Characterization Of Composites Research Articles

Preparation and Characterization of Al-ZrB2 Composites by Planetary Milling and Equal Channel Angular Pressing: Effect of ZrB2 Amount and Milling Time on Wear Behavior and Compressive Strength

Preparation and Characterization of Al-ZrB2 Composites by Planetary Milling and Equal Channel Angular Pressing: Effect of ZrB2 Amount and Milling Time on Wear Behavior and Compressive Strength

Development and characterization of new lightweight waste-based plaster composites for building applications

The development of new environmentally friendly construction materials that incorporate waste as an alternative to traditional raw materials is becoming increasingly important and necessary for the construction sector. Gypsum plasters composites are characterised by their versatility and wide range of applications in precast construction due to their excellent technical performance and low cost. This research presents a new material that incorporates EPS waste in solution and recycled rubber aggregates as secondary raw materials, partially replacing traditional plaster material. In this way, partial mass substitutions of up to 12.5 % have been achieved compared to the reference composites without additions. The results show how the incorporation of EPS in solution allows a more homogeneous integration of the residue in the plaster composite matrix. Although it is true that the incorporation of both residues has slightly reduced mechanical resistance to bending and compression, reaching minimum values of 3.71 MPa and 5.08 MPa respectively, the results obtained greatly exceed the minimum values required by current regulations. On the other hand, in the study conducted with prefabricated false ceiling plates, it has been observed that the combined effect of both residues allows for greater resistance to simple bending than traditional composites, with a reduction in bulk density and thermal conductivity of up to 30.1 % and 26.5 %, respectively. Thus, this work presents a viable alternative for the development of new plaster composites that are more sustainable, lightweight and conducive to advancing towards the industrialisation of the construction sector.

Characterisation of 3D woven textile composites in presence of minor weft tow undulations and cross-section variations

Characterisation of 3D woven textile composites in presence of minor weft tow undulations and cross-section variations

Recovering Low-Density Polyethylene Waste for Gypsum Board Production: A Mechanical and Hygrothermal Study.

In recent decades, plastic waste management has become one of the main environmental challenges for today's society. The excessive consumption of so-called single-use plastics causes continuous damage to ecosystems, and it is necessary to find alternatives to recycle these products. In this work, a mechanical and hygrothermal characterisation of novel plaster composites incorporating LDPE waste in their interior was carried out. Thus, prefabricated plasterboards have been designed with a partial replacement of the original raw material with recycled LDPE in percentages of 5-10-15% by volume. The results show how these new composites exceeded the 0.18 kN minimum breaking load in panels in all cases, while decreases in density and thermal conductivity of up to 15% and 21%, respectively, were obtained. In addition, an increase of 3.8%in thermal resistance was obtained by incorporating these new gypsum boards in lightweight façade walls through simulations. In this way, a new pathway was explored for the recovery of these wastes and their subsequent application in the construction sector.

Microwave-assisted fabrication of high-strength natural fiber hybrid composites for sustainable applications: An experimental and computational study

The present study deals with the fabrication of hybrid composites using biodegradable and ecologically friendly natural fibers and a recyclable thermoplastic matrix. Pure and hybrid natural fiber composites of high-density polyethylene (HDPE) with Kenaf and Ramie fiber, 20 wt%, were fabricated using microwave-assisted compression molding. The composite's mechanical characterization was performed using tensile, flexural, impact, and hardness tests. X-ray diffraction was done to investigate the crystallinity percentage, and scanning electron microscopy of fractured surfaces was performed to determine failure mechanisms. The hybrid composite of HDPE/Ramie and Kenaf exhibited the highest ultimate tensile strength (UTS) at 29.3 ± 1.2 MPa, surpassing HDPE/Kenaf (21.6 ± 1.1 MPa) and HDPE/Ramie (24.3 ± 1.4 MPa) composites. In terms of flexural strength, HDPE/Ramie demonstrated the highest at 19.9 ± 1.5 MPa, while HDPE/Kenaf had the lowest at 18 ± 1.1 MPa. The hybrid composite's flexural strength was intermediate at 19 ± 1.3 MPa. Impact strength followed a similar trend, with the hybrid composite leading at 40.2 KJ/m2, followed by HDPE/Ramie (26.9 KJ/m2) and HDPE/Kenaf (12.3 KJ/m2). Hardness tests revealed the highest hardness in the hybrid composite and the lowest in HDPE/Kenaf. A computational study has been performed to develop a model for predicting the hybrid composites. A strong agreement between both studies has been observed. The developed composite is deemed suitable for various light-duty applications, such as roofing, car interior panels, and mobile covers, offering potential benefits in reducing carbon footprint.

Machine Learning Applied to Terahertz Signal Analysis For Hygrothermal Aging Characterization of Composites

Given their noncontact nature, ease of inspecting nonmetallic materials, and ability to detect small structural changes, terahertz waves were chosen as the study methodology for this project. Initially, characterization data was pretreated and standardized. The data were then reduced in dimensionality using principal component analysis and classified using other machine learning methods. The results demonstrated that the terahertz wave technique could accurately distinguish between different temperature and aging time scenarios. They also indicated that nondestructive in-service characterization of composite repairs is feasible and can provide invaluable information for decision-making. The main benefits of this approach include ensuring the safe operation of offshore piping and optimizing resources when deciding whether to replace the repair or keep it in service.

Correlated 4D-STEM and EDS for the classification of fine Beta-precipitates in aluminum alloy AA 6063-T6

Tuning the properties of aluminum alloys AA 6063-T6 involves artificial aging to induce precipitate formation, particularly β’’ and β’ phases. Previous characterization challenges due to their similar appearance are addressed here by correlating 4D scanning transmission electron microscopy (4DSTEM) and energy-dispersive spectroscopy (EDS) mapping. This approach allows us to analyze the structure and composition of precipitates individually, overcoming limitations of conventional imaging and structural analysis techniques when the precipitates appear simultaneously, as is often the case. We present detailed characterizations of needle-shaped Beta precipitates, revealing distinct diffraction patterns (DPs) and compositional differences. The method's applicability extends beyond aluminum alloys, offering a promising strategy for complex composite material characterization with multimodal scanning transmission electron microscopy (STEM) techniques.

Construction of quaternary ammonium nitroxy-hybrid magnetic mesoporous silica adsorbent system and its selective adsorption research of Re(Ⅶ)/Cu(Ⅱ)

This study focussed on the development of a quaternary ammonium nitroxy-hybrid magnetic mesoporous silica adsorption system (Fe3O4@MS-SiO2@3-CPTES@Tetra-N-ACE, Fe3O4@MS-SiO2@3-CPTES@Tetra-2N@ACE and Fe3O4@MS-SiO2@3-CPTES@Tetra-DE) was established with adsorption structures consisting of 1,4,7,10,13-pentaoxa-16-azacyclooctadecane (N-ACE), 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (2N-ACE) and a similar linear structure, 3,6-dioxy-1,8-octylenediamine (DE) for the selective separation of Re/Cu. The composites were characterized by Fourier transform Infrared spectroscopy(FT-IR), Energy dispersive spectrometer(EDS), X-ray Diffraction(XRD), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) measurements. The characterization of composites exhibits mesoporous and rich functional groups. The experimental results demonstrated that the Fe3O4@MS-SiO2@3-CPTES@Tetra-2N@ACE and Fe3O4@MS-SiO2@3-CPTES@Tetra-DE possessed superior adsorption capacities of Re(VII) in a wide acidic environment (pH=3–6). The maximum adsorption capacity of Fe3O4@MS-SiO2@3-CPTES@Tetra-2N@ACE and Fe3O4@MS-SiO2@3-CPTES@Tetra-DE were respectively up to 331.77 mg·g−1, 395.54 mg·g−1 at pH 5.0. Furthermore, the adsorption rate of these adsorbents was fast for only 2 h to absorb more than 80 % of Re(VII). Notably, when Fe3O4@MS-SiO2@3-CPTES@Tetra-2N@ACE and Fe3O4@MS-SiO2@3-CPTES@Tetra-DE were added into the rhenium copper binary solution with the concentration ratio from 1:1 and 1:50, the Re (Ⅶ) / Cu (Ⅱ) selectivity was constantly excellent (SelRe/Cu value > 1.46, SelRe/Cu max = 4.96). After 5 desorption processes for Re (Ⅶ) with 3 mol·L−1 NaCl and 1 mol·L−1 NaCl, respectively, the adsorption efficiency decreased by less than 10 % at Fe3O4@MS-SiO2@3-CPTES@Tetra-2N@ACE and Fe3O4@MS-SiO2@3-CPTES@Tetra-DE. The adsorption mechanism between the adsorbents and Re(VII) was mainly electrostatic interaction and ion exchange through TEM-EDS, FT-IR, and XPS. This novel adsorption system had a promising application in the selective separation of Re(VII)/Cu(Ⅱ).

The Effect of Carbon Nanotubes and Carbon Microfibers on the Piezoresistive and Mechanical Properties of Mortar

Sustainability, safety and service life expansion in the construction sector have gained a lot of scientific and technological interest during the last few decades. In this direction, the synthesis and characterization of smart cementitious composites with tailored properties combining mechanical integrity and self-sensing capabilities have been in the spotlight for quite some time now. The key property for the determination of self-sensing behavior is the electrical resistivity and, more specifically, the determination of reversible changes in the electrical resistivity with applied stress, which is known as piezoresistivity. In this study, the mechanical and piezoresistive properties of mortars reinforced with carbon nanotubes (CNTs) and carbon micro-fibers (CMFs) are determined. Silica fume and a polymer with polyalkylene glycol graft chains were used as dispersant agents for the incorporation of the CNTs and CMFs into the cement paste. The mechanical properties of the mortar composites were investigated with respect to their flexural and compressive strength. A four-probe method was used for the estimation of their piezoresistive response. The test outcomes revealed that the combination of the dispersant agents along with a low content of CNTs and CMFs by weight of cement (bwoc) results in the production of a stronger mortar with enhanced mechanical performance and durability. More specifically, there was an increase in flexural and compressive strength of up to 38% and 88%, respectively. Moreover, mortar composites loaded with 0.4% CMF bwoc and 0.05% CNTs bwoc revealed a smooth and reversible change in electrical resistivity vs. compression loading—with unloading comprising a strong indication of self-sensing behavior. This work aims to accelerate progress in the field of material development with structural sensing and electrical actuation via providing a deeper insight into the correlation among cementitious composite preparation, admixture dispersion quality, cementitious composite microstructure and mechanical and self-sensing properties.

Preparation, Characterization of Zirconium Phosphate Composites and Their Adsorption Properties of Phenolic Wastewater

Preparation, Characterization of Zirconium Phosphate Composites and Their Adsorption Properties of Phenolic Wastewater

Preparation and characterization of chitosan and hydroxyapatite composite

Chitosan and hydroxyapatite (HAp) composites were prepared at different ratios (60% chitosan & 40% HAp, 50% chitosan & 50% HAp, 40% chitosan & 60% HAp). The mixtures are dissolved in a 2% acetic acid solution and heated to about 60°C-70°C with continuous stirring for about 1 hour. After that, the solutions are naturally dried on heat-sealing paper placed above a glass sheet. After about 24 hours, chitosan and hydroxyapatite composite films are prepared. Fourier Transform Infrared Spectroscopy (FTIR) analysis showed that Hydroxyapatite is mainly found at lower wave numbers in the range 400–600 cm-1. X-ray diffraction patterns were showed, the crystalline properties of the composites increase with Hydroxyapatite. Differential Thermal Gravimetry (DTG) analysis of the composites indicated that the material is thermally stable up to 300°C. This paper aims to review the literature concerning chitosan-hydroxyapatite composites for bone restoration and discuss the primary methods of preparation and mechanical properties of these materials.

Topical Gel Containing <i>Wrightia tinctoria</i> Extract: Optimization by Central Composite Design, Characterization and Bio-activity Assessment

Topical Gel Containing <i>Wrightia tinctoria</i> Extract: Optimization by Central Composite Design, Characterization and Bio-activity Assessment

Efficient fabrication technique and dynamic property characterization of macro fiber composites

This paper proposes an efficient technique for the fabrication of macro fiber composite (MFC) and characterizes the properties of MFC under dynamic voltage. First, the fabrication process is described in detail. Then, the effects of peak-to-peak value, frequency and dc bias on the electric-field-induced strain are analyzed. Finally, the mechanical properties are evaluated based on the mixing rules, and the prediction model of electrical parameters is established using the fitting functions. The experimental results show that the proposed fabrication technique effectively suppresses the generation of defects and the electric field variation has significant effects on the actuating properties.

The synthesis and characterization of alkaline niobate-based ceramic composites containing L-lysine Hydrochloride

Some lead-free piezoelectric ceramics are known to have high dielectric and piezoelectric properties but are limited by their brittle nature. A few amino acids have recently been reported to exhibit rather low dielectric and piezoelectric properties but have the advantage of being biocompatible and flexible. It would therefore be interesting to form a composite that will combine the inherent advantage of high dielectric properties from the ceramics and flexibility from the biomolecule. In this research, the properties of lead-free (K0.45Na0.51Li0.04)(Nb0.85Ta0.1Sb0.05)O3 (KNNLST) ceramics and L-lysine hydrochloride (L-LHCl) have been combined to produce dielectric composites. The samples were produced by mixing the constituents from 0 wt.% to 100 wt.%, pelletising and heat-treating them. Bulk density, X-ray diffraction, scanning electron microscopy, and dielectric characterisation were techniques used to determine the density, phases, morphology, and dielectric properties of the produced composites. The results show an increasing bulk density value from 1.2 g/cm3 for L-LHCl to 4.67 g/cm3 for the KNNLST ceramics. The morphology of the composite shows very tiny grains when small amounts of the ceramics were introduced. The L-LHCl transforms from an amorphous phase to a crystalline phase having the orthorhombic-tetragonal structure with the introduction of the KNNLST ceramics. The dielectric constant values increased with increasing KNNLST ceramics content from 10 @1 kHz to 200 for the composite with 80 wt%. KNNLST content. The dielectric loss values decreased for L-LHCl from 0.9 @1 kHz to 0.2 @1kHz. The electrical conductivity values increased with increasing KNNLST ceramics content. The results show that the composites produced from these constituents may be suitable for dielectric applications.

Metal-Organic Framework on Fullerene (MOFOF) as a Hierarchical Composite by the Integration of Coordination Chemistry and Supramolecular Chemistry.

There is a synergy between coordination chemistry and supramolecular chemistry that has led to the development of innovative hierarchical composites with diverse functionalities. Here, we present a novel approach for the synthesis and characterization of a metal-organic framework on fullerene (MOFOF) composites, achieved through the integration of coordination chemistry and supramolecular chemistry principles. The hierarchical nature of the MOFOF harnesses the inherent properties of metal-organic frameworks and fullerenes. The two-step synthesis procedure involves controlled assembly of fullerenes as tube-like nanostructures (fullerene nanotube: FNT), their surface functionalization, and the on-surface growth of the MOF (in this case, ZIF-67). The method permits the precise tuning of morphology, effective distribution of MOF-on-FNT, and tight compositional control. The materials were comprehensively structurally characterized using electron microscopy, spectroscopic techniques, and other methods to elucidate the unique features and interactions within the MOFOF composites. The main findings reveal that the novel synthesis and characterization of MOFOF composites demonstrate the successful integration of coordination chemistry and supramolecular chemistry for the designing and fabricating of advanced hierarchical composites with tailored properties, including micro- and mesopore channels, interfacial facets, and defect sites. These properties are expected to lead to numerous potential applications such as gas storage and separation, catalysis, sensing, energy storage, and environmental remediation. However, only the capability of acid vapor sensing was tested and is described here.

Characterization and Mechanism Elucidation of Nano-TiO2 Composites Prepared by Gaseous Detonation Method.

In this study, a series of nano-TiO2 composite materials, including nano-TiO2, nano-SnO2/TiO2, nano-SiO2/TiO2, and nano-Fe2O3/TiO2, were successfully synthesized via the gaseous detonation method. Comprehensive characterization of the synthesized samples was carried out through X-ray diffraction (XRD), transmission electron microscopy/high-resolution TEM (TEM/HRTEM), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), Brunauer-Emmett-Teller (BET) method, and Fourier transform infrared (FTIR) analysis, which unveiled the significant influence of precursor types on the microstructure of the composite materials. Specifically, the incorporation of Sn4+ promoted the transformation of TiO2 to the rutile phase, reducing particle sizes from 25 to 19 nm and increasing the specific surface area from 44 to 86 m2/g. In contrast, the introduction of SiO2 impeded the rutile phase formation, leading to a marked reduction in particle size to 14 nm and an enhancement of the specific surface area to 104 m2/g. Furthermore, the presence of Fe3+ promoted the formation of the rutile phase and enabled particle growth to 44 nm. These findings not only deepen the understanding of structural control in the synthesis of nano-TiO2 composite materials via the gaseous detonation method but also highlight the critical role of precursor selection in determining the properties of the resulting materials.

Synthesis and Characterization of Titania-Coated Hollow Mesoporous Hydroxyapatite Composites for Photocatalytic Degradation of Methyl Red Dye in Water

Hollow mesoporous hydroxyapatite (HM-HAP) composites coated with titania are prepared to increase the stability and catalytic performance of titania for azo dyes present in the wastewater system. In this work, HM-HAP particles were first synthesized by a hydrothermal method utilizing the CaCO3 core as a template and then coated with titania to form TiO2/HM-HAP composites. Utilizing SEM, XRD, XPS, BET, FTIR, EDS, UV–vis DRS spectroscopy, and point of zero charge (PZC) analysis, the coating morphological and physicochemical parameters of the produced samples were analyzed. The photocatalytic efficiency of the synthesized coated composites was assessed by the degradation of methyl red (MR) dye in water. The results indicated that TiO2/HM-HAP particles could efficiently photodegrade MR dye in water under UV irradiation. The 20% TiO2/HM-HAP coating exhibited high catalytic performance, and the degradation process was followed by the pseudo-first-order (PFO) kinetic model with a rate constant of 0.033. The effect of pH on the degradation process was also evaluated, and the maximum degradation was observed at pH 6. The analysis of degraded MR dye products was investigated using LC-MS and FTIR analysis. Finally, a good support material, HM-HAP for TiO2 coatings, which provides a large number of active adsorption sites and has catalytic degradation performance for MR dye, was revealed.

Mechanical, microstructural, and thermal characterization of geopolymer composites with nano‐alumina particles and micro steel fibers

AbstractCement production is responsible for 5%–7% of global CO2 emissions, highlighting the need for sustainable alternatives like geopolymer composite (GCOMP) to meet the growing demand for concrete. This study investigates the mechanical, microstructural, and thermal properties of GCOMP by incorporating nano‐alumina (n‐alumina) and MSF (MSF). The n‐alumina content was varied at 1%, 2%, and 3% by weight of the mix, while the MSF content remained fixed at 0.5% by weight. Thermal characterization was conducted up to 800°C. The performance of GCOMP blends with n‐alumina was compared to a control blend consisting of only 0.5% MSF. Various mechanical properties were evaluated for all GCOMP blends. Microstructural and mineralogical characteristics were analyzed using scanning electron microscopy (SEM), X‐ray diffraction (XRD), and Fourier‐transform infrared spectroscopy (FTIR). Thermogravimetric and differential thermal analysis were performed up to 800°C for the thermal analysis of the GCOMP mix. The results indicate that the optimal mechanical properties were achieved with 2% n‐alumina (compressive and flexural strength increased by 35.65% and 77.7%, respectively). Additionally, the incorporation of n‐alumina improves the interfacial zones and results in a denser structure. GCOMP mortars portrayed a mass loss between 25°C and 250°C, with a marginal mass loss occurring between 250°C and 715°C. No mass loss was observed between 715°C and 800°C. The MSF‐reinforced GCOMP mortars experienced an ultimate mass loss of approximately 12%, with the MSF showing negligible influence. The addition of n‐alumina particles to MSF‐reinforced GCOMP resulted in the development of stronger samples characterized by the presence of C–S–H, calcium aluminate oxide hydroxide, and quartz.

Transformative potential: Utilizing Teos-modified mugwort for sustainable construction

Exploring innovative materials derived from natural sources holds significant promise in pursuing sustainable construction practices. This study investigates the modification of mugwort (Artemisia dubia Wall.) with TEOS (tetraethyl orthosilicate) and its application as a sustainable reinforcement material in construction applications. It aims to integrate the plant's inherent strength with TEOS-enhanced mechanical properties and assess the feasibility of incorporating TEOS-modified mugwort into a lime-based matrix. The modified mugwort and its lime-based composite characterisation were conducted using FTIR, SEM-EDS, thermogravimetric analysis, compressive strength tests, and nitrogen adsorption analysis. FTIR analysis showcases significant structural enhancements post-modification, corroborated by SEM-EDS findings indicating increased silicon content. Peaks at 2915, 2845, and 1256 cm⁻¹ confirm successful modification with octadecyl amine and Si-C bond integration. Silica-related peaks at 1052, 801, and 456 cm⁻¹ indicate the presence of Si-O-Si structures. SEM analysis observes the presentation of Si as a layer confirming line scan position results, and EDS analysis findings indicate an increased silicon content of 15.16 %. Thermogravimetric analysis of modified samples displayed improved stability at low temperatures and more significant mass loss at high temperatures (72.01 % for modified and 28.91 % for unmodified samples) due to the decomposition of new chemical components. Nitrogen adsorption measurements reveal enhanced porosity in modified mugwort, suggesting diverse applications. The surface area of modified mugwort increased by 85 % compared to unmodified samples. Compressive strength analyses underscore the material's suitability for construction, with modified samples exhibiting denser structures at 8.5 % and higher strength at 13.3 % compared to unmodified samples. Macrostructure analysis further supports this, highlighting enhanced compatibility with binding materials. Overall, modified mugwort emerges as a versatile, eco-friendly reinforcement material with improved mechanical and thermal properties, poised for various applications in sustainable construction.

Characterization of silane-treated wheat husk biomass Si3N4 and castor stem sheath fibre-epoxy composite

Characterization of silane-treated wheat husk biomass Si3N4 and castor stem sheath fibre-epoxy composite