Characterization Of Composites Research Articles

Statistical Methods in the Analysis of the Effect of Carbonisate on the Hardness of Epoxy-Resin-Based Composites

This research concerns the manufacture and characterisation of epoxy composites with the addition of carbonisate, obtained by the pyrolysis of MDF (medium-density fibreboard) furniture board waste. The laminated composites were made by hand lamination, with the carbonisate used as a filler to improve the mechanical properties of the composite. The carbonisate was obtained by the thermal decomposition of MDF waste in an anaerobic environment by pyrolysis, which is an efficient method of waste management and material recycling. The resulting carbonisate was integrated into an epoxy resin matrix to investigate its potential as a reinforcing agent. The article describes a study on the hardness of epoxy-resin-based composites to which carbonisate was added in different fractions and percentages. The aim of the research was to test the possibility of using char as a component in improving the mechanical properties of epoxy composites with a view towards creating a durable recycled material with optimal parameters. As part of the study, a statistical analysis of the results of hardness measurements was carried out to accurately assess the effect of the quantity and size of the carbonate particles on the mechanical properties of the materials. The analysis identified significant differences between samples and verified the repeatability of the results. It was found that the addition of carbonisate to the A0 base sample (without the addition of carbonisate) leads to a significant hardening of the material. This was confirmed by the higher medians of samples A01 (carbonisate 5% with a 0.5 mm fraction), A02 (carbonisate 7.5% with a 0.5 mm fraction), and A03 (carbonisate 5% with a 1.0 mm fraction) compared to the base sample. The most homogeneous hardness was shown in sample A02, with the highest concentration of results and the lowest values of standard deviation and spread. The results indicated that the addition of carbonate significantly increased the hardness of the composite materials, with optimal stability achieved at 7.5% (by weight) of carbonate with a 0.5 mm fraction. The conducted research precisely determined the influence of the amount and characteristics of carbonisate particles on the mechanical properties of the materials, which enables the more effective designing of future composites. The statistical results provide a reliable basis for evaluating the potential applications of these materials in various industrial sectors, such as construction, automotive and aerospace, where high hardness and durability are important.

Preparation and Characterization of Graphene and Carbon Nanotube Hybrid Polydimethylsiloxane Composites for Protective Coating Applications

In this work, the synergistic effect of graphene nanosheets (GNs), as well as multiwalled carbon nanotubes (MWCNTs), as reinforcing agents of polydimethylsiloxane (PDMS) was investigated, in order to explore the possibilities of designing composite materials, tailored for use in the field of coatings, which might be, in fact, a very interesting application. It was shown that the addition of GNs and MWCNTs in PDMS matrices significantly improves the thermal stability of the obtained nanocomposites, especially those reinforced exclusively with GNs. The tensile tests indicated that strength increased for all the examined composites. It was also observed that the Young’s moduli had an increasing trend, with the exception of the composites containing only GNs, while those reinforced solely with MWCNTs exhibited the best performance. The O2 permeability measurements revealed that the highest reduction in the permeability was observed in GN-MWCNT/PDMS composite membranes, in comparison to those reinforced only with graphene or carbon nanotubes. Dielectric relaxation spectroscopy showed that all the examined composites, and especially those of MWCNTs, possess electrical conductivity, apart from the samples reinforced exclusively with graphene. The electromagnetic shielding effectiveness was also improved at higher filler loadings, which is more evident in composites reinforced with MWCNTs. It was concluded that the improved properties of the above studied hybrid composites make them suitable for protective coating applications.

Preparation and Characterization of Waste Cotton Fabric Reinforced Polylactic Acid Green Composites with Multifunctional Properties in a Low-Carbon Process

The development and design of eco-friendly materials prove crucial for promoting the recycling of waste cotton textiles and reducing environmental pollution. In this study, waste cotton fabric (WCF) and polylactic acid (PLA) serve to produce cotton fabric-reinforced PLA composite material (CF/P). The CF/P is then integrated with traditional porous sound-absorbing materials to create a novel composite plate. This research highlights the potential of WCF reinforced plates for sound absorption and thermal insulation applications in the construction field of construction and reports the effects of variables such as hot pressing temperature, WCF mass fraction, and WCF layer alignment angle on the material properties. The optimum tensile strength, water absorption, and thermal conductivity of the prepared CF/P are 64.2 ± 1.8MPa, 1.98% ± 0.04%, and 0.03W/(m·K), respectively. By combining with porous sound-absorbing materials and modifying the layering structure of composite plates, its acoustic performance can be adjusted. The highest Sound Absorption Average (SAA) of plates with a multilayer composite structure is 0.67. Direct shaping through hot pressing diminishes the use of adhesives, thereby reducing costs and health hazards. This approach offers a practical and efficient solution for the recycling and repurposing of natural fibers.

Effects of exopolysaccharides from Rhizobium tropici on transformation and aggregate sizes of iron oxides

Iron oxide transformations in soil significantly impact nutrient availability and plant health. This study investigated the interaction between exopolysaccharides (EPS), produced by Rhizobium tropici, and iron oxide (Fe3O4), focusing on their impact on the transformation, particle size, and zeta potential of iron oxides. The characterization of the EPS-iron oxide composites was carried out using X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM)/Energy Dispersive X-ray Analysis (EDX). The EPS adsorption kinetics revealed chemisorption and diffusion as controlling processes for EPS adsorption on Fe3O4, while isotherm data with releasing proton indicated possible ion exchange and heterogeneous layered adsorption. Desorption studies suggested the high stability of EPS-iron complexes. Notably, EPS significantly increased the aggregate size of EPS-iron complexes at low EPS/iron oxide molar ratios but shrank the aggregate size at higher ratios (> EPS/iron oxide 2 × 10−4). Additionally, EPS complexation resulted in a shift in the zeta potential towards more negative surface functionality. Functional groups within EPS, specifically –COOH, –OH and –NH played a crucial role in the interaction of EPS with iron oxides. The study concluded that EPS coating prevented the transformation of Fe3O4 into other iron oxide forms like β-FeOOH, α-Fe2O3, and γ-Fe2O3, elucidating the significant role of EPS in soil mineral processes.

Tribological characterization of PTFE composites for ball bearing applications

Tribological characterization of PTFE composites for ball bearing applications

Development and characterization of glass fiber composites impregnated with limestone powder and bagasse fiber

Abstract Materials development is essential for all industries to meet the current demands Limestone powder (LS), coconut shell fiber (CSF) and sugarcane bagasse fiber (SBF) were impregnated in a laminated glass fiber polymer matrix. The fiber to matrix ratio is 50 %, while SBF and CSF start replacing natural fibers at a rate of 5–15 %, and LS is always 5 %. The proposed fiber-reinforced composites were manufactured by compression molding (CMM) and the test samples were cut according to the ASTM for tensile, impact, moisture, scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric (TGA) tests. The results showed that the strength of the materials is influenced by the impregnation of the fibers into the matrix phase. Impregnation of natural fibers in glass fiber composite structures at 10–15 % loading demonstrated a weight saving of 7–8 %, tensile strength ranging from 330 to 350 MPa, maximum moisture absorption of 3.4 g, and thermal stability around 300 °C. Addition of limestone powder resulted in improved bonding ability, better surface finish, and reduced porosity, as demonstrated by SEM analysis.

Development and characterization of PLA food packaging composite

AbstractThis study focuses on the development of bioactive packaging materials by incorporating grape pomace and copper particles into polylactic acid (PLA) composites. The goal is to increase the shelf life of packaged foods while benefiting the health of consumers through the use of these active materials. 6 recipes of composite materials based on polylactic acid and Proviplast 2624 plasticizer were obtained. The additives added were: grape pomace, added at 0.5%, 1% and 1.5%, and copper particles, formed using PEG 600 + CuSO₄, added at 2%, 5% and 8%. Material characterization techniques: FTIR Spectroscopy, used to study the chemical structure. Differential scanning calorimetry (DSC): examined thermal transitions such as glass transition and melting temperatures. Thermogravimetric analysis (TGA) and differential thermogravimetry (DTG): evaluated thermal stability and degradation temperatures. Scanning electron microscopy (SEM) and atomic force microscopy (AFM): analyzed the surface morphology and structure. Mechanical tests: evaluated tensile strength, elongation at break and flexibility.Thermal property analyzes revealed that the additives acted as plasticizers, reducing the intermolecular forces between PLA chains, which decreased the glass transition temperature (Tg), cold crystallization temperature (Tcc) and melting temperature (Tm). The addition of grape pomace and copper particles decreased the degradation temperature of PLA composites, indicating a slight reduction in thermal stability. The transformation temperatures changed and the nature of the thermal transitions (exothermic or endothermic) varied with additive concentrations. Mechanical properties indicated a reduction in tensile strength with increasing additive concentration. Elongation at break and longitudinal modulus of elasticity increased significantly, especially with grape pomace, improving the flexibility of PLA. These changes indicate that the material can absorb more energy before breaking, making it more ductile and more suitable for flexible packaging applications. Increased flexibility and improved thermal resistance ensure that these materials can withstand the demands of packaging, handling and shipping. The combination of improved flexibility, thermal resistance and moderate tensile strength makes these PLA-based composites incorporated with grape pomace or copper particles, enhance the aspect of sustainability by recycling agricultural waste, making the material both ecological and functional, making it a viable option for active food packaging.

Enhanced biocompatibility and antibacterial efficacy of CuO-HAp nanocomposite for hard tissue regeneration and repair

This study focuses on the synthesis and characterization of CuO-decorated HAp composites for potential biomedical applications, particularly in hard tissue regeneration. XRD analysis confirmed the coexistence of CuO and HAp phases, with CuO influencing the crystallinity of HAp without altering its lattice parameters. Williamson-Hall (W-H) method analysis showed a significant increase in the crystallite size of CuO by approximately 92.7%, while the crystallite size of HAp decreased by 19.4% in the CuO-HAp composite. FTIR spectroscopy verified the successful integration of CuO and HAp in the nanocomposite while SEM and TEM revealed the morphological interaction between CuO nanoflakes and HAp nanorods. The antimicrobial activity of CuO-HAp demonstrated an 8.7% larger zone of inhibition against Escherichia coli compared to Staphylococcus aureus. The composite also exhibited superior antioxidant properties compared to ascorbic acid and showed improved hemocompatibility. Zebrafish embryo toxicity assays confirmed the non-toxic nature of the composite. Although in vitro cytotoxicity assays with Saos-2 cells indicated slightly reduced viability and proliferation due to CuO’s inherent cytotoxicity, the CuO-HAp composite enhanced cellular responses, highlighting its potential for tissue engineering and other biomedical applications.

Development and Characterization of Al-SiC Metal Matrix Composites Through Microwave Processing and Extrusion

Metal matrix composites (MMCs) have garnered significant attention due to their exceptionally lightweight nature, adaptability for a wide range of applications, and exceptional mechanical properties. This investigation delves into the tribological characteristics of aluminum-silicon carbide (Al-SiC) microelectrodes. These MMCs were refined through extrusion after being fabricated using a novel microwave-assisted powder metallurgy process. The impact of reinforcement content on the material's mechanical strength and wear resistance was assessed by varying the weight percentages of SiC (10%, 15%, and 20%). The results indicate that the uniform distribution of SiC within the aluminum matrix significantly enhances the composite's hardness and wear resistance. The addition of 20% SiC resulted in a 28% reduction in the wear rate compared to pure aluminum. In addition, the extrusion procedure improved these properties by aligning the SiC particulates in the direction of extrusion and reducing porosity. This investigation demonstrates that the combination of microwave sintering and extrusion can produce high-performance Al-SiC MMCs with enhanced abrasion resistance and mechanical properties, making them suitable for industrial applications that require lightweight materials and durability.

A study of epoxy based polymer composites: Tailoring mechanical and piezoelectric characteristics

AbstractIn this study, epoxy based piezoelectric polymer composites were fabricated using two different curing agents and varying compositions of poly(vinylidene) fluoride (PVDF), barium titanate (BaTiO3), and conductive silver nanoparticles. The effect of piezoelectric ceramic and conductive nanofillers on enhancing the PVDF β phase within the composite structure was investigated. Structural, thermal, and morphological characterizations of the polymer composites were performed using x‐ray diffraction, differential scanning calorimetry, and scanning electron microscopy. Furthermore, a comprehensive analysis of mechanical properties and fracture toughness was conducted in addition to the piezoelectric behavior. A voltage output of 1.35 V was generated by a polymer composite containing 20 wt% BaTiO3, with a Young's modulus of 2 GPa and a fracture energy of 2.3 kJ/m2. The findings of this study contribute to expanding the knowledge and understanding of piezoelectric polymer composites, enabling their potential utilization in various scientific and technological applications.Highlights Enhancing mechanical and piezoelectric properties of epoxy based piezoelectric composites. A clear and comprehensive description of the experimental procedures employed. Comparative analysis methods: structural, thermal, mechanical, fracture, and piezoelectric property analyses.

Prediction of frictional behaviour through regression equations: A statistical modelling approach validated with machine learning

Prediction of frictional behaviour through regression equations: A statistical modelling approach validated with machine learning

Development and Characterization of Novel Dental Composites Using Locally Sourced Materials in Pakistan

Development and Characterization of Novel Dental Composites Using Locally Sourced Materials in Pakistan

Rare Earth Carbide (Nd-C and Ce-C) Synthesis and Characterization to Inform Phase Equilibrium in Advanced Nuclear Fuels

As advances are being made regarding the performance of nuclear fuels, uranium carbides, and composites, such as (U,Zr)C and UO2 + UCx, have recently gained significant interest for deployment in nuclear space propulsion and high temperature gas-cooled reactors, respectively. However, the phase equilibria of several fission products in carbide systems remain unknown and may impact the overall fuel performance, specifically for particle nuclear fuels that are designed for commercial nuclear energy. Furthermore, comprehensive thermodynamic data on Rare Earth (RE) carbides, such as the Nd-C and Ce-C binary systems, remain limited. Presented in this study are the synthesis methods and characterizations of several Nd-C and Ce-C compositions. The findings from this research provide insights on the stability of RE-C binaries that form in irradiated nuclear fuels and address a critical knowledge gap in the current state of thermodynamics for two key RE-C systems.

A Comprehensive Study of Cellulignin Production from Sugarcane Bagasse, Sugarcane Straw, and Energy Cane for Advanced Biofuels: Liquor Composition and Cellulignin Characterizations

A Comprehensive Study of Cellulignin Production from Sugarcane Bagasse, Sugarcane Straw, and Energy Cane for Advanced Biofuels: Liquor Composition and Cellulignin Characterizations

Mechanical characterization of natural fiber composites prepared with untreated and treated ficus religiosa root fibers

Surface modification techniques are used to modify the surface of the natural fibers in order to improve the surface characteristics; in turn other relevant significant properties of the fiber and its composites. In the present work, epoxy composites have been prepared with the untreated and treated F. religiosa root fiber samples at 5, 10, 15, 20, and 25 wt.% fiber loading. Mechanical properties such as tensile, flexural and impact strength of the prepared composite specimens have been tested as per the ASTM standards. From the results, it has been identified that the strength of the proposed composites increases with the increase in fiber loading, and the composites made up of 20 wt.% of the NaOH solution treated fiber sample exhibits better properties under mechanical characterization study. Alkalization filled the holes, cracks, and pores on the outer layer of fibers and significantly improved the surface roughness, which was reflected in the improvement of the proposed composites.

Synthesis and characterization of submicron spherical core-shell high-energy composites via electrospray method

In this study, submicron spherical core-shell high-energy composites of RDX/F2311@CuO/Al were synthesized using the electrospray method. The results demonstrate that the combustion time of composite high-energy microspheres, prepared via electrospraying, was significantly reduced to 460.0 ms from an original 2296.0 ms observed in samples prepared by physical mixing. Additionally, the flame burning was more concentrated, and the combustion process exhibited greater stability. Additionally, the flame combustion exhibited greater concentration and the overall combustion process was more stable. Furthermore, by manipulating the proportion of non-energy-containing components, it is possible to obtain composites with adjustable combustion rates. By manipulating the ratio of aluminium thermal agent, it is possible to procure a composite material with a more vigorous combustion process, thereby enabling the functional modulation of said composite material. Compared to the raw material RDX, the H50 value of the composite microspheres has increased from 14.49 cm to 25.16 cm, indicating a significant enhancement in impact resistance along with a remarkable desensitization effect. Additionally, the explosion percentage of the composite microspheres has been reduced from 84 % to 68 %. These significant desensitization effects highlight the morphological advantages of the core-shell structure and the synergistic reaction energy benefits of the components involved.

Fabrication and mechanical characterization of AlSi10Mg-reinforced hybrid composites using bottom pouring top-loaded stir-casting method

Fabrication and mechanical characterization of AlSi10Mg-reinforced hybrid composites using bottom pouring top-loaded stir-casting method

Sonochemical synthesis characterization and biocompatibility studies of polymeric composites for biomedical applications

In this work the in situ synthesis of mixtures of Polymethylmethacrylate (PMMA), High Density Polyethylene (HDPE) and Polypropylene (PP) with biocompatible ceramics was carried out, using high frequency ultrasound as an energy source. Starting from calcium hydroxide and ammonium hydrogen phosphate, two different crystalline phases were obtained: hydroxyapatite (HA) and calcite (CaCO3). FTIR and XRD studies showed that for the materials prepared with HDPE, only CaCO3 was formed during the synthesis process. When Polypropylene used, mixtures of HA with CaCO3 were obtained, while for the materials synthesized with Polymethylmethacrylate, only pure HA was obtained. DSC analyses did not reveal any significant changes in the melting temperatures of HDPE and PP, nor in the glass transition temperature of PMMA with the incorporation of HA and CaCO3, in the polymeric matrices. TGA, showed that the decomposition temperatures of these materials increased with respect to those of the polymers alone, indicating a significant thermal stability. Biocompatibility tests with osteoblastic cells and Scanning Electron Microscopy (SEM) studies showed that the composites of PMMA with HA, PP with HA/CaCO3 and HDPE with CaCO3, are capable of promoting cell adhesion and proliferation mechanisms, revealing potential applications as biomaterials for bone replacement.

Effect of curing temperature, silica fume, and waste tire rubber aggregate on material characterization of lightweight geopolymer composite

This study investigates the potential effect of curing temperature (80 °C and 100 °C), the effect of using waste tire rubber aggregates (WTRA), and silica fume (SF) on the properties of lightweight geopolymer (LG) composite. In LG, SF replaced 20 % of the ground granulated blast furnace slag (GGBS), and WTRA replaced pumice aggregate to varying degrees (15 %, 30 %, and 45 % by volume). The physical properties of the LG composite were assessed through apparent porosity, water absorption, and hardened density. The mechanical properties were examined by testing compressive strength (CS) and flexural strength (FS). The effect of high temperature (300 °C and 600 °C) was examined on CS and mass loss of LG composite. The durability of the LG composite was analyzed using mercury intrusion porosimetry (MIP), capillary water absorption, freeze-thaw, and thermal conductivity. The material characterization of the composite was done using scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential thermogravimetry (DTG) curves. After 28 days, LG composites showed increased porosity and water absorption with the increased WTRA and SF, with higher values at 100 °C. Compressive and flexural strengths decreased with the increased WTRA and SF, especially at higher temperatures. The TGA-DTG curves show that the LG-0–80 mix had the lowest mass loss (15.25 % at 400°C and 19.36 % at 600 °C), while the LG-SF-45–100 mix had the highest mass loss (22.22 % and 24.53 %, respectively). XRD and TGA-DTG analyses reveal that using SF increases Ca(OH)₂ peaks and alters the geopolymer composition, improving the mechanical performance of the LG-SF-0–80 mix and enhancing the thermal stability of the composites.

Unveiling the effect of bovine serum albumin on the corrosion resistance of high nitrogen stainless steel for cardiac stents

Herein, the effect of bovine serum albumin (BSA) on the corrosion resistance of high nitrogen stainless steel (HNS) is systematically investigated based on experimental characterizations and first-principle calculations. Electrochemical measurements firstly prove that the anodic dissolution rate of HNS has significantly increased due to BSA adsorption and the potential deterioration of the passive film. By subsequent morphology and composition characterizations, it is demonstrated that BSA forms a 1.9 μm porous adsorption layer on HNS surface via the peptide bond mostly in -helix and -turn structure. Furthermore, Mott-Schottky tests confirm that the carrier (cation vacancy) density in the passive film has dramatically risen from 6.29×1021 cm-3 to 1.97×1022 cm-3 after BSA adsorption, which could be ascribed to the detachment of Cr atom from its original lattice due to the preference interaction between BSA molecule and Cr atom. Most importantly, such an increased defects will further promote the dissolution process of both the passive film and HNS matrix according to point defect model (PDM), which will definitely undermine the protective ability of the passive film and eventually result in the declined corrosion resistance of HNS in BSA-contained solution.