherban’, Irina Razveeva First page: 287 Abstract: High-Performance Concrete (HPC) and Ultra-High-Performance Concrete (UHPC) have many applications in civil engineering industries. These two types of concrete have as many similarities as they have differences with each other, such as the mix design and additive powders like silica fume, metakaolin, and various fibers, however, the optimal percentages of the mixture design properties of each element of these concretes are completely different. This study investigated the differences and similarities between these two types of concrete to find better mechanical behavior through mixture design and parameters of each concrete. In addition, this paper studied the correlation matrix through the machine learning method to predict the mechanical properties and find the relationship between the concrete mix design elements and the mechanical properties. In this way, Linear, Ridge, Lasso, Random Forest, K-Nearest Neighbors (KNN), Decision tree, and Partial least squares (PLS) regressions have been chosen to find the best regression types. To find the accuracy, the coefficient of determination (R2), mean absolute error (MAE), and root-mean-square error (RMSE) were selected. Finally, PLS, Linear, and Lasso regressions had better results than other regressions, with R2 greater than 93%, 92%, and 92%, respectively. In general, the present study shows that HPC and UHPC have different mix designs and mechanical properties. In addition, PLS, Linear, and Lasso regressions are the best regressions for predicting mechanical properties. Citation: Journal of Composites Science PubDate: 2024-07-26 DOI: 10.3390/jcs8080287 Issue No:Vol. 8, No. 8 (2024)
Authors:Tatiana Zhiltsova, Andreia Costa, Mónica S. A. Oliveira First page: 288 Abstract: Agro-waste fibres for polymer composite reinforcement have gained increased interest in industry and academia as a more sustainable alternative to synthetic fibres. However, natural fibre composite (NFC) hygroscopicity is still an issue that needs to be solved. This work investigates how prolonged exposure to water affects the properties of the polypropylene (PP)-based injection-moulded composites reinforced with different contents of rice husk (rh) and olive pit (op) fibres. Both rh and op composites became more hydrophilic with increased fibre charge due to the affinity of cellulose and hemicellulose OH groups. Meanwhile, lignin contributes to the protection of the composites from thermo-oxidative degradation caused by water immersion. The PPrh composites had a higher saturation water content of 1.47% (20 wt.% rh) and 2.38% (30 wt.% rh) in comparison to PPop composites with an absorption of 1.13% (20 wt.% op) and 1.59% (30 wt.% op). The tensile elastic modulus has slightly increased, at the cost of the increased saturated composites’ rigidity, in composites with 30% rh and op fibre content (up to 13%) while marginally decreasing (down to 8%) in PP30%op compared to unsaturated counterparts. A similar trend was observed for the flexural modulus, enhanced up to 18%. However, rh and op composites with 30% fibre content ruptured in bending, highlighting their fragility after hydrolytic ageing. Citation: Journal of Composites Science PubDate: 2024-07-26 DOI: 10.3390/jcs8080288 Issue No:Vol. 8, No. 8 (2024)
Authors:Yunhua Luo First page: 289 Abstract: Functionally graded materials (FGMs) are revolutionizing various industries with their customizable properties, a key advantage over traditional composites. The rise of voxel-based 3D printing has furthered the development of FGMs with complex microstructures. Despite these advances, current design methods for FGMs often use abstract mathematical functions with limited relevance to actual performance. Furthermore, conventional micromechanics models for the analysis of FGMs tend to oversimplify, leading to inaccuracies in effective property predictions. To address these fundamental deficiencies, this paper introduces new gradation functions for functionally graded beams (FGBs) based on bending strain energy density, coupled with a voxel-based design and analysis approach. For the first time, these new gradation functions directly relate to structural performance and have proven to be more effective than conventional ones in improving beam performance, particularly under complex bending moments influenced by various loading and boundary conditions. This study reveals the significant role of primary and secondary gradation indices in material composition and distribution, both along the beam axis and across sections. It identifies optimal combinations of these indices for enhanced FGB performance. This research not only fills gaps in FGB design and analysis but also opens possibilities for applying these concepts to other strain energy density types, like shearing and torsion, and to different structural components such as plates and shells. Citation: Journal of Composites Science PubDate: 2024-07-28 DOI: 10.3390/jcs8080289 Issue No:Vol. 8, No. 8 (2024)
Authors:Tatjana Glaskova-Kuzmina, Sergejs Vidinejevs, Olegs Volodins, Jevgenijs Sevcenko, Andrey Aniskevich, Vladimir Špaček, Dalius Raškinis, Gediminas Vogonis First page: 290 Abstract: This research aims to develop fiber-reinforced composites (FRC) with enhanced fire resistance, which can be particularly useful for the transport industry (e.g., aviation, automotive, and train production). The fire retardation was achieved through epoxy matrix modification with hexachlorocyclotriphosphazene (HCTP). First, the fire-resistant and mechanical properties of the epoxy matrix filled with different HCTP contents (4.8, 7.2, and 9.5 wt.%) were studied to select the most effective HCTP content for the impregnation of FRC. Then, glass, basalt, and carbon fiber fabrics were impregnated with epoxy filled with 7.2 wt.% of HCTP, and the fire resistance, flexural, and interlaminar fracture properties were studied to select the most effective HCTP-modified type of fiber reinforcement based on the test results. It was concluded that basalt fiber impregnated with epoxy filled with HCTP could be selected as the most effective reinforcement type, allowing excellent mechanical and flame-retardant properties. Citation: Journal of Composites Science PubDate: 2024-07-29 DOI: 10.3390/jcs8080290 Issue No:Vol. 8, No. 8 (2024)
Authors:Marina Ruggles-Wrenn, Joshua Schmidt First page: 291 Abstract: Fully reversed tension–compression fatigue of a hybrid material comprising polymer matrix composite (PMC) co-cured with a ceramic matrix composite (CMC) was investigated. The PMC portion had a polyimide matrix reinforced with 15 plies of carbon fibers woven in an eight-harness satin weave (8HSW). The CMC portion had three plies of a quartz-fiber 8HSW fabric in a zirconia-based ceramic matrix. The hybrid PMC/CMC was developed for use in aerospace thermal protection systems (TPS). Hence, the experimental setup aimed to simulate the TPS service environment—the CMC side was kept at 329 °C, whereas the PMC side was open to laboratory air. Compression stress–strain response was studied, and compressive properties were measured at room and elevated temperature. Tension–compression fatigue tests were conducted at elevated temperature at 1.0 Hz. The evolution of tensile and compressive strains with fatigue cycles, as well as changes in the stress–strain hysteresis behavior and stiffness were examined. The tension–compression fatigue of a PMC with the same constituents and fiber architecture as the PMC portion of the PMC/CMC was studied for comparison. Tension–compression fatigue was found to be more damaging than tension–tension fatigue for both materials. The PMC outperformed the PMC/CMC in tension–compression fatigue. Post-test examination showed widespread delamination and striking non-uniform deformation modes of the PMC/CMC. Citation: Journal of Composites Science PubDate: 2024-07-29 DOI: 10.3390/jcs8080291 Issue No:Vol. 8, No. 8 (2024)
Authors:Xinman Yuan, Bo Li, Feng Feng, Jie Xu, Ge Song, Yiying Liang, Yuan Ma, Chao Xu, Fuji Wang, Pingfa Feng First page: 292 Abstract: Composite materials are widely used in the new generation of aviation equipment due to their comprehensive performance. However, the part fixture is usually difficult during the machining of composites with soft and brittle characteristics, such as the Nomex honeycomb. Therefore, the holding method based on the false boss connection can be utilized due to its advantages of low cost, less pollution, and a short preparation period. In this study, the method to determine and optimize the critical parameters of the false boss design is proposed to address the issue that they previously relied heavily on the experience of engineers, which often results in much waste of materials. To determine the critical parameters, a simulation model is constructed for Nomex honeycomb core parts machining with a false boss holding. Based on the simulation model, the stability of the machining process is analyzed, and the weak link of the false boss between different milling areas is studied. Furthermore, the difference in the shape of different parts is considered, and the reasonable critical parameters of the false boss are obtained through analysis. Citation: Journal of Composites Science PubDate: 2024-07-29 DOI: 10.3390/jcs8080292 Issue No:Vol. 8, No. 8 (2024)
Authors:Lida Najmi, Zhong Hu First page: 293 Abstract: Carbon nanotubes (CNTs) are considered an advanced form of carbon. They have superior characteristics in terms of mechanical and thermal properties compared to other available fibers and can be used in various applications, such as supercapacitors, sensors, and artificial muscles. The properties of single-walled carbon nanotubes (SWNTs) are significantly affected by geometric parameters such as chirality and aspect ratio, and testing conditions such as temperature and strain rate. In this study, the effects of geometric parameters and temperature on the mechanical properties of SWNTs were studied by molecular dynamics (MD) simulations using the Large-scaled Atomic/Molecular Massively Parallel Simulator (LAMMPS). Based on the second-generation reactive empirical bond order (REBO) potential, SWNTs of different diameters were tested in tension and compression under different strain rates and temperatures to understand their effects on the mechanical behavior of SWNTs. It was observed that the Young’s modulus and the tensile strength decreases with increasing SWNT tube diameter. As the chiral angle increases, the tensile strength increases, while the Young’s modulus decreases. The simulations were repeated at different temperatures of 300 K, 900 K, 1500 K, 2100 K and different strain rates of 1 × 10−3/ps, 0.75 × 10−3/ps, 0.5 × 10−3/ps, and 0.25 × 10−3/ps to investigate the effects of temperature and strain rate, respectively. The results show that the ultimate tensile strength of SWNTs increases with increasing strain rate. It is also seen that when SWNTs were stretched at higher temperatures, they failed at lower stresses and strains. The compressive behavior results indicate that SWNTs tend to buckle under lower stresses and strains than those under tensile stress. The simulation results were validated by and consistent with previous studies. The presented approach can be applied to investigate the properties of other advanced materials. Citation: Journal of Composites Science PubDate: 2024-07-30 DOI: 10.3390/jcs8080293 Issue No:Vol. 8, No. 8 (2024)
Authors:Orlando Donfrancesco, Alessio Zanza, Rodolfo Reda, Luca Testarelli, Michela Relucenti, Marco Seracchiani First page: 294 Abstract: This study investigated the marginal adaptation of three recently introduced bioceramic root repair materials, EdgeBioCeramic RetroFill, Endocem MTA, and One-Fil PT, using VP-SEM analysis. Extracted single-rooted lower incisors were used to simulate retrograde fillings. The results showed no statistically significant differences in the marginal gap between the materials and the dentin walls. All three materials exhibited good dimensional stability, with gap sizes comparable to previously published research on similar materials. The mean GAP was 3.91 ± 2.56 for EdgeBioCeramic RetroFill, 4.32 ± 2.69 for Endocem MTA, and 4.50 ± 2.54 for One-Fil PT. This study employed VP-SEM, a valuable tool for analyzing bioceramic materials without altering their properties. The findings suggest the possibility of daily clinical use of these bioceramics by endodontists and general practitioners that could find applications in retrograde fillings and perforation repairs. However, further in vivo studies are needed to confirm long-term stability and assess the influence of sample preparation methods. Citation: Journal of Composites Science PubDate: 2024-08-01 DOI: 10.3390/jcs8080294 Issue No:Vol. 8, No. 8 (2024)
Authors:Chiara Romeo, Giulia Fredi, Emanuela Callone, Francesco Parrino, Sandra Dirè First page: 295 Abstract: The miniaturization and high-power density of modern electronic devices pose significant thermal management issues, particularly affecting their performance and lifetime. Ladder-like polysilsesquioxanes (LPSQs) offer a promising solution due to their remarkable thermal, mechanical, and chemical properties. By incorporating thermally conductive fillers, LPSQ composites can achieve high thermal conductivity (TC), making them ideal for thermal management in advanced electronic applications. In this study, LPSQ-based nanocomposites containing functionalized alumina nanoparticles were prepared by solution casting and UV curing, and the effects of varying amounts of Irgacure-184 photoinitiator on their structural and thermal properties were investigated. Three sets of samples were prepared with a fixed amount of LPSQs, 80 wt.% of nanoparticles, and 1, 5, or 10 wt.% of photoinitiator with respect to the matrix. TC was evaluated from the measured values of heat capacity, density, and thermal diffusivity. TC values increased by 60%, 71.2%, and 93.1% for the three samples, respectively, compared to the neat matrix. Results indicate that an intermediate amount of photoinitiator (5%) preserved LPSQs’ structural integrity, namely the presence of long linear silsesquioxane chains, and provided good filler dispersion and distribution, high polymerization degree, thermal stability, and high TC. Citation: Journal of Composites Science PubDate: 2024-08-01 DOI: 10.3390/jcs8080295 Issue No:Vol. 8, No. 8 (2024)
Authors:Ravi Prakash Babu Kocharla, Raghu Kumar Bandlamudi, Abdul Ahad Mirza, Murahari Kolli, Ragavanantham Shanmugam, Muralimohan Cheepu First page: 296 Abstract: In recent years, natural fiber-reinforced hybrid composites have been utilized in many applications because of their lower cost, biodegradability, and low density. The aim of this research is to convert crab shell waste into an effective reinforcement in jute/carbon fiber hybrid composites. Various weight percentages of crab shell powder (0%, 1%, 3%, 5%, and 7%) were used to prepare crab shell powder hybrid composites. The performance of the crab shell powder hybrid composites was evaluated by preparing the specimens to conduct tensile, flexural, impact, and hardness tests as per ASTM standards. The results show that the inclusion of 5% crab shell powder displayed a better enhancement in the properties of the hybrid composite compared to other weight percentages. The tensile, flexural, and impact strengths of the 5% crab shell powder hybrid composite increased by 21%, 52%, and 50%, respectively. Also, the hardness of the hybrid composite was enhanced by 33%. Scanning electron microscopy (SEM) tests were conducted on the tensile-fractured specimen surfaces, and their morphology and structure confirmed the presence of a well-bonded interface between the fiber and matrix. Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG) analysis have shown that the crystallization behavior and thermal stability of the composite were enhanced with the inclusion of crab shell powder. The presence of crab shell powder in the hybrid composite was identified using SEM with Energy-Dispersive X-ray Spectroscopy (EDS). Citation: Journal of Composites Science PubDate: 2024-08-01 DOI: 10.3390/jcs8080296 Issue No:Vol. 8, No. 8 (2024)
Authors:Hamdi Beji, Tanguy Messager, Toufik Kanit First page: 297 Abstract: The objective of this study is to investigate the synergistic integration of machine learning and evolutionary algorithms for the discovery of equivalent morphologies exhibiting analogous behavior within the domain of composite materials. To pursue this objective, two comprehensive databases are meticulously constructed. The first database encompasses randomly positioned inclusions characterized by varying volume fractions and contrast levels. Conversely, the second database comprises microstructures of diverse shapes, such as elliptical, square, and triangular, while maintaining consistent volume fraction and contrast values across samples. Label assignment for both databases is conducted using a finite-element-method-based computational tool, ensuring a standardized approach. Machine learning techniques are then applied, employing distinct methodologies tailored to the complexity of each database. Specifically, an artificial neural network ANN model is deployed for the first database due to its intricate parameter configurations, while an eXtreme Gradient Boosting XGBoost model is employed for the second database. Subsequently, these developed models are seamlessly integrated with a genetic algorithm, which operates to identify equivalent morphologies with nuanced variations in geometry, volume fraction, and contrast. In summation, the findings of this investigation exhibit notable levels of adaptation within the discovered equivalent morphologies, underscoring the efficacy of the integrated machine learning and evolutionary algorithm framework in facilitating the optimization of composite material design for desired behavioral outcomes. Citation: Journal of Composites Science PubDate: 2024-08-01 DOI: 10.3390/jcs8080297 Issue No:Vol. 8, No. 8 (2024)
Authors:Rabindra Dharai, Harekrushna Sutar, Rabiranjan Murmu, Debashis Roy First page: 298 Abstract: It is difficult to select low-cost filler materials. Specifically, carbon-based filling materials are a matter of concern, and developing a carbon-filled polymer composite with enhanced properties is necessary. In this study, the authors developed a polymer composite using virgin polypropylene (PP) as a matrix and affordable micrographite (µG) as a filler. The developed composite has many potential applications in the automotive, aerospace, and electronic industries. To prepare the test specimens, the composite was prepared using a twin-screw extruder containing 3, 6, 9, 12, or 15 wt.% µG powder (BET surface area ≈ 29 m2/g; particle size > 50 µm) followed by injection molding. Different mechanical properties like the tensile, flexural, and impact strengths were determined. The prepared composites were further characterized by means of XRD, TGA, DSC, FTIR, DMA, FESEM, and PLM tests. The results were analyzed and compared with those for PP. Improved tensile (up to ≈ 34 MPa) and flexural (up to ≈ 40 MPa) strength was observed with an increase in the µG content. However, the impact strength continuously decreased (maximum ≈ 32 J/m for PP) with fractures. These findings underscore that graphite plays a significant role in controlling the deformation behavior and ultimate strength of composites. An XRD analysis revealed that adding graphite restructured the crystalline arrangement of PP and altered the composite’s crystallographic properties. Nonetheless, no induction effect (β-phase formation) was observed. A moderate enhancement in the thermal stability was observed owing to a small increase in the melt (Tm), onset (Tonset), and residual (TR) temperatures. A microstructural analysis showed that the micrographite powder strongly prevented spherulite growth and modified the graphite powder’s rate of dispersion and agglomeration in a polymer matrix. The results show that graphite could be a viable low-cost alternative carbon-based filler material in polypropylene matrices. Citation: Journal of Composites Science PubDate: 2024-08-01 DOI: 10.3390/jcs8080298 Issue No:Vol. 8, No. 8 (2024)
Authors:Dionysis E. Mouzakis, Panagiotis J. Charitidis, Stefanos P. Zaoutsos First page: 299 Abstract: Boeing and Airbus developed a special testing procedure to investigate the compressive response of laminates that have been impacted (following standards ASTM D 7137 and DIN 65561). This study focuses on both experimental and numerical analysis of Kevlar plates subjected to compression after impact. To ensure high quality and appropriate mechanical properties, the composite plates were manufactured using autoclaving. The DIN 65561 protocol was followed for all three test systems. Initially, ultrasonic C-scanning was performed on all plates before testing to confirm they were free of any significant defects arising from the manufacturing process. Subsequently, low-energy impact testing was conducted at levels ranging from 0 to 8 Joules. Three specimens were tested at each energy level. After the impact, all specimens underwent ultrasonic C-scanning again to assess the internal delamination damage caused by the impactor. Finally, both pristine and impacted specimens were subjected to compressive testing using the special jig specified in DIN 65561. The compressive impact strength results obtained from these tests were plotted against the delamination area measured by C-scanning. These data were then compared to the results obtained from specimens with artificial damage. Semi-empirical equations were used to fit both sets of curves. The same procedure (impact testing, C-scanning, and data analysis) was repeated to investigate the relationship between impact energy and total delamination area. Lastly, finite element modeling was employed to predict the buckling stresses that develop under compression in the impacted systems studied. These modeling approaches have demonstrated good accuracy in reproducing experimental results for CAI tests. Citation: Journal of Composites Science PubDate: 2024-08-01 DOI: 10.3390/jcs8080299 Issue No:Vol. 8, No. 8 (2024)
Authors:Giovanni Angiulli, Salvatore Calcagno, Fabio La Foresta, Mario Versaci First page: 300 Abstract: Non-destructive testing (NDT) techniques are crucial in making informed decisions about reconstructing or repairing building structures. The SonReb method, a combination of the rebound hammer (RH) and the ultrasonic pulse velocity (UPV) tests, is widely used for this purpose. To evaluate the compressive strength, CS, of the concrete under investigation, the ultrasonic pulse velocity Vp and the rebound index R must be mapped to the compressive strength CS using a suitable conversion model, the identification of which requires supplementing the NDT measurements with destructive-type measurements (DT) on a relatively large number of concrete cores. An approach notably indicated in all cases where the minimization of the number of cores is essential is to employ a pre-existing conversion model, i.e., a model derived from previous studies conducted in the literature, which must be appropriately calibrated. In this paper, we investigate the performance of Gaussian process regression (GPR) in calibrating the pre-existing SonReb conversion models, exploiting their ability to handle nonlinearity and uncertainties. The numerical results obtained using experimental data collected from the literature show that GPR calibration is very effective, outperforming, in most cases, the standard multiplicative and additive techniques used to calibrate the SonReb models. Citation: Journal of Composites Science PubDate: 2024-08-01 DOI: 10.3390/jcs8080300 Issue No:Vol. 8, No. 8 (2024)
Authors:Lamies Elgholmy, Hani Salim, Alaa Elsisi, Abdallah Salama, Hesham Shaaban, Ahmed Elbelbisi First page: 301 Abstract: This study aims to enhance the ultimate capacity and stiffness of steel–concrete composite beams through external strengthening with prestressed carbon fiber-reinforced polymer (CFRP) plates and post-tensioned CFRP tendons. A 3D finite element model was developed using ANSYS and validated using experiments. The impact of various parameters on the capacity of the beam was investigated, including the level of post-tensioning in the CFRP tendons, tendon profile, degree of shear connection, and beam load level when adding strengthening CFRP tendons. Results indicate that reinforcing composite beams with bonded CFRP plates using post-tensioning tendons with trapezoidal and parabolic profiles can increase maximum load capacity by 37% and 60%, respectively, while maintaining high stiffness. This study also indicates that the optimal strengthening conditions for the composite beam are when the beam is loaded up to 70% of its capacity and has a composite action degree of 100%. Citation: Journal of Composites Science PubDate: 2024-08-04 DOI: 10.3390/jcs8080301 Issue No:Vol. 8, No. 8 (2024)
Authors:Daniel T. Oyekunle, Marzieh Heidari Nia, Lee D. Wilson First page: 302 Abstract: The preservation of meat via sustainable methods and packaging is an area of continued interest driven by the need to address food security. The use of biomaterial films and coatings has gained significant attention due to their non-toxicity and biodegradability compared with conventional synthetic films. Starch and chitosan are sustainable sources for the preparation of films/coatings owing to their relatively low cost, natural abundance derived from numerous sources, biocompatibility, biodegradability, and antimicrobial, antioxidant, and film-forming attributes. These remarkable features have notably increased the shelf life of meat by inhibiting lipid oxidation and microbial activity in food products. Furthermore, recent studies have successfully incorporated binary biopolymer (starch and chitosan) systems to combine their beneficial properties upon composite formation. This literature review from 2020 to the present reveals that chitosan- and starch-based films and coatings have potential to contribute to enhanced food security and safety measures whilst reducing environmental issues and improving sustainability, compared with conventional synthetic materials. Citation: Journal of Composites Science PubDate: 2024-08-05 DOI: 10.3390/jcs8080302 Issue No:Vol. 8, No. 8 (2024)
Authors:Zaidong Liu, Yalei Wang, Xiang Xiong, Hongbo Zhang, Zhiyong Ye, Quanyuan Long, Jinming Wang, Tongqi Li, Congcong Liu First page: 303 Abstract: In this study, two types of porous Cf/Cm composites were obtained by introducing pyrolytic carbon (PyC) and pyrolytic carbon/furan resin carbon (PyC/FRC). Subsequently, Cf/Cm-SiC-(ZrxHf1−x)C composites with different carbon matrices were prepared by introducing SiC and (ZrxHf1−x)C matrices into the porous Cf/Cm composites via the reactive melt infiltration method, specifically termed as Cf/PyC-SiC-(ZrxHf1−x)C and Cf/PyC/FRC-SiC-(ZrxHf1−x)C composites. The microstructures of the porous Cf/Cm and Cf/Cm-SiC-(ZrxHf1−x)C composites with different carbon matrices were examined, and a comprehensive analysis was conducted on microstructural evolution and mechanical behaviors of the Cf/Cm-SiC-(ZrxHf1−x)C composites. The results indicate that both Cf/Cm-SiC-(ZrxHf1−x)C composites underwent similar microstructural evolution processes, differing only in terms of evolution kinetics and final microstructure. Differences in the pore structures of porous Cf/Cm composites, as well as in the reactivities of carbon matrices, were identified as primary influencing factors. Additionally, both Cf/Cm-SiC-(ZrxHf1−x)C composites exhibited “pseudo-ductile” fracture characteristics, with flexural strengths of 214.1 ± 8.8 MPa and 149.6 ± 12.2 MPa, respectively. In the Cf/PyC-SiC-(ZrxHf1−x)C composite, crack initiation during loading primarily originated from the ceramic matrix, while in the Cf/PyC/FRC-SiC-(ZrxHf1−x)C composite, failure initially arose from the residual FRC matrix. Excessive fiber corrosion and the presence of residual low-modulus FRC matrix resulted in lower mechanical performance. Citation: Journal of Composites Science PubDate: 2024-08-05 DOI: 10.3390/jcs8080303 Issue No:Vol. 8, No. 8 (2024)
Authors:Perla Y. Sauceda-Oloño, Bárbara G. S. Guinati, Ashlyn D. Smith, Rhett C. Smith First page: 304 Abstract: Plastics and composites for consumer goods often require flame retardants (FRs) to mitigate flammability risks. Finding FRs that are effective in new sustainable materials is important for bringing them to the market. This study evaluated various FRs in SunBG90 (a composite made from triglycerides and sulfur)—a high sulfur-content material (HSM) promising for use in Li–S batteries, where flame resistance is critical. SunBG90 was blended with FRs from several classes (inorganic, phosphorus-based, brominated, and nitrogen-containing) to assess compliance with UL94 Burning Test standards. Inorganic FRs showed poor flame retardancy and lower mechanical strength, while organic additives significantly improved fire resistance. The addition of 20 wt. % tetrabromobisphenol A enabled SunBG90 to achieve the highest flame retardancy rating (94V-0), while also enhancing wear resistance (52 IW, ASTM C1353) and bonding strength (26 psi, ASTM C482). Selected organic FRs also enhance compressive strength compared to the FR-free SunBG90. This research highlights the potential of HSMs with traditional FRs to meet stringent fire safety standards while preserving or enhancing the mechanical integrity of HSM composites. Citation: Journal of Composites Science PubDate: 2024-08-05 DOI: 10.3390/jcs8080304 Issue No:Vol. 8, No. 8 (2024)
Authors:Antonella Patti First page: 305 Abstract: This study investigated the effect of two critical variables for environmental process sustainability, i.e., extruder temperature and printing rate, on thermomechanical performance and accuracy in overall sample sizes, when printing bio-based materials. In this context, 3D specimens produced from basic polylactide (n-PLA) and wood-filled PLA polymer (f-PLA) were realized using extrusion-based additive manufacturing technology (MEX) by varying the nozzle temperatures (200 °C, 210 °C, and 220 °C) and speed (from 70 mm/s to 130 mm/s). Dynamic mechanical analysis (DMA) was carried out on the produced specimens, providing information on changes in storage modulus at testing temperature of 30 °C (E′30) and glass transition temperature (Tg) for each printing condition. Measurements of sample sizes allowed for printing precision considerations as a function of processing temperature and speed. The results revealed similar trends in E′30 changes in printed specimens at a fixed extruder temperature as a function of printing speed for n-PLA and f-PLA. Infrared spectroscopy was performed on printed samples and unextruded material to attest potential material degradation under various operating conditions. Finally, images of sample surface allowed to verify the homogeneity of the diameter of the extruded material and the layer–layer contact at the interface. Citation: Journal of Composites Science PubDate: 2024-08-05 DOI: 10.3390/jcs8080305 Issue No:Vol. 8, No. 8 (2024)
Authors:Yerkebulan Kocherov, Alexandr Kolesnikov, Gulnaz Makulbekova, Aigul Mamitova, Lazzat Ramatullaeva, Bahtiyor Medeshev, Olga Kolesnikova First page: 306 Abstract: In this article, one of the main scientific directions was the search for ways of recycling coal mining waste to produce expanded clay granules. There are a number of scientific studies devoted to the use of various industrial wastes in the production of thermal insulation and fireproof expanded clay granules. The authors consider the production of granular porous aggregates based on pulverized fractions of igneous rocks—basalt, granite, and synertite, as well as man-made materials of various origins, to be promising. According to the results of the conducted studies, it was found that the optimal interval of the amount of waste in expanded clay was 4.0–6.0%, and the optimal firing temperature was 1150 °C with the production of samples with a bulk density of 0.337–0.348 t/m3 and with a compressive strength of 1.37–1.51 MPa under these conditions. Citation: Journal of Composites Science PubDate: 2024-08-06 DOI: 10.3390/jcs8080306 Issue No:Vol. 8, No. 8 (2024)
Authors:Jiadeng Zhu First page: 307 Abstract: Fibers with lengths much larger than their widths have been developed over centuries because of their unique properties [...] Citation: Journal of Composites Science PubDate: 2024-08-06 DOI: 10.3390/jcs8080307 Issue No:Vol. 8, No. 8 (2024)
Authors:Erwei Song, Peiyao Liu, Yifan Lv, Erqiang Wang, Cun-Yue Guo First page: 308 Abstract: Thermoelectric (TE) materials are capable of realizing the direct conversion between heat and electricity, holding a giant prospect in the sustainable development of modern society. Conductive polymers (CPs) are suitable for the preparation of TE materials given their low-cost, lightweight, flexible, and easy processing properties. With the accelerating pace of flexible composite development, there is intensive interest in their emerging applications in various aspects such as wearable electronics and thermoelectric sensors. In order to further improve the thermoelectric properties, a series of new methods have been proposed to prepare conductive polymer-based thermoelectric composites and improve their thermoelectric properties. In this review, we discuss the compositing methods, properties, and applications of conductive polymer-based TE composites. The challenges and future development directions in the design and application of conductive polymer matrix composites are also pointed out. Citation: Journal of Composites Science PubDate: 2024-08-08 DOI: 10.3390/jcs8080308 Issue No:Vol. 8, No. 8 (2024)
Authors:Bingfeng Ge, Jitao Zhang, Sujoy Saha, Sabita Acharya, Chaitrali Kshirsagar, Sidharth Menon, Menka Jain, Michael R. Page, Gopalan Srinivasan First page: 309 Abstract: This report is on magneto-electric (ME) interactions in bulk composites with coaxial fibers of nickel–zinc ferrite and PZT. The core–shell fibers of PZT and Ni1−xZnxFe2O4 (NZFO) with x = 0–0.5 were made by electrospinning. Both kinds of fibers, either with ferrite or PZT core and with diameters in the range of 1–3 μm were made. Electron and scanning probe microscopy images indicated well-formed fibers with uniform core and shell structures and defect-free interface. X-ray diffraction data for the fibers annealed at 700–900 °C did not show any impurity phases. Magnetization, magnetostriction, ferromagnetic resonance, and polarization P versus electric field E measurements confirmed the ferroic nature of the fibers. For ME measurements, the fibers were pressed into disks and rectangular platelets and then annealed at 900–1000 °C for densification. The strengths of strain-mediated ME coupling were measured by the H-induced changes in remnant polarization Pr and by low-frequency ME voltage coefficient (MEVC). The fractional change in Pr under H increased in magnitude, from +3% for disks of NFO–PZT to −82% for NZFO (x = 0.3)-PZT, and a further increase in x resulted in a decrease to a value of −3% for x = 0.5. The low-frequency MEVC measured in disks of the core–shell fibers ranged from 6 mV/cm Oe to 37 mV/cm Oe. The fractional changes in Pr and the MEVC values were an order of magnitude higher than for bulk samples containing mixed fibers with a random distribution of NZFO and PZT. The bulk composites with coaxial fibers have the potential for use as magnetic field sensors and in energy-harvesting applications. Citation: Journal of Composites Science PubDate: 2024-08-08 DOI: 10.3390/jcs8080309 Issue No:Vol. 8, No. 8 (2024)
Authors:Mingjun Han, Taotao Yu, Yinghe Zhang, Xue Chen, Xiao-Jia Chen, Qing Peng, Ho-Kin Tang First page: 310 Abstract: Quasi-hexagonal-phase fullerene (qHPC60) is an asymmetrically ordered arrangement of fullerene in the two-dimensional plane, which has been synthesized recently. In this study, we performed a comprehensive investigation of the anisotropic mechanical properties of a qHPC60/graphene composite by means of molecular dynamics simulations. We assessed the mechanical properties of the 2D torsion-angle fullerene model with three force-fields: AIREBO, REAXFF, and TERSOFF. The results of the uniaxial tensile tests show that while the variations in fracture stress and fracture strain, with respect to pre-crack size, had similar trends for the three force-fields, AIREBO was more sensitive than REAXFF. The presence of cracks degraded the mechanical properties. Simulations of tensile tests on the qHPC60/graphene composite revealed that the graphene substrate significantly increased mechanical strength. Our results suggest qHPC60 holds various promising implications for composites. Citation: Journal of Composites Science PubDate: 2024-08-08 DOI: 10.3390/jcs8080310 Issue No:Vol. 8, No. 8 (2024)
Authors:Joaquín Alejandro Hernández Fernández, Rodrigo Ortega-Toro, Eduardo Antonio Espinosa Fuentes First page: 311 Abstract: The industrial production of polypropylene–polyethylene composites (C-PP-PE) involves the generation of waste that is not usable, resulting in a significant environmental impact globally. In this research, we identified different concentrations of aluminum (8–410 ppm), chlorine (13–205 ppm), and iron (4–100 ppm) residues originating from traces of the Ziegler–Natta catalyst and the triethylaluminum (TEAL) co-catalyst. These residues accelerate the generation of plastic waste and affect the thermo-kinetic performance of C-PP-PE, as well as the formation of volatile organic compounds that reduce the commercial viability of C-PP-PE. Several families of organic compounds were quantified by gas chromatography with mass spectrometry, and it is evident that these concentrations varied directly with the ppm of Al, Cl, and Fe present in C-PP-PE. This research used kinetic models of Coats–Redfern, Horowitz–Metzger, Flynn–Wall–Ozawa, and Kissinger–Akahira–Sunose. The activation energy values (Ea) were inversely correlated with Al, Cl, and Fe concentrations. In samples PP0 and W3, with low Al, Cl, and Fe concentrations, the values (Ea) were 286 and 224 kJ mol−1, respectively, using the Horowitz method. Samples W1 and W5, with a high ppm of these elements, showed Ea values of 80.83 and 102.99 kJ mol−1, respectively. This knowledge of the thermodynamic behavior and the elucidation of possible chemical reactions in the industrial production of C-PP-PE allowed us to search for a suitable remediation technique to give a new commercial life to C-PP-PE waste, thus supporting the management of plastic waste and improving the process—recycling to promote sustainability and industrial efficiency. One option was using the antioxidant additive Irgafos P-168 (IG-P168), which stabilized some of these C-PP-PE residues very well until thermal properties similar to those of pure C-PP-PE were obtained. Citation: Journal of Composites Science PubDate: 2024-08-09 DOI: 10.3390/jcs8080311 Issue No:Vol. 8, No. 8 (2024)
Authors:Getahun Tefera, Glen Bright, Sarp Adali First page: 312 Abstract: The present experimental study assesses the mechanical properties of glass/carbon/glass hybrid composite laminates after being exposed to moisture in a deep freezer and elevated temperatures for extended periods. The top and bottom layers of the hybrid laminates are reinforced with glass fibre, and the middle layer is reinforced with carbon fibre using the epoxy matrix as a binder polymer material. The hybrid laminates were manufactured using the resin transfer moulding method, and their compressive and tensile properties were determined using a tensile testing machine. The storage modulus, loss modulus, and damping factors of all groups of laminates were identified using a dynamic mechanical analysis as a function of temperature and vibration frequency. The experimental results on compressive and tensile properties revealed slight variations when the hybrid laminates were kept at low temperatures in a deep freezer for extended periods. This might occur due to the increasing molecular crosslinking of the polymer network. As the testing temperature increased, compressive, tensile, storage modules, loss modulus, and damping factors decreased. This might occur due to the increasing mobility of the binder material. Particularly, the highest stiffness parameters were obtained at −80 °C/GCG (glass/carbon/glass) laminates due to the presence of a beta transition in the glassy region. The relationships between the glass transitions and the targeted frequencies were characterized. The values of the glass transition shift towards higher temperatures as the frequency increases. This might occur due to a reduction in the gaps between the crosslinking of the epoxy network when the frequency increases. The accuracy of the storage modulus results was compared with the empirical models. The model based on the Arrhenius law provided the closest correlation. Meanwhile, another model was observed that was not accurate enough to predict when gamma and beta relaxations occur in a glassy state. Citation: Journal of Composites Science PubDate: 2024-08-09 DOI: 10.3390/jcs8080312 Issue No:Vol. 8, No. 8 (2024)
Authors:Sruthi Sreekumar Kavitha, Mini K. Madhavan, Karingamanna Jayanarayanan, Prabir Kumar Sarker First page: 313 Abstract: Fiber-reinforced polymer confinement is considered to be effective in the retrofitting of concrete structures. The current study explores the effectiveness of one- and two-layer carbon fiber reinforced polymer (CFRP) and multiwalled carbon nanotube (MWCNT) incorporated three-layer glass fiber reinforced polymer (GFRP) confinement on concrete cylinders under aggressive exposures, such as acid, alkaline, marine, water, and elevated temperatures. At 1 wt.% MWCNT by weight of the epoxy matrix, mechanical characteristics of the laminate show a significant improvement. In the case of acid exposure, the axial load-carrying capacity of concrete specimens with single-layer CFRP confinement was equal to that of MWCNT incorporated three-layer GFRP confinement (GF3C1-AC). The axial strain of GF3C1-AC was 23% and 12% higher than one and two-layer CFRP confinement. After exposure at 400 °C, in comparison with one- and two-layer CFRP confinement, the axial strain of MWCNT incorporated three-layer GFRP confined specimens increased by 50% and 20%, respectively, which proved the efficacy of MWCNT as a heat-resistant nanofiller. The ultrasonic pulse velocity (UPV) test indicates that the confinement system protects the concrete core from sudden failure by impeding crack propagation. The test results proved that the MWCNT incorporated FRP system can be considered as a prospective substitute for CFRP systems for retrofitting applications in severe environmental conditions. Citation: Journal of Composites Science PubDate: 2024-08-09 DOI: 10.3390/jcs8080313 Issue No:Vol. 8, No. 8 (2024)
Authors:Mildred Guillén-Espinoza, Fabián Vásquez Sancho, Ricardo Starbird-Perez, Roy Zamora-Sequeira First page: 314 Abstract: The medical device industry is constantly innovating in the search for materials that demonstrate superior performance, better intrinsic characteristics, profitability, and a positive impact on potential patients. The thermoplastic polymer resin Pebax® 5533D is one of the most widely used commercial materials for manufacturing medical device parts due to its easy processability. However, its mechanical and thermal properties require improvements to mitigate identified manufacturing defects, such as a decrease in material flexibility, high susceptibility to moisture, and thermal degradation during processing. Therefore, this study integrated different materials, such as plasticizers and filler additives, to produce a polymer compound prototype formula as a solution technique to enhance the current material’s performance. Modifying mechanical and rheological properties allows to evaluate the impacts on the polymeric material’s flexibility and thermal behavior. This was achieved by processing mixed additives using injector-molding equipment to obtain equal-molded samples of every formula. In addition, material characterization was performed to determine the variations in the samples’ crystallization, flexural strength, and moisture content. Calcium stearate was determined to be the most significant component serving as a mechanical resistance modifier and thermal stabilizer alongside calcium chloride as a moisture content reducer combined with Pebax® 5533D. Citation: Journal of Composites Science PubDate: 2024-08-09 DOI: 10.3390/jcs8080314 Issue No:Vol. 8, No. 8 (2024)
Authors:Anna Soćko, Jacek Andrzejewski First page: 315 Abstract: The conducted study was focused on the development of a new type of technical blend reinforced with natural fillers. The study was divided into two parts, where, in the first stage of the research, unmodified POM was reinforced with different types of natural fillers: cellulose, wood flour, and husk particles. In order to select the type of filler intended for further modification, the mechanical characteristics were assessed. The 20% wood flour (WF) filler system was selected as the reinforcement. The second stage of research involved the use of a combination of polyoxymethylene POM and poly(lactic acid) PLA. The POM/PLA blend (ratio 50/50%) was modified with an elastomeric compound (EBA) and chain extender as the compatibilized reactive (CE). The microscopic analysis revealed that for the POM/PLA system, the filler–matrix interface is characterized by better wettability, which might suggest higher adhesion. The mechanical performance revealed that for POM/PLA-based composites, the properties were very close to the results for POM-WF composites; however, there is still a significant difference in thermal resistance in favor of POM-based materials. The increase in thermomechanical properties for POM/PLA composites occurs after heat treatment. The increasing crystallinity of the PLA phase allows for a significant increase in the heat deflection temperature (HDT), even above 125 °C. Citation: Journal of Composites Science PubDate: 2024-08-10 DOI: 10.3390/jcs8080315 Issue No:Vol. 8, No. 8 (2024)
Authors:Hayrettin Irmak, Steffen Tinkloh, Thorsten Marten, Thomas Tröster First page: 316 Abstract: The use of hybrid materials as a combination of fibre-reinforced plastic (FRP) and metal is of great interest in order to meet the increasing demands for sustainability, efficiency, and emission reduction based on the principle of lightweight design. These two components can therefore be joined using the intrinsic joining technique, which is formed by curing the matrix of the FRP component. In this study, for the hybrid joint, unidirectionally pre-impregnated semi-finished products (prepregs) with duromer matrix resin and micro-alloyed HC340LA steel were used. In order to conduct a detailed investigation, the damage mechanisms of intrinsically produced fibre metal laminates (FMLs), a new clamping device, and a novel pressing tool were designed and put into operation. The prepregs were prestressed by applying a preloading force using a specially designed prestressing frame. Hybrid specimens were then produced and subjected to nanoindentation and a shear tensile test. In particular, the effect of the residual stress state by varying the defined prestressing force on the damage mechanisms was studied. The results showed that no fracture patterns occurred in the interface of the specimens without preloading as a result of curing at 120 °C, whereas specimens with preloading failed at the boundary layer in the tensile range. Nevertheless, all specimens cured at 160 °C failed at the boundary layer in the tensile range. Furthermore, it was proven that the force and displacement of the preloaded specimens were promisingly higher than those of the unpreloaded specimens. Citation: Journal of Composites Science PubDate: 2024-08-10 DOI: 10.3390/jcs8080316 Issue No:Vol. 8, No. 8 (2024)
Authors:Purba Purnama, Zaki Saptari Saldi, Muhammad Samsuri First page: 317 Abstract: Polylactide materials present a promising alternative to petroleum-based polymers due to their sustainability and biodegradability, although they have certain limitations in physical and mechanical properties for specific applications. The incorporation of nanoparticles, such as layered silicate (clay), carbon nanotubes, metal or metal oxide, cellulose nanowhiskers, can address these limitations by enhancing the thermal, mechanicals, barriers, and some other properties of polylactide. However, the distinct characteristics of these nanoparticles can affect the compatibility and processing of polylactide blends. In the polylactide nanocomposites, well-dispersed nanoparticles within the polylactide matrix result in excellent mechanical and thermal properties of the materials. Surface modification is required to improve compatibility and the crystallization process in the blended materials. This article reviews the development of polylactide nanocomposites and their applications. It discusses the general aspect of polylactides and nanomaterials as nanofillers, followed by the discussion of the processing and characterization of polylactide nanocomposites, including their applications. The final section summarizes and discusses the future challenges of polylactide nanocomposites concerning the future material’s requirements and economic considerations. As eco-friendly materials, polylactide nanocomposites offer significant potential to replace petroleum-based polymers. Citation: Journal of Composites Science PubDate: 2024-08-10 DOI: 10.3390/jcs8080317 Issue No:Vol. 8, No. 8 (2024)
Authors:Chantal Lewis, Burak Ogun Yavuz, Marco L. Longana, Jonathan P.-H. Belnoue, Karthik Ram Ramakrishnan, Carwyn Ward, Ian Hamerton First page: 318 Abstract: Aligned discontinuous fibre-reinforced composites are becoming more popular because they have the potential to offer stiffness and strength comparable to their continuous counterparts along with better manufacturability. However, the modelling of highly aligned discontinuous fibre composites is still in its infancy. This paper aims to provide a comprehensive review of the available literature to understand how modelling techniques have developed and consider whether all aspects which could affect the performance of aligned discontinuous fibre composites have been addressed. Here, for the first time, a broad view of the advantages, perspectives, and limitations of current approaches to modelling the performance and behaviour of aligned discontinuous fibre composites during alignment, forming, and mechanical loading is provided in one place as a route to design optimisation. Citation: Journal of Composites Science PubDate: 2024-08-12 DOI: 10.3390/jcs8080318 Issue No:Vol. 8, No. 8 (2024)
Authors:Boyu Li, Konstantinos P. Baxevanakis, Vadim V. Silberschmidt First page: 319 Abstract: This study investigates the effect of void features in additively manufactured polymers on water diffusion, focusing on polyethylene terephthalate glycol (PETG) composites. The additive manufacturing (AM) of polymers, specifically, material extrusion AM (MEAM), results in manufacturing-induced voids, therefore affecting the water resistance of the printed parts. The research analyses the effects of size, shape, orientation and the hydrophilicity of voids on moisture diffusion in PETG composites employing numerical (finite-element) simulations. Two void types were examined: voids of Type I that retard the moisture propagation and voids of Type II that enhance it. Simulations demonstrate that a higher volume fraction of voids and their orientation with regard to the diffusion direction significantly hinder the moisture transport for Type I voids. Conversely, due to their high diffusivity, Type II voids serve as channels for rapid moisture transmission. Consequently, for such materials, the global diffusion rates mainly depend on the volume fraction of voids rather than their shape. These findings indicate the critical role of voids in the design of AM parts for environments exposed to moisture, such as marine and offshore applications. Understanding the void effects is critical for optimising the durability and performance of MEAM components underwater exposure. Citation: Journal of Composites Science PubDate: 2024-08-12 DOI: 10.3390/jcs8080319 Issue No:Vol. 8, No. 8 (2024)
Authors:Gaetano Giunta, Domenico Andrea Iannotta, Levent Kirkayak, Marco Montemurro First page: 320 Abstract: Variable-Angle Tow (VAT) laminates can improve straight fiber composites’ mechanical properties thanks to the application of curvilinear fibers. This characteristic allows one to achieve ambitious objectives for design and performance purposes. Nevertheless, the wider design space and the higher number of parameters result in a more complex structural problem. Among the various approaches that have been used for VAT study, Carrera’s Unified Formulation (CUF) allows one to obtain multiple theories within the same framework, guaranteeing a good compromise between the results’ accuracy and the computational cost. In this article, the linear buckling behavior of VAT laminates is analyzed through the extension of CUF 2D plate models within Reissner’s Mixed Variational Theorem (RMVT). The results show that RMVT can better approximate the prebuckling nonuniform stress field of the plate when compared to standard approaches, thus improving the prediction of the linear buckling loads of VAT composites. Citation: Journal of Composites Science PubDate: 2024-08-13 DOI: 10.3390/jcs8080320 Issue No:Vol. 8, No. 8 (2024)
Authors:Aliya Kalizhanova, Ainur Kozbakova, Murat Kunelbayev, Zhalau Aitkulov, Anar Utegenova, Ulzhan Imanbekova First page: 321 Abstract: Currently, there is a lot of interest in smart sensors and integrated composite materials in various industries such as construction, aviation, automobile, medical, information technology, communication, and manufacturing. Here, a new conceptual design for a force and temperature sensor system is developed using fiber-optic Bragg grating sensors embedded within composite materials, and a mathematical model is proposed that allows one to estimate strain and temperature based on signals obtained from the optical Bragg gratings. This is important for understanding the behaviors of sensors under different conditions and for creating effective monitoring systems. Describing the strain gradient distribution, especially considering different materials with different Young’s modulus values, provides insight into how different materials respond to applied forces and temperature changes. The shape of the strain gradient distribution was obtained, which is a quadratic function with a maximum value of 1500 µ, with a maximum value at the center of the lattice and a symmetrically decreasing strain value with distance from the central part of the fiber Bragg grating. With the axial strain at the installation site of the Bragg grating sensor under applied force values ranging from 10 to 11 N, the change in strain was linear. As a result of theoretical research, it was found that the developed system with fiber-optic sensors based on Bragg gratings embedded in composite materials is resistant to external influences and temperature changes. Citation: Journal of Composites Science PubDate: 2024-08-14 DOI: 10.3390/jcs8080321 Issue No:Vol. 8, No. 8 (2024)
Authors:A. M. Bakry, Lamiaa S. El-Sherif, S. Hassaballa, Essam R. Shaaban First page: 322 Abstract: The research referred to in this study examines the morphological, structural, and optical characteristics of kesterite (Cu1−xAgx)2ZnSnS4 (CAZTS) thin films, which are produced using a process known as thermal evaporation (TE). The study’s main goal was to determine how different Ag contents affect the characteristics of CAZTS systems. X-ray diffraction (XRD) and Raman spectroscopy were used to confirm the crystal structure of the CAZTS thin films. Using a mathematical model of spectroscopic ellipsometry, the refractive index (n) represented the real part of the complex thin films, the extinction coefficient (k) portrayed the imaginary part, and the energy bandgap of the fabricated thin films was calculated. The energy bandgap is a crucial parameter for solar cell applications, as it determines the wavelength of light that the material can absorb. The energy bandgap was found to decrease from 1.74 eV to 1.55 eV with the increasing Ag content. The ITO/n-CdS/p-CAZTS/Mo heterojunction was well constructed, and the primary photovoltaic characteristics of the n-CdS/p-CAZTS junctions were examined for use in solar cells. Different Ag contents of the CAZTS layers were used to determine the dark and illumination (current–voltage) characteristics of the heterojunctions. The study’s findings collectively point to CAZTS thin layers as potential absorber materials for solar cell applications. Citation: Journal of Composites Science PubDate: 2024-08-15 DOI: 10.3390/jcs8080322 Issue No:Vol. 8, No. 8 (2024)
Authors:Tarek Dayyoub, Mikhail Zadorozhnyy, Kseniia V. Filippova, Lidiia D. Iudina, Dmitry V. Telyshev, Pavel V. Zhemchugov, Dmitriy G. Ladokhin, Aleksey Maksimkin First page: 323 Abstract: The development of fast-responding electrically conductive polymers as actuators activated by low electrical current is now regarded as an urgent matter. Due to their limited electrical conductivity, actuators based on polymeric hydrogels must be activated using a high voltage (up to 200 V) and frequency (up to 500 Hz) when employing AC power. In this work, to improve the electrical conductivity of the hydrogel and decrease the required activation voltage of the hydrogel actuators, lithium chloride (LiCL) was added as a conductive filler to the polymer matrix of polyvinyl alcohol (PVA). In order to ascertain the deformation of actuators, activation and relaxation times, actuator efficiencies, and generated force under the conditions of activation, linear actuators that can be activated by extension/contraction (swelling/shrinking) cycles were prepared and investigated depending on the LiCl content, applied voltage, and frequency. Under a load of approximately 20 kPa and using a 90 V AC power at a 50 Hz frequency with a 30 wt.% LiCl content, it was found that the actuators’ total contraction, reinforced by a woven mesh braided material, was about 20% with a ~2.2 s activation time, while the actuators’ total extension, reinforced by a spiral weave material, was about 52% with a ~2.5 s activation time, after applying a 110 V AC at a 50 Hz frequency with a 10 wt.% LiCl content. Furthermore, as the lowest voltage, a 20 V AC power can operate these actuators by increasing the LiCl weight content to the same PVA mass content. Moreover, the PVA/LiCl hydrogels’ activation force can be greater than 0.5 MPa. The actuators that have been developed have broad applications in soft robotics, artificial muscles, medicine, and aerospace fields. Citation: Journal of Composites Science PubDate: 2024-08-15 DOI: 10.3390/jcs8080323 Issue No:Vol. 8, No. 8 (2024)
Authors:Rajita Sanaka, Santosh Kumar Sahu, P. S. Rama Sreekanth, K. Senthilkumar, Nitesh Dhar Badgayan, Bathula Venkata Siva, Quanjin Ma First page: 324 Abstract: Shape-memory polymers (SMPs) possess unique properties that respond to external stimuli. The current review discusses types of SMPs, fabrication methods, and the characterization of their mechanical, thermal, and shape recovery properties. Research suggests that SMP composites, when infused with fillers, demonstrate enhanced mechanical and thermal characteristics. On the other hand, blends, particularly incorporating polylactic acid (PLA), exhibit the most efficient shape recovery. Furthermore, the crosslinking density in polymer blends impacts the shape recovery force, showcasing a correlation between energy storage capacity and shape recovery force in SMP networks. Overall, SMP blends show promising mechanical, thermal, and shape recovery features, rendering them advantageous for applications of artificial muscles, soft actuators, and biomedical devices. This review also discusses the future prospectives of SMP for robust applications. Citation: Journal of Composites Science PubDate: 2024-08-16 DOI: 10.3390/jcs8080324 Issue No:Vol. 8, No. 8 (2024)
Authors:Chih-Chiang Hong First page: 325 Abstract: The shear effect is usually considered in the numerical calculation of thick composited FGM plates. The characteristics that have the greatest effect on thickness are displacement type, shear correction coefficient, material property and temperature. For the advanced frequency study of thick composited functionally graded material (FGM) plates, it is interesting to consider the extra effects of the nonlinear coefficient c1 term of the third-order shear deformation theory (TSDT) of displacement on the calculation of varied shear correction coefficients. The values of nonlinear shear correction coefficients are usually functions of c1, the power-law exponent parameter and environment temperature. Numerical frequency computations are calculated using a simple homogeneous equation, and are investigated using TSDT and the nonlinear shear correction coefficient for thick composited FGM plates. Results for natural frequencies are found via the functions of length-to-thickness ratio, the power-law exponent parameter, c1 and environment temperature. This novel study in advanced frequency aims to determine the effects of the TSDT and nonlinear shear correction on thick FGM plates under free vibration. Citation: Journal of Composites Science PubDate: 2024-08-16 DOI: 10.3390/jcs8080325 Issue No:Vol. 8, No. 8 (2024)
Authors:Arash Ramian, Rani Elhajjar First page: 326 Abstract: Fatigue and fracture prediction in composite materials using cohesive zone models depends on accurately characterizing the core and facesheet interface in advanced composite sandwich structures. This study investigates the use of machine learning algorithms to identify cohesive zone parameters used in the fracture analysis of advanced composite sandwich structures. Experimental results often yield non-unique solutions, complicating the determination of cohesive parameters. Numerical determination can be time-consuming due to fine mesh requirements near the crack tip. This research evaluates the performance of Support Vector Regression (SVR), Random Forest (RF), and Artificial Neural Network (ANN) machine learning methods. The study uses features extracted from load–displacement responses during the fracture of the Asymmetric Double-Cantilever Beam (ADCB) specimen. The inputs include the displacement at the maximum load (δ*), the maximum load (Pmax), the total area under the load–displacement curve (At), and the initial slope of the linear region of the load–displacement curve (m). There are two objectives in this research: the first is to investigate which method performs best in identifying the interfacial cohesive parameters between the honeycomb core and carbon-epoxy facesheets, while the second objective is to reduce the dimensionality of the dataset by reducing the number of input features. Reducing the number of inputs can simplify the models and potentially improve the performance and interpretability. The results show that the ANN method produced the best results, with a mean absolute percentage error (MAPE) of 0.9578% and an R-squared (R²) value of 0.7932. These values indicate a high level of accuracy in predicting the four cohesive zone parameters: maximum normal contact stress (σI), critical fracture energy for normal separation (GI), maximum equivalent tangential contact stress (σII), and critical fracture energy for tangential slip (GII). Citation: Journal of Composites Science PubDate: 2024-08-17 DOI: 10.3390/jcs8080326 Issue No:Vol. 8, No. 8 (2024)
Authors:Wei-Zhi Zhang, Kan Wang, Ning Bao, Shou-Nian Ding First page: 327 Abstract: Much progress has been made in the determination of As (III), while numerous electrochemical sensors based on metal nanomaterials with significant sensitivity and precision have been developed. However, further research is still required to achieve rapid detection and avoid interference from other metal ions (especially copper ions). In this study, bimetallic AuPt nanoparticles are electrochemically modified with screen printing electrodes. What’s more, L-cysteine also self-assembles with AuNPs through Au-S bond to enhance the electrochemical performance. To overcome the interference of Cu (II) in the sensing process, the reduced iron powder was chosen to remove Cu (II) and other oxidizing organics in aqueous solutions. The lowest detectable amount is 0.139 ppb, a linear range of 1~50 ppb with superlative stability by differential pulse anodic stripping voltammetry. Fortunately, the reduced iron powder could eliminate the Cu (II) with no effect on the As (III) signal. Citation: Journal of Composites Science PubDate: 2024-08-18 DOI: 10.3390/jcs8080327 Issue No:Vol. 8, No. 8 (2024)
Authors:Jinsong Li, You Zhou, Jiatao Chen, Hongtao Hu, Mingze Sun First page: 328 Abstract: In this study, we compared the physical properties of coconut fiber/polypropylene (PP) composite materials with coconut fiber as a reinforcing agent, produced through a hybrid injection molding process and a layered hot-pressing process. Through comparative experiments, the mechanical properties of both the hybrid injection-molded and layered hot-pressed materials were validated. The results indicated that, when using a coconut fiber content of 5%, the layered hot-pressed composite material exhibited optimal comprehensive performance. Specifically, its tensile strength reached 25.12 MPa, showing a 37.6% increase over that of pure PP materials of the same brand and batch. Its tensile modulus was 1.17 GPa, representing an 11.4% decrease. Additionally, its bending strength was 35.94 MPa, marking a 49.8% increase, and its bending modulus was 2.69 GPa, which is nearly double that of pure PP materials. Furthermore, through Creo modeling and an ANSYS simulation analysis, it was verified that this material could be applied to airbag covers in the field of automotive safety. This study confirmed that layered hot-pressed coconut fiber/PP composite materials exhibit superior mechanical properties to traditional materials and injection-molded composite materials, making them more suitable for airbag covers. Citation: Journal of Composites Science PubDate: 2024-08-19 DOI: 10.3390/jcs8080328 Issue No:Vol. 8, No. 8 (2024)
Authors:Denis Petrukhin, Vitalii Salnikov, Aleksey Nikitin, Ibtissame Sidane, Sawssen Slimani, Stefano Alberti, Davide Peddis, Alexander Omelyanchik, Valeria Rodionova First page: 329 Abstract: Bismuth ferrite (BiFeO3, BFO) is one of the few single-phase crystalline compounds exhibiting strong multiferroic properties at room temperature, which makes it promising for use in various fields of science and technology. The remarkable characteristics of BFO at the nanoscale position it as a compelling candidate for enhancing the functionalities of polymeric nanocomposite materials. In this study, we explore the fabrication of polyvinylidene fluoride (PVDF) nanocomposites with a variable content of BFO nanopowders (0, 5, 10, 15, 20, and 25 wt%) by solution casting in the form of thin films with the thickness of ~60 µm. Our findings reveal that the presence of BFO nanoparticles slightly facilitates the formation of β- and γ-phases of PVDF, known for their enhanced piezoelectric properties, thereby potentially expanding the utility of PVDF-based materials in sensors, actuators, and energy harvesting devices. On the other hand, the increase in filler concentration leads to enlarged spherulite diameter and porosity of PVDF, as well as an increase in filler content above 20 wt% resulting in a decrease in the degree of crystallinity. The structural changes in the surface were found to increase the hydrophobicity of the nanocomposite surface. Magnetometry indicates that the magnetic properties of nanocomposite are influenced by the BFO nanoparticle content with the saturation magnetization at ~295 K ranging from ~0.08 emu/g to ~0.8 emu/g for samples with the lowest and higher BFO content, respectively. Citation: Journal of Composites Science PubDate: 2024-08-20 DOI: 10.3390/jcs8080329 Issue No:Vol. 8, No. 8 (2024)
Authors:Mahmoud T. Nawar, Mohamed Selim, Mahmoud Zaghlal, Ayman El-Zohairy, Mohamed Emara First page: 330 Abstract: In coastal regions, the deterioration of structures and bridges due to environmental conditions and corrosion is a significant concern. To combat these issues, the use of corrosion-resistant materials like fiber-reinforced polymers (FRPs) materials, engineered cementitious composites (ECCs), and rubberized ECCs (RECC) shows promise as normal concrete (NC) alternatives by providing increased ductility and energy absorption properties. The effectiveness of confining concrete columns using GFRP tubes with ECC/RECC was assessed in this research by evaluating their performance through compression and push-out tests. The study explored key parameters such as GFRP tube thickness and the presence of shear connectors along the tube height, as well as examining various types of concrete. Additionally, a comprehensive parametric investigation utilizing finite element analysis (FEA) was conducted to analyze how different factors influence the behavior of confined concrete columns. These factors included the effect of GFRP tube thickness and diameter on the overall behavior of different types of confined concretes. The results demonstrate that GFRP tubes significantly enhance column capacity, while the presence of ECC/RECC exhibits even greater improvements in capacity, stiffness, and toughness compared to NC. This approach shows promise in reinforcing coastal infrastructure and addressing corrosion-related concerns effectively. Citation: Journal of Composites Science PubDate: 2024-08-20 DOI: 10.3390/jcs8080330 Issue No:Vol. 8, No. 8 (2024)
Authors:Valentina Giammaria, Giulia Del Bianco, Monica Capretti, Simonetta Boria, Lorenzo Vigna, Andrea Calzolari, Vincenzo Castorani First page: 331 Abstract: Recent pressure on scientists and industries to use renewable resources, as well as the need to produce environmentally friendly materials, has led researchers and manufacturers to use natural fibres as possible reinforcements for their composites. Although they seem to be “ideal” due to their low cost, light weight and interesting energy absorption properties, they cannot be compared to synthetic fibres. To solve this problem, hybridization techniques can be considered, since the combination of synthetic and natural fibres allows for good performances. The aim of this study was to characterize the delamination and in-plane crashworthiness behaviour of carbon, flax and hybrid composites from experimental and numerical points of view. Double Cantilever Beam and Four-Point End Notched Flexure tests were carried out to determine the interlaminar fracture modes. In-plane crashworthiness tests were then performed to investigate the delamination phenomenon and the energy absorption capacity considering two different geometries: flat and corrugated. Numerical models were created and validated on both geometries, comparing the obtained load–displacement curves with the experimental ones. Crush force efficiency and specific energy absorption were quantified to provide a proper comparison of the investigated materials. The good results achieved represent a promising starting point for the design of future and more complex structures. Citation: Journal of Composites Science PubDate: 2024-08-21 DOI: 10.3390/jcs8080331 Issue No:Vol. 8, No. 8 (2024)
Authors:Alejandra López-Suárez, Dwight R. Acosta First page: 332 Abstract: Polycrystalline zinc oxide (ZnO) thin films were deposited on soda-lime glass substrates using the chemical spray pyrolysis method at three different substrate temperatures: 400, 450, and 500 °C. The solvents used in the precursor solution consisted of either ethanol or methanol. The effects of these solvents on the compositional, structural, morphological, electrical, and optical properties were studied with different techniques, including Rutherford Backscattering Spectrometry (RBS), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), four-point method, and Ultraviolet and Visible Spectroscopy (Uv-Vis). The results show that both temperature and the type of solvent modify the properties of the materials. An essential outcome of the study was that at 500 °C, the ZnO thin films prepared with either ethanol or methanol exhibited almost the same high-quality crystallinity, stoichiometry, average crystallite size, energy band gap, and resistivity. These findings contribute to our understanding of the properties of these materials and their potential applications. Citation: Journal of Composites Science PubDate: 2024-08-22 DOI: 10.3390/jcs8080332 Issue No:Vol. 8, No. 8 (2024)
Authors:Pannipa Tepamatr, Sumittra Charojrochkul, Navadol Laosiripojana First page: 239 Abstract: The water–gas shift (WGS) performance of 10%Ni/Al2O3, 20%Ni/Al2O3 and 10%Ni/CaO-Al2O3 catalysts was studied to reduce CO concentration and produce extra hydrogen. Ni was added onto the Al2O3 support by an impregnation method. The physicochemical properties of nickel catalysts that influence their catalytic activity were examined. The most influential factors in increasing the CO conversion for the water–gas shift reaction are Ni dispersion and surface acidity. Ni metal sites were identified as the active sites for CO adsorption. The main effect of nickel metal was reducing the adsorbed CO amount by reducing the active site concentration. The 10%Ni/Al2O3 catalyst was more active for the WGS reaction than other catalysts. This catalyst presents a high CO conversion rate (75% CO conversion at 800 °C), which is due to its high Ni dispersion at the surface (6.74%) and surface acidity, thereby favoring CO adsorption. A high Ni dispersion for more surface-active sites is exposed to a CO reactant. In addition, favored CO adsorption is related to the acidity on the catalyst surface because CO reactant in the WGS reaction is a weak base. The total acidity can be evaluated by integrating the NH3-Temperature-Programmed Desorption curves. Therefore, an enhancement of surface acidity is identified as the favored CO adsorption. Citation: Journal of Composites Science PubDate: 2024-06-25 DOI: 10.3390/jcs8070239 Issue No:Vol. 8, No. 7 (2024)
Authors: Markuniene, Palevicius, Vezys, Augustyniak, Perkowski, Urbaite, Janusas First page: 240 Abstract: Typically, polymer composites and ceramics are used to create biosensors. Materials with properties that are ideal for biosensors and chemical sensors include AgNO3 (silver nitrate), PVDF (polyvinylidene fluoride), and HA (hydroxyapatite). Polyvinylidene fluoride (PVDF) polymer has been widely used in several applications because of its well-known superior ferroelectric characteristics and biocompatibility. The brittleness and low bending strength of hydroxyapatite limit its applicability. Several HA and polymer composite formulations have been developed to compensate for HA’s mechanical weakness. The final product contains a significant amount of HA, making HA/polymer composites highly biocompatible. When the right amount of silver is deposited, the maximum piezoelectric activity is generated, and silver nitrate has antimicrobial properties. The non-toxic solvent DMSO (dimethyl sulfoxide) and the solvent casting method were chosen for the preparation of the film. Surface roughness was chosen to measure the Str and Sdr properties of the thin film. For liquid preparation, the multifractal spectra analysis was chosen for each sample. SEM was used to examine the samples morphologically. EDX and mapping analyses were presented for chemistry distribution in the samples. Citation: Journal of Composites Science PubDate: 2024-06-25 DOI: 10.3390/jcs8070240 Issue No:Vol. 8, No. 7 (2024)
Authors: Raydan, Charrier, Kowaluk, Robles First page: 241 Abstract: Global poultry waste production is substantial, with billions of poultry raised annually for meat and egg production, resulting in significant feather waste. Conventional poultry waste disposal methods are restricted due to environmental concerns. Meanwhile, wood-composite panel industries face raw material shortages, emphasizing the need for sustainable, renewable fiber sources. In this study, in the core layer of panels, wood particles were replaced with 5 wt% clean duck feathers without pretreatment to take advantage of feather attributes like hydrophobicity, thermal insulation, and sound damping as an alternative construction material. Three adhesives—urea-formaldehyde (UF), polymeric 4,4′-diphenylmethane diisocyanate (pMDI), and polyvinyl acetate (PVAc)—were examined for resin–feather compatibility. The control panels in this study were identical but wood was not replaced with feathers. The results revealed that wood–feather particleboard with pMDI and PVAc resins meets the requirements of the relevant standard for P2 boards (where applicable) concerning their modulus of rupture (MOR: 11 N·mm−2), modulus of elasticity (MOE: 1600 N·mm−2), internal bond (IB: 0.35 N·mm−2), and screw withdrawal resistance (SWR). However, those produced with UF resin did not meet the standards for IB and MOE. Furthermore, the physical properties showed similar water resistance and thickness swelling to control panels with pMDI. Notably, substituting 5 wt% wood with feathers improved thermal insulation by approximately 10% for UF and pMDI resins. Additionally, particleboard with feathers demonstrated improved sound absorption at high frequencies, ranging from 2500 to 500 Hz, particularly with pMDI resin, approaching Class B classification according to EN ISO 11654:1997. This study identifies the higher compatibility of pMDI over PVAc and UF adhesives for feather-based composite materials in construction applications. Citation: Journal of Composites Science PubDate: 2024-06-25 DOI: 10.3390/jcs8070241 Issue No:Vol. 8, No. 7 (2024)
Authors:Feyi Adekunle, Ang Li, Rahul Vallabh, Abdel-Fattah M. Seyam First page: 242 Abstract: Fiber-reinforced laminates with flexibility (FRLs) are becoming increasingly crucial across diverse sectors due to their adaptability and outstanding mechanical attributes. Their ability to deliver high performance relative to their weight makes them indispensable in lighter-than-air (LTA) applications, such as aerostats, inflatable antennas, surge bladders, gas storage balloons, life rafts, and other related uses. This research delved into employing woven fabrics as the reinforcement material and explored how their specific parameters, like fiber type, fabric count (warp thread density × weft thread density), fabric areal density, and fabric cover influence the bonding and mechanical properties of laminates. A thorough analysis encompassing standard T-peel (ASTM standard D1876) and a newly proposed yarn pullout in laminate test were conducted on laminates fabricated with various woven reinforcements, each with its unique specifications. The T-peel test was utilized to gauge the adhesive strength between FRL components, offering crucial insights into interfacial bonding within the laminates. Nevertheless, challenges exist with the T-peel test, including instances where the adherents lack the strength to withstand rupture, resulting in unsuccessful peel propagation and numerous outliers that necessitate costly additional trials. Thus, our research group introduced a novel yarn pullout in laminate test to accurately assess adhesion in FRLs. This study uncovered correlations between both adhesion tests (T-peel and yarn pullout in laminate), indicating that the innovative yarn pullout in laminate test could effectively substitute for characterizing adhesion in FRLs. Furthermore, the findings unveiled a complex relationship between woven fabric specifications and laminate properties. We noted that variations in fiber type, yarn linear density, and adhesive type significantly impacted adhesion strength. For instance, Kevlar exhibited markedly superior adhesion compared to Ultra-High Molecular Weight Polyethylene (UHMWPE) when paired with Thermoplastic Polyurethane (TPU) adhesive, whereas UHMWPE demonstrated better adhesion with Ethylene Vinyl Acetate (EVA). Moreover, the adhesion quality lessened as fabric count increased for the same adhesive quantity. These discoveries carry practical implications for material selection and design across industries, from automotive to aerospace, offering avenues to enhance FRL performance. Citation: Journal of Composites Science PubDate: 2024-06-26 DOI: 10.3390/jcs8070242 Issue No:Vol. 8, No. 7 (2024)
Authors:Kishore Chand, M. Mustafa Azeem, Muhammad Nazim Lakhan, Mukhtiar Ahmed, Muhammad Jehanzaib Aslam, Ahmer Hussain Shah First page: 243 Abstract: The emergence of 2D materials has significantly expanded the wide range of nanomaterials with diverse applications. Notably, their high conductivity, catalytic efficiency, and hydrophobicity have fueled heightened research interests for water treatment applications. This research aimed to investigate the synthesis and characterization of MXene and reduced graphene oxide (rGO) nanocomposites with silver nanoparticles (Ag) for enhanced catalytic activity in the decomposition of Direct Blue-24 dye. In this study, we employed well-established methods, previously documented in the literature, to prepare two distinct nanocomposites. Novel nanocomposites, namely reduced graphene oxide–silver nanoparticles (rGO–Ag) and MXene–silver nanoparticles (MXene–Ag), were synthesized using the hydrothermal and direct reduction method with an ammoniacal solution (aqueous solution). Comprehensive characterization using advanced tools revealed that the introduced Ag particles integrated seamlessly onto the parent nanofilms of the Carbon derivatives, forming a secondary phase with enhanced catalytic functionality. These nanocomposites demonstrated significant improvements in the catalytic decomposition reactions in simulated wastewater. Verification involved the reduction reaction of Direct Blue-24 dye at known nanocomposite concentrations. The results indicated that MXene–Ag exhibited a superior catalytic activity of 98% in 10 min compared to the rGO–Ag nanocomposite films, which achieved 96% in 35 min. The results indicated that MXene–Ag nanocomposites exhibited a 20–25% increase in catalytic efficiency compared to the rGO–Ag nanocomposites. The outcomes of this research hold promise for practical applications in textile wastewater management and various industrial sectors dealing with mutagenic and carcinogenic chemicals containing azo and/or phthalocyanine products. Citation: Journal of Composites Science PubDate: 2024-06-26 DOI: 10.3390/jcs8070243 Issue No:Vol. 8, No. 7 (2024)
Authors:Corentin Musa, Mohammed Zaidi, Michaël Depriester, Yamina Allouche, Naïm Naouar, Alain Bourmaud, Dominique Baillis, François Delattre First page: 244 Abstract: In the present work, an innovative range of foams based on flax gum-filled epoxy resin was developed, reinforced or not by flax fibers. Foams and composites with different gum and epoxy resin contents were produced and their mechanical and thermal performances were characterized. To enhance the organic flax gum filler’s cross-linking, we exploited the oxidized components’ reactivity with the amine hardener (isophorone diamine). We compared the materials obtained with those derived from the native components. The flax gum and fibers were primarily characterized by chemical analysis, NMR, and FTIR to evaluate the mild oxidation of the native materials. The formation of chemical bonds between the oxidized polymer chains, epoxy resin, and hardener was evidenced by FTIR, and the materials were then studied by SEM and X-ray computed micro-tomography (CT) and submitted to mechanical and thermal tests. The relevance of the oxidation treatment was highlighted through a significant increase in density and mechanical performance (+36% and +81%, respectively, for the 100% flax gum material). The positive effect of the flax fibers on homogeneity evidenced through micro-CT analysis was also clearly addressed. This set of promising results paves the way for the future development of fully flax-based insulation composite materials. Citation: Journal of Composites Science PubDate: 2024-06-27 DOI: 10.3390/jcs8070244 Issue No:Vol. 8, No. 7 (2024)
Authors:Bharath Sankaralingam, Gobi Saravanan Kaliaraj, Isha Rameshbabu, Padmapriya Rajendran, Kamalan Kirubaharan Amirtharaj Mosas First page: 245 Abstract: Researchers have extensively studied borate bioactive glass (BBG) for bone regeneration and wound healing applications. In the current study, 13-93B3 (54.6% B2O3, 22.1% CaO, 7.9% K2O, 7.7% MgO, 6.0% Na2O, and 1.7% P2O5) was synthesized using a sol–gel technique and doped with different molar concentrations of Cu (0.01, 0.05, and 0.25 M) into BBG for possible biomedical applications. Then, the antibacterial activity was tested against E. coli and S. aureus. The maximum zone of inhibition against S. aureus was achieved at 100 μg/mL of 0.25 M Cu-doped BBG. At 50 μg/mL of 0.25 molar copper concentration, E. coli showed a significant reduction in colony-forming units. Hydroxyl radical production, influenced by the BBG powder, was most effective against S. aureus, followed by E. coli. Protein leakage studies demonstrated significant leakage after treatment with BBG powder, demonstrating a strong effect on bacterial strains. This shows a change in protein synthesis, which is essential for central metabolism and gene transcription, affecting proteins in the periplasm and inner and outer membranes. Furthermore, carbohydrate leakage studies showed that BBG is effective against all three categories of cellular carbohydrate, namely membrane-bound, transmembrane, and intracellular carbs. This study focuses on the diverse antibacterial processes of Cu-doped BBG, which has emerged as a promising contender for biological applications that require strong antibacterial characteristics. Citation: Journal of Composites Science PubDate: 2024-06-28 DOI: 10.3390/jcs8070245 Issue No:Vol. 8, No. 7 (2024)
Authors:Neshat Sayah, Douglas E. Smith First page: 246 Abstract: Short carbon fiber-reinforced polymer composites are widely used in polymer extrusion additive manufacturing (AM), including large-area additive manufacturing (LAAM), due to their enhanced mechanical properties as compared to neat polymers. However, the mechanical properties of these composites depend on microstructural characteristics, including fibers and micro-voids, which are determined during processing. In this work, the correlation between fibers and micro-voids within the microstructure of LAAM polymer composites throughout various processing stages of short carbon fiber-reinforced acrylonitrile butadiene styrene (SCF/ABS) is investigated. The processing stages considered here include the incoming pellets, a single freely extruded strand, a single regularly deposited bead, and a single regularly deposited bead pressed by a mechanical roller. A high-resolution X-ray micro-computed tomography (µCT) system is employed to characterize the microstructural features in terms of the fibers (volume fraction, fiber orientation tensor) and micro-voids (volume fraction, sphericity) in the SCF/ABS samples. The results indicate that micro-voids exist within the microstructure of the SCF/ABS composite in all four stages considered here and that the micro-void volume fraction and micro-void sphericity vary among the test samples. Moreover, the results show a considerable variation in fiber orientation and fiber volume fraction within the microstructure throughout all the stages considered; however, all the samples show the highest alignment in the extrusion/print direction. Furthermore, a correlation is identified between the fiber orientation and the micro-void volume fraction within samples from all four stages considered here. This finding suggests that fibers tend to align more in the extrusion/print direction in regions with less micro-void content. Citation: Journal of Composites Science PubDate: 2024-06-28 DOI: 10.3390/jcs8070246 Issue No:Vol. 8, No. 7 (2024)
Authors:Benny Susanto, Vishnu Vijay Kumar, Leonard Sean, Murni Handayani, Farid Triawan, Yosephin Dewiani Rahmayanti, Haris Ardianto, Muhammad Akhsin Muflikhun First page: 247 Abstract: The study investigates the fabrication and analysis of nickel microparticle-reinforced composites fabricated using the digital light processing (DLP) technique. A slurry is prepared by incorporating Ni-micro particles into a resin vat; it is thoroughly mixed to achieve homogeneity. Turbidity fluctuations are observed, initially peaking at 50% within the first two minutes of mixing and then stabilizing at 30% after 15–60 min. FTIR spectroscopy with varying Ni wt.% is performed to study the alterations in the composite material’s molecular structure and bonding environment. Spectrophotometric analysis revealed distinctive transmittance signatures at specific wavelengths, particularly within the visible light spectrum, with a notable peak at 532 nm. The effects of printing orientation in the X, Y, and Z axes were also studied. Mechanical properties were computed using tensile strength, surface roughness, and hardness. The results indicate substantial enhancements in the tensile properties, with notable increases of 75.5% in the ultimate tensile strength and 160% in the maximum strain. Minimal alterations in surface roughness and hardness suggest favorable printability. Microscopic examination revealed characteristic fracture patterns in the particulate composite at different values for the wt.% of nickel. The findings demonstrate the potential of DLP-fabricated Ni-reinforced composites for applications demanding enhanced mechanical performance while maintaining favorable printability, paving the way for further exploration in this domain. Citation: Journal of Composites Science PubDate: 2024-06-29 DOI: 10.3390/jcs8070247 Issue No:Vol. 8, No. 7 (2024)
Authors:Spyridon Psarras, Maria-Panagiota Giannoutsou, Vassilis Kostopoulos First page: 248 Abstract: This study aimed to optimize the geometry of composite stepped repair patches, using a parametric algorithm to automate the process due to the complexity of the optimization problem and various factors affecting efficiency. More specifically, the algorithm initially calculates the equivalent strengths of the repaired laminate plate according to a max stress criterion, then calculates the dimensions of several elliptical repair patches, taking into account several design methods extracted from the literature. Next, it creates their finite element models and finally, the code conducts an assessment of the examined patch geometries, given specific user-defined criteria. In the end, the algorithm reaches a conclusion about the optimum patch among the designed ones. The algorithm has the potential to run for many different patch geometries. In the current research, five patch geometries were designed and modeled under uniaxial compressive loading at 0°, 45° and 90°. Overall, the code greatly facilitated the design and optimization process and constitutes a useful tool for future research. The results revealed that elliptical stepped patches can offer a near-optimum solution much more efficient than that of the conservative option of the circular patch, in terms of both strength and volume of healthy removed material. Citation: Journal of Composites Science PubDate: 2024-06-30 DOI: 10.3390/jcs8070248 Issue No:Vol. 8, No. 7 (2024)
Authors:Vyacheslav Krysanov, Maria Gadebskaya, Tatyana Krysanova, Tamara Kravchenko, Oleg Kozaderov First page: 249 Abstract: The results of a study of the kinetics of oxygen sorption from water by silver-containing nanocomposites synthesized on the base of macroporous ion exchangers with different pore sizes are presented. In the case of the Lewatit K 2620 ion exchanger, the pore size was fixed (41 nm), and for KU-23, it varied in the range from 10 to 100 nm. The nanocomposite materials Ag0⸱KU-23 and Ag0⸱Lewatit K 2620 were prepared by chemical precipitation. Using the different physicochemical methods, it was found that due to the monoporosity of the ion exchanger, the average size of the silver particles in the Ag0⸱Lewatit K 2620 nanocomposite is smaller than for KU-23. This effect contributes to the intensification of oxygen absorption and is proved by the results of studying the rate and degree of oxygen sorption by nanocomposites in the entire studied range of their capacity on metal. On the other hand, the polyporosity of the KU-23 ion exchanger, due to its better diffusion permeability, contributes to the more uniform distribution of silver over the volume of nanocomposite grains and ensures the steady state of the sorption process. Based on the presented experimental results, the synthesized silver-containing nanocomposites can be recommended as multifunctional materials with bactericidal action and catalytic effect for different industrial applications, including the deep removal of dissolved oxygen in the production of ultrapure water for energetics and microelectronics. Citation: Journal of Composites Science PubDate: 2024-07-01 DOI: 10.3390/jcs8070249 Issue No:Vol. 8, No. 7 (2024)
Authors:Meysam Mehdinia, Mohammad Farajollah Pour, Hossein Yousefi, Ali Dorieh, Anthony J. Lamanna, Elham Fini First page: 250 Abstract: This study introduces the development of a novel bio-nano composite via the dispersion of cellulose nanofibers (CNF) in epoxy. The surface of cellulose nanofibers was functionalized using a two-step chemical treatment to enhance dispersion. The interfacial characteristics of CNF were improved using alcohol/acetone treatments. The modified CNF (M-CNF) demonstrated enhanced compatibility and improved dispersion in the epoxy matrix as evidenced by scanning electron microscopy. Based on the analysis of X-ray diffraction patterns, M-CNF did not disturb the crystalline phases at the interface. The results of mechanical testing showed that M-CNF worked as a reinforcing agent in the bio-nano composite. The flexural modulus increased from 1.4 to 3.7 GPa when M-CNF was introduced. A similar trend was observed for tensile strength and impact resistance. The optimum performance characteristics were observed at M-CNF of 0.6%. At higher dosages, some agglomeration was observed, which weakened the interfacial properties. This study promotes sustainability and resource conservation while offering CNF as a sustainable reinforcing agent to develop bio-nano composites. Citation: Journal of Composites Science PubDate: 2024-07-01 DOI: 10.3390/jcs8070250 Issue No:Vol. 8, No. 7 (2024)
Authors:Christina Gioti, Konstantinos C. Vasilopoulos, Maria Baikousi, Angelos Ntaflos, Zacharias Viskadourakis, Alkiviadis S. Paipetis, Constantinos E. Salmas, George Kenanakis, Michael A. Karakassides First page: 251 Abstract: This article explores the cutting-edge advancement of gypsum or cement building boards infused with shape-stabilized n-octadecane, an organic phase change material (PCM). The primary focus is on improving energy efficiency and providing electromagnetic interference (EMI) shielding capabilities for contemporary buildings. This research investigates the integration of these materials into construction materials, using red-mud carbon foam (CCF) as a stabilizer for n-octadecane (OD@CCF). Various analyses, including microstructural examination, porosity, and additive dispersion assessment, were conducted using X-ray microtomography and density measurements. Thermal conductivity measurements demonstrated the enhancement of composite boards as the OD@CCF content increased, while mechanical tests indicated an optimal additive content of up to 20%. The thermally regulated capabilities of these advanced panels were evaluated in a custom-designed room model, equipped with a homemade environmental chamber, ensuring a consistent temperature environment during heating and cooling cycles. The incorporation of OD@CCF into cement boards exhibited improved thermal energy storage properties. Moreover, the examined composite boards displayed efficient electromagnetic shielding performance within the frequency range of 3.2–7.0 GHz, achieving EMI values of approximately 18 and 19.5 dB for gypsum and cement boards, respectively, meeting the minimum value necessary for industrial applications. Citation: Journal of Composites Science PubDate: 2024-07-01 DOI: 10.3390/jcs8070251 Issue No:Vol. 8, No. 7 (2024)
Authors:Tanaya Mandal, Unal Ozten, Louis Vaught, Jacob L. Meyer, Ahmad Amiri, Andreas Polycarpou, Mohammad Naraghi First page: 252 Abstract: Carbon fiber reinforced polymer (CFRP) composites are renowned for their exceptional mechanical properties, with applications in industries such as automotive, aerospace, medical, civil, and beyond. Despite these merits, a significant challenge in CFRPs lies in their repairability and maintenance. This study, for the first time, delves into the processing and self-healing capability of aromatic thermosetting co-polyester vitrimer-based carbon fiber composites through mechanical testing. Vitrimers are an emerging class of thermosetting polymers, which, owing to their exchangeable covalent bonds, enable the re-formation of bonds across cracks. The specific vitrimer chosen for this study is an aromatic thermosetting co-polyester (ATSP). The mechanical properties of samples were analyzed initially through three-point bending (3PB) testing at room temperature before and after healing (by curing samples for 2 h at 280 °C). Samples were also 3PB tested at 100 °C to analyze their mechanical properties at an elevated temperature for comparison to the samples tested at room temperature. To investigate the fracture properties, optical microscopy images of samples were taken after 3PB tests, which were analyzed to observe crack initiation and crack growth behavior. Through load–displacement curves from double cantilever beam (DCB) mechanical testing, the Mode I crack initiation fracture toughness values of self-healed composites and control composites were calculated to evaluate healing efficiency in ATSP CFRP composites cured at 280 °C for 2 h. Scanning electron microscopy (SEM) showed a similar surface morphology of cracks before and after self-healing. Micro-computed tomography (CT) X-ray imaging confirmed that the healed samples closely resembled the as-fabricated ones, with the exception of some manufacturing voids, caused by outgassing in the initial healing cycle. This research demonstrated the ability for the in situ repair of ATSP CFRPs by restoring the fracture toughness to values comparable to the pristine composite (~289 J/m2). Citation: Journal of Composites Science PubDate: 2024-07-01 DOI: 10.3390/jcs8070252 Issue No:Vol. 8, No. 7 (2024)
Authors:Jae-Hun Kim, Jin-Ju Jeong, Jung-Soo Lee First page: 253 Abstract: Nanocellulose (NC) has emerged as a promising biodegradable material with applications in various industrial fields owing to its high mechanical strength, thermal stability, and eco-friendly properties. Traditional methods for isolating NC from wood-based biomass (WB) involve high energy consumption and extensive chemical usage, leading to environmental and sustainability concerns. This study explored an alternative approach to isolate NC from seaweed-based biomass (SB) (SNC), which contains fewer non-cellulosic components and a higher cellulose content than WB, thereby yielding a more efficient e-isolation process. We employed a combination of modified-acid solution and electron beam (E-beam) technology to isolate NC from SB. The E-beam process enhanced the crystallinity while reducing the particle size, thus facilitating NC isolation with reduced environmental impact and processing time. Moreover, our method significantly reduced the need for harsh chemical reagents and energy-intensive processes, which are typically associated with traditional NC isolation methods. We fabricated biodegradable films with improved mechanical properties using NC as a reinforcing agent in polymer composites, thereby demonstrating the potential of NC-based materials for various applications. Therefore, our proposed approach offers a sustainable and efficient method for NC isolation and serves as a guide for the development of eco-friendly industrial processes. Our findings contribute to ongoing efforts to create sustainable materials and reduce the environmental footprint of the manufacturing industry. Citation: Journal of Composites Science PubDate: 2024-07-01 DOI: 10.3390/jcs8070253 Issue No:Vol. 8, No. 7 (2024)
Authors:Mario Ceddia, Giuseppe Solarino, Giorgio Giannini, Giuseppe De Giosa, Maria Tucci, Bartolomeo Trentadue First page: 254 Abstract: Total hip arthroplasty is one of the most common and successful orthopaedic operations. Occasionally, periprosthetic osteolysis associated with stress shielding occurs, resulting in a reduction of bone density where the femur is not properly loaded and the formation of denser bone where stresses are confined. To enhance proximal load transfer and reduce stress shielding, approaches, including decreasing the stiffness of femoral stems, such as carbon fibre-reinforced polymer composites (CFRPCs), have been explored through novel modular prostheses. The purpose of the present study was to analyse, by the finite element analysis (FEA) method, the effect that the variation of material for the distal part of the femoral stem has on stress transmission between a modulable prosthesis and the adjacent bone. Methods: Through three-dimensional modelling and the use of commercially available FEA software Ansys R2023, the mechanical behaviour of the distal part of the femoral stem made of CFRPC or Ti-6Al-4V was obtained. A load was applied to the head of the femoral stem that simulates a complete walking cycle. Results: The results showed that the use of a material with mechanical characteristics close to the bone, like CFRPC, allowed for optimisation of the transmitted loads, promoting a better distribution of stress from the proximal to the distal part of the femur. This observation was also found in some clinical studies in literature, which reported not only an improved load transfer with the use of CFRPC but also a higher cell attachment than Ti-6Al-4V. Conclusions: The use of a material that has mechanical properties that are close to bone promotes load transfer from the proximal to the distal area. In particular, the use of CFRPC allows the material to be designed based on the patient’s actual bone characteristics. This provides a customised design with a lower risk of prosthesis loss due to stress shielding. Citation: Journal of Composites Science PubDate: 2024-07-02 DOI: 10.3390/jcs8070254 Issue No:Vol. 8, No. 7 (2024)
Authors:Hadisehsadat Farrokhi, Mojtaba Koosha, Navid Nasirizadeh, Mahshid Salari, Majid Abdouss, Tianduo Li, Yinghua Gong First page: 255 Abstract: Nanoclays are a class of nanomaterials extensively used to prepare polymer nanocomposites. In this study, four types of common nanoclays were selected to prepare chitosan–polyvinyl alcohol (CP) nanocomposite films. Montmorillonite cloisite Na+ (MMT), organically modified montmorillonite (OMMT), and bentonite (BNT), as layered aluminosilicates, and halloysite nanotubes (HNT), as a tubular nanoclay, were blended with CP films at concentrations of 1.5, 3 and 4.5%. The nanocomposite films were characterized by FTIR, XRD, SEM/EDX, AFM, tensile strength, and antibacterial tests. SEM/EDX results showed a more uniform distribution of the OMMT and HNT nanoclays in the polymer matrix. AFM images showed a rougher surface for nanocomposite films compared to CP film. Increasing the nanoclay concentration in the films from 1.5 to 4.5% resulted in higher tensile strength for HNT and MMT while the trend was reversed for OMMT and BNT. Among the samples, nanocomposite films composed of OMMT and BNT showed the highest tensile strength at the lowest concentrations (CP-OMMT1.5 99 ± 3.7 MPa, CP-B1.5 81 ± 1.5 MPa). The nanocomposite films prepared from OMMT showed the highest antibacterial activity against E. coli and S. aureus with an inhibition zone of 15 and 19 mm, respectively. The results of this study showed that BNT and OMMT are promising nanoclays for enhancing the mechanical properties and antibacterial activity of hydrophilic polymers. The results of this research can provide new insights into selecting suitable nanoclays for different applications. Citation: Journal of Composites Science PubDate: 2024-07-02 DOI: 10.3390/jcs8070255 Issue No:Vol. 8, No. 7 (2024)
Authors:Mihaela Fanache, Leonid Vasiliu, Maria Harja First page: 256 Abstract: Fiberglass is a waste generated in the construction materials industry, which is not dangerous for the environment, but long-term and very long-term storage is expensive. Finding a method of reuse as in creating a useful composite material led to the research work in this study. The impact of waste fiberglass and furnace slag on the characteristics of novel composite materials was examined in this study. The density and mechanical properties of the composite samples were examined to determine the impact of waste fiberglass (WFG) concentration in it. Washed river aggregates were replaced with WFG in various ratios in our laboratory tests. Concrete class C16/20 was utilized, having 0.35–0.7 w. % WFG and 2–10% slag. The obtained material was evaluated for density, workability, and compressive strength. The experiments were carried out in an accredited concrete station laboratory. The density of the resulting materials decreased as the WFG content was increased. The densities were higher than the witness sample, ranging from 2358 to 2405 kg/m3. The findings show that adding WFG and slag to concrete has a positive impact on its characteristics. With the addition of WFG, the mixture became more non-homogenous, but these characteristics can be optimized in future. Because of the differential in density between WFG and natural coarse aggregates, the fresh density of obtained composites dropped as the percentage of WFG increased; this could be an advantage, as the newly obtained material became lighter. The findings show that adding waste to concrete has a detrimental impact on its qualities. The introduction of blast furnace slag up to 5% does not modify the compressive strength, compared to the reference samples, but 10% slag causes a decrease in compressive strength of 4.2%. A proportion of 0.25% WFG causes a slight increase in mechanical strength; therefore, 0.25% WFG and 5% slag increased the compressive strength, the maximum value being obtained for a composite with 0.25% WFG, 5% slag, 5% sand and aggregates. Capitalization of WFG and slag resulted in significant economic and environmental benefits by reducing waste storage costs and production costs, and advantages resulted from the new material. Citation: Journal of Composites Science PubDate: 2024-07-02 DOI: 10.3390/jcs8070256 Issue No:Vol. 8, No. 7 (2024)
Authors:Aknur Kuandykova, Bakhitzhan Taimasov, Ekaterina Potapova, Bakhitzhan Sarsenbaev, Alexandr Kolesnikov, Meiram Begentayev, Erzhan Kuldeyev, Mukhtar Dauletiyarov, Nurgali Zhanikulov, Baurzhan Amiraliyev, Aidana Abdullin First page: 257 Abstract: The possibility of producing cement clinker using low-energy, resource-saving technologies is studied. The composition of industrial waste for low-energy-intensive production of Portland cement clinker at factories in Southern Kazakhstan is analyzed. The possibility of replacing the deficient iron-containing corrective additive with “Waelz clinker for zinc ores” is shown. “Waeltz clinker from zinc ores” as part of the raw material charge performs several tasks: it is a ferrous corrective additive, works as a mineralizer for clinker formation processes, introduces coal into the charge and allows one to reduce the consumption of natural fuel. The processes of burning raw mixtures, wholly or partially consisting of industrial waste, are completed at 1350 °C. This reduces the consumption of main burner fuel for clinker burning and reduces CO2 emissions into the atmosphere. High-quality cement clinker is obtained based on raw material mixtures with Waeltz clinker from zinc ores from the Achisai Metallurgical Plant, phosphorus slag, coal mining waste from Lenger mines and sodium fluoride. The phase composition and microstructure of low-energy clinkers are revealed. Involving industrial waste in raw material circulation will reduce environmental pollution and improve the environment. Citation: Journal of Composites Science PubDate: 2024-07-03 DOI: 10.3390/jcs8070257 Issue No:Vol. 8, No. 7 (2024)
Authors:Elaf N. Mahrous, Muhammad A. Hawwa, Abba A. Abubakar, Hussain M. Al-Qahtani First page: 258 Abstract: A multiscale model is developed for vertically aligned carbon nanotube (CNT)-based membranes that are made for water purification or gas separation. As a consequence of driving fluids through the membranes, they carry stress waves along the fiber direction. Hence, a continuum mixture theory is established for a representative volume element to characterize guided waves propagating in a periodically CNT-reinforced matrix material. The obtained coupled governing equations for the CNT-based composite are found to retain the integrity of the wave propagation phenomenon in each constituent, while allowing them to coexist under analytically derived multiscale interaction parameters. The influence of the mesoscale characteristics on the continuum behavior of the composite is demonstrated by dispersion curves of harmonic wave propagation. Analytically established continuum mixture theory for the CNT-based composite is strengthened by numerical simulations conducted in COMSOL for visualizing mode shapes and wave propagation patterns. Citation: Journal of Composites Science PubDate: 2024-07-03 DOI: 10.3390/jcs8070258 Issue No:Vol. 8, No. 7 (2024)
Authors:Sajan Shakya, Alexandra Hain First page: 259 Abstract: Concrete-filled fiber-reinforced polymer (FRP) tubes (CFFTs) offer an alternative to traditional reinforced concrete columns for new construction applications due to their high strength, ductility, and corrosion resistance properties. Despite their popularity, there is a lack of accurate analytical models for the cyclic/seismic performance of CFFT columns. This is due to the absence of precise stress–strain models for FRP tubes and confined concrete under cyclic loading. Previous experiments on CFFT columns suggest that even minimal reinforcement (≤1%) provides essential energy dissipation for extreme events. However, existing stress–strain models for FRP-confined concrete often neglect the contribution of longitudinal and transverse steel reinforcement. While some researchers have proposed material models to address this issue, the analytical modeling of confinement effects from both steel reinforcement and FRP tubes, especially under lateral cyclic loading, continues to pose a significant challenge. This study aims to use previously collected experimental data to evaluate current analytical modeling approaches in OpenSeesPy3.5.1.12 to simulate the lateral cyclic behavior of CFFT columns with ±55° glass fiber-reinforced polymer (GFRP) fiber orientation. Both the lumped inelasticity and the distributed inelasticity modeling approaches are applied. The performance of various FRP confinement models is compared. The effect of plastic hinge length is also considered in the lumped plasticity approach. The findings suggest that integrating a fiber element section into the plastic hinge zone enhances the efficiency of the distributed inelasticity approach. This method accurately captures the non-linear behavior in the critical region and precisely predicts the shape of the hysteretic curve, all while reducing computational costs. Conversely, the lumped inelasticity modeling approach effectively forecasts energy dissipation and peak load values across the entire cyclic hysteresis curve, offering significant computational savings. Finally, a generalized modeling methodology for predicting the response of CFFTs under cyclic lateral load is proposed and subsequently validated using experimental results found in the existing literature. Citation: Journal of Composites Science PubDate: 2024-07-04 DOI: 10.3390/jcs8070259 Issue No:Vol. 8, No. 7 (2024)
Authors:Ashwath Pazhani, Syed Saad Salman, M. Venkatraman, Alicia Patel, M. Anthony Xavior, Andre Batako, Jeyapandiarajan Paulsamy, Joel Jayaseelan First page: 260 Abstract: This research presents a comprehensive dynamic finite element analysis (FEA) of a cryogenic fuel tank made from an innovative aluminium/lithium–graphene nano-composite material, assessing its suitability for aerospace launch vehicles carrying cryogenic hydrogen and oxygen. The study focuses on the effects of lightweighting, utilizing 0.5 wt.% reinforced graphene in the Al 2195 matrix, a material poised to revolutionize the aerospace industry. Objectives include developing a digital twin of the fuel tank, CAD modeling to aerospace standards, and conducting ANSYS simulations under launch conditions to evaluate stress, strain, and deformation. Numerical results reveal a significant weight reduction of approximately 19,420 kg and a notable maximum stress reduction of 1.3% compared to traditional Al 2195 alloy tanks. The novelty of this research lies in its pioneering analysis of aluminium/lithium–graphene composites for lightweighting in cryogenic fuel tanks under space launch conditions. Conclusions affirm the composite’s viability, advocating for the development of lighter yet robust aerospace structures and fostering innovation in spacecraft design and materials science. Citation: Journal of Composites Science PubDate: 2024-07-04 DOI: 10.3390/jcs8070260 Issue No:Vol. 8, No. 7 (2024)
Authors:Dora Mohenski, Mihaela Vrebac, Eva Klarić Sever, Timor Grego, Kristina Goršeta, Ana Ivanišević First page: 261 Abstract: Ionizing radiation in therapeutic doses alters the composition and properties of dentin and resin composites. This may influence the adhesion of restorative materials to irradiated dentin and compromise the success of the restorative treatment. The objective of this study was to evaluate the effect of ionizing radiation on the shear bond strength (SBS) of bulk-fill composite materials to dentin. Coronal dentin slabs (N = 90) were embedded in acrylate and randomly assigned to six groups (N = 15) depending on the time of radiation (70 Gy) and material (SDR Plus Bulk Fill Flowable and Tetric EvoFlow Bulk Fill (TET)): (1) control group (CG) SDR; (2) CG TET; (3) radiation + SDR; (4) radiation + TET; (5) SDR + radiation; and (6) TET + radiation. Composite cylinders were bonded to the dentin slabs using Scotchbond Universal Plus Adhesive. The specimens were stored in distilled water and fractured in shear mode after 7 weeks. Radiation before and after restoration resulted in an SBS decrease. The SBS was statistically significantly lower in groups 5 and 6 (p < 0.05). The difference between the bulk-fill composites was not significant (p > 0.05). In the CGs, adhesive fractures prevailed. In groups 3 and 4, cohesive fractures in the dentin were more frequent, and in groups 5 and 6, cohesive fractures in the material. Radiotherapy affects the SBS of bulk-fill composites to dentin. Immediate radiation after restoration resulted in the lowest SBS in both bulk-fill composite materials. Citation: Journal of Composites Science PubDate: 2024-07-05 DOI: 10.3390/jcs8070261 Issue No:Vol. 8, No. 7 (2024)
Authors:Omar Faye, Inimfon A. Udoetok, Jerzy A. Szpunar, Lee D. Wilson First page: 262 Abstract: The quest for a smooth transition from fossil fuels to clean and sustainable energy has warranted studies on alternative energy materials. Herein, we report on an experimental and theoretical study focused on hydrogen generation through the hydrolysis of microcrystalline cellulose (MCC) treated in different media (deionized water, sodium hydroxide) and MCC functionalized with magnesium (MCC-Mg), titanium (MCC-Ti), and niobium (MCC-Nb). The XRD results reveal the decreased crystallinity of MCC due to ball milling along with the formation of metal oxide composites between MCC and various metals (magnesium, titanium, and niobium). Theoretical studies using NVT molecular dynamic simulations with the NH chain thermostat implemented in the Dmol3 provides further support to the experimental results reported herein. The results from the experimental and theoretical studies revealed that ball milling and composite formation with metal species enhanced the kinetics of the hydrolysis of MCC and, consequently, hydrogen generation, while the addition of NaOH and urea inhibited the hydrogen yield. Citation: Journal of Composites Science PubDate: 2024-07-06 DOI: 10.3390/jcs8070262 Issue No:Vol. 8, No. 7 (2024)
Authors:Weidong Liu, Yan Luo, Yonghua Zhao, Haipeng Zhou, Sansan Ao, Yang Li First page: 263 Abstract: Diverse industries are witnessing an increase in demand for hybrid structures of metals and carbon-fiber-reinforced thermoplastic composites (CFRTPs). Welding is an essential technique in the manufacture of metal–CFRTP hybrid structures. However, achieving high-strength metal–CFRTP welded joints faces serious challenges due to the considerable disparities in material characteristics. As an effective method to strengthen metal–CFRTP joints, surface texturing on metal is gaining significant attention. This study introduces an emerging surface texturing approach, electrochemical jet machining (EJM) using a film electrolyte jet, for enhancing the performance of AA6061-CF/PA66 hot-pressure-welded (HPW) joints. Parametric effects on surface morphology and roughness in the EJM of AA6061 are investigated. The results show that a rough surface with multiscale pores can be generated on AA6061 by EJM, and that surface morphology can be modulated by adjusting the applied current density and jet translational speed. Subsequently, the effects of different EJM-textured surface morphologies on the performance of HPW joints are examined. Surface textures created by EJM are demonstrated to significantly enhance the mechanical interlocking effect at the bonding interface between AA6061 and CF/PA66, resulting in a substantial increase in joint strength. The maximum joint strength attained in the present work with EJM texturing is raised by 45.29% compared to the joints without surface texturing. Additionally, the joint strength slightly improves as the roughness of EJM-textured surfaces rises, with the exception of rough surfaces that are textured with a combination of low current density and rapid translational speed. Overall, these findings suggest that EJM texturing using a film jet prior to welding is a potential approach for the manufacture of high-performance metal–CFRTP hybrid structures. Citation: Journal of Composites Science PubDate: 2024-07-07 DOI: 10.3390/jcs8070263 Issue No:Vol. 8, No. 7 (2024)
Authors:Girts Bumanis, Laura Vitola, Xiangming Zhou, Danutė Vaičiukynienė, Diana Bajare First page: 264 Abstract: A sophisticated characterisation of a porous material structure has been challenging in material science. Three-dimensional (3D) structure analysis allows the evaluation of a material’s homogeneity, pore size distribution and pore wall properties. Micro-computed tomography (micro-CT) offers a non-destructive test method for material evaluation. This paper characterises a novel ternary binder’s porous structure using micro-CT. Gypsum–cement–pozzolan (GCP) ternary binders are low-carbon footprint binders. Both natural and industrial gypsum were evaluated as a major components of GCP binders. Porous GCP binder was obtained by a foaming admixture, and the bulk density of the material characterised ranged from 387 to 700 kg/m3. Micro-CT results indicate that pores in the range from 0.017 to 3.0 mm can be effectively detected and described for porous GCP binders. The GCP binder structure proved to be dominant by 0.1 to 0.2 mm micropores. For GCP binders produced with natural gypsum, macropores from 2.2 to 2.9 mm are formed, while GCP binders with phosphogypsum possess pores from 0.2 to 0.6 mm. Micro-CT proved to be an effective instrument for characterising the homogeneity and hierarchical pore structure of porous ternary binders. Citation: Journal of Composites Science PubDate: 2024-07-08 DOI: 10.3390/jcs8070264 Issue No:Vol. 8, No. 7 (2024)
Authors:Jordi Uyttersprot, Wouter De Corte, Wim Van Paepegem First page: 265 Abstract: This study investigates the mechanical properties of tiled laminates, frequently used in FRP bridges, and a completely new class of composites for which currently no experimental literature is available. In this paper, first a microscopic examination of laminates extracted from bridge deck flanges is performed, revealing complex multi-ply structures and tiled laminates in the transverse direction of the bridge deck. The subsequent fabrication of tiled laminates in the transverse (i.e., weak) and longitudinal (i.e., strong) span direction explores stiffness and strength characteristics depending on the stacking angle. It is observed that the stiffness in both directions is only slightly reduced with increasing stacking angles, reaching a maximum decrease of 10%, while the failure strength is significantly reduced, particularly with longitudinal tiling, dropping by approximately 70% for a 2° stacking angle. Transverse tiling demonstrates a more moderate 45% strength reduction due to the presence of some 90° plies. Given the small reduction in the stiffness and the fact that in many applications the design is mainly governed by serviceability (i.e., stiffness) requirements than strength, this strength reduction may be acceptable, considering other advantages of the concept. Additionally, this research sheds light on failure mechanisms, emphasizing the role of ply assembly in stress distribution and highlighting the importance of gradual ply ends in reducing strain concentrations. These findings provide valuable insights for optimizing tiled laminates in structural applications, ensuring their effective and reliable use. Citation: Journal of Composites Science PubDate: 2024-07-08 DOI: 10.3390/jcs8070265 Issue No:Vol. 8, No. 7 (2024)
Authors:Zheng Wang, Long Geng, Jiateng Zhao, Wenyuan Qiao, Changhui Liu First page: 266 Abstract: As one of the most common fossil derivatives, plastics are widely used for their exceptional chemical stability, low density, and ease of processing. In recent years, there has been a significant increase in the production of waste plastics, coupled with a low recycling rate, resulting in serious environmental pollution. To enhance the use of waste plastics, this research synthesized flame-retardant materials from hypercrosslinked polystyrene with different molar fractions of flame retardants. Waste polystyrene foam was used as the raw material, while aniline, triphenylphosphine, and melamine were employed as flame-retardant additives. The flame-retardant additives were successfully doped into the porous skeleton structure of hypercrosslinked polystyrene through a chemical reaction or physical mixing to achieve in situ flame retardancy, and the materials were shaped by a phenolic resin prepolymer. Then, the samples were characterized in detail, and the results indicate that the addition of a flame retardant enhances the flame retardancy of the material. In addition, the material has excellent thermal insulation performance, with a minimum thermal conductivity of 0.04176 W/(m·K). Citation: Journal of Composites Science PubDate: 2024-07-10 DOI: 10.3390/jcs8070266 Issue No:Vol. 8, No. 7 (2024)
Authors:Sanat Tolendiuly, Jaafar Nur-Akasyah, Sergey Fomenko, Ahmet Turan, Sharafhan Assylkhan, Aigul Abisheva First page: 267 Abstract: There is a wide variety of superconducting materials, but only a few of them are suitable for practical industrial use, and one of the most promising superconductors is MgB2. Its main advantages are a critical temperature close to 40 K, which allows for operation in a cryogenic environment, low cost of precursors, and the ease of manufacture. In this paper, we attempted to obtain superconducting materials based on magnesium diboride in a new way by using a high-temperature centrifuge and then investigated how centrifugal acceleration could affect the superconducting characteristics of the materials in a greater way during combustion synthesis. As a brief result of this research, it was found that the value of centrifugal acceleration affected the critical current density (Jc = 1.4 A/cm2) of the MgB2 composites, although it did not considerably impact the critical transition temperature of the MgB2 materials (remained at around 37.5–38 K). Citation: Journal of Composites Science PubDate: 2024-07-11 DOI: 10.3390/jcs8070267 Issue No:Vol. 8, No. 7 (2024)
Authors:Chenkai Zhu, Zhiwei Qiao, Hongwei Wang, Changyong Huang First page: 268 Abstract: The flame-retardant performance of carbon fiber-reinforced composites is crucial for ensuring structural stability. Traditional additive flame-retardant methods often struggle to balance structural integrity with fire resistance. Herein, Ni(OH)2 and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) were used as flame-retardant agents and mixed with glass fibers to construct the flame-retardant functional fiber veil which was used as the skin layer on the composite surface for fire protection. The structure performance and flame retardancy of composites were characterized via Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and a cone calorimeter test. The results confirmed that a flame-retardant glass fiber mat could effectively improve the flame-retardant and smoke-suppressive properties of the composite material. Due to the synergistic flame-retardant mechanism of Ni(OH)2 and DOPO, the C-N3-D2 composite with the highest LOI value of 32.3% has shown significant reduction in peak heat release rate (PHRR) and total smoke production (TSP) by 31.3% and 19.5%, respectively. In addition, due to flame-retardant agents only being employed in the skin layer of the composite, the core layer of a carbon fiber-reinforced structure could be protected without structure disruption. This approach maintained consistent interlayer shear strength, highlighting the effectiveness of using a flame-retardant fiber veil as a protective skin layer. This strategy could offer a viable solution for safeguarding high-performance composite materials from fire hazards without compromising their structural integrity. Citation: Journal of Composites Science PubDate: 2024-07-11 DOI: 10.3390/jcs8070268 Issue No:Vol. 8, No. 7 (2024)
Authors:Hossein Omidian, Erma J. Gill First page: 269 Abstract: This review explores the design, fabrication, and biomedical applications of nanofibrous scaffolds, emphasizing their impact on tissue engineering and regenerative medicine. Advanced techniques like electrospinning and 3D printing have enabled precise control over scaffold architecture, crucial for mimicking native tissue structures. Integrating bioactive materials has significantly enhanced cellular interactions, mechanical properties, and the controlled release of therapeutic agents. Applications span bone, cardiovascular, soft tissue, neural regeneration, wound healing, and advanced drug delivery. Despite these advancements, challenges such as scalability, biocompatibility, and long-term stability remain barriers to clinical translation. Future research should focus on developing smart scaffolds and utilizing AI-enhanced manufacturing for more personalized and effective regenerative therapies. Citation: Journal of Composites Science PubDate: 2024-07-12 DOI: 10.3390/jcs8070269 Issue No:Vol. 8, No. 7 (2024)
Authors:Erik Biehler, Qui Quach, Tarek M. Abdel-Fattah First page: 270 Abstract: Alternative fuel sources are necessary in today’s economic and environmental climate. Hydrogen fuel arises as an environmentally friendly and energy dense option; however, the volatility of hydrogen gas makes it dangerous to store and utilize. The evolution of hydrogen from hydrogen feedstock materials may prove to overcome this safety barrier, but a catalyst for this reaction is necessary to optimize production. In this work, a composite catalyst comprised of palladium nanoparticles embedded on mesoporous carbon materials (Pd-MCM) was synthesized and characterized by Transmission Electron Microscope (TEM), Powder X-Ray diffraction (P-XRD), Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscope (EDS). Various reaction conditions such as concentration of reactant, temperature, and pH were applied in measuring the catalytic activity of Pd-MCM. Results show the catalytic activity of the Pd-MCM composite catalysts increased with increasing concentrations of sodium borohydride, increasing temperature, and lower pH. The reaction involving the Pd-MCM composite had an activation energy of 27.9 kJ mol−1. Reusability trials showed the Pd-MCM composite remained stable for up to five consecutive trials. Citation: Journal of Composites Science PubDate: 2024-07-12 DOI: 10.3390/jcs8070270 Issue No:Vol. 8, No. 7 (2024)
Authors:Andrei Honciuc, Oana-Iuliana Negru, Mirela Honciuc, Ana-Maria Solonaru First page: 271 Abstract: Several traditional methods for producing polymer microparticle adsorbents for metal ions exist, such as bulk polymerization followed by milling and crushing the material to micron-size particles, precipitation from organic solvents, and suspension polymerization utilizing surfactants. Alternative methods that are easily scalable and are environmentally friendly are in high demand. This study employs Pickering Emulsion Polymerization Technology (PEmPTech) to synthesize nanostructured polymer microspheres that incorporate Schiff-base ligands, which can be utilized for metal ion adsorption, and specifically Cu(II) ions. Our innovative approach makes use of nanoparticle-stabilized, surfactant-free emulsions/suspensions, enabling the straightforward production of ligand-bearing microspheres while allowing for the precise modulation of the polymer matrix chemistry to maximize adsorption capacities. Through this method, we demonstrate notable enhancements in Cu(II) ion adsorption, which correlates with both the polarity of the monomers used and the concentration of Schiff-base ligands within the microspheres. Notably, our results offer insights into the structure–activity relationships essential for designing tailored adsorbents. This work provides a scalable method to produce high-performance adsorbents and also contributes to sustainable methodologies by excluding harmful surfactants and solvents. Citation: Journal of Composites Science PubDate: 2024-07-13 DOI: 10.3390/jcs8070271 Issue No:Vol. 8, No. 7 (2024)
Authors:Sven Meißner, Jiri Kafka, Hannah Isermann, Susanna Labisch, Antonia Kesel, Oliver Eberhardt, Harald Kuolt, Sebastian Scholz, Daniel Kalisch, Sascha Müller, Axel Spickenheuer, Lothar Kroll First page: 272 Abstract: Additively manufactured polymer structures often exhibit strong anisotropies due to their layered composition. Although existing methods in additive manufacturing (AM) for improving the mechanical properties are available, they usually do not eliminate the high degree of structural anisotropy. Existing methods for continuous fiber (cF) reinforcement in AM can significantly increase the mechanical properties in the strand direction, but often do not improve the interlaminar strength between the layers. In addition, it is mostly not possible to deposit cFs three-dimensionally and curved (variable–axial) and, thus, in a path that is suitable for the load case requirements. There is a need for AM methods and design approaches that enable cF reinforcements in a variable–axial way, independently of the AM mounting direction. Therefore, a novel two-stage method is proposed in which the process steps of AM and cF integration are decoupled from each other. This study presents the development and validation of the method. It was first investigated at the specimen level, where a significant improvement in the mechanical properties was achieved compared to unreinforced polymer structures. The Young’s modulus and tensile strength were increased by factors of 9.1 and 2.7, respectively. In addition, the design guidelines were derived based on sample structures, and the feasibility of the method was demonstrated on complex cantilevers. Citation: Journal of Composites Science PubDate: 2024-07-14 DOI: 10.3390/jcs8070272 Issue No:Vol. 8, No. 7 (2024)
Authors:Ahmed Ali Farhan Ogaili, Ali Basem, Mohammed Salman Kadhim, Zainab T. Al-Sharify, Alaa Abdulhady Jaber, Emad Kadum Njim, Luttfi A. Al-Haddad, Mohsin Noori Hamzah, Ehsan S. Al-Ameen First page: 273 Abstract: The incorporation of fiber reinforcements into polymer matrices has emerged as an effective strategy to enhance the mechanical properties of composites. This study investigated the tensile and fracture behavior of 3D-printed polylactic acid (PLA) composites reinforced with chopped carbon fibers (CCFs) through experimental characterization and finite element analysis (FEA). Composite samples with varying CCF orientations (0°, 0°/90°, +45°/−45°, and 0°/+45°/−45°/90°) were fabricated via fused filament fabrication (FFF) and subjected to tensile and single-edge notched bend (SENB) tests. The experimental results revealed a significant improvement in tensile strength, elastic modulus, and fracture toughness compared to unreinforced PLA. The 0°/+45°/90° orientation exhibited a 3.6% increase in tensile strength, while the +45°/−45° orientation displayed a 29.9% enhancement in elastic modulus and a 29.9% improvement in fracture toughness (259.12 MPa) relative to neat PLA (199.34 MPa√m). An inverse correlation between tensile strength and fracture toughness was observed, attributed to mechanisms such as crack deflection, fiber bridging, and fiber pull-out facilitated by multi-directional fiber orientations. FEA simulations incorporating a transversely isotropic material model and the J-integral approach were conducted using Abaqus, accurately predicting fracture toughness trends with a maximum discrepancy of 8% compared to experimental data. Fractographic analysis elucidated the strengthening mechanisms, highlighting the potential of tailoring CCF orientation to optimize mechanical performance for structural applications. Citation: Journal of Composites Science PubDate: 2024-07-15 DOI: 10.3390/jcs8070273 Issue No:Vol. 8, No. 7 (2024)
Authors:Alaa El-Sisi, Hani Salim, Iqbal Alshalal, Mahmoud Nawar, Mohamed H. El-Feky First page: 274 Abstract: Friction-type bolted joints are widely used in both the civil and aerospace industries. Uncontrolled excessive bolt clamping force can cause damage to the laminated fiber-reinforced polymeric (FRP) composite through the thickness and damage the joint before applying the service loads. The effect of the friction coefficient (between 0 and 0.3), bolt clearance, joint type, and other parameters on failure modes and the maximum bolt clamping force of the carbon FRP lapped joint is studied. A three-dimensional finite element (FE) model consisting of a bolt, a washer, a laminate FRP composite plate, and steel plates was developed for the simulation of the double- (3DD) and single (3DS)-lapped bolted joint. The FE model was validated by using experimental results and was able to predict the experimental results by a difference of between 2.2 and 6.7%. The joint capacity of the clamping force was found to be greatly increased by adopting the double lap technique, which involves placing an FRP composite plate between two steel plates. Also, it was recommended to use an internal washer diameter less than or equal to the FRP composite plate hole diameter since a larger washer clearance can produce higher contact pressure and reduce the resistance by 22%. In addition, reducing the bolt head diameter can lead to a 65% reduction in the 3DS joint clamping strength. Citation: Journal of Composites Science PubDate: 2024-07-15 DOI: 10.3390/jcs8070274 Issue No:Vol. 8, No. 7 (2024)
Authors:Patricio Martinez, Steven Nutt First page: 275 Abstract: Composite laminates were produced by RTM using similar glass and flax fabrics and both vitrimer epoxy and aerospace-grade epoxy, both formulated for liquid molding. Tensile and flexural properties were measured and compared, revealing that the vitrimer composites exhibited equivalent performance in flexural strength and tensile modulus, but slightly lower performance in tensile strength relative to reference epoxy composites. In general, glass–fiber composites outperformed flax–fiber composites in tension. However, both glass and flax–fiber composites yielded roughly equivalent flexural strength and tensile modulus-to-weight ratios. Flax fabrics were recovered from composites by matrix dissolution, and a second-life laminate showed full retention of the mechanical properties relative to those produced from fresh flax. Finally, a demonstration of re-forming was undertaken, showing that simple press-forming can be used to modify the composite shape. However, re-forming to a flat configuration resulted in local fiber damage and a decrease in mechanical properties. An alternative forming method was demonstrated that resulted in less fiber damage, indicating that further refinements might lead to a viable forming and re-forming process. Citation: Journal of Composites Science PubDate: 2024-07-16 DOI: 10.3390/jcs8070275 Issue No:Vol. 8, No. 7 (2024)
Authors:Lucas Jacquet, Antoine le Duigou, Olivier Kerbrat First page: 276 Abstract: The competitive sailing boat industry uses carbon fibre for high-performance purposes. Nevertheless, this material is known to cause environmental issues during its manufacturing. We can currently observe, based on the literature, difficulty integrating a reliable, justified, and transparent inventory of carbon-fibre production for LCA applications of high-performance composite materials. The current study aims to gain a better understanding of carbon fibre’s environmental impacts by suggesting a justified, reliable, and transparent inventory, based on the life-cycle assessment methodology. It also aims at providing a LCA of high-performance composites. An EcoInvent flows inventory is suggested, based on the literature presenting primary inventories. It is then discussed in terms of data quality, flows under study, and indicators calculated. Eventually, the inventory is used to assess the environmental impact of carbon fibre-reinforced composites applied to an industrial example representative of the competitive sailing boat industry: a hydrofoil mould. Regarding results on carbon fibres’ scale and impacts, indicators commonly highlighted by the literature, were calculated in this study (GWP = 72 kgCO2eq and CED = 1176 MJ), as well as other indicators. These indicators are two to five times higher than the inventories suggested in the literature, due to high heat-production value, production scales, or the quality of the fibre under study. The composite scale results show a major contribution from carbon fibre compared to other flows under study, highlighting the need to suggest a reliable inventory of carbon-fibre production. Citation: Journal of Composites Science PubDate: 2024-07-16 DOI: 10.3390/jcs8070276 Issue No:Vol. 8, No. 7 (2024)
Authors:Tamás Mikó, Dionysios Markatos, Tamás I. Török, Gábor Szabó, Zoltán Gácsi First page: 277 Abstract: Nowadays, powder-based manufacturing processes are recognized as cost-efficient methods frequently employed for producing parts with intricate shapes and tight tolerances in large quantities. However, like any manufacturing method, powder-based technologies also have several disadvantages. One of the most significant issues lies in the degree of porosity. By modifying the morphology of the gas-atomized spherical 17-4PH stainless steel powder via prior ball milling and then raising both the pressure of cold compaction (1.6 GPa) and sintering temperature (1275 °C), the porosity could be reduced considerably. In our novel powder metallurgical (PM) experimental process, an exceptionally high green density of 92% could be reached by employing die wall lubrication instead of internal lubrication and utilizing induction heating for rapid sintering. After sintering (at temperatures of 1200, 1250, and 1275 °C), the samples aged in the H900 condition were then mechanically tested (Charpy impact, HV hardness, and tensile tests) as a function of porosity. Sintering at 1275 °C for one hour enabled porosity reduction to below 4%, resulting in 1200 MPa yield strength and 1350 MPa ultimate tensile strength with significant (16%) fracture strain. These values are comparable to those of the same alloy products fabricated via ingot metallurgy (IM) or additive manufacturing (AM). Citation: Journal of Composites Science PubDate: 2024-07-16 DOI: 10.3390/jcs8070277 Issue No:Vol. 8, No. 7 (2024)
Authors:Arne Hindersmann, Constantin Bäns, Lutz Beyland First page: 278 Abstract: The rotor blades of wind turbines are becoming increasingly longer, which increases the diameter at the blade connection. Transport problems are the result, as the rotor blades no longer fit under highway bridges, for example. The increase in diameter can be prevented by increasing the bearing strength of the laminate using fiber metal laminates (FMLs). Individual layers of fiber material are replaced by metal foils in FMLs. This work is focused on the infusion of thick-walled FMLs, with infiltration experiments being carried out in-plane and out-of-plane. For the out-of-plane infusion tests, the metal foils are perforated and it is investigated whether the holes should be arranged alternately or aligned in the metal foils. It has been shown that greater laminate thicknesses can be realized with aligned holes. For the determination of voids and dry-spots, the metal foils are treated with a release agent before infusion and after curing the laminate can be demolded ply by ply. The samples made of glass fiber-reinforced plastic (GFRP) and steel/aluminum measure 500 mm by 800 mm by 20 mm. Citation: Journal of Composites Science PubDate: 2024-07-16 DOI: 10.3390/jcs8070278 Issue No:Vol. 8, No. 7 (2024)
Authors:Xin-Gang Chen, Yang-Fei Zhang First page: 279 Abstract: Ag-nanoparticle-reinforced polymethyl methacrylate (AgNP/PMMA) composites are widely used in healthcare, electronics, construction, transportation and many other fields. As the service temperature fluctuates easily, it is necessary to study the temperature effect on the properties of AgNP/PMMA composites. In this work, a preparation method of mixing and hot-pressing was used to fabricate multifunctional AgNP/PMMA composites that are suitable for large-scale industrial production. AgNPs are found to disperse homogeneously in the PMMA matrix. The thermal conductivity of the composite with 15 vol% AgNPs is 116.19% higher than that of PMMA and decreases as the temperature rises. Flexural strength increases first and then decreases with the rising of AgNP content and service temperature, while the flexural modulus decreases gradually. The minimum electrical resistivity of the composite achieves 1.37 × 10−3 Ω·m, with a low percolation threshold of 5 vol%, an improvement of nine orders of magnitude over PMMA. The results demonstrate that the service temperature has a significant effect on the comprehensive properties of AgNP/PMMA composites. Citation: Journal of Composites Science PubDate: 2024-07-17 DOI: 10.3390/jcs8070279 Issue No:Vol. 8, No. 7 (2024)
Authors:Indraneel R. Chowdhury, John Summerscales First page: 280 Abstract: Fibres in different textile forms (woven, knitted, stitched, and non-crimp) are used to reinforce composites for multifaced applications, including automotive, aerospace, marine, rail, energy, construction, and defence sectors. Textile fabric-based fibre reinforcements for composites possess some outstanding features, such as good dimensional stability, subtle conformability, deep draw moldability/processability, lightweightness, high strength and stiffness, and low cost. The greatest advantage of textile fibre-reinforced composites is the freedom to tailor their strength and stiffness properties for specific applications. Therefore, the design of composites involves defining the fabric geometry, stacking sequence, and orientation of fibres to optimise the system. Compared to knitted, stitched, and non-crimp fabrics, woven fabric-based fibre-reinforced composites are widely used in the industry. The properties of woven fabric-reinforced composites depend on several factors, such as types of fibre, compositions, polymeric matrices, and fibre/matrix interfacial strength. Some of the advantages are reduced preforming process steps, good impact and delamination resistance, and thermo-mechanical properties. This review has been written to provide detailed information and discussions, including the fabrication processes, relationship between fabric structure and composite properties, and morphological characteristics encompassing the current state-of-the-art in woven fabrics for composite reinforcement. Citation: Journal of Composites Science PubDate: 2024-07-18 DOI: 10.3390/jcs8070280 Issue No:Vol. 8, No. 7 (2024)
Authors:Aliya Alzhanova, Yuri Mastrikov, Darkhan Yerezhep First page: 281 Abstract: Recent studies show that zinc oxide (ZnO) nanostructures have promising potential as an absorbing material. In order to improve the optoelectronic properties of the initial system, this paper considers the process of adsorbing multilayer graphene-like ZnO onto a Si (111) surface. The density of electron states for two- and three-layer graphene-like zinc oxide on the Si (111) surface was obtained using the Vienna ab-initio simulation package by the DFT method. A computer model of graphene-like Zinc oxide on a Si (111)-surface was created using the DFT+U approach. One-, two- and three-plane-thick graphene-zinc oxide were deposited on the substrate. An isolated cluster of Zn3O3 was also considered. The compatibility of g-ZnO with the S (100) substrate was tested, and the energetics of deposition were calculated. This study demonstrates that, regardless of the possible configuration of the adsorbing layers, the Si/ZnO structure remains stable at the interface. Calculations indicate that, in combination with lower formation energies, wurtzite-type structures turn out to be more stable and, compared to sphalerite-type structures, wurtzite-type structures form longer interlayers and shorter interplanar distances. It has been shown that during the deposition of the third layer, the growth of a wurtzite-type structure becomes exothermic. Thus, these findings suggest a predictable relationship between the application method and the number of layers, implying that the synthesis process can be modified. Consequently, we believe that such interfaces can be obtained through experimental synthesis. Citation: Journal of Composites Science PubDate: 2024-07-20 DOI: 10.3390/jcs8070281 Issue No:Vol. 8, No. 7 (2024)
Authors:Ashraf H. Farha, Adil Alshoaibi, Osama Saber, Shehab A. Mansour First page: 282 Abstract: A simple approach was used to create Fe3O4-methylcellulose (MC) nanocomposites, which were then analyzed using XRD, FTIR, and FE-SEM to determine their structure. The effective factors for enhancing the ratio of magnetite NPs in the samples were investigated using RTFM and optical absorbance. Fe3O4 was synthesized utilizing the reverse co-precipitation technique and magnetic characteristics. Fe3O4/MC nanocomposites with magnetite/MC weight ratios of 0, 0.07, 0.15, and 0.25 have been developed. The diffraction pattern of magnetite is well indexed in accordance with the spinal reference pattern of Fe3O4 (space group: R¯3m), as confirmed by the Rietveld analysis of XRD data of magnetite NPs with an average crystallite size of 50 nm. Magnetite’s insertion into the MC network causes a red shift in the band gap energy (Eg) as the weight percentage of magnetite nanoparticles in the samples rises. The MC, MC-7, MC-15, and MC-25 samples have Eg values of 5.51, 5.05, 2.84, and 2.20 eV, respectively. Citation: Journal of Composites Science PubDate: 2024-07-20 DOI: 10.3390/jcs8070282 Issue No:Vol. 8, No. 7 (2024)
Authors:Rafael González-Cuello, Luis Gabriel Fuentes, Heliana Milena Castellanos, Joaquín Hernández-Fernández, Rodrigo Ortega-Toro First page: 283 Abstract: In this study, active coatings based on carboxymethylcellulose (CMC) were prepared using liposomes filled with an aqueous extract of Melissa officinalis retained in high acyl gellan gum (HAG), low acyl gellan gum (LAG), and their mixture (HAG/LAG). The objective was to investigate the effect of these coatings on postharvest preservation of tomato (Solanum lycopersicum) fruits. The tomato fruits were divided into four groups: (i) coating with HAG-based liposomes (WL-HAG), (ii) coating with LAG-based liposomes (WL-LAG), (iii) coating with HAG/LAG-based liposomes (WL-HAG/LAG), and (iv) control group treated with sterile water. Over a period of 10 days, various quality attributes, such as respiration rate, soluble solids, titratable acidity, luminosity, weight loss, malondialdehyde (MDA) content, hydrogen peroxide, total phenols, and DPPH scavenging ability, were studied. The results indicated that the WL-HAG coatings significantly (p < 0.05) decreased the respiration rate, hydrogen peroxide, and MDA content compared to the control fruits and other coatings. Therefore, WL-HAG could be considered a promising option to enhance postharvest preservation of tomato fruits in the Colombian fruit and vegetable industry. Citation: Journal of Composites Science PubDate: 2024-07-22 DOI: 10.3390/jcs8070283 Issue No:Vol. 8, No. 7 (2024)
Authors:Laila M. Kalimoldina, Sandugash O. Abilkasova, Saule O. Akhmetova, Mariya Sh. Suleimenova, Zhanat E. Shaikhova First page: 284 Abstract: This article presents the results of research on the development of chemically resistant polymer–mineral casting composites based on industrial waste. The aim of this work is to develop a technological basis for obtaining effective inorganic fillers and highly filled composites for use in chlorine-containing environments. On the basis of theoretical data, mineral fillers and a polymer binder for filling composites were selected, optimal quantities of input hardeners and an appropriate thermal curing mode were determined, and the influence of the filling degree on the properties of composites was studied. The influence of various factors on the properties of the obtained composites was also studied, and the possibility of using local raw materials to obtain special-purpose composites was investigated. Ash from a thermal power plant (TPP) was used as an acid-resistant filler in composites. Two components were chosen as binders: phenol formaldehyde resin and mineral filler (TPP ash). As the third component, hydrolytically active fillers—anhydrite, phosphogypsum and phosphate slag—were used. The degree of filling has a significant influence on the properties of composites, including the compressive strength, chemical resistance and degree of curing, the values of which were elucidated across a wide range of composite variations based on the degree of filling. The conducted research allowed us to establish the limit of admissible anhydrite content, which should not exceed 15 mas.%. To optimize the chemical resistance and durability of the composites of the investigated substances, the method of mathematical planning was used. According to the results of this study, the optimal compositions of composites, in terms of anhydrite, phosphogypsum and phosphorus slag contents, were selected. At the maximum possible degree of filling, these composites exhibit high target characteristics. Citation: Journal of Composites Science PubDate: 2024-07-22 DOI: 10.3390/jcs8070284 Issue No:Vol. 8, No. 7 (2024)
Authors:Bruno Alderete, Christian Schäfer, U. Pranav Nayak, Frank Mücklich, Sebastian Suarez First page: 285 Abstract: Switching elements are crucial components in electrical and electronic systems that undergo severe degradation due to the electrical arc that is generated during breaking. Understanding the behavior of the electrical arc and modifying its characteristics via proper electrode design can significantly improve durability while also promoting optimal performance, reliability, and safety in circuit breakers. This work evaluates the feasibility of carbon nanotube (CNT)-reinforced silver and copper metal matrix composites (MMCs) as switching electrodes and the influence of CNT concentration on the characteristics of the arcs generated. Accordingly, three different concentrations per MMC were manufactured via powder metallurgy. The MMCs and reference materials were subjected to a single break operation and the electrical arcs generated using 100 W and 200 W resistive loads were analyzed. The proposed MMCs displayed promising results for application in low-voltage switches. The addition of CNTs improved performance by maintaining the arc’s energy in the silver MMCs and reducing the arc’s energy in the copper MMCs. Moreover, a CNT concentration of at least 2 wt.% is required to prevent unstable arcs in both metallic matrices. Increased CNT content further promotes the splitting of the electrical arc due to a more complex phase distribution, thereby reducing the arc’s spatial energy density. Citation: Journal of Composites Science PubDate: 2024-07-22 DOI: 10.3390/jcs8070285 Issue No:Vol. 8, No. 7 (2024)
Open Access journal
