Properties Of Composites Research Articles

Developments, Novel Concepts, and Challenges of Current Collectors: From Conventional Lithium Batteries to All‐Solid‐State Batteries

AbstractWith the innovation and evolution of lithium batteries, different active materials are loaded onto the current collectors, leading to remarkable changes in the components that directly interact with the current collectors. The surface/interface of current collectors in lithium batteries is gradually becoming one of the key factors to improve the overall performance. The thickness, material composition, surface morphology, and intrinsic properties of current collectors are crucial for understanding chemo‐mechanical changes during electrochemical reactions. Despite the widely acknowledged importance of highly efficient electron transportation and improved interfacial performance of current collectors as one of the determinants of exceptional lithium battery performance, insufficient attention has been given to exploring targeted design strategies for current collectors used in various lithium batteries. Particularly, as the development of solid‐state lithium batteries in full swing, there are limited studies focused on current collectors in all‐solid‐state lithium batteries (ASSLBs). This review introduces recent advancements in current collector technology, while highlighting both similarities and differences between negative current collectors applied in conventional lithium batteries and ASSLBs. Furthermore, we propose promising prospects for utilization of alloy materials as next‐generation negative current collectors.

Fluoride export is required for the competitive fitness of pathogenic microorganisms in dental biofilm models.

Dental caries is a globally prevalent condition that occurs when pathogenic species, including Streptococcus mutans and Candida albicans, outcompete beneficial species, such as Streptococcus gordonii, in the dental biofilm. Fluoride is routinely used in oral hygiene to prevent dental caries. Fluoride also has antimicrobial properties, although most microbes possess fluoride exporters to resist its toxicity. This work shows that sensitization of cariogenic species S. mutans and C. albicans to fluoride by genetic knockout of fluoride exporters alters the microbial composition and pathogenic properties of dental biofilms. These results suggest that the development of drugs that inhibit fluoride exporters could potentiate the anticaries effect of fluoride in over-the-counter products like toothpaste and mouth rinses. This is a novel strategy to treat dental caries.

Sewage Sludge Plasma Gasification: Characterization and Experimental Rig Design

The treatment of wastewater worldwide generates substantial quantities of sewage sludge (SS), prompting concerns about its environmental impact. Various approaches have been explored for SS reuse, with energy production emerging as a viable solution. This study focuses on harnessing energy from domestic wastewater treatment (WWT) sewage sludge through plasma gasification. Effective syngas production hinges on precise equipment design which, in turn, depends on the detailed feedstock used for characterization. Key components of plasma gasification include the plasma torch, reactor, heat exchanger, scrubber, and cyclone, enabling the generation of inert slag for landfill disposal and to ensure clean syngas. Designing these components entails considerations of sludge composition, calorific power, thermal conductivity, ash diameter, and fusibility properties, among other parameters. Accordingly, this work entails the development of an experimental setup for the plasma gasification of sewage sludge, taking into account a comprehensive sludge characterization. The experimental findings reveal that domestic WWT sewage sludge with 40% humidity exhibits a low thermal conductivity of approximately 0.392 W/mK and a calorific value of LHV = 20.78 MJ/kg. Also, the relatively low ash content (17%) renders this raw material advantageous for plasma gasification processes. The integration of a detailed sludge characterization into the equipment design lays the foundation for efficient syngas production. This study aims to contribute to advancing sustainable waste-to-energy technologies, namely plasma gasification, by leveraging sewage sludge as a valuable resource for syngas production.

Development of hBN / natural fibers reinforced polymer composites using Grey Relation Grade Analysis for thermal and electrical applications

Abstract The objective of this work is to enhance the thermal conductivity and electrical properties of polymer hybrid composites through a systematic novel Grey Relation Grade Analysis (GRGA) optimization approach. This involves reinforcing the hybrid composites with hexagonal Boron Nitride (hBN) and various kinds of natural fibers or fillers. The development of a unique technology to produce multiphase composites using 2% of natural fibers or fillers such as coir fiber (CF), rice husk filler (RF), wood filler (WF), banana fiber (BF) and sugarcane fiber (SF) along with hBN (1, 3, 5 wt.%) particulates as reinforcements in epoxy matrix. The Taguchi L15 matrix array is utilized to fabricate interlaced composite samples via hand layup molding. Ultrasonic waves are used to ensure the uniform distribution of hBN filler into the matrix. Analysis of variance (ANOVA) and GRGA reveal the significant results. It shows that the multiphase hybrid composites exhibit good thermal conductivity when higher content of hBN (5 wt.%) particulate for all the micro particulate polymer (MPP) composites. Multi-response optimization shows that the micro banana fiber (2 wt.%) interlaces with hBN (5 wt.%) composite exhibits the higher thermal conductivity and electrical resistance compared to all other natural fiber interlaced composites. The aforementioned MPP composite has thermal conductivity of 1.03 W/m.K and electrical resistance of 279.88 Giga Ohms. Besides, the wood filler interlaced hBN (5 wt.%) composite shows the minimum dielectric constant compared to all other natural fiber composites. This desirable result is caused by the proper dispersion of hBN with the matrix which encourages interlocking with the fiber and the matrix. Maximum electrical resistance is observed for composite containing 5 wt.% of h-BN and 2 wt.% of BF. The developed MPP composite could be used in heat shields, electrical insulation components, and interior automotive components like dashboards, luggage compartments and interior walls.

Effect of ground tyre rubber content on self-healing properties of natural rubber composites

Abstract In this investigation, we study the influence of the loading of ground tyre rubber (GTR), referred to as rubber dust 40 mesh (RD40), on the intrinsic self-healing natural rubber (NR) based on metal-thiolate ionic networks. The loading of RD40 particles was varied at 10, 20, and 30 phr to assess the optimum amount for interfacial bonding, mechanical and dynamic properties, and healing efficiency. The quantitative measurement of metal-thiolate ion networks and covalent crosslinks was assessed through swelling tests. The effects of RD40 loading on the dynamic mechanical properties and morphological characteristics were also investigated. Tensile properties of the rubbers before and after healing were measured using universal testing tester to obtain healing efficiency of the materials. The results showed that the developed materials have the ability to autonomously repair themselves at room temperature without the need for manual intervention. The results also revealed the tensile strength and elongation at break of self-healing NRs filled with 10 phr of RD40 were recovered 92 % and 93 %, respectively. The findings demonstrated the benefits of utilizing GTR as an effective sustainable filler and advanced the understanding of self-healing strategies and the interaction between ground tyre rubber and rubber matrices.

Hybrid Nickel‐Copper Oxide Nanoparticles: A Multiparametric Study for the Influence of Synthetic Parameters on the Optical and Physical Properties

AbstractThe hybrid nanoparticles of nickel and copper oxide are optimized by varying synthetic conditions such as precursor salt concentration, rate of reagent addition, pH, and temperature. The resulting nanoparticles are characterized by using UV‐Visible and fluorescence spectroscopy, hydrodynamic size, zeta potential, polydispersity index, SEM, EDX, XRD, and FTIR spectroscopy. The control over composition and physical properties of these hybrid oxides are analyzed through careful variations in the synthetic parameters. UV‐Vis analysis demonstrated the successful synthesis of NiO‐CuO hybrid nanoparticles at various concentrations. NiO dominant hybrids are obtained by quick addition of the reagent and at higher pH, while CuO dominant hybrids require slower addition of reagent and lower pH. The increase in the temperature causes a hypochromic shift in the UV‐Vis absorption, whereas fluorescence is enhanced with increase in the CuO concentration. The fluorescence generally remained stable by varying time of reagent addition, pH, and temperature. More stable and least‐sized NiO‐CuO hybrid nanoparticles are obtained at ratios of 75 : 25 and 25 : 75, by quick addition of reagent, at higher pH levels, and at higher temperatures. A better understanding of their physical and optical properties obtained by varying synthetic parameters may potentially result in their enhanced applications.

Characterization of Wheat Husk-Derived Holey Carbon/(RGO)x/CoFe2O4/PVA Nanocomposites: Insights into Structural, Optical, Magnetic, and Dielectric Properties

Abstract In this particular study, an uncomplicated method involving chemical co-precipitation was employed to create nanocomposites known as wheat husk-derived holey carbon/reduced graphene oxide/cobalt ferrite/polyvinyl alcohol (WHHC/(RGO)x/CF/PVA). The utilization of biomass materials is a noteworthy aspect that has caught the attention of researchers in this field. It is worth mentioning that the characteristics related to both magnetism and dielectricity in the flexible WHHC/(RGO)x/CF/PVA nanocomposites can be controlled by adjusting the amount of RGO present in the composition. To explore the composite's absorption properties, the influence of RGO content was investigated, and it was found that there is a direct correlation between higher RGO content and increased absorption. The WHHC/(RGO)x/CF/PVA structure exhibits an enhanced impedance matching due to the strong interfacial interaction between RGO and cobalt ferrite nanoparticles. This porous composition possesses an optimal structure for capturing and collecting light effectively. Moreover, the WHHC/(RGO)x/CF/PVA nanocomposites have exhibited great potential in manufacturing flexible electronic devices such as light-dependent resistors (LDRs), when employed as an electronic material. Their lightweight characteristics and flexibility are key contributors to the success achieved in this aspect. However, it is important to note that their overall shape tends to resemble that of traditional absorber equipment commonly used in the field.

Optogenetic control of mRNA condensation reveals an intimate link between condensate material properties and functions.

Biomolecular condensates, often assembled through phase transition mechanisms, play key roles in organizing diverse cellular activities. The material properties of condensates, ranging from liquid droplets to solid-like glasses or gels, are key features impacting the way resident components associate with one another. However, it remains unclear whether and how different material properties would influence specific cellular functions of condensates. Here, we combine optogenetic control of phase separation with single-molecule mRNA imaging to study relations between phase behaviors and functional performance of condensates. Using light-activated condensation, we show that sequestering target mRNAs into condensates causes translation inhibition. Orthogonal mRNA imaging reveals highly transient nature of interactions between individual mRNAs and condensates. Tuning condensate composition and material property towards more solid-like states leads to stronger translational repression, concomitant with a decrease in molecular mobility. We further demonstrate that β-actin mRNA sequestration in neurons suppresses spine enlargement during chemically induced long-term potentiation. Our work highlights how the material properties of condensates can modulate functions, a mechanism that may play a role in fine-tuning the output of condensate-driven cellular activities.

Experimental Investigation of Date seed and Neem Powder Reinforced Natural Fiber Composites

Natural fillers have received great attention among researchers due their its light weight, high strength, degradability, and eco-friendly behavior. This work is focused on developing a laminate of date palm seed powder and neem gum powder reinforced epoxy resin. Epoxy resin is an excellent thermoset polymer with anoutstanding cost to performance ratio. Date palm seeds have highly competitive properties in improving the mechanical and thermal properties of composites by their good adherence to polymer matrix. Neem gum powder is used as a binder in increasing ratios of 0 %, 10 %, 15 %, 20 %, 25 %, and 30 % to test their strength in different compositions. Date seed powder has been reinforced in decreasing weight percent as 30 %, 25 %, 20 %, 15 %, 10 %, 5 %, and 0 %. The specimens prepared through the compression moulding technique were subjected to various mechanical tests like a tensile test, flexural test, and impact test as per the ASTM standards. Fractography analysis using FESEM (Field Emission Scanning Electron Microscopy) and FT-IR(Fourier Transform Infrared spectroscopy) test have determined the surface characteristics and chemical composition of the samples. The result shows that, by adding neem gum powder in increasing quantities the mechanical properties like tensile and flexural decreases. However, it does not affect the impact strength of the material. A detailed study of their behavior is discussed in this work.

Supported Ionic Liquid-Phase Materials (SILP) as a Multifunctional Group of Highly Stable Modifiers and Hardeners for Carbon and Flax Epoxy Composites.

This paper introduces a novel approach to enhance epoxy resin formulations by using SILP materials as multifunctional hardeners and fillers in composite structures reinforced with carbon and flax fibers. This study explores the integration of ionic liquids (ILs) onto a silica support structure, presenting various permutations involving silica selection, ionic liquid choice, and concentration. The focus of this study was to elucidate the influence of SILP on resin curing ability and the mechanical properties of the resulting composites. Detailed research was conducted, including Brunauer-Emmett-Teller analysis (BET) for SILP materials and curing characterization for epoxy resin formulations with different SILP materials. Furthermore, the mechanical properties of the obtained composites were determined by Scanning Electron Microscopy analysis (SEM) (the force at break, the maximum elongation at break, tensile strength, and modulus of elasticity). Through SILP incorporation, the mechanical properties of composites, including the modulus of elasticity and tensile strength, are substantially improved, a phenomenon akin to traditional filler effects. The findings highlight SILP materials as prospective candidates for concurrent hardening and filling roles within composites (through a single-step procedure, with prolonged storage stability and controlled processing conditions), particularly pertinent as the composite industry veers toward epoxy bioresins necessitating liquefaction via temperature application.

Predictive Modeling and Experimental Validation for Assessing the Mechanical Properties of Cementitious Composites Made with Silica Fume and Ground Granulated Blast Furnace Slag

Using sustainable cement-based alternatives, such as secondary cementitious raw materials (SCMs), could be a viable option to decrease CO2 emissions resulting from cement production. Previously conducted studies to determine the optimal mix designs of concrete primarily focused on either experimental approaches or empirical modeling techniques. However, in these experimental approaches, few tests could be performed for optimization due to time restrictions and lack of resources, and empirical modeling methods cannot be relied on without external validation. The machine learning-based approaches are further characterized by certain shortcomings, including a smaller number of data points, a less robust connection among the controlling factors, and a lack of comparative analyses among machine learning models. Furthermore, the literature on predicting the performance of concrete utilizing binary SCMs (silica fume (SF) and ground granulated blast furnace slag (GGBS)) is not available. Therefore, to address these drawbacks, this research aimed to integrate ML-based models with experimental validations for accurate predictions of the compressive strength (CS) and tensile strength (TS) of concrete that includes SF and GGBS as SCMs. Three soft computing techniques, namely the ANN, ANFIS, and GEP methods, were used for prediction purposes. Eight major input parameters, including the W/B ratio, cement, GGBS, SF, coarse aggregates, fine aggregates, superplasticizer, and the age of the specimens, were considered for modeling. The validity of the established models was assessed by using external experimental validation criteria, statistical metrics, and performance measures. In addition, sensitivity and parametric analyses were performed. Based on statistical measures, the ANFIS models outperformed other models with higher correlation and lower statistical error values. However, the GEP models exhibited superior performance compared to ANFIS and ANN with respect to the closeness of the RMSE, MAE, RSE, and R2 values between the training, validation, and testing sets for both the CS and TS models. Experimental validation showed strong evidence for the applicability of the proposed models with an R2 of 0.88 and error percentages of less than 10%. Sensitivity and parametric investigations demonstrated that the input variables exhibited the patterns described in the experimental dataset and the available literature. Hence, the proposed models are accurate, have better prediction performance, and can be used for design purposes.

Influence of the Parameters of Middle Frequency Magnetron Sputtering on the Elemental Composition, Microstructure, and Mechanical Properties of Ti–Al–Ta–N Coatings

Influence of the Parameters of Middle Frequency Magnetron Sputtering on the Elemental Composition, Microstructure, and Mechanical Properties of Ti–Al–Ta–N Coatings

Strengthening and self‐healing of natural fiber composites via PLA core–shell nanofibers as healing agent carrier

AbstractThe resin‐rich region between the fiber laminates of a fiber‐reinforced composite is susceptible to matrix damage impeding the composite's integrity. Hence, this study intends to interlayer core–shell poly(lactic) acid (PLA) nanofibers between the flax fibers as a preventive and reactive mechanism to matrix damages in the resin‐rich area. The nanofibers prevent premature damage by suppressing or mitigating crack propagation and in the event of damage to the nanofibers, it reacts by releasing the encapsulated healing agent. Upon interlayering the flax fiber laminates with self‐healing core–shell nanofibers, the flexural modulus exhibited an increment of 31% whereas the short beam strength improved by 19%. Self‐healing traits of the composites were assessed by subjecting the composites to repeated flexural or short beam strength tests for several load cycles. Upon initial damage to the composites, the composites exhibited a full retention and improvement in mechanical properties. The self‐healing composites were also able to withstand more loading cycles than the conventional composite under repeated short‐beam strength tests. Under both configurations, the damaged self‐healing composites exhibited a residual strength greater than or equivalent to the ultimate strength of a pristine flax fiber composite.Highlights Fabrication of EP/flax self‐healing composites by PLA core–shell nanofibers. Interlayering healing nanofiber mats between flax fabrics in an FRP composite. Nanofiber interlayers exhibited a profound impact on the composite properties. Nano mats facilitate autonomous repair of internal defects within matrices. The self‐healing composites showed full retention and mechanical strength.

Mechanical and Thermal Characterization of Bamboo and Interlaminar Hybrid Bamboo/Synthetic Fibre-Reinforced Epoxy Composites

The main objective of this study was to investigate the mechanical and thermal properties of bamboo, as well as interlaminar hybrid composites reinforced with both bamboo and synthetic fibres in an epoxy matrix. Bamboo and glass, aramid, and carbon bidirectional fabrics were used with a bi-component epoxy matrix to fabricate the composite materials using the vacuum bagging process. The synthetic fabrics were placed on the outer layers, while the bamboo fabrics were used as the core of the hybrid composites. The developed composites were characterized and compared in terms of morphological, physical, and mechanical properties. Further, thermogravimetric (TGA) analysis was used to measure and compare the degradation temperature of the composites studied. Finally, a Scanning Electron Microscopy (SEM) analysis was performed in order to examine the fracture surfaces of the specimens tested. It was found that the fibre hybridization technique significantly improved the general mechanical properties. TGA analysis showed an increase in the thermal stability of the composites obtained by incorporating the synthetic fibres, confirming the effect of hybridization and efficient fibre matrix interfacial adhesion. The results from this work showed that the use of synthetic fibre reinforcements can help to significantly improve the mechanical and thermal properties of bamboo fibre-reinforced composites.

Modeling and analysis of TiO2 filler's impact on specific wear rate in flax fiber-reinforced epoxy composite under abrasive wear using Taguchi approach

PurposeThis study explores how titanium oxide (TiO2) filler influences the specific wear rate (SWR) in flax fiber-reinforced epoxy composites (FFRCs) through a Taguchi approach. It aims to boost abrasive wear resistance by incorporating TiO2 filler, promoting sustainable and eco-friendly materials.Design/methodology/approachThis study fabricates epoxy/flax composites with TiO2 particles (0–8 wt%) using hand layup. Composites were tested for wear following American Society for Testing and Materials (ASTM) G99-05. Statistical analysis used Taguchi design of experiments (DOE), with ANOVA identifying key factors affecting SWR in abrasive sliding conditions.FindingsThe study illuminates how integrating TiO2 filler particles into epoxy/flax composites enhances abrasive wear properties. Statistical analysis of SWR highlights abrasive grit size (grit) as the most influential factor, followed by normal load, wt% of TiO2 and sliding distance. Grit size has the highest effect at 43.78%, and wt% TiO2 filler contributes 15.61% to SWR according to ANOVA. Notably, the Taguchi predictive model closely aligns with experimental results, validating its reliability.Originality/valueThis paper integrates TiO2 filler and flax fibers to form a novel hybrid composite with enhanced tribological properties in epoxy composites. The use of Taguchi DOE and ANOVA offers valuable insights for optimizing control variables, particularly in natural fiber-reinforced composites (NFRCs).

Effect of temperature on flexural and interlaminar shear strength properties of carbon‐epoxy composites: Experiment and modeling

AbstractCarbon fiber composites are known for excellent specific mechanical properties at room temperature. It is important to model the effect of temperature on flexural strength and interlaminar shear strength (ILSS). In this study, T700 carbon fiber composites with two different epoxy resins (Epofine, LY556) were prepared using filament winding and named as TE and TL composites. The dynamic mechanical analysis (DMA) tests revealed Tg of 177 and 192°C for TE and TL composites, respectively. Three‐point bending (flexural) and short‐beam shear (ILSS) tests were performed at −20, 0, RT, 90, 105, 150, 170, and 200°C. It was observed that flexural strength and ILSS decreases linearly with increase in temperature. Fracture analysis of flexural samples revealed fiber breakage at −20°C and micro‐buckling at elevated temperature are dominant failure mechanisms. Fracture analysis of ILSS samples showed delamination with microcracking at −20°C and plastic deformation of matrix at elevated temperature. A new empirical model was proposed to predict the temperature dependent flexural strength and ILSS. With this model, variation of flexure strength and ILSS with temperature can be estimated from respective values at RT, Tg and storage modulus values from DMA, thus extensive experimentation at high temperatures can be avoided.Highlights Mechanical properties of filament wound composites are tested from −20 to 200°C. Flexural strength and ILSS linearly decreases with increase in temperature. Fiber breakage at −20°C and micro bucking at 200°C are dominant in flexure. Delamination at −20°C and plastic deformation at 200°C are dominant in ILSS. Analytical model for finding temperature dependent flexural strength and ILSS.

Implications of husking process on the nutritional composition of sorghum grains: diverse varieties and regions

SummarySorghum, known for its nutritional value, health benefits and gluten‐free status, is now widely produced and suitable for human consumption in developed regions due to advancements in sorghum research and processing techniques. The research looked at how well the husking fraction time unit (HFTU) technique worked by examining its effects on the nutritional value of three varieties of sorghum grain. The efficiency of the husking process was assessed at 87% for concentrated and redistributed nutritional contents and 60% for variation of mineral contents based on bran/ endosperm. The technique reduced the T.K.W. compared to whole grain to the endosperm (grits). Moreover, the redistribution of the crude protein % showed the precision of the HFTU procedure by demonstrating an average of 26.6% as a variation ratio of the bran/endosperm in the data set. Contrary to the content of the total dietary fibre content, for example, the variation of TDF % attributed to bran/endosperm was 10.9%. On the other hand, the average ash % of whole grains (hummer) and husked products (TM05C) was increased by 33.2% based on averages of 1.5% and 2.1%, respectively. Accordingly, it was approved that the HFTU procedure effectively separated the endosperm (grits) and bran. This study also found that minerals such as Ca, Cu, Fe, K, Mg, Mn, Na, P, S and Zn changed over 30‐to‐80‐time units by 29%, 13%, 8%, 4%, 17%, 18%, 1%, 13%, 6% and 12% in the bran and endosperm. The HFTU process has influenced the colour attributes of variation sorghum varieties, particularly within a time scale of 80 (S) units. The research revealed that the husking technique substantially impacted the different sorghum grain varieties’ nutritional composition and colour properties. The method can be useful for developers in enhancing sorghum grain products’ nutritional properties attributed to various varieties and regions, allowing them to provide high nutritional quality sourced from sustainable products.

Effect of microwave-assisted treatment on proximate, techno-functional, thermal, structural, and storage properties of TGN (Cyperus esculentus L.) flour.

The use of the emerging technique of microwave-assisted roasting on TGN (TGN) flour was investigated. Tiger nuts were subjected to microwave irradiation at 450, 600, and 900 W each at 5, 10, and 15 min, and milled to flour. The flours were analyzed for proximate, bioactive, techno-functional, morphological, thermal, and storage effects on their composition. An untreated sample was the control. The results revealed that microwave treatment significantly (P < 0.05) elicited various modifications in the proximate composition and techno-functional properties. The treatment improved the bioactive composition of phenolic content together with the antioxidant activity of the flour. Progressive microwave treatment of TGNs resulted in flours with darker colors and reduced pasting parameters. Structural modification of starch granules, protein denaturation, and starch-protein complexes occasioned by microwave treatment were evidenced in the functional group analysis, including morphological agglomeration, increased particle size, and thermal properties. Treatment also enhanced the microbiological qualities of flour after 8 weeks of storage. This study shows that microwave treatment produces excellent physical modifications that lead to improvements in the nutritional, functional, sensory, and color properties, and safety attributes of TGN flour for food application. This is a development that could present opportunities for novel food formulation by the food industry and related industries. © 2024 Society of Chemical Industry.

Effect of fiber orientation on mechanical properties of betel nut (areca palm) stem fiber reinforced laminated polyester composites

ABSTRACT This study explored the effect of fibre orientation on the mechanical properties of Betel Nut (Areca palm) stem fibres (BNSF)-reinforced laminated polyester composites. Composites are fabricated by hand lay-up method with 15% (vol.) fibre loading and 0°/90°/0° and −45°/0°/45° orientations. The mechanical properties of composites are determined by testing as per ASTM standards and revealed that composite strengths vary significantly with fibre orientation. The tensile, flexural, and impact strengths of the composite are found 58.19 MPa, 153.96 MPa, and 25.68 kJ/m2, respectively, for the 0°/90°/0° fibre orientation, which are higher than the composite of −45°/0°/45° fibre orientation. Furthermore, strengths are found greater than the betel nut husk and leaf, bamboo, coir, banana, and jute fibres-reinforced polymer composites. The bonding between fibres and matrix, voids, micro-cracks, etc. are investigated by optical microscopy of a tensile-fractured specimen. This study revealed that BNSF would be a novel and potential natural fibre for reinforcing polymer composites. Its strength can be enhanced by choosing suitable numbers of fibre laminations and orientations. Since areca palm trees grow extended, moderate-sized composite boards/panels can be produced from BNSF to replace synthetic fibres-based ones. It will help reduce environmental pollution as a green composite.

The Synergistic Effect of Carbon Black/Carbon Nanotube Hybrid Fillers on the Physical and Mechanical Properties of EPDM Composites after Exposure to High-Pressure Hydrogen Gas

This study investigated the synergistic effect of carbon black/multi-wall carbon nanotube (CB/MWCNT) hybrid fillers on the physical and mechanical properties of Ethylene propylene diene rubber (EPDM) composites after exposure to high-pressure hydrogen gas. The EPDM/CB/CNT hybrid composites were prepared by using the EPDM/MWCNT master batch (MB) with 10 phr CNTs to enhance the dispersion of CNTs in hybrid composites. The investigation included a detailed analysis of cure characteristics, crosslink density, Payne effect, mechanical properties, and hydrogen permeation properties. After exposure to 96.3 MPa hydrogen gas, the hydrogen uptake and the change in volume and mechanical properties of the composites were assessed. We found that as the MWCNT volume fraction in fillers increased, the crosslink density, filler–filler interaction, and modulus of hybrid composites increased. The hydrogen uptake and the solubility of the composites decreased with an increasing MWCNT volume fraction in fillers. Moreover, after exposure to hydrogen gas, the change in volume and mechanical properties exhibited a diminishing trend with a higher MWCNT volume fraction. We conclude that the hybridization of CB and CNTs formed strong filler–filler networks in hybrid composites, consequently reinforcing the EPDM composites and enhancing the barrier properties of hydrogen gas.