Application Of Composite Materials Research Articles

Changes in Current Transport and Regulation of the Microstructure of Graphene/Polyimide Films under Joule Heating Treatment

The excellent electrical properties of graphene have received widespread attention. However, the difficulty of electron transfer between layers still restricts the application of graphene composite materials to a large extent. Therefore, in this study, graphene/polyimide films were subjected to a Joule heating treatment to improve the electrical conductivity of the film by ~76.85%. After multiple Joule thermal cycle treatments, the conductivity of the graphene/polyimide film still gradually increased, but the increase in amplitude tended to slow down. Finally, after eight Joule heat treatments, the conductivity of the graphene/polyimide film was improved by ~93.94%. The Joule heating treatment caused the polyimide to undergo atomic rearrangement near the interface bonded to the graphene, forming a new crystalline phase favourable for electron transport with graphene as a template. Accordingly, a model of the bilayer capacitive microstructure of graphene/polyimide was proposed. The experiment suggests that the Joule heating treatment can effectively reduce the distance between graphene electrode plates in the bilayer capacitive micro-nanostructures of graphene/polyimide and greatly increases the number of charge carriers on the electrode plates. The TEM and WAXS characterisation results imply atomic structure changes at the graphene/polyimide bonding interface.

Application of carbon fiber composite materials in aircraft

Carbon fiber composite is a material with excellent mechanical properties. Compared with other high-performance fiber materials, carbon fiber composites have the advantages of high strength and high modulus even at ultra-high temperatures. In addition, the carbon fiber composite material also has excellent electrical and thermal conductivity and electromagnetic shielding performance. Carbon fiber composites are widely used in the aircraft manufacturing industry due to their incomparable performance with other composite materials. In recent years, the amount of carbon fiber composite materials in newly developed aircraft products has reached more than 50%. This paper aims to explore the application of carbon fiber in aircraft, and to reflect the importance of carbon fiber composite materials by comparing models that use composite materials and models that do not use composite materials. The study explores the application of carbon fiber composite materials in aircraft through a comprehensive literature analysis and review. Key findings indicate significant advantages of these materials in enhancing aircraft performance, including reduced weight and increased strength. The paper also discusses the challenges in manufacturing and environmental impacts, offering insights into future research directions for sustainable aviation technologies.

Mesoporous silica@polypyrrole and its epoxy composites with ultra-broadband electromagnetic wave absorption properties

Composite of powders with exceptional electromagnetic wave absorption (EMA) properties with resins is an important tactic for preparing electromagnetic wave (EMW) stealth composites. However, high expenditure, low yield and the complex synthesis of these powders constrain their utilization in composite materials. Moreover, composite materials need greater thickness to fulfill EMA requirements. This work reported a facilely producible absorber, mesoporous Silica@Polypyrrole (MSU-J@PPy), which exhibits enhanced EMA performance. The polymerization of PPy in the connected three-dimensional pores as well as on the surface of MSU-J led to the creation of conductive network thereby enhancing the conductive loss. MSU-J contributes to the lightweighting and impedance matching and promotes the formation of a non-homogeneous interface. By varying the ratio of PPy to MSU-J, precise control of EMA was realized. When the proportion of PPy to MSU-J by weight is 1.5:1, the reflection loss (RL) of MSU-J@PPy reaches an impressive −46.44 dB at 1.9 mm. The effective absorption bandwidth (EAB) is 6.08 GHz (11.92–18 GHz) at 2.1 mm thickness of the sample. Further, MSU-J@PPy and carboxylated multi-walled carbon nanotubes (cMWCNTs) was composited with epoxy resin (EP) to develop a wave-absorbing composites MSU-J@PPy/cMWCNTs/EP with ultra-broadband absorption properties and outstanding mechanical characteristics. At a thickness of 1.7 mm, the composite can effectively absorb EMW in the entire Ku band, and effective absorption across the 5.4–18 GHz range can be attained through changing the matching thickness. This work offers a novel approach for developing cost-effective, easily synthesized, and high-yield EMW absorbers, as well as their application in absorber composite materials.

The research progress on photocatalytic performance of graphene-based nanocomposites

As soon as nanomaterials were discovered, they attracted a lot of attention because of their unique and excellent properties and became major hot research. They are regarded as the most promising materials in the 21st century. With the growth of industrial production, photocatalytic technology has been pursued as an efficient, green, and economical way of industrial production and treatment of pollution. However, the low light energy utilization of traditional semiconductor materials is a drawback that cannot be ignored. Graphene, as one of the most common and widely used 2D nanomaterials, has a special structure and characteristics that can effectively solve this problem. The paper briefly introduces the structure, properties, preparation method, and basic principle of photocatalysis of graphene. At the same time, a review is provided on the application of graphene-based composite materials in the field of photocatalysis, including dye degradation, photocatalytic treatment of other emerging pollutants, photocatalytic treatment of air pollutants, and water decomposition. By summarizing and integrating the photocatalytic properties of several graphene-based composites, this article lays the foundation and helps to discover new graphene composites.

Free vibration analysis of fiber-reinforced composite multilayer cylindrical shells under hydrostatic pressure

With the development and application of composite materials in deepwater submersibles, the influence of high external pressure from deepwater environments on the vibration characteristics of composite pressure-resistant cylindrical shells cannot be ignored. In this paper, the free vibration characteristics of prestressed composite multilayer shells are methodically examined by establishing partial differential equations based on the three-dimensional elasticity theory. To solve these equations, the state-space technique and double Fourier series expansion are employed to transform them into state-space ordinary differential equations. These equations are utilized to analyze vibration problems of simply supported composite multilayer cylindrical shells with arbitrary layered angles. The initial stress equilibrium equation is solved to determine the prestress induced by the hydrostatic pressure. This overcomes the limitation of membrane stress and considers non-uniform distributions of radial and interlaminar prestresses. The proposed theoretical model and solution strategies are validated by comparing with theoretical and experimental results from the existing literature and the finite element method. Additionally, the present investigation reveals that the natural frequencies of thick shells can be calculated more accurately using the prestress derived by the proposed approach, especially subjected to noticeable hydrostatic pressure. Finally, the performed investigations indicate that the circumferential prestressing has a more pronounced effect on the shell's natural frequencies than axial prestressing.

Study on preparation and property of coir fiber reinforced epoxy resin composite geogrid

Based on the development and application of green composite building materials, this study prepared a coir fiber reinforced epoxy resin composite grid using coir fiber as the reinforcement material. Through tensile tests of a multi rib grid, the effects of coir fiber content, length, and rib spacing on the composite grid were studied. The results showed that with increase in the coir fiber content, the tensile yield force first increased and then decreased, reaching the maximum value at coir fiber content of 1%. When the coir fiber content exceeded 1%, the tensile properties of the composite grid were lower than that of pure epoxy resin. With the increase in the coir fiber length, the tensile yield force of composite grid also first increased and then decreased. At a fiber length of 1 cm, the maximum tensile yield force was obtained, which was 34.33% higher than that of pure epoxy resin grid. Compared with the influence of fiber length and content on the composite grid, the influence of rib spacing on the composite grid was more obvious. At a rib spacing of 1 cm, the tensile yield force reached its maximum.

Tensile behavior of ultra-high-performance concrete (UHPC) strengthened with fiber reinforced polymer (FRP) grid

In order to enhance the tensile strength and toughness of Ultra-High Performance Concrete (UHPC) at the macro level, this study developed Fiber-Reinforced Polymer (FRP)-reinforced UHPC composite materials. The steel fibers and FRP grids in UHPC play a reinforcing and toughening effect on UHPC at two different levels. Therefore, this paper examined, evaluated 48 FRP grid-UHPC specimens. The study includes independent parameters such as grid type (Carbon-FRP, Basalt-FRP, stainless steel wire mesh), grid size (5×5 mm, 10×10 mm, 20×20 mm), steel fiber content (0%, 0.5%, 1.0%, 1.5%, 2.0%), grid layers (1 layer, 2 layers, 3 layers, 4 layers), and the fiber bundle impregnation status. Based on the test results, a simplified tensile stress-strain relationship for FRP grid-UHPC was proposed. The test results show that when the steel fiber content is less than 1%, the FRP grid does not exert its reinforcing effect. The FRP grid-UHPC composite material exhibits strain-softening behavior. However, when the steel fiber content is greater than 1%, the FRP grid-UHPC specimens all exhibit strain-hardening phenomena. Compared to other grids type, the enhancement and toughening effects on UHPC are more pronounced when using CFRP grids. Specifically, when using a 20×20 mm CFRP grid, the tensile stress can be increased by 30.36%. Regardless of whether dry grids or impregnated grids are used, increasing the grid layers greatly improves the peak strain and stress of UHPC. Compared to dry grids, impregnation with epoxy resin further improves the stress state between fiber filaments in FRP grids, resulting in a more significant improvement in the tensile performance of FRP grid-UHPC composite materials. Finally, based on experimental data, a tensile stress-strain model for FRP grid-UHPC considering different mesh ratios was proposed and validated against experimental results. These conclusions and findings are of great significance for understanding and optimizing the performance of FRP grid-UHPC composite materials, providing valuable references for the future research and application of FRP grid-UHPC composite materials.

Analytical Study on the Application of Composite Materials in Pedestrian Protective Fences Around Educational Facilities

Analytical Study on the Application of Composite Materials in Pedestrian Protective Fences Around Educational Facilities

The Influence of e-glass epoxy composite laminate material application on the crack pattern of cylinder concrete column cross-section

In order to better understand the phenomenon of applying GEC reinforcement to RCC based on the percentage of surface crack pattern (PCP), this research will use e-glass epoxy composite laminate (GEC) to obtain the damage pattern of reinforced concrete column specimens (RCC) utilizing GEC. Additionally, it will compare the splitting tensile strength (STS) and SCP. In accordance with ASTM C496 guidelines, the RCC specimens used in this investigation had a cylindrical shape and measured 150 mm in length and 50 mm in diameter. GEC material, consisting of 0–4 layers of woven e-glass fiber sheets, was applied as an extra layer on top of the RCC. In compliance with ASTM C496 guidelines, a Universal Testing Machine (UTM) was used to perform the split tensile test. With the aid of Adobe Photoshop software, the Histogram approach was used to calculate the crack pattern's proportion. The study's findings demonstrated that the specimens reinforced with four layers of GEC exhibited the highest damage pattern. This suggests that the reinforced specimens must be subjected to a sizable load in order to be damaged. Hence, the damage that occurs in the specimens can be lessened by applying GEC layers on RCC. Further information about the performance of RCC reinforced with GEC is also provided by a comparison of the splitting tensile strength and the percentage of fracture pattern

Synthesis of adhesion promoter for lead frame bonding and application of epoxy composite materials

AbstractPolymer adhesion promoters were formulated to improve the adhesion strength of lead frame/epoxy composites. The poly(itaconic acid‐co‐acrylamide) (IAcAAM) was synthesized via free radical polymerization to improve the interfacial adhesion between Ni and Cu lead frames and epoxy composites. IAcAAM was synthesized by setting itaconic acid (IA) and acrylamide (AAM) at molar ratios of 7:3, 5:5, and 3:7. The interfacial adhesion mechanism was investigated by introducing IAcAAM with three different comonomer molar ratios. The adhesion strength between EMC and Cu and Ni substrates to which each IAcAAM was applied was measured using a universal testing machine, and the effect of IAcAAM with various IA:AAM molar ratios on the surface energy of EMC was closely studied. As a result, the adhesion properties of Ni lead frame/epoxy composite and Cu lead frame/epoxy composite were improved as small amounts of all IAcAAM samples were added to the epoxy mixture. We confirmed that IAcAAM with an appropriate molar ratio can be used in the EMC process and has the potential to increase the adhesion of epoxy composites and metal lead frames.Highlights A polymeric adhesive promoter was synthesized to enhance the adhesion strength of lead frame/epoxy composites. Poly(itaconic acid‐co‐acrylamide) (IAcAAM) was copolymerized from itaconic acid and acrylamide for this purpose. The adhesion strength of lead frame/epoxy composites was compared for different IAcAAM monomer contents and with a commercial adhesive promoter. IAcAAM showed superior adhesion strength in the Ni lead frame/epoxy composite material. The highest adhesion strength was achieved at a monomer composition of 5:5.

Valorisation of Brewer’s Spent Grain: Lignocellulosic Fractionation and its Potential for Polymer and Composite Material Applications

Valorisation of Brewer’s Spent Grain: Lignocellulosic Fractionation and its Potential for Polymer and Composite Material Applications

Thermally conductive high‐voltage insulation composites with outstanding comprehensive properties through particle grading design

AbstractIn order to meet the requirements of practical applications, the comprehensive performance of thermally conductive high‐voltage insulating composites is worth evaluating. Guided by the particle packing theory, spherical alumina particles with different particle size distributions were compounded and filled into low‐density polyethylene (LDPE), and the thermal conductivity (TC) and mechanical breakdown of different compound systems were systematically investigated. The results show that the particle grading design of small‐particle filled composites has better comprehensive properties than that of single‐scale or large‐particle filled composites, which proves the superiority and feasibility of particle grading design. The 110–40 wt.% composite has a higher TC (0.47 W/(m K)) compared with LDPE, while maintaining excellent insulation properties (227 kV/mm) and mechanical properties (tensile strength of 10 MPa and elongation at break of 720%). Finally, studies on the application of composite materials in the field of thermal management and ice melting of steel‐core aluminum insulated wires were applied, and both studies show good prospects for the applications of Al2O3/LDPE thermal conductive high‐voltage insulation composites.

Awareness of possible complications associated with direct composite restorations: A multinational survey among dentists from 13 countries with meta-analysis

ObjectivesResin-based composites (RBCs) evolved into favoured materials for teeth restorations, marking a significant change in dental practice. Despite many advantages, RBCs exhibit various limitations in their physical and chemical properties. Therefore, we assessed the dentists' awareness of possible complications after direct composite restorations and their opinions about this material. MethodsThe online questionnaire was created in English in May 2023. A 16-item survey was dedicated to general dentists and specialists. The first section included four questions related to demographic characteristics. The second section comprised twelve questions and focused on awareness of potential side effects of composite restorations, the most crucial advantages and disadvantages of composite resins, and the frequency of experienced clinical complications after the application of composite materials. ResultsA total of 1830 dentists from 13 countries took part in the survey. Dentists most often declared awareness of low adhesion to the dentine (77.5 %) and, most rarely, solubility in oral fluids (42.6 %). Aesthetics was identified as the main advantage of composite fillings (79 %), followed by the possibility of repair (59 %) and adhesion to enamel (57 %). Polymerisation shrinkage was a major disadvantage for most countries (70 % overall). Analysing the declared potential clinical complications for all countries, statistically significant findings were obtained for marginal discolouration (OR=2.982, 95 % CI: 1.321–6.730, p-value=0.009) and borderline significance for secondary caries (OR=1.814, 95 % CI: 0.964–3.415, p-value=0.065). ConclusionsDentists value aesthetics and repairability but are aware of shrinkage and experience discolouration. The issue of toxicity and solubility seems to be the least known to dentists.Clinical significance: Dentists should use RBCs with critical caution due to possible side effects. Despite the undoubted aesthetics of direct composite restorations, it is necessary to remember potential clinical complications such as marginal discolouration or secondary caries.

Preparation and Application of Composite Phase Change Materials

With the popularity of lithium-ion batteries, thermal runaway accidents occur frequently. The importance of thermal management was becoming increasingly prominent. In this paper, a new composite phase change material (CPCM) was developed and applied to the thermal management of lithium-ion batteries. The chemical and microstructure of the material were deeply analyzed by scanning XRD and SEM. The thermal stability of the material was tested by using DSC and TG techniques. The thermal conductivity was exhaustively analyzed. The experimental results showed that CPCM containing 9% Aluminum phenylphosphinate exhibits optimal thermal storage performance and flame retardant efficiency, which effectively delayed and reduced the risk of thermal runaway in lithium batteries.

Thermal, Physical, and Electrical Characterization of Millettia Pinnata Leaf Powder, Alumina, Glass Sheet, Boron Nitride Reinforced Epoxybased Hybrid Composites: An Experimental Scrutiny

Aims and objectives:: The aim of this study was to fabricate epoxy resin-based hybrid composites reinforced with biodegradable Millettia pinnata leaf powder in conjunction with glass sheets, boron nitride, and alumina for the production of printed circuit boards. Method:: For this application, various thermal, physical, and electrical tests were conducted by the authors. The thermal test results showed that the alumina-based epoxy hybrid composite has more thermal stability than the neat epoxy. Moreover, upon adding BN/Alumina, the flame retarding properties of the epoxy hybrid composites improved. We also observed that with the increase in the content of BN and alumina, the thermal conductivity of the hybrid composite was enhanced. From the water absorption tests, the hybrid composite with 6g BN showed the least amount of water consumption. Particularly, adding BN and leaf powder from 2 to 6 g gave better results for the decrease in water absorption, as compared to adding alumina in the epoxy-based hybrid composite. Result:: Lastly, from the electric tests, we observed that with the increase in frequencies, the dielectric constant of the hybrid composite decreases. At a lower frequency range, the hybrid composite having 2g of BN and millettia pinnata leaf powder shows the lowest dielectric constant, whereas, at a higher frequency range, 2g of alumina and millettia pinnata leaf powder shows the lowest dielectric constant. Conclusion:: We predict that the results reported in this investigation will aid in accelerating the engineering applications of epoxy resin-based hybrid composite materials and help patent the material compositions for specific purposes.

Stable and highly efficient extraction of U(VI) from seawater by covalent organic frameworks and amidoxime co-functionalized MXene

Seawater is rich in uranium resources, but the marine environment is complicated and changeable, as well as the presence of a lot of competing ions. These are disturbing factors that cannot be ignored in seawater uranium extraction. The synthesis of adsorbents with good stability, high selectivity and large adsorption capacity has been the focus of attention. The composite adsorbent MXene-AO@LZU1 was prepared using electrostatic self-assembly of transition metal carbides and nitrides (MXenes) with structurally stable covalent organic frameworks (COF-LZU1). The results of characterizations showed that MXene-AO@LZU1 was rich in functional groups and had an effective improvement in specific surface area. MXene-AO@LZU1 exhibited an efficient performance for [UO2(CO3)3]4- with an adsorption saturation capacity of 88.8 mg·g−1. The adsorption amount in the simulated seawater also reached 6.8 mg·g−1. MXene-AO@LZU1 had a good selectivity for uranium and outstanding stability under various extreme conditions. In addition, XPS showed that the adsorption of uranium by MXene-AO@LZU1 relied mainly on the complexation of oxygen/nitrogen-containing functional groups with [UO2(CO3)3]4-. This study explored the great potential of MXenes and COFs in seawater uranium extraction, indicating that MXene-AO@LZU1 was an efficient and stable adsorbent with good development prospects. This finding was of great importance for the application of composite materials in actual environmental cleanup, and could be extended to efficiently remove other pollutants by rational ligands design.

Preparation of biomimetic reinforced modified carbon fiber composites and study of their friction properties

Because aluminum-based parts cannot be used for long-term applications in large load-wear environments, nickel–tungsten (molybdenum disulfide)/carbon fiber/aluminum composites were successfully prepared in this study for that purpose. By adjusting the plating solution ratio, nickel–tungsten was used as a carrier to introduce molybdenum disulfide nanoparticles, forming a nickel–tungsten/molybdenum disulfide composite coating on the surface of carbon fibers. To enhance the interfacial bonding strength between the carbon fiber and aluminum matrix, a laser was employed to induce the formation of a honeycomb-like structure on the surface of the aluminum base. This increased the contact area between the carbon fiber, aluminum matrix, and epoxy resin adhesives, forming a nickel–tungsten (molybdenum disulfide)/carbon fiber/aluminum composite material. The performance of this composite material was tested and analyzed. The results demonstrated that compared with the carbon fiber/aluminum composite material, the shear strength of the nickel–tungsten (molybdenum disulfide)/carbon fiber/aluminum composite material was increased by 129.7 %, and the friction coefficient and wear rate were reduced by 54.8 % and 83 %, respectively. Next, investigation of the mechanism underlying the honeycomb structure's contribution to the adhesive strength of the composites and their resistance to shear load revealed that the wear-resistant mechanism of molybdenum disulfide nanoparticles reinforced the nickel–tungsten composite coatings. The preparation and study of nickel–tungsten (molybdenum disulfide)/carbon fiber/aluminum composites provide a reference for expanding the applications of aluminum-based composite materials to meet the service requirements of complex environments.

Efficient luteolin detection sensor achieved by CdS-MoS2 heterostructures

Luteolin a widely occurring flavonoid compound in its natural state within numerous plant species, has attracted extensive attention for its diverse pharmacological activities in recent years. In this study, we present a novel sensor designed to detect luteolin by employing a bimetallic composite material, denoted as CdS-MoS2. By leveraging the distinct structural advantages inherent in the CdS-MoS2 composite, reinforced through the synergistic interplay of their constituent components, the electrodes fabricated with CdS-MoS2 exhibit a significant surface area and favorable electrical conductivity. Consequently, these electrodes demonstrate good electrocatalytic oxidation performance and exceptional sensing capabilities specifically tailored to luteolin. With its advantageous properties, the electrode generated from CdS-MoS2 can detect luteolin within a linear range spanning from 0.0001 µM to 2.28 µM and 2.28 µM to 27.49 µM and show low detection limit of 0.018 nM. Furthermore, it showcases reasonably good resistance to external disturbances and cyclic stability. The application of the CdS-MoS2 composite material in the detection of luteolin within authentic drug samples yields satisfactory outcomes. Also, it can trace luteolin in Duyiwei soft capsules with good recovery rates ranging from 99.30 % to 101.17 %. This underscores the potential of the CdS-MoS2 composite as a promising candidate for practical and reliable luteolin detection.

Nonlinear electro-elastic finite element analysis with neural network constitutive models

In the present work, the applicability of physics-augmented neural network (PANN) constitutive models for complex electro-elastic finite element analysis is demonstrated. For the investigations, PANN models for electro-elastic material behavior at finite deformations are calibrated to different synthetically generated datasets describing the constitutive response of dielectric elastomers. These include an analytical isotropic potential, a homogenised rank-one laminate, and a homogenised metamaterial with a spherical inclusion. Subsequently, boundary value problems inspired by engineering applications of composite electro-elastic materials are considered. Scenarios with large electrically induced deformations and instabilities are particularly challenging and thus necessitate extensive investigations of the PANN constitutive models in the context of finite element analyses. First of all, an excellent prediction quality of the model is required for very general load cases occurring in the simulation. Furthermore, simulation of large deformations and instabilities poses challenges on the stability of the numerical solver, which is closely related to the constitutive model. In all cases studied, the PANN models yield excellent prediction qualities and a stable numerical behavior even in highly nonlinear scenarios. This can be traced back to the PANN models excellent performance in learning both the first and second derivatives of the ground truth electro-elastic potentials, even though it is only calibrated on the first derivatives. Overall, this work demonstrates the applicability of PANN constitutive models for the efficient and robust simulation of engineering applications of composite electro-elastic materials.

New Advances in the Application of Bacterial Cellulose Composite Materials in the Field of Bone Tissue Engineering

Bacterial cellulose (BC) is a type of extracellular polymeric nanomaterial secreted by microorganisms over the course of their growth. It has gained significant attention in the field of bone tissue engineering due to its unique structure of three-dimensional fibrous network, excellent biocompatibility, biodegradability, and exceptional mechanical properties. Nevertheless, BC still has some weaknesses, including low osteogenic activity, a lack of antimicrobial properties, small pore size, issues with the degradation rate, and a mismatch in bone tissue regeneration, limiting its standalone use in the field of bone tissue engineering. Therefore, the modification of BC and the preparation of BC composite materials have become a recent research focus. Herein, we summarized the relationships between the production, modification, and bone repair applications of BC. We introduced the methods for the preparation and the modification of BC. Additionally, we elaborated on the new advances in the application of BC composite materials in the field of bone tissue engineering. We also highlighted the existing challenges and future prospects of BC composite materials.