Characterization Of Composites Research Articles

Processing and characterization of flame-retardant natural fibre-reinforced epoxy composites and construction of selection charts for engineering applications

Processing and characterization of flame-retardant natural fibre-reinforced epoxy composites and construction of selection charts for engineering applications

Synthesis and characterization of the functional porous ceramic composite of ZrO 2 -TiO 2 with addition of lithium perchlorate to be used as a relative humidity sensor

Resumo Os autores investigaram as respostas elétricas de três diferentes espessuras de cerâmica de 0,5ZrO2-0,5TiO2 com adição de LiClO4. Os sensores foram obtidos seguindo a rota de processamento tradicional e a escolha por um estudo preliminar na variação na espessura deve-se ao fato de que a distância entre as placas paralelas influi na capacitância que é inversamente proporcional a distância entre as placas, sendo que, para criar o efeito capacitivo, as superfícies planas superior e inferior das pastilhas foram revestidas com fita adesiva de carbono, sendo esta escolha da fita uma forma inédita de montagem. A análise de difração de raios-X mostrou a presença de zircônia monoclínica, titânia rutilo e de uma terceira fase cristalina oriunda de uma reação entre o Li+ do perclorato de lítio e a titânia, formando uma nova fase, o titanato de lítio. O sensor com 2 mm de espessura apresenta potencial para uso como sensor de umidade relativa do ar.

Reliability of Digital Image Correlation Techniques for Cementitious Composite Fracture Characterization

Reliability of Digital Image Correlation Techniques for Cementitious Composite Fracture Characterization

Composite material thermal characterization for a digital twin-based model of an automated tape-laying process

Composite material thermal characterization for a digital twin-based model of an automated tape-laying process

Quantitative Automated Detection of Voids, Pores, Cracks, and Fibre Orientation in Scanning Electron Microscopy Images Utilising Mask Convolutional Neural Networks (M-CNN) for Natural Fibre Composite Characterisation

Quantitative Automated Detection of Voids, Pores, Cracks, and Fibre Orientation in Scanning Electron Microscopy Images Utilising Mask Convolutional Neural Networks (M-CNN) for Natural Fibre Composite Characterisation

Effects of adding carbonyl Fe or Mn–Zn ferrite powders to fibre-based soft magnetic composites prepared via hybrid cold sintering/spark plasma sintering

This manuscript presents the preparation and characterisation of fibres-based soft magnetic composites that incorporates a secondary magnetic phase such as carbonyl Fe and Mn–Zn ferrite nanopowder. Amorphous Fe77.7Si7.5B15 at.% fibres were coated with a dielectric layer of ZnO via thermal evaporation. SEM-EDX investigations revealed that the thermal evaporation technique leads to a complete coating of the fibres with a ZnO coating having a thickness of 150–250 nm as demonstrated via STEM-EDX analysis. The hybrid cold sintering/spark plasma sintering technique was used for the first time for the preparation of soft magnetic composites. Substituting 10 wt% of ZnO with carbonyl Fe resulted in an increase in the saturation magnetisation of the composite from 0.61 T to 0.7 T. In contrast, substituting it with Mn–Zn ferrite led to a decrease in saturation magnetisation from 0.61 T to 0.5 T. The coercivity of the composites increased when ZnO was partially substituted with Fe or Mn–Zn ferrite, rising from 16.9 A/m to 22.7 A/m and 36.8 A/m, respectively. AC magnetic characterization revealed that the relative permeability of the composites remains constant across the entire frequency range tested for all composites. However, the introduction of carbonyl Fe or Mn–Zn ferrite led to a reduction in the relative permeability values of the composites from 1310 to 1200 and 890, respectively. The core losses of the composites were also influenced by the secondary magnetic phase used. The use of Mn–Zn ferrite or carbonyl Fe resulted in a significant increase in the hysteresis losses of the composites. When carbonyl Fe was used for partial substitution of ZnO, a substantial increase of the eddy currents losses of the composites was noted.

Synthesis and characterization of Zn-modified hydroxyapatite photoactive composites from eggshell residues for bone regeneration

Photoactive composites based on hydroxyapatite containing zinc (HAp-Zn x%, x = 0, 0.5, 2.5, 5.0, 10.0, 15.0 and 100 mol% Zn2+) were produced by precipitation method and using calcium nitrate converted from eggshell residues. These materials were carefully designed to be used in bone regeneration, and the results demonstrated essential properties to improve the bone repair processes, such as nanometric size, spherical and/or spherocylindrical morphology, negative zeta potential, antioxidant action and ability to scavenger reactive oxygen species (ROS). In addition, antimicrobial tests demonstrated that the modification of HAp with zinc ions induced a photomodulated antibacterial action on HAp, since all tested composites containing zinc exhibited an inhibitory effect against Staphylococcus aureus (S. aureus) bacteria, which was expressively intensified after irradiation with visible light. This photomodulated antibacterial action is essentially interesting to prevent the occurrence of post-surgical infections common in placement of bone implants. Among these materials, HAp-Zn 15.0% is noteworthy, since it presented the lowest minimum inhibitory concentration (MIC) of 0.12 mg mL−1 in the absence of light, and 0.06 mg mL−1 after 3 h of exposure to the visible light. In this context, our new findings showed that the antibacterial activity of these photoactive composites against S. aureus is not attributed only to the leaching of zinc ions, but also to action of •OH and O2•− radicals, which can be generated even in the absence of irradiation. Additionally, our multifunctional composites were able of inhibit S. aureus bacteria and concomitantly stimulate the growth of pre-osteoblastic cells, ensuring its efficient use in regenerative medicine.

Sliding wear characterization of epoxy composites filled with wood apple dust using Taguchi analysis and finite element method

AbstractIn this research, a new class of composite made up of wood apple dust (WAD) and epoxy is developed using the hand lay‐up process. The impact of WAD filler on the physical and wear characteristics of epoxy‐based composites are examined. The composite samples are prepared by varying the weight content of WAD (0, 3, 6, 9, and 12 wt%). The composites are subjected to dry sliding wear testing in accordance with the L25 Taguchi design to calculate the specific wear rate (SWR). An optimum parametric combination of control factors is established for the composites to have the least amount of wear loss. The SWR of WAD/epoxy composites is also predicted using commercial finite element method (FEM) software ANSYS 2019 R2. The experimental findings are compared with the predicted wear rates of the composites. The results revealed that addition of WAD powder improved the wear resistance of the composites. A remarkable increase in tensile, compressive and flexural strength values of 34.79%, 10.12%, and 22.66% respectively, is observed. Neat polymer has tensile, compressive and flexural strengths of 48, 82, and 22.5 MPa respectively, and the values increased to 64.7, 90.3, and 27.6 MPa with addition of 12 wt% WAD. It is further observed that out of the four control factors the most influencing control factor affecting the wear rate of the composites in decreasing order are WAD content, sliding velocity, sliding distance, and normal load.Highlights In this study a natural fiber‐based waste, wood apple dust (WAD) is successfully used as a potential filler material in epoxy matrix. Physical and mechanical properties of the epoxy‐WAD composites are analyzed. Effects of filler contents on the wear behavior are studied using design of experiment. The wear rate of WAD/epoxy composites is predicted using finite element method.

Multiscale characterization and design of cellulose composites based on polymers with movable cross-links

To combine the conflicting properties of impact resistance, stiffness, and toughness, we focused on composite materials reinforced with cellulose nanofibers and polymers with movable cross-links using cyclic macromonomers and analyzed their mechanical properties through experiments and computational simulations. Based on the experimental foundation, the mechanical properties of cellulose nanofibers modified with citric acid and flexible crosslinked polymer composites using cyclodextrin were investigated. On the other hand, multi-scale finite element analysis simulation based on homogenization theory was employed to systematically clarify the effects of aspect ratio and content ratio of cellulose fibers by considering polymer blending and modification of molecular structure in the base material. For modification of the matrix polymers and the fiber morphologies, the elastic modulus of the cellulose composite was comprehensively organized by the fiber contribution based on strain energy. A design method for cellulose composites based on fiber contribution proportion was also developed. The design method was applied to a new cellulose composite with a different polymer of the matrix, and it was demonstrated that the elastic modulus can be predicted with an error of less than 10 %.

The Production and Characterization of Seashell Reinforced Epoxy Composite Material

In this study, it was aimed to examine the production, characterization and mechanical properties of epoxy matrix composites added with seashells collected from different coastal locations of the Mersin Region, which is a natural raw material. Natural seashells with different mass ratios were ground into different sizes and added into epoxy, the matrix material. By performing physical and chemical characterization of the produced composites, the next step is to analyze and produce the product with the best and most superior properties.

Photocatalytic Conversion of Diluted CO2 into Tunable Syngas via Modulating Transition Metal Hydroxides.

The conversion of diluted CO2 into tunable syngas via photocatalysis is critical for implementing CO2 reduction practically, although the efficiency remains low. Herein, we report the use of graphene-modified transition metal hydroxides, namely, NiXCo1-X-GR, for the conversion of diluted CO2 into syngas with adjustable CO/H2 ratios, utilizing Ru dyes as photosensitizers. The Ni(OH)2-GR cocatalyst can generate 12526 μmol g-1 h-1 of CO and 844 μmol g-1 h-1 of H2, while the Co(OH)2-GR sample presents a generation rate of 2953 μmol g-1 h-1 for CO and 10027 μmol g-1 h-1 for H2. Notably, by simply altering the addition amounts of nickel and cobalt in the transition metal composite, the CO/H2 ratios in syngas can be easily regulated from 18:1 to 1:4. Experimental characterization of composites and DFT calculations suggest that the differing adsorption affinities of CO2 and H2O over Ni(OH)2-GR and Co(OH)2-GR play a significant role in determining the selectivity of CO and H2 products, ultimately affecting the CO/H2 ratios in syngas. Overall, these findings demonstrate the potential of graphene-modified transition metal hydroxides as efficient photocatalysts for CO2 reduction and syngas production.

Biodegradable Pla/Ha Composite Material Production and Mechanical Characterization for Temporary Implant Applications

Hard tissues in the human body are damaged due to age, trauma, and bone diseases. Metal implants/prostheses are traditionally preferred to repair and treat these damaged tissues. Today, metals and their alloys meet the mechanical requirements of the musculoskeletal system well. However, the need to develop alternative composite materials has increased since metals are very stiff materials compared to bone. Problems such as stress shielding, and aseptic loosening can arise due to their high modulus of elasticity, and the need for secondary revision operations for such reasons. Also, the metal implant/prostheses should be removed after the healing that causes the undesirable secondary operation. In this study, polylactic acid (PLA) and hydroxyapatite (HA)-based composite materials were produced and their mechanical characteristics evaluated for possible implant applications. In addition, the PLA/HA composite materials stayed in Artificial Body Fluid (ABF) at different times, and the change in the mechanical properties were determined. PLA granules and HA powders were mixed in different ratios of weight (weight ratio 1:0, 9:1, 7:3, and 1:1) to produce 80 samples using the solvent casting technique. PLA was dissolved with chloroform in a magnetic stirrer at 200 rpm and room temperature, and then nano HA was added and mixed until homogeneity was achieved. After casting and drying, the samples were cut into appropriate standard sizes. The samples were subjected to biodegradability in-vitro test. In the results of this study, the modulus of elasticity increased with the increase of HA in the samples; however, the yield strength, ultimate strength, and yield strain of the samples decreased. In addition, it was observed that the existence of HA decreases the rate of degradation; therefore, the percentage of weakening in mechanical strength decreased in the measurements made at the end of the 15th day. According to these results, it was concluded that PLA/HA biodegradable composites can be developed to use as implant/prosthesis material.

Fabrication and characterization of In2O3-biochar composites for highly efficient adsorption and photodegradation of dyes

In this study, the In2O3-carbonization wood (In2O3-CW) composites were prepared using waste poplar wood through a comprehensive process involving “delignification-bleaching-impregnation-carbonization”. The morphology, crystal structure, elemental chemical state and photocatalytic activity of In2O3-CW were investigated by SEM, HRTEM, BET, XRD, XPS, UV–vis DRS, PL, EIS, ESR, TOC and LC-MS. Malachite green (MG) served as a model organic pollutant to assess the adsorption and visible-light photocatalytic performance of In2O3-CW in dye degradation. The results indicated a significant enhancement in the adsorption-photocatalytic performance of In2O3 nanoparticles loaded with biomass, leading to a significant increase in the MG degradation rate from 24 % to 76 %. Specifically, when the concentration of MG was 100 mg·L−1, 20 mg of 0.5In2O3-CW removed more than 96 % of MG to 481 mg·g−1. The negatively charged surface of In2O3-CW was observed to be effective in adsorbing MG molecules. Moreover, In2O3-CW exhibited a narrow band gap, high photocatalytic activity, and excellent light harvesting ability, facilitating enhanced photogenerated electron-hole separation and the generation of potent active substances (OH and O2−). Given this knowledge, a detailed deduction of the dye discoloration mechanism was presented, offering a novel approach for the effective treatment of dye wastewater pollution and the realization of high-value applications for waste biomass resources from agriculture and forestry.

Retracted: Processing and Characterization of Novel Bio-Waste Hybrid Brick Composites for Pollution Control.

[This retracts the article DOI: 10.1155/2022/3127135.].

Mechanical Characterization of Waste Wood Polymer Composites: Exploring Sustainable and Eco-Friendly Alternative

Mechanical Characterization of Waste Wood Polymer Composites: Exploring Sustainable and Eco-Friendly Alternative

Preparation and characterization of quaternary bacterial cellulose composites for antimicrobial oil‐absorbing materials

AbstractThe treatment of various types of oily wastewater is paramount for environmental protection. Bacterial cellulose (BC) stands out as a highly promising material for oil/water separation, owing to its exceptional mechanical properties and three‐dimensional porous structures. However, excessive hydroxyl groups on BC make it highly hydrophilic, reducing oil absorption and promoting bacterial growth, affecting its stability. To address these challenges, we developed a straightforward in situ polymerization method for the preparation of BC‐DMC composites. The innovation lies in the concurrent enhancement of BC's hydrophobicity and antimicrobial properties only through the addition of 2‐(Methacryloyloxy)ethyltrimethylammonium chloride (DMC), considerably simplifying the synthesis of materials possessing oil‐absorbing and antimicrobial properties. Morphological and structural characterization results confirmed the successful combination of DMC onto BC while maintaining its porous structure. After process parameter optimization, the BC‐DMC composites exhibited a remarkable increase in contact angle (117.7° compared with pure BC's 19.5°). It also demonstrated excellent oil absorption performance, with maximum capacities exceeding 30 g/g for different oils, maintaining values above 20 g/g even after eight cycles. In addition, the BC‐DMC composites exhibited strong antibacterial activity, with rates of 82.4% against Escherichia coli and 97.5% against Staphylococcus aureus. The antibacterial mechanism of the BC‐DMC composites was also discussed. Our novel BC‐DMC composites provides excellent oil absorption and antibacterial properties, making it highly applicable in the field of oily wastewater treatment and serving as a valuable reference for other researchers.

Fabrication and Mechanical Characterization of Green Composites using Basalt and Jute Fibers for Agriculture Applications

Several researches are going on the hybridization of natural composites by adding SiC as a filler and epoxy due to its higher thermal and physical properties, biodegradable, economic and excellent mechanical properties as compared to synthetic fibers such as glass, Kevlar etc. Jute fiber is an important natural fiber which is abundantly found in India, whereas Basalt fiber is obtained from basalt rock, which is also present in India in a high percentage. Jute fibers are used in geotextiles and agrotextiles for sustainable development in agriculture. The Eco-friendly basalt fibers are used in agriculture and biological applications for soil improvement and fabrication of stucco fireproof netting for animal housings etc. In this paper, basalt and jute fiber reinforced green composites were fabricated using hand layup technique by addition of SiC as filler material in different wt% (0%, 5%, and 10%). The properties of composite material such as impact strength, tensile strength, and flexural strength along with the water absorption test were investigated as per the ASTM standards. Significant improvements were obtained in their mechanical behavior by addition of different wt% of SiC. SEM images showed improved microstructures of green composites with less fractured surfaces at 10% addition of SiC.

Comparison between the Effect of Adding MSGNP and B4C-WC Nanoparticles on the Metallurgical and Mechanical Characterization of Al-7075 Composites Produced by Stir Casting

Comparison between the Effect of Adding MSGNP and B4C-WC Nanoparticles on the Metallurgical and Mechanical Characterization of Al-7075 Composites Produced by Stir Casting

Development and mechanical characterization of PLA composites reinforced with jute and nettle bio fibers

Development and mechanical characterization of PLA composites reinforced with jute and nettle bio fibers

In vitro degradation analysis and mechanical characterization of PLA-CF composites prepared by fused filament fabrication technique for bio-medical applications

The objective of this research work is to study the in vitro degradation behavior of as-fabricated and annealed Poly Lactic Acid (PLA) composites reinforced with varying volume fractions of carbon fiber (CF).The composites are prepared by fused filament fabrication technique (FFF). Specimens are immersed in simulated body fluid (SBF) for 8 weeks to study the degradation behavior of the composites by examining the change in weight, change in pH and degradation in mechanical properties. The obtained results show that the addition of carbon fiber reinforcement reduces the tensile strength, flexural strength, impact strength and compressive strength of the composites. Further, CF addition enhances the tensile modulus of the composite. The mechanical properties of annealed composites are enhanced when compared to as-fabricated composites. Differential Scanning Calorimeter (DSC) is employed to study the thermal characteristics of the composites and % crystallinity of the composites. CF addition reduces the crystallinity of the composites. Fractographs of the tensile fractured specimens are studied using a scanning electron microscope (SEM). The addition of the carbon fiber reinforcement is found to accelerate the degradation behavior of the composites. There is significant change in weight and pH as well as degradation in mechanical properties of PLA-CF composites immersed in SBF than pure PLA composites. Annealed composites show better degradation resistance than as-fabricated composites. SEM is employed to study the surface morphology of the composites immersed in SBF.