Characterization Of Composites Research Articles

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

ZnO:CuO Composites Obtained by Rapid Joule Heating for Photocatalysis.

Semiconductor oxides belonging to various families are ideal candidates for application in photocatalytic processes. One of the challenges facing photocatalytic processes today is improving their efficiency under sunlight irradiation. In this study, the growth and characterization of semiconductor oxide nanostructures and composites based on the ZnO and CuO families are proposed. The selected growth method is the resistive heating of Zn and Cu wires to produce the corresponding oxides, combined with galvanic corrosion of Zn. An exhaustive characterization of the materials obtained has been carried out using techniques based on scanning electron microscopy and optical spectroscopies. The method we have followed and the conditions used in this study present promising results, not only from a degradation efficiency point of view but also because it is a cheap, easy, and fast growth method. These characteristics are essential in order to scale the process beyond the laboratory.

Enhanced Mechanical Properties of Carbon Fiber/Epoxy Nanocomposites Modified with Amine-Functionalized Graphene

<div>Since the beginning of time, people have desired the best materials for production. Metals are often too heavy to be used in manufacturing. Polymer matrix composites (PMC) can be considered more dependable than metals in practical applications because of their high strength-to-weight ratio so it is a good alternative of metals. The article’s objective is to investigate the various PMC properties that are reinforced with carbon fiber. CFRP (Carbon fiber-reinforced polymer) was first made using the hand layup method with carbon fiber as a reinforcement and epoxy resin as a matrix after a thorough literature review. As CFRP have higher stiffness and superior “strength-to-weight ratio,” fiber-reinforced polymer (FRP) composites perform notably better than various conventional metallic materials. The qualities of the matrix can be changed to enhance the characterization of FRP composites. The mechanical qualities of FRP composites have risen as a result of significant advancements in the application of nanoparticles for betterment of the matrix and various tests were conducted to calculate the properties of the composite.</div>

Effect of various aging conditions and treatment methods on thermal degradation of coffee waste/epoxy composites

In composites containing lignocellulosic fillers, the chemical composition of the filler mostly determines the heat resistance. Based on the rules of green chemistry, new bio-based composites were developed from the waste of industrial crop product coffee (CW), and their thermal stability in different aging environments was examined by thermogravimetric analysis (TGA). Alkali (NaOH), microwave (MW), ultrasound (US), and alkali pretreatment followed by microwave (NaOH+MW) were applied to modify the CW. The effect of various applied treatment methods and environmental conditions such as UV radiation, water sorption, seawater, and hydrothermally agings on the thermal properties of the composites was investigated. Fourier-transform infrared spectroscopy (FTIR) and Field emission scanning electron microscopy (FE-SEM) were used in the characterization of composites. Among the environmental factors tested, seawater and hydrothermal aging affected the thermal resistance of the composites the most, while NaOH+MW affected it most among the processing methods. Although the thermal stability of unaged and UV-exposed MW-CW composites was found to be the highest, it was more affected by aging in seawater, pure water, and hydrothermal environments. As a result, MW was found to be more effective among the treatment methods in terms of thermal properties under UV conditions, confirming that the adoption of environmentally friendly methods and surface modification of the filler can provide superior composites.

Mechanical and Antimicrobial Properties of the Graphene-Polyamide 6 Composite.

This paper presents the synthesis and characterization of graphene-polymer composites, focusing on their mechanical and antibacterial properties. Graphene flakes were obtained via an electrochemical method and integrated into polyamide 6 (PA6) matrices using melt intercalation. Various characterization techniques confirmed the quality of the graphene flakes, including X-ray diffraction (XRD), Raman spectroscopy, and infrared (IR) spectroscopy, as well as scanning and transmission electron microscopy (SEM and TEM) imaging. Mechanical tests showed an increase in the elastic modulus with graphene incorporation, while the impact strength decreased. The SEM analysis highlighted the dispersion of the graphene flakes within the composites and their impact on fracture behavior. Antimicrobial tests demonstrated significant antibacterial properties of the composites, attributed to both oxidative stress and mechanical damage induced by the graphene flakes. The results suggest promising applications for graphene-polymer composites in advanced antimicrobial materials.

Characterization of rubber-clay composites as recycled waste lightweight construction materials

Characterization of rubber-clay composites as recycled waste lightweight construction materials

Cross-linked ZnAl-LDH/PEDOT:PSS/MoS2 coating in-situ grown on aluminum alloy for excellent protection against both corrosion and wear

In this study, a new Al-LPM composite coating was in-situ deposited on the Al alloy via a facile one-pot hydrothermal method. Morphological and compositional characterizations revealed a tri-layered structure of the Al-LPM coating, namely, zinc aluminum-layered double hydroxide (ZnAl-LDH)/poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS)/MoS2. ZnAL-LDH was deposited closest to the surface of Al alloy, and the metallic ion-cross-linking of PEDOT:PSS makes the 3D coating more robust. The unique structure endows the coating with superior protective properties against both corrosion and wear. For anti-corrosion, the Al-LPM coating showed very high self-corrosion potential (-0.092 V) and small self-corrosion current density (46.0 μA cm−2) (vs. Al substrate with -1.157 V and 354.8 μA cm−2, respectively), long-lasting high corrosion resistance (>57,000 Ω cm2) during the immersion test, and the almost intact surface morphology and composition after 360 h corrosion. For anti-wear, the friction coefficient of the Al-LPM coating was determined to be < 0.2, which was much smaller than for the Al substrate (> 0.4). Also, there were no serious wear marks and grooves left after the dry-friction test.

Development and characterization of hybrid aluminium matrix composites through stir-squeeze casting using distinct reinforcements for structural applications

Development and characterization of hybrid aluminium matrix composites through stir-squeeze casting using distinct reinforcements for structural applications