Properties Of Composites Research Articles

Investigating the effectiveness of carbon nanotubes for the compressive strength of concrete using AI-aided tools

Sustainable development in the building industry can be achieved through the use of versatile cementitious composites. Thus, incorporating nanoparticles into cement composites can create materials with enhanced performance and numerous applications. The utilization of carbon nanotubes (CNTs) in the construction industry has great promise for developing efficient solutions to establish a sustainable ecosystem with diverse characteristics. However, forecasting the characteristics of these composites is a significant challenge due to their intricate composite structure and nonlinear behavior. Designing and conducting laboratory experiments on diverse samples and across multiple age groups is challenging, time-consuming, and costly. Moreover, there is presently a lack of a forecasting model that can predict concrete's compressive strength (fc') with nanoparticles. Three machine learning (ML) techniques, K-nearest neighbor (KNN), linear regression (LR), and artificial neural network (ANN), were used to predict the fc' of nanocomposites containing CNTs in this research. A thorough database consisting of 282 data entities for the CNTs-based concrete and the model's reliability was assessed using the R2 test and statistical error analysis. The ANN model had the most outstanding R2 value of 0.885, while the KNN and LR models had R2 values of 0.838 and 0.744, respectively. Moreover, RReliefF analysis is utilized to evaluate the primary components in predicting concrete outcomes. This research shows that the properties of CNT-based concrete composites are greatly affected by the water-to-binder ratio, followed by the proportions of cement and coarse aggregates. The ML algorithms exhibited superior generalization capabilities, suggesting their enhanced potential for accurate predictions of CNTs-based concrete properties.

Influence of Fiber Orientation on the Strength Properties of Paper-Epoxy Composites

Influence of Fiber Orientation on the Strength Properties of Paper-Epoxy Composites

CRFP Mechanical Properties—Stated Values Versus Experimental Data

Abstract This study thoroughly examines the mechanical properties of carbon fiber-reinforced polymers (CFRPs), motivated by the critical need for accurate composite property data in investigating fracture control measures for structures subjected to barely visible impact damage. We compared experimental results with manufacturer-stated values, focusing on discrepancies in fiber volume fraction and its impact on elastic modulus. Experimental findings showed an increase in elastic modulus to 190 GPa for 0 deg orientation samples, compared to the manufacturer's stated value of 159.27 GPa. The recalculated fiber volume fraction increased from the expected 57% to an actual value of 60.96%. This increase in fiber content, determined through the Voigt modulus equation and corroborated by SEM image analysis, directly contributed to the observed variations in elastic modulus. Tension tests at 0 deg and 90 deg angles exhibited average percentage errors of 14.83% and 11.57%, respectively, while compression tests at 0 deg displayed a deviation of approximately −13.92% after adjusting for values beyond 0.05% compressive strain. The study underscores the critical impact of fiber volume fraction on CFRP properties and highlights the importance of precise empirical evaluation for accurate CFRP characterization in applications such as aerospace engineering.

Composites with Immobilized Bioactive Spirulina on an Inorganic Substrate (Yellow Clay, Hydroxyapatite, SiO2, TiO2, ZnO).

In order to improve the structural properties of clays and composites of powdered spirulina, clay, nanosilica, hydroxyapatite, TiO2 and ZnO were used as an additive for mechanical processing. As a result, composites with natural nanostructured materials (NNM) are prepared with improved structural properties and bioactivity. The mixtures based on NNM with crystalline kaolinite, clays and admixtures were processed in a knife mill. The materials were characterized using FTIR spectroscopy, nitrogen adsorption and desorption, SEM release of bioactive components (anthocyanin 0,004-0,07 mg/g; chlorophyll 20-29 mg/g), composite toxicity level (below 25%), particle size measurement and surface charge density, zeta potential. Adsorption enthalpies during the formation of an intermolecular complex during the interactions of an anthocyanin molecule with the appropriate component of the composite were also calculated. There are regularities in the characteristics depending on the type of NNM, particle morphology and textural features of solids. The morphological and structural properties of the components changed slighty in the blends because the processing was conducted under relatively low mechanical stress. The morphological, textural and structural characteristics of the composites as well as the transformation to a nanostructured state, assume great bioactive activity of the composites, interesting for practical applications in medicine and cosmetics.

Tribological Properties of EP Composites Reinforced with Short Glass Fiber, Graphite, PTFE and B4C Under Oil Lubrication

Tribological Properties of EP Composites Reinforced with Short Glass Fiber, Graphite, PTFE and B4C Under Oil Lubrication

Advanced polymer composites and polymer hybrids for cartilage tissue engineering

AbstractThe repair and regeneration of cartilage is a challenge for scientists and clinical surgery. Achieving cell adhesion and regeneration, anti‐inflammatory, lubrication, targeted drug delivery and controlled release simultaneously in cartilage treatment are the goals of researchers. Polymer composites and hybrids have the potential to realize above functions in cartilage tissue engineering. This review refers to cartilage injuries, current clinical techniques, and their benefits and limitations, focusing on the most relevant and state of art of advanced polymers for cartilage tissue engineering. The frontier applications of multifunctional polymer composites and hybrids in cartilage tissue engineering are discussed in depth, including polymer scaffold, polymer bio‐lubricant, and zwitterionic polymer for drug delivery and sustained drug release. A summary of comprehensive properties of polymers such as processability, mechanical properties, biocompatibility, biodegradability, hydrophilicity, cytotoxicity, etc., and their mechanisms are analyzed. Furthermore, some key challenges and outstanding concerns on polymer‐based materials for cartilage tissue engineering are presented followed by future perspectives.Highlights The state of art of advanced polymers for cartilage tissue engineering. The advanced bionic property and mechanism of polymer composites and hybrids. Polymers for scaffold, biolubricant, drug delivery, sustained drug release. Future perspectives on polymer composites, hybrids‐based cartilage materials.

Chemical composition, source characteristics, and hygroscopic properties of organic-enriched aerosols in the high Arctic during summer

Arctic regions are extremely sensitive to global warming. Aerosols are one of the most important short-lived climate-forcing agents affecting the Arctic climate. The present study examines the summertime chemical characteristics and potential sources of various organic and inorganic aerosols at a Norwegian Arctic site, Ny-Ålesund (79°N). The results show that organic matter (OM) accounts for 60 % of the total PM10 mass, followed by sulfate (SO42−). Water-soluble organic carbon (WSOC) contributes 62 % of OC. Photochemical processes involving diverse anthropogenic and biogenic precursor compounds are identified as the major sources of WSOC, while water-insoluble organic carbon (WIOC) aerosols are predominantly linked to primary marine emissions. Despite being a remote pristine site, the aerosols show a sign of chemical aging, evidenced by a significant chloride depletion, which was about 82 % on average during the study period. Nitrogen-containing aerosols are likely stemming from migratory seabird colonies and local dust sources around the sampling site. While biogenic, crustal, and sea salt-derived SO42- account for 37%, 8%, and 5% respectively, the remaining 50% is attributed to anthropogenic SO42-. Through chemical tracers, Pearson correlation coefficient matrix, and Hierarchical Cluster Analysis (HCA), the present study identifies soil biota (terrestrial biogenic) and marine emissions, along with their photochemical oxidation processes, as potential sources of Arctic aerosols during summer, while biomass burning and combustion-related sources have a minor contribution. The chemical closure of hygroscopicity highlights that while organics predominantly control aerosol hygroscopicity in the Arctic summer, specific inorganic components like (NH4)2SO4 can significantly increase it on certain days, affecting aerosol-cloud interactions and climate processes over the Arctic during summer. The present study highlights the high abundance of organics and their vital role in the Arctic climate during summer when natural aerosols are conquered.

Innovative Approaches for Manufacturing Epoxy-Modified Wood and Cellulose Fiber Composites: A Comparison between Injection Molding and 3D Printing.

The current study focused on improving the properties of polylactic acid (PLA) for wider application in load-bearing scenarios. Various methods were explored to optimize the interaction between PLA and natural fibers, particularly wood fibers (WFs). Alkalized and epoxy-impregnated WFs were evaluated against untreated WFs and cellulose fibers in both injection molding (IM) and fused deposition modeling (FDM). FTIR analysis revealed the removal of hemicellulose and lignin in alkalized WFs and uniform epoxy curing. Addition of fibers reduced PLA's thermal stability while acting as nucleating agents. Additionally, fibers augmented the storage modulus of biocomposites, with alkalized fibers exhibiting the highest tensile modulus in IM. FDM samples with a 0° raster angle showed superior impact resistance compared to IM counterparts. Moreover, raster angle significantly influenced FDM biocomposite properties, enhancing the tensile strength and modulus of untreated WF and cellulose fibers at 0°. Although FDM did not produce alkalized WF samples, epoxy impregnation emerged as a promising method for enhancing PLA/WF composite mechanical properties in the IM process, offering valuable insights for composite material development.

Date pomace polysaccharide: ultrasonic-assisted deep eutectic solvent extraction, physicochemical properties, biological activities, gut microbiota modulation, and rheological properties

BackgroundThis study utilized ultrasonication-assisted green extraction techniques to explore the physicochemical, rheological, biological, and prebiotic properties, alongside gut modulation abilities of novel polysaccharides extracted from date pomace. The extraction aimed at enhancing the utilization of date pomace, a by-product of date fruit processing, by investigating its potential as a functional food ingredient. The research focused on optimizing the extraction process, understanding the complex structure of the polysaccharides, and assessing their various health-related functionalities.ResultsThe ultrasonically extracted polysaccharides (UPS) were identified as a mixture of significant bioactive compounds including galacturonic acid, galactose, glucose, arabinose, and fructose, showcasing a high molecular weight of 537.7 kDa. The study found that UPS exhibited outstanding antioxidant activities, with scavenging abilities ranging from 59 to 82% at a concentration of 1000 mg/L. Additionally, UPS demonstrated potent inhibitory effects on α-amylase (83%), α-glucosidase (81%), and ACE-inhibition (45%), alongside strong antiproliferative activities against Caco-2 and MCF-7 cancer cell lines and broad-spectrum antimicrobial properties. Remarkably, UPS also enhanced the abundance of beneficial gut microbiota, including Actinobacteria, Firmicutes, and Proteobacteria, during in vitro fermentations and positively modulated gut metabolic pathways, promoting the production of major short-chain fatty acids. UPS had higher abundance in pathways related to cofactors, vitamins, electron carriers, and prosthetic groups biosynthesis compared to blank.ConclusionsThe findings affirm the potential of UPS extracted from date pomace as an innovative and promising functional food ingredient. Its high molecular weight, complex sugar composition, significant antioxidant, antimicrobial, antiproliferative activities, and prebiotic properties make it a valuable resource for promoting health and managing diseases. This study paves the way for further research on the bioavailability and physiological effects of UPS in vivo, highlighting the importance of sustainable utilization of agricultural by-products in developing functional foods that support human health.Graphical

Effect of vacuum infiltration temperature on the microstructure and tribological properties of honeycomb-filled tube-reinforced aluminum matrix composites

The purpose of this work is to optimize the penetration temperature to obtain 316 L honeycomb-filled tube/aluminum matrix composite (HFT/AMC) with good wear resistance. Utilized selective laser melting technology to fabricate honeycomb-filled tubes as reinforcement for the composite material. HFT/AMC was prepared by filling aluminum into honeycomb-filled tubes under three different temperatures of 800 °C, 850 °C, and 900 °C through vacuum infiltration casting. And performed tissue characterization and performance testing. Microstructure, hardness, XRD, and EDS studies showed that the composite materials generate intermetallic compound transition layers of over 100 μm, and the overall strength of the interface was improved. A large number of intermetallic compounds and honeycomb-filled tubes distributed in the aluminum matrix inside the cells jointly strengthen the aluminum-based material. Inspection of worn surfaces of HFT/AMCs revealed abrasive and oxidative wear as the main wear mechanisms. Considering the wear of the produced HFT/AMC under certain conditions, the most suitable infiltration temperature is 850 °C (wear rate: 0.52 ± 0.16 [(mm3/N·m) × 10−3]). This study confirmed that honeycomb-filled tubes can significantly improve the tribological properties of aluminum-based materials.

Examine the static and dynamic mechanical properties of alkali-treated Cannabis sativa plant fiber-reinforced composites

Examine the static and dynamic mechanical properties of alkali-treated Cannabis sativa plant fiber-reinforced composites

A novel and convenient zeolite modification strategy for enhancing the fire resistance of epoxy resin

The preparation process of new environmentally friendly flame retardants to endow epoxy resin (EP) with excellent flame retardancy and mechanical properties remains a challenging task. In this study, a novel Zeolite@DPA-Cu flame retardant was designed and prepared by a simple and environmentally friendly aqueous preparation process using zeolite, copper sulfate and diphenylphosphonic acid as main raw materials. As expected, Zeolite@DPA-Cu significantly improved the flame retardancy and mechanical properties of EP composites. The results showed that the LOI and UL-94 grade of the EP/5 wt% Zeolite@DPA-Cu composite reached 32.4 % and V-0 rating, respectively. The synergistic effect of the physical barrier, free radical capture and catalytic char formation of Zeolite@DPA-Cu significantly improved the flame retardancy of EP. In addition, due to the strong interfacial interaction between Zeolite@DPA-Cu and EP, the tensile strength and elongation at break of the EP were increased to 57.92 MPa and 4.7 %, respectively. Generally, this study proposed a modification strategy that takes into account both flame retardancy and mechanical properties, which is extremely important for the practical application of EP flame retardant materials.

Progress on Microwave Absorption Performance of Carbon Fiber Reinforced Composites

AbstractThe current electromagnetic environment exhibits a growing demand for efficient microwave‐absorbing materials. Developing multifunctional and efficient wave‐absorbing materials poses a challenging research hotspot. Numerous researchers have dedicated their efforts to developing high‐performance broadband wave‐absorbing materials with outstanding mechanical properties. Utilizing carbon fiber‐reinforced polymer composites (CFRP) for electromagnetic wave absorption (EMA) is a rapidly evolving field. Carbon fiber‐based EMA composites are characterized by high dielectric loss, high thermal stability, and low density, enabling them to achieve EMA properties while meeting mechanical property requirements. This review summarizes the principles of electromagnetic EMA, focusing on dielectric and magnetic losses, the preparation methods of CFRP, such as organic polymer synthesis, chemical vapor deposition, and vacuum forming processes, as well as their underlying principles. It also evaluates the research progress on the EMA properties of CFRP composites, particularly highlighting CFRP matrix modification and coating treatment. Finally, the challenges of CFRP EMA and potential future development directions are discussed. This analysis offers multiple recommendations for future researchers.

Colchicine-capped ZnO nanoparticles: Elucidation of their cytotoxicity potential against MDA-MB 231 cancer cells

This research descibes a pioneering approach aimed at preparing zinc oxide nanoparticles (ZnO-NPs) with colchicine as the reducing and capping agent. Colchicine-loaded ZnO-NPs (CHZnO-NPs) were prepared by adding colchicine to the zinc sulfate heptahydrate solution. The CHZnO-NPs formulation was then characterized to determine the morphology, size, crystallinity, elemental composition and vibrational properties. Upon characterization, CHZnO-NPs were studied for their cytotoxic effect against the breast cancer cell line (MDA-MB-231). The successful biosynthesis of CHZnO-NPs was initially confirmed visually by the changes in the mixture color, from light-yellow to white cloudy. The best CHZnO-NPs formulation selected was F3, which possessed 10 mg/mL of colchicine. Formulation (F3) had the smallest mean particle diameter of 43.77 nm and the lowest zeta potential of −19.60 mV. It also had 92.21 ± 0.012 % encapsulation efficiency and 20.86 ± 0.005 % drug loading. Formulation (F3) displayed a hexagonal wurtzite structure with irregular morphology. The observation of colchicine peaks on the FTIR spectra of F3 proved the role of colchicine as a reducing and capping agent during the synthesis of ZnO-NPs. Besides, the in-vitro cell cytotoxicity study on the MDA-MB-231 cell line revealed a significant reduction in cell proliferation at the concentration of 25 μg of colchicine and F3. Further, studies on the cellular migration potential also demonstrated concentration-dependent activity. Overall, CHZnO-NPs were shown to be successfully synthesized via an environmental-friendly procedure and colchicine acted as a capping agent to regulate the particle size, and aggregation, in addition to its anticancer properties.

Design, fabrication, and clinical characterization of additively manufactured tantalum hip joint prosthesis

Abstract The joint prosthesis plays a vital role in the outcome of total hip arthroplasty. The key factors that determine the performance of joint prostheses are the materials used and the structural design of the prosthesis. This study aimed to fabricate a porous tantalum (Ta) hip prosthesis using selective laser melting (SLM) technology. The feasibility of SLM Ta use in hip prosthesis was verified by studying its chemical composition, metallographic structure, and mechanical properties. In vitro experiments proved that SLM Ta exhibited better biological activities in promoting osteogenesis and inhibiting inflammation than SLM Ti6Al4V. Then, the topological optimization design of the femoral stem of the SLM Ta hip prosthesis was carried out by finite element simulation, and the fatigue performance of the optimized prosthesis was tested to verify the biomechanical safety of the prosthesis. A porous Ta acetabulum cup was also designed and fabricated using SLM. Its mechanical properties were then studied. Finally, clinical trials were conducted to verify the clinical efficacy of the SLM Ta hip prosthesis. The porous structure could reduce the weight of the prosthesis and stress shielding and avoid bone resorption around the prosthesis. In addition, anti-infection drugs can also be loaded into the pores for infection treatment. The acetabular cup can be custom-designed based on the severity of bone loss on the acetabular side, and the integrated acetabular cup can repair the acetabular bone defect while achieving the function of the acetabular cup.

Effects of Genotype, Nitrogen, and Sulfur Complex Fertilization on the Nutritional and Technological Characteristics of Buckwheat Flour.

The present study investigated the effect of nitrogen fertilization (NF) at the levels of 0, 45, and 90 kg·ha-1 combined with selected sulfur complex fertilization (SCF) levels of 0 and 45 kg·ha-1 on the nutritional and technological characteristics of buckwheat flour from five varieties. The results showed that the genotype was a critical factor affecting the chemical composition and physicochemical properties of buckwheat flour. NF significantly increased protein, total starch, and amylose content as well as mineral composition but decreased particle size, color value, and water hydration properties. However, SCF enhanced the ash content and decreased the protein content but had no significant effect on the pasting temperature. In addition, the combination of NF and SCF significantly reduced granule size, water solubility, viscosity, and rheological properties with increasing fertilization levels. This study can guide the cultivation of buckwheat with the desired physicochemical properties and provide information for buckwheat-based products in the food industry.

Preparation and mechanical properties of Cf/SiC composites via pressure-assisted gel impregnation and PIP

Non-uniform shrinkage of SiC precursors will lead to cracking and thus weaken the mechanical properties of the Cf/SiC composites. This study used the pressure-assisted gel impregnation method to introduce SiC particles (SiCp) into the carbon fiber preform and combined the PIP technique to fabricate Cf/SiC composites. The mechanism of enhancing the mechanical properties of composites was studied. Results showed that SiCp effectively eliminated matrix cracking, and the PyC interface layer inhibited interfacial crack propagation. The combined effect of the two resulted in a significant improvement in the mechanical properties of the composites. Specifically, the maximum flexural strength of the Cf/SiC composites was 360.63±26.02 MPa, and the maximum fracture toughness was 8.57±1.82 MPa·m1/2.

Fibre geometries and their contribution to the global unidirectional tensile properties of enset fibre-reinforced epoxy composites

This study investigated the potential forms of enset fibres and their tensile properties. Microscopic images of the fibre cross-section were collected, and image analysis was carried out in MATLAB. As a result, four distinct fibre shapes were identified and their likelihood of occurring as well as- their area contribution to the fibre bundle were determined. These fibres have distinct tensile strength, Young’s modulus, and strain-to-failure values, distinguishing the strongest and weakest fibres. The strength distribution of these fibre shapes does not conform to the Weibull theory. However, it follows the scenario that fibres with the biggest perimeter-to-area ratio provide the weakest values and vice versa. This shows that the tensile properties of fibres are influenced not only by their material properties but also by their geometric shape. As a result, fibres of different shapes contribute differently to the global tensile properties of the fibre-polymer composites.

Bending behavior of multi-layer sandwich composites reinforced with weft-knitted spacer fabrics

In this study, the bending properties of multi-layer sandwich composites (MLSCs) were investigated. For this purpose, first, 1 × 1- and 5 × 5-Rib gaiting weft-knitted spacer fabrics were produced using E-glass yarns. Then, glass/epoxy sandwich composites were prepared using produced fabrics as reinforcement and epoxy resin as matrix. Considering both the pattern of reinforcements and the arrangement of layers, different types of MLSCs were fabricated by the implementation of different stacking sequences. The prepared samples were subjected to the three-point bending test. Generally, the orientation of samples, structures of each sandwich’s layer, and stacking sequence of layers, as three impressive parameters affected the bending behavior of MLSCs. The results showed that in all samples, the maximum bending force (MBF) of MLSCs in the longitudinal direction is generally higher than that in the transverse direction. The MBF of MLSCs included both 5 × 5-Rib gaiting layers and 1 × 1-Rib gaiting layers increased with increasing the number of 5 × 5-Rib gaiting layers to 1 × 1-Rib gaiting layers. The MBF of MLSCs included of same number of 5 × 5-Rib gaiting and 1 × 1-Rib gaiting structures increases by placing the 5 × 5-Rib gaiting fabrics in the bottom layers, which shows the influence of stacking sequence on the bending behavior of MLSCs. According to the generated geometrical models, two-layer MLSCs are numerically simulated using the FEM. FE simulation and the experimental results brought about the same bending behavior of MLSCs.

Effect of hygrothermal aging on mechanical properties of continuous flax fiber composites

AbstractThe influence of hygrothermal aging on the mechanical properties of flax fiber‐reinforced polymer (FFRP) composites was studied by examining the mechanical properties and failure mechanism of the composite laminates exposed in distilled water at different temperatures. The resin transfer molding (RTM) process was used to manufacture FFRP laminates, which were then subjected to accelerated aging tests in distilled water at different temperatures. The moisture absorption characteristics of FFRP were analyzed by a water absorption test. Tensile, bending, and low‐velocity impact tests of laminates after different aging conditions were performed. Combined with DSC and FTIR tests, the failure mechanism of FFRP exposure to hygrothermal aging was analyzed. The result indicated that the increase in temperature will accelerate the moisture absorption process of FFRP, and the hygroscopic behaviors at different temperatures conform to Fick's law. In the early stage of hygrothermal aging, the composites undergo post‐curing, and the tensile and bending strengths increase. After that, the tensile and bending strengths are decreased because of the thermo‐oxygen aging of materials and fiber/matrix interface damage. After hygrothermal aging, the impact peak force of FFRP decreases obviously while the absorbed energy increases due to the increase of internal defects and plasticization of composites. The increase of hygrothermal aging temperature aggravates the aging of materials, resulting in a more obvious decline in the tensile, bending, and impact properties of the composites.Highlights The effect of hygrothermal aging on the mechanical properties of FFRP is investigated. With the increase of hygrothermal aging time, the tensile and bending strength of FFRP increased at the early stage of aging and then decreased. After hygrothermal aging, the impact peak force of FFRP decreases and the absorbed energy increases due to the increase of internal defects and plasticization of composites.