High-performance Composite Materials Research Articles

A Proposal for a Carbon Fibre-Manufacturing Life-Cycle Inventory: A Case Study from the Competitive Sailing Boat Industry

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.

Quantitative and deep learning based fourier transform infrared radiation and tensile characteristics study on chemically treated hibiscus rosa-sinensis plant fibers

Incorporation of natural fibers with Fiber Reinforced Polymers (FRPs) is a promising avenue for sustainable and high-performance composite materials. The fibers, derived from outer bark portion of plants, offer significant merits such as renewability, low cost, and eco-friendly. Unique mechanical and physical properties, and widespread availability of Hibiscus Rosa-sinensis have made them subject of intense research interest. The present study investigated the chemically treatment of HRS Fibers using Sodium Hydroxide (NaOH), Potassium Permanganate (KMnO4), and Acetic Acid (CH3COOH) bat varying weight percentages (3, 4, 5 Wt%) and solutionizing times (1, 2, 3 h) based on Taguchi’s L27 orthogonal array. Fourier Transform Infrared (FT-IR) analysis revealed significant changes in O–H, C–H stretching, C=O moiety, aromatic ring, and C–O/C–C stretching. Potassium Permanganate treatment at 4 Wt% and 3 h of solutionizing time has yielded the best results. Multi-Layer Perceptron Artificial Neural Network (MLP-ANN) has been successfully applied to accurately predict the output physical characteristics of chemically treated HRS fibers using experimental data. Further Single Fiber Pull-out test results in Potassium Permanganate at 4 Wt% and 3 h solutionizing time as best sample with highest Tensile Strength and Modulus. This research underscores the effectiveness of the chemical treatment process in enhancing the properties of HRS plant fibers for potential composite applications.

In situ TEM nanomechanical study on enhanced toughness of graphene-nanoparticle nanocomposite

Although theoretical studies and experimental research have shown outstanding mechanical properties of graphene, its brittleness and low toughness restrict its widespread industrial use. Here, we conducted a study to examine the impact of encapsulated Ag nanoparticles on the mechanical properties of graphene through in situ nanomechanical testing in an aberration-corrected transmission electron microscope (TEM). The presence of Ag nanoparticles was found to decrease crack propagation speed, enabling the TEM observation of crack deflection around the nanoparticles at nanoscale, as well as real-time measurement of the concomitant increase in stress. Using our nanomechanical testing data, we were able to quantitatively estimate the stress intensity factor, which serves as a measurement of fracture toughness for graphene, and then compared our results with previously reported values. We further discuss the role of nanoparticles in the propagation of cracks and their potential to enhance the toughness of materials. These findings have practical implications for the development of high-performance graphene composite materials.

A novel high-performance composite material with low dielectric constant and excellent hydrophobicity

A novel high-performance composite material with low dielectric constant and excellent hydrophobicity

In situ semi-etching of bimetallic LDH nanosheet arrays into FeNi-LDH/MOF to boost oxygen evolution reaction

The inherent sluggish kinetics of water oxidation is the core issue for electrochemical hydrogen production from water splitting. Metal organic frameworks (MOFs) with tunable porous structures, abundant coordination metal centers and large specific surface area are expected as efficient electrocatalysts. In this paper, FeNi-LDH/MOF composite nanostructures were successfully constructed on carbon cloth (CC) through partially converting iron-nickel layered double hydroxide (FeNi-LDH) into FeNi-MOF (NiFe(CN)5NO) by an in-situ semi-etching method. The MOF nanocrystals in this material are in-situ decorated on the surface of FeNi-LDH nanosheets, providing abundant open active sites and mass transfer channels for electrocatalysis. Thanks to the synergistic effect of the LDH and MOF, as well as the exceptional hierarchical architecture, the FeNi-LDH/MOF/CC as a self-supported electrode exhibits distinguished electrocatalytic OER performance, with a low overpotential of 263 mV@100 mA cm−2 and a small Tafel slope of 50.2 mV dec-1 in 1.0 M KOH. In addition, the catalyst exhibits good durability with almost constant current density during 24 h OER test. This work provides an effective way to design high-performance MOFs-based composite electrocatalytic materials.

Radiation-induced cross-linking polymerization: Recent developments for coating and composite applications

Abstract Radiation-initiated cross-linking polymerization of multifunctional monomers is an attractive method used for drying solvent-free liquid coatings, inks, and adhesive as well as for fabricating high-performance composite materials. The method offers a number of advantages compared with thermal curing processes. Free radical and cationic polymerization have been investigated in detail over the past years. A high degree of control over curing kinetics and material properties can be exerted by adjusting the composition of matrix precursors and/or by acting on the process parameters (overall dose, dose rate, dose increment, initial temperature). Several pending issues that require deeper investigations are as follows: (i) the fast polymerization of multifunctional monomers generates micro-heterogeneous networks requiring detailed characterization and quantification by microscopic, thermal, and spectroscopic analyses; (ii) the adhesion and surface properties of radiation-cured coatings are quite sensitive to processing parameters; and (iii) significant enhancement of the toughness is needed to qualify potential matrices based on simple difunctional monomers for high-performance composites. Recent results show that the bulk and surface properties of radiation-cured materials can be improved by advanced formulation of matrix precursors and by a parametric study of the processing factors.

Electrical Heating of Carbon Textile Reinforced Concrete—Possible Effects on Tensile Load-Bearing Behavior

Carbon-textile-reinforced concrete (CTRC) is currently used as a high-performance composite material in the construction industry, comprising concrete and a non-metallic reinforcement. In addition to remarkable material properties such as tensile-load-bearing behavior, durability and density, this innovative material features high electrical conductivity, offering the potential for electrical heat generation within building components. This paper contributes to the field by exploring the unique combination of properties exhibited by carbon-textile reinforcements (CTR) electrically heated up to 80 °C. The impact of the electrical heating of CTR was evaluated by conducting stationary tests on load-bearing behavior. The tests were conducted on two different CTRs: one impregnated with polystyrene, and the other with epoxy resin additionally surface-modified with quartz sand. In order to quantify the influence of individual material parameters, tensile tests were conducted on the components comprising CTR and mortar, as well as the composite CTRC. The analysis focused on electrically heated carbon-textile reinforcements, comparing them through experiments conducted at varying ambient temperatures. This study presents pioneering findings on heated CTRC, determining that electrical heating decreases tensile strength with increasing temperature for the investigated reinforcement materials. The softening of the impregnation materials proved to be a decisive factor. This interdisciplinary approach bridges materials science with thermal management in construction, offering insights into the practical applications of CTR in innovative building designs.

High performance composite phase change materials enhanced via evaporation-induced hydrogen bond network refactoring

Composite phase change materials (CPCMs) with real-time thermal harvesting are in high demand in the solar-thermal energy conversion industry. However, poor heat conduction, lack of strength and leakage problem severely restrict its availability. In this study, we develop an evaporation-inspired, facile, and versatile strategy for manufacturing shape stable CPCMs from organohydrogels with enhanced thermal performances for advanced thermal energy storage and management. Organohyodrogels contained with graphene nanoplatelets (GNPs) served as the template. By oven-drying the organohydrogel, hydrogen bonding reconstruction would assist in the formation of a dense polymer layer to encapsulate PCMs, forming the non-leakage CPCMs. The strong capillary force generated during the oven-drying process would induce the alignment of GNPs, forming thermal conduction pathways. The as-prepared composite exhibits a high thermal conductivity (1.25 W m-1K−1), satisfactory latent heat storage (171.5 J g−1) and excellent Young’s modulus (8.3 MPa). When subjected to solar radiation, solar energy is converted to heat and stored inside the material, with a conversion efficiency as high as 95.8 %. The robust composite with high performance is expected to be an efficient and reliable thermal management material in solar-thermal energy conversion.

Micromechanics stiffness upscaling of plant fiber-reinforced composites

Fiber-reinforced green composites made from natural plant fibers are an increasingly popular sustainable alternative to conventional high-performance composite materials. Given the variety of natural fibers themselves, and the even larger variety of possible composites with specific fiber dosage, fiber orientation distribution, fiber length distribution, and fiber–matrix bond characteristics, micromechanics-based modeling is essential for characterizing the macroscopic response of these composites. Herein, an analytical multiscale micromechanics model for elastic homogenization is developed, capable of capturing the variety. The model features (i) a nanoscopic representation of the natural fibers to predict the fiber stiffness from the universal stiffness of the fiber constituents, mainly cellulose, (ii) a spring-interface model to quantify the compliance of the fiber–matrix bond, and (iii) the ability to model any (and any combination of) orientation distribution and aspect ratio distribution. Validation is performed by comparing the predicted stiffness to experimental results for as many as 73 composites available in the literature. Extensive sensitivity analyses quantify the composite stiffening upon increasing fiber volume fraction, fiber alignment, fiber length, and fiber–matrix interface stiffness, respectively.

Glued-bamboo composite based on a highly cross-linked cellulose-based adhesive and an epoxy functionalized bamboo surface

Bamboo, as a renewable bioresource, exhibits advantages of fast growth cycle and high strength. Bamboo-based composite materials are a promising alternative to load-bearing structural materials. It is urgent to develop high-performance glued-bamboo composite materials. This study focused on the chemical bonding interface to achieve high bonding strength and water resistance between bamboo and dialdehyde cellulose–polyamine (DAC-PA4N) adhesive by activating the bamboo surface. The bamboo surface was initially modified in a directional manner to create an epoxy-bamboo interface using GPTES. The epoxy groups on the interface were then chemically crosslinked with the amino groups of the DAC-PA4N adhesive, forming covalent bonds within the adhesive layer. The results demonstrated that the hot water strength of the modified bamboo was improved by 75.8 % (from 5.17 to 9.09 MPa), and the boiling water strength was enhanced by 232 % (from 2.10 to 6.99 MPa). The bonding and flexural properties of this work are comparable to those of commercial phenolic resin. The activation modification of the bamboo surface offers a novel approach to the development of low-carbon, environmentally friendly, and sustainable bamboo engineering composites.

Facile design and enhanced interface polarization of CoFe-PBA/MXene towards microwave absorption, EMI shielding and energy storage

Electromagnetic properties and electrochemical properties of MXene hybrid materials have been one of the research hotspots. The development of high-performance MXene multifunctional composite materials is a challenging task. In this work, the free-stack CoFe-PBA/Ti3C2Tx MXene with lots of interfaces were fabricated using simple hydrothermal technology. The material can be used for microwave absorption, electromagnetic interference shielding and charge storage. Among them, CoFe-PBA/Ti3C2Tx MXene with the mass ratio of 1:3 achieved a maximum absorbing bandwidth of 4.72 GHz at 1.74 mm, covering the complete X-band; and certain electromagnetic shielding performance and good supercapacitance characteristics. The excellent electromagnetic attenuation characteristics derives from the intrinsic properties of charge transport and dielectric relaxation interface within CoFe-PBA/Ti3C2Tx MXene, and its rich active sites and carrier transport characteristics determine its good electrochemical performance. These results show that CoFe-PBA/Ti3C2Tx MXene is an excellent multifunctional material with potential application prospects in technical fields such as macrowave absorption, electromagnetic shielding and energy storage.

Preparation of a long-term mildew resistant and strong soy protein adhesive via constructing multiple crosslinking networks

Developing strong soy protein-based adhesive (SPA) to replace harmful formaldehyde-based resins in the wood-based panel industry is a hot research. However, the lack of long-term antibacterial and antifungal properties of SPA significantly impacts its durable bonding performance and limits application. The commonly used anti-mold agents often decrease the protein compatibility and strength. Inspired by the robust and resilient dissipative matrix found in slug mucus, a green and sustainable adhesive with long-term antibacterial, antifungal properties, and excellent bonding performance was prepared using classic self-assembly and building toughened crosslinked networks. Specifically, caffeic acid and L-arginine were grafted onto tubuchitosan via acylation to prepare a chitosan with strong cationic graft modification (CCL), which combined with self-made triglycidylamine as a crosslinking agent to synergically strengthen the adhesive network. The SPA demonstrated excellent antibacterial properties against Staphylococcus aureus (20 mm) and Escherichia coli (19 mm). The prepared plywood and liquid/cured adhesive showed effective antifungal periods of 30, 80, and 120 days, respectively. Moreover, the incorporation of CCL significantly enhanced the dry and wet shear strengths of the prepared plywood to 2.73 MPa and 1.86 MPa, respectively. And a dry shear strength of 2.10 MPa and a wet shear strength of 1.53 MPa maintained even after a 30-day antifungal observation period, which still meet the interior use plywood requirement (≥0.7 MPa). The corresponding plywood after placing 30 days (1.46 MPa) is obviously higher than E0 level (0.05 mg/m3, GB18580-2017, Climate chamber method) of melamine-urea–formaldehyde resin (0 MPa after ten days). This study provides a straightforward and effective strategy for developing high performance and durable bio-based composite material, including adhesive, film, hydrogel.

Towards dynamic in situ observation of flax fibres under varying water contents through environmental SEM and X-ray tomography

Flax fibre represents one of the most promising natural components for the development of new innovative high-performance biobased composite materials. Their properties are closely related to the lumen, the central cavity of the fibre, which was only studied, to date, under unrealistic environments as in dry conditions. The objective of the current study is to characterise, at a micrometre-scale, the surface and volume modifications induced by exposure of fibres to humid atmospheres. Different dynamic characterization strategies have shown a significant opening of the hydrated lumen "channel". Values of this opening rate are discussed in the light of potential biases linked to the investigation technique (SEM versus X-ray tomography), and to the adopted acquisition approach (in situ versus ex situ). By eSEM, after a 5 min. exposure to the water-saturated environment for instance, the lumen opening value was measured at 36 ± 2% for ex-situ hydration of the bundles with a subsequent delamination of the fibre, while it was only 15 ± 2% when hydration was progressively conducted into the SEM chamber. By microtomography, the lumen swelling for the single fibre was estimated to be within the same order of magnitude, about 7%, after hydration and measurements performed under realistic atmospheric pressure.

Experimental Study of Dimensional Effects on Tensile Strength of GFRP Bars

This study explores the mechanical properties of Glass Fiber-Reinforced Polymer (GFRP), a high-performance composite material, focusing on how varying diameters affect its tensile strength, modulus, and elongation. Experimental data obtained from three sets of tensile tests on 10, 12, and 25 mm bars helped establish a stress–strain relationship for GFRP reinforcements, considering diameter changes, and a formula for calculating the ultimate tensile strength based on diameter. Utilizing the weakest chain theory and the Weibull distribution, the research found that GFRP’s tensile strength diminished with increased diameter, while the elastic modulus behaves oppositely. The analysis, grounded in the weakest chain theory, identifies the specimen’s effective volume as a critical factor in the size effect of GFRP bars. Moreover, the study proves a significant size effect on GFRP’s tensile properties, validating the theory’s application in predicting the strength of GFRP bars of varying sizes and recommending a specimen length range of 30–40 times its diameter for standardization purposes.

A hydrogel-based moist-electric generator with superior energy output and environmental adaptability

Harvesting energy from ubiquitous moisture has emerged as a promising way to collect energy irrespective of location and time. However, the electrical output of moist-electric generators (MEGs) is currently insufficient for practical applications. In this study, a highly efficient electricity-generating film was constructed by combining silicon dioxide (SiO2) nanofibers, sodium alginate (SA) and reduced graphene oxide (rGO) matrix impregnated with calcium chloride. The resulting SA–SiO2–rGO (SSG) film demonstrates a strong moisture-adsorption ability of 1.6 g/g at 80 % RH and 30 °C, and a relatively high ionic conductivity of 1.46 S m-1. The SSG film's strong moisture-adsorption capacity allows rapid ion dissociation, and its excellent electrical conductivity enhances ion migration. Thus, a single centimeter-sized device generates an open-circuit voltage (Voc) of up to ∼0.6 V and a short-circuit current (Isc) of ∼2.24 mA (0.14 mA cm−2). This short-circuit current is more than 10 times those of most reported MEGs. Moreover, an SSG-film-based MEG maintains a voltage output of ∼0.6 V over rather wide ranges of temperature (0–40 °C) and relative humidity (20 %–80 %), demonstrating superior environmental adaptability. In summary, this study provides fresh insights into the design of high-performance composite materials for efficient moist-electric energy conversion.

Effect of graphene reinforcement on the tensile and flexural properties of thermoplastic polyurethane nanocomposite using experimental and simulation approach

ABSTRACT This study investigates the integration of graphene (Gr) nanoparticles into polyurethane (PU) matrices to enhance mechanical properties, focusing on Young’s modulus, tensile strength, and flexural strength. Utilising a Representative Volume Element (RVE) analysis with 1 × 1 × 1 μm dimensions, the research evaluates PU/Gr composites at varying volume fractions. Results indicate substantial improvements in mechanical properties, with the 0.05 PU/Gr composite exhibiting the highest enhancements, including a 25% increase in Young’s modulus and 26% and 31% enhancements in tensile and flexural strengths, respectively, compared to pure PU. Fractography confirms the transition from ductile to brittle behaviour with Gr incorporation. The RVE method accurately predicts Young’s modulus, aligning closely with experimental and micromechanical model data. Additionally, ANSYS simulation tests show results within a 10% error margin. The findings suggest significant potential for the development of high-performance composite materials applicable across industries like aerospace, automotive, and construction.

Application Analysis of New Civil Engineering Materials

In recent years, with the continuous development of the technical level in the field of construction, new civil engineering materials have a wide range of applications in various fields, the limitations of traditional building materials lead to the need for more sustainable and cost-effective alternative materials to meet the construction needs of civil engineering. This paper analyzes the new civil engineering materials, discusses the characteristics of high-performance concrete, new steel and composite materials, and analyzes the application strategies of new civil engineering materials in practical application fields, aiming to provide constructive suggestions for improving the construction quality of civil engineering and the application efficiency of new materials.

The investigation of flame-retardant fiber mats for high performance composites: flame retardancy and structure performance

The flame-retardant performance of carbon fiber reinforced composites serves as a critical metric for structural stability. Nonetheless, the prevalent methodologies for improving the flame retardancy of composites struggle to reconcile the dual objectives of flame retardancy and mechanical robustness, due in part to the constraints imposed by the conventional additive-based approach on the material interface. This study introduced a novel method involving a glass fiber mat, which was augmented with a polyurethane-based treatment integrated with flame-retardant substances, in particular ammonium polyphosphate and nickel hydroxide. This fiber mat was strategically applied to the composite surface, conferring both flame retardancy and enhanced structural resilience. The structure performance and flame retardancy of composites were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and the cone calorimeter test. Experimental comparisons with nontreated controls indicated that the innovative composites exhibited a reduction in total heat release and total smoke production by 13.7% and 18.8%, respectively. Concurrently, a notable enhancement in mechanical properties was observed, with increases of 20.9% and 23.1% for tensile and flexural strength. This well-balanced performance is attributable to the structure design, with toughened glass fiber mats to protect the composite surfaces from structural failure, and flame-retardant agent composition for combustion resistance and smoke suppression. Consequently, the proposed integrative flame-retardant structural design, enriched with specific flame-retardant treatments, offers a promising avenue for fabricating high-performance composite materials with potential utility in the aviation and aerospace sectors.

Zirconium-based metal–organic frameworks/porous carbon hybrids as high-performance anode materials for highly stable lithium- and potassium-ion batteries

Metal-organic framework (MOF)-derived carbon materials have been widely investigated as advanced electrode materials. However, post-synthetic modifications suffer from certain limitations in morphology, surface area, and pore size control. Herein, we report a simple strategy to synthesize surface-confined Zirconium(Zr)-based MOF UiO-66-NH2 carbon hybrids (Zr-MOF@C; denoted as Zr-MOF, Zr-MOF@C10, Zr-MOF@C25, and Zr-MOF@C50) through a covalent assembly/amide linkage between the MOFs and hierarchical porous carbon (PC) in various proportions under solvothermal conditions. Zr-MOF@C hybrids have been utilized as the anode materials for lithium- (LIBs) and potassium-ion batteries (KIBs). In LIBs, the Zr-MOF@C10, Zr-MOF@C25 and Zr-MOF@C50 anodes delivered the discharge capacities of 126, 65 and 94 mA h g−1 at 100 mA g−1 after 100 cycles, respectively. In KIBs, the Zr-MOF@C10 and Zr-MOF@C25 exhibited the high discharge capacities of 78 and 70 mA h g−1 at 100 mA g−1 over 100 cycles. In addition, the Zr-MOF@C25 and Zr-MOF@C50 anodes exhibited an outstanding rate capability with a reversible capacity of ∼166 mA h g–1 vs. K/K+ and 176 mA h g–1 for Li/Li+, respectively, while well-maintained long-term cyclic stabilities of ∼57 mA h g–1 (Zr-MOF@C25 vs. K/K+) and ∼140 mA h g–1 (Zr-MOF@C50 vs. Li/Li+) at 1 A g–1 over 1000 cycles. The electrochemical kinetics studies revealed that Li+ and K+ storage efficiencies of all anodes were dominated by a surface-charge capacitive effect and diffusion-driven charge storage mechanism, respectively. These findings provide new insights for designing high-performance surface-confined MOF-based carbon composite materials for next-generation high-energy storage devices.

Preparation and Mechanical Properties of PBAT/Silanized Cellulose Composites

Polybutylene adipate-terephthalate (PBAT) is a fully biodegradable polyester, which has been proven to be the most suitable alternative to traditional plastics. However, due to the low strength of PBAT (17.2 MPa) and high price, the use of PBAT has a degree of limitations. To obtain a cost-effective and high-performance composite material of PBAT, for this study we selected microcrystalline cellulose, which is inexpensive and easily available, as the reinforcing medium. However, due to the hydrophobicity of PBAT, the mechanical properties of PBAT when mixed with hydrophilic cellulose were low. In order to improve the compatibility of cellulose and PBAT, this study selected hexadecyltrimethoxysilane (HDTMS) containing long carbon chains to silanize microcrystalline cellulose (MCC) to obtain silanized cellulose (SG). Three types of SGs with different degrees of silanization were obtained by controlling HDTMS with different mass ratios (1:10; 3:10; 5:10) to react with MCC. Characterization of these three types of SGs was conducted using FTIR, TEM, and water absorption analysis. The results demonstrated the successful synthesis of SG. With the increase in the reaction ratio of HDTMS and MCC, the size of the nanoparticles increases, and the water absorption decreases significantly. Subsequently, PBAT/SG composites were prepared by blending three kinds of silanized cellulose with PBAT in different proportions by the sol-gel method. To study the thermal stability and compatibility, the mechanical properties of the composites were evaluated, including thermogravimetric testing, scanning analysis, and dynamic thermomechanical testing. The optimal blending ratio and the optimal type of silane cellulose were found. Analysis of the mechanical properties revealed that the tensile strength initially increased and then decreased with increasing blending ratio for all three composites tested. Among them, the PBAT/SG2 composites exhibit superior performance, with a maximum tensile strength reaching 22 MPa at an 85/15 blending ratio, nearly 30% higher than that of pure PBAT alone. The addition of SG significantly improved the strength of the PBAT, and SG2 is more suitable for preparing high-strength composite materials. In addition, after the addition of SG, the yield stress of the composite is improved while maintaining good thermal stability. Both the SEM and DMA results indicated good compatibility of the PBAT/SG composites. This study provides a new idea for the industrial-scale development of degradable polyesters with low cost and good mechanical properties.