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J. Compos. Sci., Volume 7, Issue 11 (November 2023) – 36 articles

Cover Story (view full-size image): Heavy metal ions (HMIs) pose an imminent threat to both human well-being and the delicate balance of ecosystems due to their acute toxic effects. Detecting these hazardous elements with precision is paramount for safeguarding health and the environment. In recent years, a surge in research has harnessed the potential of various nanocomposite materials, including metal–organic frameworks (MOFs), organic conducting polymers (OCP), carbon nanotubes (CNTs), graphene oxide (GO), reduced graphene oxide (rGO), graphitic carbon nitride (gC3N4), metal oxides, chitosan, MXenes, and metal nanoparticle-based nanocomposites. This comprehensive review encapsulates the cutting-edge progress in electrochemical sensors crafted from diverse nanocomposite materials for HMI detection in real-world scenarios, such as environmental monitoring, food safety, and clinical diagnosis. View this paper
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23 pages, 8677 KiB  
Article
Nano Propolis, Zinc Oxide Nanoparticles, and Their Composites: A Novel Green Synthesis with Synergistic Antioxidant and Anticancer Properties
J. Compos. Sci. 2023, 7(11), 480; https://doi.org/10.3390/jcs7110480 - 20 Nov 2023
Viewed by 1470
Abstract
Nanoparticles of zinc oxide (ZnO NPs), propolis, and the ZnO–propolis composite (ZnO-P NCs) have been synthesized using a biomimetic approach. Zeta potential analysis and Fourier-transform infrared spectroscopy (FT-IR) proved the formation and stability of nanomaterials. Findings using X-ray diffraction (XRD), scanning electron microscopy [...] Read more.
Nanoparticles of zinc oxide (ZnO NPs), propolis, and the ZnO–propolis composite (ZnO-P NCs) have been synthesized using a biomimetic approach. Zeta potential analysis and Fourier-transform infrared spectroscopy (FT-IR) proved the formation and stability of nanomaterials. Findings using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), EDX-imaging, and transmission electron microscopy (TEM) demonstrated that the particle size of ZnO-P NCs was 9.70 nm. The antioxidant (DPPH radical scavenging) activity of synthesized nanomaterials was investigated. IC50 values of zinc oxide, propolis, and ZnO-P NCs nanoparticles were 2.75, 1.7, and 1.45 mg mL−1, respectively. In addition, their selectivity and anticancer activity for cancer cell lines (Hela and MCF-7) and human normal (W138) cell lines were investigated. ZnO-P NCs were highly effective against the cell line for breast cancer with an IC50 value of 18 µg/mL, indicating its anticancer-promising potent cytotoxicity in breast cancer treatment, and 23 µg/mL against cervical cancer. In addition, the higher observed safety, antioxidant, and anticancer activities for synthesized ZnO-P NCs confirmed the synergistic effect of this combination. It was obtained that the specific mechanisms underlying the synergy effect between zinc oxide nanoparticles and nanopropolis in their composite formulation varied depending on the preparation method, ratio, and concentration of the components. Full article
(This article belongs to the Section Composites Manufacturing and Processing)
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13 pages, 2383 KiB  
Article
Ultrasonic Attenuation of Carbon-Fiber Reinforced Composites
J. Compos. Sci. 2023, 7(11), 479; https://doi.org/10.3390/jcs7110479 - 17 Nov 2023
Viewed by 1095
Abstract
Ultrasonic attenuation measurements were conducted on cross-ply and quasi-isotropic lay-ups of eight types of carbon-fiber reinforced composites (CFRPs) using through-transmission methods with diffraction correction. Attenuation values were substantially higher than those of unidirectional composites and other structural materials. Wave modes, fiber distributions, matrix [...] Read more.
Ultrasonic attenuation measurements were conducted on cross-ply and quasi-isotropic lay-ups of eight types of carbon-fiber reinforced composites (CFRPs) using through-transmission methods with diffraction correction. Attenuation values were substantially higher than those of unidirectional composites and other structural materials. Wave modes, fiber distributions, matrix resins, and consolidation methods affected total attenuation. Transverse mode, quasi-isotropic lay-up, and polyimide and thermoplastic resins generally produced higher attenuation. No clear trends from the fiber distribution were revealed, indicating that it is not feasible presently to predict the attenuation of various lay-ups from the unidirectional values. That is, direct attenuation tests for different laminate lay-ups are needed. This work expanded the existing attenuation database by properly determining the attenuation coefficients of two additional layup types of CFRP laminates. Results showed the merit of ultrasonic attenuation measurements for quality control and structural health monitoring applications. A crucial benefit of the through-transmission methods is that they enable the prediction of Lamb wave attenuation in combination with software like Disperse (ver. 2.0.20a, Imperial College, London, UK, 2013). Full article
(This article belongs to the Section Polymer Composites)
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15 pages, 6626 KiB  
Article
Enhanced Wear Resistance in Carbon Nanotube-Filled Bio-Epoxy Composites: A Comprehensive Analysis via Scanning Electron Microscopy and Atomic Force Microscopy
J. Compos. Sci. 2023, 7(11), 478; https://doi.org/10.3390/jcs7110478 - 15 Nov 2023
Cited by 1 | Viewed by 1277
Abstract
This investigation focuses on the wear resistance and surface morphology of multi-walled carbon nanotube (MWCNT)-filled bio-based epoxy composites. This study examines the impact of different MWCNT concentrations (0 Wt.%, 0.25 Wt.%, 0.50 Wt.%, and 0.75 Wt.%) on the wear properties of these composites. [...] Read more.
This investigation focuses on the wear resistance and surface morphology of multi-walled carbon nanotube (MWCNT)-filled bio-based epoxy composites. This study examines the impact of different MWCNT concentrations (0 Wt.%, 0.25 Wt.%, 0.50 Wt.%, and 0.75 Wt.%) on the wear properties of these composites. Techniques such as scanning electron microscopy (SEM) and atomic force microscopy (AFM) were utilized for comprehensive surface characterization. The results demonstrated a direct correlation between the MWCNT content and the wear resistance of the composites, which were corroborated by robust statistical analysis. Furthermore, SEM and AFM observations disclosed incremental enhancements in both wear resistance and surface quality as the MWCNT concentration increased. This research not only augments the understanding of wear mechanisms in bio-based epoxy composites but also aligns with the burgeoning focus on sustainable materials. Full article
(This article belongs to the Section Carbon Composites)
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24 pages, 9853 KiB  
Article
Collapse Resistance of Composite Structures with Various Optimized Beam–Column Connection Forms
J. Compos. Sci. 2023, 7(11), 477; https://doi.org/10.3390/jcs7110477 - 15 Nov 2023
Viewed by 1039
Abstract
Steel–concrete composite structures are widely used in composite frame structures and super high-rise buildings. However, the lack of relevant building design standards to ensure their structural stability under extreme conditions has led to potential failures in beam–column connections due to excessive loads. These [...] Read more.
Steel–concrete composite structures are widely used in composite frame structures and super high-rise buildings. However, the lack of relevant building design standards to ensure their structural stability under extreme conditions has led to potential failures in beam–column connections due to excessive loads. These failures can trigger the progressive collapse of high-rise buildings, resulting in severe casualties. In this study, a comparative numerical analysis was conducted to evaluate the collapse resistance of composite structures in the event of a middle-column loss scenario, focusing on six commonly used beam–column connections. The results show that while the six connections exhibit minimal differences under normal operating conditions, they display significant variations when subjected to extreme loads. Furthermore, a design concept is proposed to enhance the collapse capacity of these structures, and its effectiveness is validated via analysis. Full article
(This article belongs to the Section Composites Manufacturing and Processing)
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17 pages, 5629 KiB  
Article
Advancements in Conductive Cotton Thread-Based Graphene: A New Generation of Flexible, Lightweight, and Cost-Effective Electronic Applications
J. Compos. Sci. 2023, 7(11), 476; https://doi.org/10.3390/jcs7110476 - 15 Nov 2023
Viewed by 1142
Abstract
Conductive threads have emerged as a highly promising platform for the advancement of smart textiles, enabling the integration of conductivity into fabric materials. In this study, we present a novel approach to fabricate highly flexible graphene-based smart threads, which exhibit exceptional electrical properties. [...] Read more.
Conductive threads have emerged as a highly promising platform for the advancement of smart textiles, enabling the integration of conductivity into fabric materials. In this study, we present a novel approach to fabricate highly flexible graphene-based smart threads, which exhibit exceptional electrical properties. Four distinct types of smart threads were meticulously prepared by drop-casting graphene dispersions onto cotton threads, utilizing various solvents. The influence of annealing temperature and the quantity of dispersed graphene on the electrical conductivity of the threads was systematically investigated. Our findings reveal that the electrical conductivity of the threads is significantly influenced by the type of solvent and the annealing temperature, while exhibiting an increasing trend with higher amounts of dispersed graphene. Remarkably, we achieved a maximum electrical conductivity of 2505.68 S cm−1 for a thread prepared with 6 mL of graphene dispersed in ethanol, annealed at a temperature of 78 °C. Furthermore, the fabricated smart threads were successfully employed as replacements for electric cables in a mobile charger and a computer mouse, demonstrating their high efficiency. This work represents a significant advancement in the development of a new generation of smart textiles, offering a simple, cost-effective, and environmentally friendly fabrication method for the production of smart threads. Full article
(This article belongs to the Section Composites Manufacturing and Processing)
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15 pages, 7074 KiB  
Article
A Study to Investigate the Influence of Machining Parameters on Delamination in the Abrasive Waterjet Machining of Jute-Fiber-Reinforced Polymer Composites: An Integrated Taguchi and Response Surface Methodology (RSM) Optimization to Minimize Delamination
J. Compos. Sci. 2023, 7(11), 475; https://doi.org/10.3390/jcs7110475 - 14 Nov 2023
Cited by 2 | Viewed by 1097
Abstract
In recent years, abrasive waterjet machining has emerged as a promising machining technique for the machining of composites because of its non-thermal nature. In the present study, the effect of machining parameters on the quality of machining has been studied and the process [...] Read more.
In recent years, abrasive waterjet machining has emerged as a promising machining technique for the machining of composites because of its non-thermal nature. In the present study, the effect of machining parameters on the quality of machining has been studied and the process parameters have been optimized to machine jute-fiber-reinforced polymer composites. The design of the experiment was used to predict the combination of the input parameters for L27 experiments. Taguchi and response surface methodology (RSM) techniques were employed to analyze the experimental data and identify the optimum combination of process parameters to achieve as little delamination as possible. The results indicate that an increase in the values of the parameters traverse speed and abrasive mass flow rate leads to an increase in the damage obtained. However, an increase in the value of the parameter stand-off distance minimizes the damage produced. To achieve minimum delamination, the optimum combination of input parameters is obtained through Taguchi and RSM. For the present experimental condition, to achieve minimum delamination, the parameter traverse speed should be set at 20 mm/min, the stand-off distance should be 4 mm, and the abrasive flow rate should be set at 0.25 kg/min. The results confirm that the optimum combination of parameters obtained through both approaches is similar. This investigation results indicated a significant improvement in the cutting quality with reduced damage, achieved through the optimized process parameters. For the considered range of parameters, graphs are plotted such that any intermediate values can be anticipated within the considered range without performing any further experiments. The present work signifies the effect of fiber orientation on delamination. Full article
(This article belongs to the Section Polymer Composites)
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14 pages, 4247 KiB  
Article
The Influence of Composite Luminescent Materials Based on Graphene Oxide on the Growth and Development of Solanum lycopersicum in Greenhouses
J. Compos. Sci. 2023, 7(11), 474; https://doi.org/10.3390/jcs7110474 - 12 Nov 2023
Cited by 1 | Viewed by 1088
Abstract
The effect of graphene oxide-based photoconversion covers on the growth and photosynthesis of tomatoes (Solanum lycopersicum) was investigated. Two types of photoconversion composite for covers were produced. In the first, only graphene oxide nanoparticles were used as a phosphor, and in [...] Read more.
The effect of graphene oxide-based photoconversion covers on the growth and photosynthesis of tomatoes (Solanum lycopersicum) was investigated. Two types of photoconversion composite for covers were produced. In the first, only graphene oxide nanoparticles were used as a phosphor, and in the second, the graphene oxide nanoparticles were used jointly with europium oxide nanoparticles. The freshly prepared composites for covers had almost identical photoluminescence spectra: an intense peak in the red region and a minor peak in the blue region. It was revealed that during operation, luminescence in the red region decreased, while in the blue region it increased, probably due to the photothermal reduction of graphene oxide. It was shown that the photoconversion covers increased productivity (25%) and intensified photosynthesis (30–35%) in the tomato plants. It is suggested that the stimulation of plant growth is caused by changes in the light spectrum induced by the photoconversion covers. Full article
(This article belongs to the Section Composites Manufacturing and Processing)
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57 pages, 12654 KiB  
Review
Electrochemical Detection of Heavy Metal Ions Based on Nanocomposite Materials
J. Compos. Sci. 2023, 7(11), 473; https://doi.org/10.3390/jcs7110473 - 11 Nov 2023
Viewed by 2150
Abstract
Heavy metal ions (HMIs) have acute toxic effects on health and are dangerous for human existence and the ecosystem. Therefore, their sensitive and selective detection is of great importance. In recent years, various nanocomposite materials have been used by researchers for the detection [...] Read more.
Heavy metal ions (HMIs) have acute toxic effects on health and are dangerous for human existence and the ecosystem. Therefore, their sensitive and selective detection is of great importance. In recent years, various nanocomposite materials have been used by researchers for the detection of HMIs by using various modalities of electrochemical techniques. This review summarizes the recent advances in developing electrochemical sensors based on numerous nanocomposite materials for detecting HMIs. Nanocomposite materials, such as metal–organic frameworks (MOFs), organic conducting polymer (OCPs), carbon nanotubes (CNTs), graphene oxide (GO), graphene/reduced graphene oxide (rGO), graphitic carbon nitride, metal oxide, chitosan, MXenes, metal nanoparticle-based nanocomposites, etc., have been explored by various researchers to improve the sensing properties of electrochemical sensors. This review emphasizes nanocomposite materials’ synthesis and characterization techniques, modalities for HMI detection using electrochemical techniques, and electrochemical sensors. Moreover, this review highlights the development of portable biosensors for detecting HMIs in real-world scenarios, such as environmental monitoring, food safety, and clinical diagnosis. This review also demonstrates the importance of electrochemical sensors based on nanocomposite materials as a reliable, sensitive, and selective tool for detecting HMIs. Full article
(This article belongs to the Section Nanocomposites)
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18 pages, 7858 KiB  
Article
Effects of Electrolyte Compositions and Electrical Parameters on Micro-Arc Oxidation Coatings on 7075 Aluminum Alloy
J. Compos. Sci. 2023, 7(11), 472; https://doi.org/10.3390/jcs7110472 - 11 Nov 2023
Viewed by 983
Abstract
Aluminum alloys are widely used in a variety of industries nowadays for their high strength-to-weight ratio, good formability, low density, and recyclability. However, their poor corrosion and wear resistance properties restrict their applications. This study investigated the effects of electrical parameters and electrolyte [...] Read more.
Aluminum alloys are widely used in a variety of industries nowadays for their high strength-to-weight ratio, good formability, low density, and recyclability. However, their poor corrosion and wear resistance properties restrict their applications. This study investigated the effects of electrical parameters and electrolyte compositions on the microstructures of micro-arc oxidation (MAO) film on a 7075 Al alloy substrate. The morphology, microstructure, and compositions of the MAO coatings were characterized using a scanning electron microscope (SEM), X-ray diffraction (XRD), and an electron probe micro-analyzer (EPMA). Furthermore, measurements of microhardness, corrosion resistance, and wear resistance were also conducted. The cathodic current and duty ratio are proportional to film thickness, which consequently improves the wear and corrosion resistance. The microstructural observations of the aluminate-based coatings revealed that increasing cathodic current reduces the pancake-like structures, and a lot of small pores appear on the top of the coatings, which makes the surface smoother. Moreover, the aluminate-based coatings are mainly composed of α-Al2O3 and γ-Al2O3, while the silicate-based coatings mainly consist of γ-Al2O3 and a small amount of α-Al2O3 phase. Due to the phase compositions, the microhardness of the aluminate-based coatings can reach 1300~1500 HV and exhibit better wear resistance than silicate-based coatings. Full article
(This article belongs to the Special Issue Multifunctional Composites, Volume III)
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15 pages, 3942 KiB  
Article
Thermal Characteristics Enhancement of AN/Mg/NC Composite Using Activated Carbon/Cobalt Oxide as Highly Effective Catalytic Additive
J. Compos. Sci. 2023, 7(11), 471; https://doi.org/10.3390/jcs7110471 - 11 Nov 2023
Cited by 1 | Viewed by 974
Abstract
Our study examined the potential of using activated carbon/nanosized cobalt oxide (AC-Co3O4) as a new catalytic additive to improve the efficiency of the parent ammonium nitrate/magnesium/nitrocellulose (AN/Mg/NC) composite. These findings demonstrate a significant improvement in the thermal characteristics of [...] Read more.
Our study examined the potential of using activated carbon/nanosized cobalt oxide (AC-Co3O4) as a new catalytic additive to improve the efficiency of the parent ammonium nitrate/magnesium/nitrocellulose (AN/Mg/NC) composite. These findings demonstrate a significant improvement in the thermal characteristics of AN/Mg/NC/AC-Co3O4 compared to the initial AN/Mg/NC. Raman spectra confirmed the multilayered nature of AC. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the presence of cobalt oxide in the synthesized additive. Differential scanning calorimetry (DSC) revealed the catalytic effect of AC-Co3O4 on the AN/Mg/NC composite, resulting in the reduction in the decomposition peak temperature (Tmax) from 277.4 °C (for AN/Mg/NC) to 215.2 °C (for AN/Mg/NC/AC-Co3O4). Thermal gravimetric analysis (TG) determined the overall mass losses (%) for AN/Mg/NC (70%), AN/Mg/NC/AC (75%), and AN/Mg/NC/AC-Co3O4 (80%). This analysis highlights the significant role of AC-Co3O4 in enhancing the energy release during decomposition. Moreover, the use of the differential thermogravimetric (DTG) technique demonstrated the two-step decomposition pathways attributed to the multi-component system. Finally, the combustion tests under the pressure of 3.5 MPa validated the catalytic efficiency of the AC-Co3O4 additive, which enhanced the burning rate (rb) of the AN/Mg/NC/AC-Co3O4 composite from 10.29 to 19.84 mm/s compared to the initial AN/Mg/NC composite. The advantageous nature of the AN/Mg/NC/AC-Co3O4 composite with a lowered decomposition temperature can be applied in rocket propulsion systems, where the precise control of combustion and ignition processes is crucial. Full article
(This article belongs to the Section Composites Manufacturing and Processing)
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19 pages, 6683 KiB  
Article
Examining Energy Storage Potential in Weakly Polar Nematic Liquid Crystals Infused with Anthraquinone Dye: A Comprehensive Approach
J. Compos. Sci. 2023, 7(11), 470; https://doi.org/10.3390/jcs7110470 - 10 Nov 2023
Viewed by 1091
Abstract
The applications of liquid crystals in the field of renewable, clean and sustainable technologies of energy storage are of utmost importance at present. This paper delves into dielectric spectroscopic studies of a weakly polar nematic liquid crystal (NLC) enriched with an anthraquinone dye. [...] Read more.
The applications of liquid crystals in the field of renewable, clean and sustainable technologies of energy storage are of utmost importance at present. This paper delves into dielectric spectroscopic studies of a weakly polar nematic liquid crystal (NLC) enriched with an anthraquinone dye. The primary objective is to assess the impact of increasing dye concentrations on various properties. Anthraquinone dye has been found to increase the dielectric permittivity of weakly polar NLC, leading to a 4.7-fold increase in dielectric anisotropy. Simultaneously, a reduction of around 11% in threshold and operating voltages of the NLC has also been recorded after using dye as the guest material. The added dipolar contributions provided by dye molecules have been attributed to this surplus permittivity. The NLC has been found to have an approximately 54% faster response to the applied field. The intrinsic polarization field of dye molecules accelerates nearby LC molecule reorientation, leading to a 56.5% faster fall time and a 29.8% faster rise time in a 3.0 wt% dye-doped LC cell. These experimental results have been validated via computational studies as well. The simulation results about dipole moment and polarizability provide robust support for our experimental results. Such composites evince their potential for energy storage and 5G communication technologies with adjustable impedance and permittivity. Full article
(This article belongs to the Section Composites Applications)
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15 pages, 3723 KiB  
Article
Synthesis of BaSnO3 as a Highly Dispersed Additive for the Preparation of Proton-Conducting Composites
J. Compos. Sci. 2023, 7(11), 469; https://doi.org/10.3390/jcs7110469 - 09 Nov 2023
Viewed by 1153
Abstract
The process of thermolysis of barium hydroxostannate BaSn(OH)6 as a precursor for preparing barium stannate BaSnO3 has been investigated using the method of differential thermal analysis. Thermal decomposition products of the precursor were characterized using X-ray diffraction, IR spectroscopy, low-temperature nitrogen [...] Read more.
The process of thermolysis of barium hydroxostannate BaSn(OH)6 as a precursor for preparing barium stannate BaSnO3 has been investigated using the method of differential thermal analysis. Thermal decomposition products of the precursor were characterized using X-ray diffraction, IR spectroscopy, low-temperature nitrogen adsorption, and scanning electron microscopy. It was shown that dehydration at nearly 270 °C resulted in the formation of an X-ray amorphous multiphase product, from which single-phase barium stannate crystallized at temperatures above 600 °C. The synthesized barium stannate was used as a functional additive to prepare composite proton electrolytes in the CsHSO4-BaSnO3 system. The structural and transport properties of the obtained system were investigated. It is shown that the highly conductive state of the salt is stabilized in a wide range of temperatures. High conductivity values of composite solid electrolytes in the medium temperature range create the possibility of their use as solid electrolyte membrane materials. Full article
(This article belongs to the Section Composites Manufacturing and Processing)
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18 pages, 3072 KiB  
Review
A Review of Delamination Damage of Composite Materials
J. Compos. Sci. 2023, 7(11), 468; https://doi.org/10.3390/jcs7110468 - 09 Nov 2023
Viewed by 1729
Abstract
The theoretical and practical achievements in the field of the theory of strength and reliability of composite materials are discussed in a review conducted on the scientific research conducted on the effect of delamination on the reliability and quality of composites. The methodological [...] Read more.
The theoretical and practical achievements in the field of the theory of strength and reliability of composite materials are discussed in a review conducted on the scientific research conducted on the effect of delamination on the reliability and quality of composites. The methodological aspects of the stability of the mechanical characteristics of composite materials under the combined action of cyclic and impact loads are examined, as are the manufacturing and processing technologies. The reasons for delamination, such as technological, manufacturing and application, free edge, joints and loads, are revealed. The influence of delamination on the bearing capacity of structural elements made of composite materials is analyzed. The mechanism of delamination growth is outlined, and the criteria and processes are defined, such as the growth of delamination cracks in a multidirectional laminated plate from a straight edge, edge delamination during plate bending, delamination in plates in the field of residual stresses, etc. The importance of taking into account the visco-plastic effect at the top of the edge crack of delamination of composite materials is emphasized. The concept of critical delamination behavior is characterized, and the issues of delamination stability are described. Full article
(This article belongs to the Section Composites Modelling and Characterization)
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12 pages, 10115 KiB  
Article
Magnesium Strengthening in 3D Printed TCP Scaffold Composites
J. Compos. Sci. 2023, 7(11), 467; https://doi.org/10.3390/jcs7110467 - 09 Nov 2023
Viewed by 980
Abstract
This study reports the production of a Mg/15%β-tricalcium phosphate Ca3(PO4)2 composite by combining direct ink writing for the β-TCP preform and liquid infiltration technique to obtain a continuous metal matrix composite. The influence of the volume fraction of [...] Read more.
This study reports the production of a Mg/15%β-tricalcium phosphate Ca3(PO4)2 composite by combining direct ink writing for the β-TCP preform and liquid infiltration technique to obtain a continuous metal matrix composite. The influence of the volume fraction of β-TCP and the in situ reaction between ceramic and metal on the microstructure and mechanical properties were investigated in detail. The β-TCP preform was uniformly distributed in the matrix, forming a continuous three-dimensional (3D) network. The obtained composite was characterized by means of relative density (He pycnometry), X-ray diffractometry (XRD), scanning electron microscopy (SEM), and electron spectroscopy (EDX). The results suggested that a highly densified composite was processed. Three phases were identified as products generated by an exothermic reaction (Mg2Ca, CaO, and MgO); based on this, the chemical reaction mechanism for MgO formation was proposed. The compression and hardness tests showed that the Mg/15%β-tricalcium phosphate Ca3 (PO4)2 composite significantly improved its mechanical properties, i.e., 27% and 15% higher than pure Mg in compressive strength and yield strength, respectively. This behavior was attributed to the high densification of the resulting composite, strong chemical interfacial bonding, phase dispersion hardening (in situ phase formation), and the geometry and continuity of the reinforcement. These provided good load transfer from the Mg matrix to the reinforcement and contributed as strengthening mechanisms. The results reported in this investigation can help to design Mg/calcium phosphate continuous composites for biomedical applications. Full article
(This article belongs to the Special Issue 3D Printed Composite Materials and Structures)
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14 pages, 9125 KiB  
Article
Spark Plasma Sintering and Hot Pressing of Cu+Al Powder Mixtures and Pre-Deposited Cu/Al Layers
J. Compos. Sci. 2023, 7(11), 466; https://doi.org/10.3390/jcs7110466 - 07 Nov 2023
Viewed by 1185
Abstract
Reactive processing of metals is interesting for materials design and achieving new sets of properties. The transformation degree of the metals, the factor governing the properties of the material as a whole, depends on the sintering/heat treatment conditions. In the present investigation, the [...] Read more.
Reactive processing of metals is interesting for materials design and achieving new sets of properties. The transformation degree of the metals, the factor governing the properties of the material as a whole, depends on the sintering/heat treatment conditions. In the present investigation, the phase and microstructure formation of materials obtained by sintering of Cu-10 wt.% Al mixtures and layered Cu/Al structures under different modes of pressing/heating is presented. The samples were obtained via spark plasma sintering (SPS), hot pressing (HP) and pressureless sintering. The products of the interaction between the metals were Al2Cu and Cu9Al4 intermetallics and Cu(Al) solid solutions. The influence of the consolidation method on the phase composition of the sintered materials was studied. The hardness of the composites was analyzed in relation to their structural features. A model experiment has been conducted to trace the structural evolution at the Cu/Al interface caused by interdiffusion. The Cu/Al layered structures obtained by detonation spraying of the powders on a steel substrate were treated by SPS or HP. The effect of electric current, which is a feature of SPS processing, was in accelerating the reaction product formation in the layered structures still containing the starting metallic reactants. Full article
(This article belongs to the Special Issue Metal Composites)
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21 pages, 17622 KiB  
Article
Multiscale Characterisation of Staple Carbon Fibre-Reinforced Polymers
J. Compos. Sci. 2023, 7(11), 465; https://doi.org/10.3390/jcs7110465 - 06 Nov 2023
Viewed by 1918
Abstract
The aim of this study was to characterise the microstructural organisation of staple carbon fibre-reinforced polymer composites and to investigate their mechanical properties. Conventionally, fibre-reinforced materials are manufactured using continuous fibres. However, discontinuous fibres are crucial for developing sustainable structural second-life applications. Specifically, [...] Read more.
The aim of this study was to characterise the microstructural organisation of staple carbon fibre-reinforced polymer composites and to investigate their mechanical properties. Conventionally, fibre-reinforced materials are manufactured using continuous fibres. However, discontinuous fibres are crucial for developing sustainable structural second-life applications. Specifically, aligning staple fibres into yarn or tape-like structures enables similar usage to continuous fibre-based products. Understanding the effects of fibre orientation, fibre length, and compaction on mechanical performance can facilitate the fibres’ use as standard engineering materials. This study employed methods ranging from microscale to macroscale, such as image analysis, X-ray computed tomography, and mechanical testing, to quantify the microstructural organisations resulting from different alignment processing methods. These results were compared with the results of mechanical tests to validate and comprehend the relationship between fibre alignment and strength. The results show a significant influence of alignment on fibre orientation distribution, fibre volume fraction, tortuosity, and mechanical properties. Furthermore, different characteristics of the staple fibre tapes were identified and attributed to kinematic effects during movement of the sliver alignment unit, resulting in varying tape thicknesses and fuzzy surfaces. Full article
(This article belongs to the Topic Advanced Carbon Fiber Reinforced Composite Materials)
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14 pages, 10673 KiB  
Article
Mechanical Properties of α-Chitin and Chitosan Biocomposite: A Molecular Dynamic Study
J. Compos. Sci. 2023, 7(11), 464; https://doi.org/10.3390/jcs7110464 - 06 Nov 2023
Viewed by 1094
Abstract
This study investigates the mechanical properties of α-chitin and chitosan biocomposites using molecular dynamics (MD) and stress–strain analyses under uniaxial tensile loading in an aqueous environment. Our models, validated against experimental data, show that α-chitin has a higher directional elastic modulus of 51.76 [...] Read more.
This study investigates the mechanical properties of α-chitin and chitosan biocomposites using molecular dynamics (MD) and stress–strain analyses under uniaxial tensile loading in an aqueous environment. Our models, validated against experimental data, show that α-chitin has a higher directional elastic modulus of 51.76 GPa in the x and 39.76 GPa in the y directions compared to its chitosan biocomposite, with 31.66 GPa and 26.00 GPa in the same directions, demonstrating distinct mechanical behaviors between α-chitin and the biocomposite. The greater mechanical stiffness of α-chitin can be attributed to its highly crystalline molecular structure, offering potential advantages for applications requiring load-bearing capabilities. These findings offer valuable insights for optimizing these materials for specialized applications. Full article
(This article belongs to the Special Issue Sustainable Biocomposites, Volume II)
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13 pages, 2819 KiB  
Article
Green Hydrogen Generation from Eco-Friendly and Cost-Effective Red Sea Water Using a Highly Photocatalytic Nanocomposite Film, As2O3/Poly-3-methylaniline
J. Compos. Sci. 2023, 7(11), 463; https://doi.org/10.3390/jcs7110463 - 05 Nov 2023
Viewed by 1463
Abstract
The primary objective of this research is to address the energy challenges by introducing an innovative nanocomposite material. This material is designed to facilitate the conversion of environmentally friendly and economically viable Red Sea water into hydrogen gas. The ultimate goal of this [...] Read more.
The primary objective of this research is to address the energy challenges by introducing an innovative nanocomposite material. This material is designed to facilitate the conversion of environmentally friendly and economically viable Red Sea water into hydrogen gas. The ultimate goal of this work is to pave the way for the development of a practical device that can be employed within households and industrial settings to directly convert water into hydrogen gas. This novel nanocomposite material synthesized through oxidative polymerization comprises As2O3 and Poly-3-methylaniline (P3MA). This material possesses an extensive absorption range, spanning up to 700 nm, and features a bandgap of 1.75 eV, making it a promising candidate for use as a photoelectrode in green hydrogen production. The unique aspect of this setup lies in the utilization of Red Sea water, a natural sacrificing agent, as the electrolyte, rendering the process eco-friendly and cost-effective. When it is employed as a photoelectrode, this material exhibits high sensitivity to green hydrogen production, generating 6 moles/10 cm2·h of hydrogen. At a voltage of −0.83 V, the current density values are measured as −0.08 mA·cm−2 (Jph) in light and −0.02 mA·cm−2 (Jo) in darkness. Furthermore, the photoelectrode’s responsiveness to light is assessed with different optical filters, revealing the optimal performance at 340 nm, where Jph reaches −0.052 mA·cm−2. These outcomes provide strong evidence of the photoactivity of the As2O3/P3MAphotoelectrode for green hydrogen production using Red Sea water. This underscores its potential for the development of an electrochemical cell for the direct conversion of sea water into H2 gas. Full article
(This article belongs to the Section Nanocomposites)
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26 pages, 7615 KiB  
Article
Multi-Response Optimization of Abrasive Waterjet Cutting on r-GO-Reinforced Fibre Intermetallic Laminates through Moth–Flame Optimization Algorithm
J. Compos. Sci. 2023, 7(11), 462; https://doi.org/10.3390/jcs7110462 - 03 Nov 2023
Viewed by 872
Abstract
Laminated metal-composite structures, also known as fibre metal laminates (FMLs), have emerged as prominent engineering materials in various industries, particularly in the domains of aircraft and automobile manufacturing. These materials are sought after due to their enhanced impact and fatigue resistance capabilities. The [...] Read more.
Laminated metal-composite structures, also known as fibre metal laminates (FMLs), have emerged as prominent engineering materials in various industries, particularly in the domains of aircraft and automobile manufacturing. These materials are sought after due to their enhanced impact and fatigue resistance capabilities. The machining of FMLs plays a crucial role in achieving near-net shapes for the purpose of joining and assembling components. Delamination is a prevalent issue encountered during the process of conventional machining, thus rendering FMLs are challenging materials to machine. This study aims to investigate the cutting process of novel fibre intermetallic laminates (FILs) using the abrasive water jet (AWJ) cutting technique. The FILs consists of carbon and aramid fibers that are adhesively bonded with a resin matrix filled with reduced graphene oxide (r-GO) nano fillers. Moreover, these laminates contain embedded Nitinol shape memory alloy sheets as the skin materials. Specifically, the study aims to investigate the impact of different factors, such as the addition of reduced graphene oxide (r-GO) in the laminates (ranging from 0 to 2 wt%), traverse speed (ranging from 400 to 600 mm/min), waterjet pressure (ranging from 200 to 300 MPa), and nozzle height (ranging from 2 to 4 mm), on the material removal rate (MRR), delamination factor (FD), and kerf deviation (KD). ANOVA was used in the statistical analysis to determine the most influential parameters and their effects on the selected responses. The optimal AWJC parameters are determined using a metaheuristic-based moth–flame optimization (MFO) algorithm in order to enhance cut quality. The efficacy of MFO is subsequently compared with similar well-established metaheuristics such as the genetic algorithm, particle swarm algorithm, dragonfly algorithm, and grey-wolf algorithm. MFO was found to outperform in terms of several performance indices, including rapid divergence, diversity, spacing, and hypervolume values, among the algorithms compared. Full article
(This article belongs to the Section Composites Manufacturing and Processing)
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12 pages, 2519 KiB  
Article
Preparation and Properties of Flexible CuI/Polyvinylpyrrolidone Nanocomposite Thermoelectric Film
J. Compos. Sci. 2023, 7(11), 461; https://doi.org/10.3390/jcs7110461 - 03 Nov 2023
Viewed by 1072
Abstract
A facile preparation method for flexible p-type CuI/polyvinylpyrrolidone (PVP) nanocomposite thermoelectric (TE) film is developed. First, CuI powder was synthesized by a one-pot method; second, PVP was coated in situ with the CuI powder; third, the CuI/PVP nanocomposite film was prepared on a [...] Read more.
A facile preparation method for flexible p-type CuI/polyvinylpyrrolidone (PVP) nanocomposite thermoelectric (TE) film is developed. First, CuI powder was synthesized by a one-pot method; second, PVP was coated in situ with the CuI powder; third, the CuI/PVP nanocomposite film was prepared on a nylon membrane by vacuum filtration and then hot-pressing. Transmission electron microscopy (TEM) observation indicates that the film consists of CuI nanograins with an average size of ~15 nm and PVP distributed at the inner wall of nanopores and the surface of the CuI nanograins. The composite film shows a large Seebeck coefficient of ~605 µVK−1 and a power factor of ~8.05 µWm−1K−2 at 300 K. The nanocomposite film also exhibits excellent flexibility (~96% of initial electrical conductivity retention after being bent 1000 times along a 4 mm radius rod). A single-leg TE module outputs a voltage of ~3.6 mV when the temperature difference is 6 K. This work provides a fast, simple, and environmentally friendly method by which to prepare flexible CuI/PVP nanocomposite TE film with a large Seebeck coefficient, which could be used as a wearable sensor. Full article
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16 pages, 4576 KiB  
Article
Evaluation of the Applicability of Modifying CdSe Thin Films by the Addition of Cobalt and Nickel to Enhance the Efficiency of Photocatalytic Decomposition of Organic Dyes
J. Compos. Sci. 2023, 7(11), 460; https://doi.org/10.3390/jcs7110460 - 03 Nov 2023
Viewed by 728
Abstract
This article presents the results of an assessment of the use of CdSe, NiCdSe, and CoCdSe thin films as a basis for photocatalysts used for the decomposition of the organic dyes rhodamine B, cargo red, and indigo carmine. Interest in this area was [...] Read more.
This article presents the results of an assessment of the use of CdSe, NiCdSe, and CoCdSe thin films as a basis for photocatalysts used for the decomposition of the organic dyes rhodamine B, cargo red, and indigo carmine. Interest in this area was determined by the need to solve a number of issues related to increasing the efficiency purifying aqueous media from the negative effects of organic dyes, which cannot be disposed of using traditional methods associated with adsorption or filtration. The use of the electrochemical synthesis method to obtain thin films of a given thickness showed that the addition of nickel or cobalt sulfates to the standard electrolyte solution used to obtain CdSe films results in the formation of CdSe films with a higher degree of structural ordering (the crystallinity degree was more than 50%), as well as a decline in the band gap. When analyzing data on the photocatalytic decomposition of organic dyes, it was found that a change in the structure of the films due to the introduction of nickel and cobalt leads, in the case of the decomposition of the rhodamine B dye, to a more efficient decomposition, and in the case of the cargo red and indigo carmine dyes, not only to their complete decomposition and mineralization, but also to a reduction in the time of photocatalytic reactions (decomposition growth rate). Moreover, an analysis of cyclic tests demonstrated that NiCdSe and CoCdSe films maintain 90% of their photocatalytic decomposition efficiency compared to that achieved during the first decomposition cycle, while CdSe degrades after three consecutive cycles and its efficiency reduces by more than 2.5–3 times. Full article
(This article belongs to the Section Composites Applications)
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19 pages, 5055 KiB  
Article
Strength and Stiffness Evaluation of a Fiber-Reinforced Cement-Stabilized Fly Ash Stone Dust Aggregate Mixture
J. Compos. Sci. 2023, 7(11), 459; https://doi.org/10.3390/jcs7110459 - 03 Nov 2023
Viewed by 1448
Abstract
The utilization of waste fly ash in road construction is primarily confined to its use in embankment filling or as a stabilizer when combined with lime and cement. Its application in structural pavement layers, such as the base and subbase, faces a challenge [...] Read more.
The utilization of waste fly ash in road construction is primarily confined to its use in embankment filling or as a stabilizer when combined with lime and cement. Its application in structural pavement layers, such as the base and subbase, faces a challenge due to the high volume of fine particles, which renders it brittle when stabilized. In this study, fly ash was blended with stone dust and aggregated to enhance its gradation. Subsequently, it was stabilized with cement to bolster its strength, rendering it suitable for pavement use. Additionally, polypropylene (PP) fibers were introduced to mitigate the brittleness of the mixture. An extensive experimental investigation was conducted to assess the strength and stiffness properties, including compressive strength, indirect tensile strength, flexural strength, cyclic indirect tensile modulus, and flexural modulus of fiber-reinforced cement-stabilized mixtures of fly ash, stone dust, and aggregate. The experimental results reveal that the addition of PP fibers up to 0.25 wt.% enhances compressive strength, but any further increase in fiber content leads to a reduction in strength. However, indirect tensile strength and flexural strength show improvement, with an increase in fiber percentage up to 0.5 wt.%. It was observed that cement content plays a dominant role in stabilizing these materials. Appropriate relationships have been established between strength and modulus parameters for stabilized mixtures. Based on the strength and stiffness study, a combination of 70% fly ash and 30% stone dust aggregate with 6% cement can be considered for the base layer. Regarding the behavior of indirect tensile strength and flexural strength, an optimum fiber percentage of 0.35% is recommended. Full article
(This article belongs to the Section Fiber Composites)
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16 pages, 3484 KiB  
Article
Mesoporous Layered Double Hydroxides: Synthesis for High Effective Uranium Ions Sorption from Seawater and Salt Solutions on Nanocomposite Functional Materials
J. Compos. Sci. 2023, 7(11), 458; https://doi.org/10.3390/jcs7110458 - 03 Nov 2023
Cited by 1 | Viewed by 1059
Abstract
A series of sorption materials based on layered double hydroxides (Co-Fe LDH, Ni-Fe LDH, and Zn-Ti LDH) were obtained by a facile and environmentally friendly method of coprecipitation. A low particle size of no more than 10 µm was achieved. The use of [...] Read more.
A series of sorption materials based on layered double hydroxides (Co-Fe LDH, Ni-Fe LDH, and Zn-Ti LDH) were obtained by a facile and environmentally friendly method of coprecipitation. A low particle size of no more than 10 µm was achieved. The use of transition metals makes it possible to obtain compounds that are mechanically and chemically stable in aggressive environments. XRD analysis revealed that the compounds have a highly organized crystalline structure. Using SEM, it was determined that Co-Fe LDH and Ni-Fe LDH had a loose, highly dispersed surface structure, while Zn-Ti LDH had a monolithic surface structure. U(VI) adsorption on the obtained materials in solutions containing Na2CO3, Na2SO4, KNO3, NaCl, K3PO4, and NaHCO3, was studied in batch mode. The degree of purification in the presence of these salts reached 99.9%, while the distribution coefficient Kd reached 105 mL/g. Sorption capacity qmax and equilibrium adsorption constants Kf and KL for U(VI) adsorption in batch mode (for 24 h) from distilled and seawater were determined using the Freundlich and Langmuir equations. The highest sorption capacity of 101.6 mg/g in seawater and 114.1 mg/g in distilled water was registered for Co-Fe-LDH. The presence of competing ions in seawater can reduce sorption efficiency by up to 40%. The provided research allowed us to conclude that the obtained materials, Co-Fe LDH, Ni-Fe LDH, and Zn-Ti LDH are promising for the sorption removal of U(VI) from aqueous media of medium salinity. Full article
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13 pages, 9441 KiB  
Article
Tensile Properties of Aluminum Matrix Composites Produced via a Nitrogen-Induced Self-Forming Process
J. Compos. Sci. 2023, 7(11), 457; https://doi.org/10.3390/jcs7110457 - 02 Nov 2023
Viewed by 1021
Abstract
This study compares the tensile properties of commercial aluminum matrix composites (AMCs) with those of AMCs produced via a nitrogen-induced self-forming process. This process is a newly developed AMCs manufacturing process that takes advantage of the price competitiveness and productivity of large-scale products [...] Read more.
This study compares the tensile properties of commercial aluminum matrix composites (AMCs) with those of AMCs produced via a nitrogen-induced self-forming process. This process is a newly developed AMCs manufacturing process that takes advantage of the price competitiveness and productivity of large-scale products produced via the liquid process. Additionally, this process has the freedom of choice of the reinforcement phase and the homogeneous dispersibility of the powder process. Compared to commercial monolithic 6061 alloys, 6061 aluminum alloy matrix composites exhibit increased Young’s modulus, yield strength, and ultimate tensile strength by 59%, 66%, and 81%, respectively. This study also compares the tensile properties of AMCs with different matrix compositions, including 2009 and 7050 aluminum alloys. The study shows that AMCs produced using the nitride-induced self-forming aluminum composite (NISFAC) process exhibit comparable or superior tensile properties to those obtained using existing commercial powder metallurgy (P/M) processes. Full article
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15 pages, 2491 KiB  
Article
An Explorative Evaluation on the Influence of Filler Content of Polyetheretherketone (PEEK) on Adhesive Bond to Different Luting Resin Cements
J. Compos. Sci. 2023, 7(11), 456; https://doi.org/10.3390/jcs7110456 - 02 Nov 2023
Viewed by 1104
Abstract
Polyetheretherketone (PEEK) is considered one of the most innovative prosthetic materials of the last few decades. Its chemically inert behavior and high biocompatibility make it a promising material in many areas of dentistry. The aim of this study was to test whether PEEK [...] Read more.
Polyetheretherketone (PEEK) is considered one of the most innovative prosthetic materials of the last few decades. Its chemically inert behavior and high biocompatibility make it a promising material in many areas of dentistry. The aim of this study was to test whether PEEK with different TiO2 filler contents achieves comparable bond strength values when using different resin cements. N = 70 PEEK samples each with different TiO2 filler content (20 wt.% TiO2 vs. 5 wt.% TiO2 vs. no filler as a control group) were divided into seven groups and cemented with various conventional (ResiCem, RelyX Ultimate, Variolink Esthetic DC) and self-adhesive resin cements (RelyXUnicem 2, Bifix SE, Panavia SA Cement Plus, SpeedCem). The shear strength of the bond was assessed after 24 h and after 25,000 thermal loading cycles. Mann-Whitney U and Wilcoxon tests were used for statistical analysis (significance level: α = 0.05). PEEK without filler showed the highest mean shear strength (24.26 MPa using RelyX Ultimate), then high-filled PEEK (22.90 MPa using ResiCem) and low-filled PEEK (21.76 MPa using RelyX Ultimate). Conventional resin cements generally achieved slightly higher adhesive strengths than self-adhesive resin cements. It appears that the filler content does not affects the adhesive bond strengths. Full article
(This article belongs to the Special Issue Innovations of Composite Materials in Prosthetic Dentistry)
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15 pages, 2705 KiB  
Article
Novel PolyPropylene–Sargassum Particles Composites: Evaluation of Thermal and Thermomechanical Properties
J. Compos. Sci. 2023, 7(11), 455; https://doi.org/10.3390/jcs7110455 - 01 Nov 2023
Viewed by 1273
Abstract
Sargassum is a type of marine algae that has caused environmental problems in Mexico because it arrives in high quantities along the Mexican coast, especially in the Mexican Caribbean. This situation has become an environmental and economic problem, impacting tourism and other activities. [...] Read more.
Sargassum is a type of marine algae that has caused environmental problems in Mexico because it arrives in high quantities along the Mexican coast, especially in the Mexican Caribbean. This situation has become an environmental and economic problem, impacting tourism and other activities. As a result, it is reasonable to try to find an application for these algae. Recently, some applications in civil construction, cosmetics, and the food industry, among others, have been reported. The present work evaluates the thermal and structural properties of new polypropylene (PP)–Sargassum-based composites. Also, the effect of adding calcium stearate (CS) to increase the interaction between PP and Sargassum particles was investigated. PP–Sargassum particle composites were prepared by a melt mixing process, and the properties of these composites were evaluated using thermal techniques such as dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and infrared spectroscopy (FTIR). The DMA results showed that composites with low concentrations of Sargassum particles perform better than those with higher concentrations. When CS was added to composites, there was a significant improvement in storage modulus compared with composites without CS. This was attributed to the good adhesion of the particles to the matrix because the mobility of macromolecules increased in the presence of CS. The thermal stability of PP–Sargassum particle composites decreases when the amount of particles increases, and the addition of CS does not positively affect the thermal behavior of composites. The findings open the possibility of using Sargassum particles in new applications of these algae as a polymer additive to generate sustainable materials. Full article
(This article belongs to the Special Issue Biopolymeric Matrices Reinforced with Natural Fibers and Nanofillers)
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13 pages, 5100 KiB  
Article
Synthesis and Properties of Rubidium Salts of Phosphotungstic Acid
J. Compos. Sci. 2023, 7(11), 454; https://doi.org/10.3390/jcs7110454 - 01 Nov 2023
Viewed by 1229
Abstract
The work is devoted to the study of the influence of synthesis conditions on the properties of water-insoluble rubidium salts of phosphotungstic acid (PTA). Such heteropoly compounds have a wide range of applications, including in the field of electrocatalysts and solid electrolytes for [...] Read more.
The work is devoted to the study of the influence of synthesis conditions on the properties of water-insoluble rubidium salts of phosphotungstic acid (PTA). Such heteropoly compounds have a wide range of applications, including in the field of electrocatalysts and solid electrolytes for various electrochemical devices. The acid salts of PTA with high activity of acid sites on the particle surface are of particular interest. It is known that the properties of water-insoluble PTA salts strongly depend on synthesis conditions, such as the ratio of reagents, temperature, concentrations, and other parameters. The work examines the influence of the ratio and concentration of reagents on the sizes of crystallites and agglomerates, specific surface area (SSA), porosity, water content, and ionic conductivity of the synthesized PTA salts. The SSA value of the obtained samples varied in the range of 84–123 m2 g−1, and the ionic conductivity was 13–90 mS cm−1 at room temperature and 75% RH. An increase in the acid concentration and the degree of proton substitution led to an increase in SSA, accompanied by an increase in particle sizes without changing the size of crystallites. The results of the work may be useful for the development of new materials based on the obtained salts in many fields, including hydrogen energy. Full article
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16 pages, 4500 KiB  
Article
Green Synthesised Silver Nanoparticles Using Anoectochilus elatus Leaf Extract: Characterisation and Evaluation of Antioxidant, Anti-Inflammatory, Antidiabetic, and Antimicrobial Activities
J. Compos. Sci. 2023, 7(11), 453; https://doi.org/10.3390/jcs7110453 - 01 Nov 2023
Viewed by 1537
Abstract
The present study investigates the green synthesis of silver nanoparticles was carried out using a leaf extract of Anoectochilus elatus (Ae-AgNPs). The synthesised Ae-AgNPs were characterised using different analytical techniques like UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR), [...] Read more.
The present study investigates the green synthesis of silver nanoparticles was carried out using a leaf extract of Anoectochilus elatus (Ae-AgNPs). The synthesised Ae-AgNPs were characterised using different analytical techniques like UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX). Additionally, in vitro activities were investigated, and they possess antioxidant, anti-inflammatory, antidiabetic, and antimicrobial properties. The UV-Vis spectra exhibited characteristic absorption peaks at approximately 480 nm. FTIR identified functional groups of the Ae-AgNPs. The crystalline structure of the Ae-AgNPs was verified via XRD analysis. SEM studies revealed that the nanoparticles exhibited a spherical morphology. The fabrication of Ae-AgNPs was established by the EDX spectrum, which exhibited prominent signals of silver atoms. The Ae-AgNPs show potent antioxidant, anti-inflammatory, and antidiabetic activity compared to standard drugs. In addition, Ae-AgNPs demonstrated the most significant zone of Inhibition. This study affirms the superior biological capability of Ae-AgNPs for target drug delivery and their potential for usage in biomedical research and therapeutics. Full article
(This article belongs to the Section Nanocomposites)
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12 pages, 4423 KiB  
Article
Investigations of Activated Carbon from Different Natural Sources for Preparation of Binder-Free Few-Walled CNTs/Activated Carbon Electrodes
J. Compos. Sci. 2023, 7(11), 452; https://doi.org/10.3390/jcs7110452 - 31 Oct 2023
Viewed by 1079
Abstract
In this study, we present another approach to fabricating high-performance supercapacitor electrodes by combining activated carbon particles with carbon nanotubes (AC/CNT). We synthesized activated carbon from diverse biomass sources using a carbonization process and chemical activation with KOH. By incorporating carbon nanotubes, we [...] Read more.
In this study, we present another approach to fabricating high-performance supercapacitor electrodes by combining activated carbon particles with carbon nanotubes (AC/CNT). We synthesized activated carbon from diverse biomass sources using a carbonization process and chemical activation with KOH. By incorporating carbon nanotubes, we significantly augmented the electrode’s surface area, resulting in exceptional ion transport and a substantial increase in specific capacitance. Our investigation reveals that the optimized composition, 85:10:5 of AC, CNT, and conductive additive, achieved outstanding specific capacitance values, notably 125.6 F g−1 at 1 mV s−1 and 118 F g−1 at 1 A g−1, along with a maximum energy density of 4 Wh kg−1. Electrochemical impedance spectroscopy (EIS) further demonstrated the superior charge transfer capabilities of these electrodes, notably at a frequency range from 100 kHz to 10 mHz. Additionally, our research highlights the influence of different biomass precursors, such as apricot kernels, walnut shells, and rice husks, on the electrochemical behavior of these electrodes. Overall, this study provides valuable insights into the development of high-performance supercapacitors, emphasizing the potential of diverse biomass sources in optimizing electrode materials. Full article
(This article belongs to the Section Carbon Composites)
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17 pages, 3450 KiB  
Article
Trimethoxy Silyl End-Capped Hyperbranched Polyglycidol/Polycaprolactone Particle Gels for Cell Delivery and Tissue Repair: Mechanical Properties, Biocompatibility, and Biodegradability Studies
J. Compos. Sci. 2023, 7(11), 451; https://doi.org/10.3390/jcs7110451 - 31 Oct 2023
Viewed by 1077
Abstract
This study focuses on the development of new biocompatible and biodegradable particle gel scaffolds based on PCL-HBPG/1SiHBPG triblock copolymers composed of a polycaprolactone (PCL) core and two outer blocks of trimethoxysilyl end-capped hyperbranched polyglycidol (HBPG/1SiHBPG) that have the potential to be used in [...] Read more.
This study focuses on the development of new biocompatible and biodegradable particle gel scaffolds based on PCL-HBPG/1SiHBPG triblock copolymers composed of a polycaprolactone (PCL) core and two outer blocks of trimethoxysilyl end-capped hyperbranched polyglycidol (HBPG/1SiHBPG) that have the potential to be used in soft tissue regeneration. The relationship between the gel’s composition, structure, mechanical properties, and performance has been investigated for the first time and the copolymer design parameters have been optimized. The particle gel scaffolds were formed from the concentrated dispersions of the most hydrophobic PCL-45HBPG/1SiHBPG at low temperatures, and were the result of the numerous hydrogen bonds formed from the HBPG/1SiHBPG moieties as well as the formation of siloxane crosslinks (i.e., Si–O–Si bonds). These gels were formed in the physiological temperature range. Gels with a mechanical strength that gradually increases were formed from the physically crosslinked PCL-45HBPG/1SiHBPG particles effectively and safely, in the absence of UV radiation. They feature high elasticity and undergo enzyme-triggered disassembly. The gels are biocompatible and have the potential to invoke cell attachment and differentiation in the absence of exogenous biological stimuli. A successful outcome of this study will be the prospect of a new approach for tissue regeneration that is currently not available. Full article
(This article belongs to the Section Biocomposites)
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