Scanning Electron Microscopy Analysis Research Articles

Mechanical and chemical characterization of biochar-reinforced polystyrene composites

This study investigates the chemical interactions and mechanical characteristics of composites made of polystyrene reinforced with biochar. Polystyrene-based resin (PBR) was combined with plantain peel-derived biochar in different weight ratios (10%, 20%, 30%, and 40%). The Brinell hardness test, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) were used to evaluate the properties of the composites. The results of the hardness test showed a non-monotonic pattern, with hardness first decreasing at low biochar loadings (10% and 20%), then significantly increasing at 30% biochar. At 40% biochar, the hardness then somewhat dropped, indicating that around 30% filler is the optimal biochar level for hardness. As the biochar loading increased, FTIR measurement showed that hydroxyl groups (-OH) were introduced and that the intensity of carbonyl groups (C = O) increased. According to SEM analysis, a uniform surface was found at lower biochar loadings, but at larger biochar contents, the surface became irregular and rough. In addition to providing insights into the chemical interactions at the interface between the biochar and the polymer matrix, these findings demonstrate the possibility of incorporating biochar to alter the mechanical properties of PBR.

Ultra-Sensitive Abscisic Acid Detection Using Gold and 4-Mercaptopyridine Perovskite-Engineered Robust Nanofibers (GLAMPER-NFs) under Surface-Enhanced Raman Spectroscopy.

This study explores the development and application of gold and 4-mercaptopyridine (MPY) perovskite-engineered robust nanofibers (GLAMPER-NFs) for the ultrasensitive detection of Abscisic acid (ABA) under Raman spectroscopy, a crucial plant hormone. The GLAMPER-NFs composite material, consisting of MAPbCl3 nanofibers integrated with MPY-coated gold nanostructures, demonstrates exceptional performance in surface-enhanced Raman scattering (SERS)-based sensing. The study elucidates the material structure and properties through comprehensive characterization using scanning electron microscopy (SEM), UV-vis spectroscopy, fluorescence spectroscopy, Fourier transform infrared, and Raman spectroscopy. The SEM analysis reveals uniform nanofibers with diameter of 107.8 ± 3.06 nm, while spectroscopic studies confirm the successful synthesis and integration of the composite components. The SERS-based detection of ABA showcases remarkable sensitivity, with a linear detection range (R2 = 0.9957) spanning 7 orders of magnitude (10-14-10-7 M) and presented a limit of detection of 10-11 and enhancement factor of 1.08 × 107. This surpasses the performance of existing sensing platforms, demonstrating clear spectral responses even at femtomolar concentrations. The synergistic effects of the perovskite structure, plasmonic gold nanoparticles, and MPY linking molecules contributed exceptional sensing capabilities to the GLAMPER-NFs material. Fluorescence studies further corroborate the sensitivity and provide insights into the photophysical interactions between ABA and the composite material. This research advances the understanding of perovskite-based hybrid materials and presents a promising GLAMPER-NFs as SERS substrate for ultrasensitive plant hormone detection, with potential applications in agricultural monitoring and plant science research.

Ultrathin electrospun nanofibrous membranes based on poly(γ-benzyl-L-glutamate).

Ultrathin electrospun nanofibrous membranes (NfMs) based on poly(γ-benzyl-L-glutamate) (PBLG) were prepared. Scanning electron microscopy analysis revealed the production of a high-quality, bead-free nanofibrous membrane. The membrane thicknesses, ranging from 1.7 to 4.5μm, were found to correlate directly with membrane porosity. Raman scattering analysis was utilized to investigate the conformation of the PBLG nanofibrous membrane and to assess the effects of addition of 1 wt. % trifluoroacetic acid (TFA) into the PBLG solutions, as well as the impact of annealing at 70 °C. In addition, x-ray photoelectron spectroscopy (XPS) characterization was performed to elucidate the chemical composition of the PBLG nanofibrous membrane. The Raman and Fourier-transform infrared spectroscopy spectra indicated the characteristic α-helical conformation in both the PBLG solution and the PBLG nanofibrous membrane. Furthermore, a comparative analysis of Raman band profiles proved the absence of TFA after annealing, supporting the hypothesis of TFA evaporation post-annealing, which was subsequently confirmed by the XPS results. In addition, the results from the small punch test revealed a significant correlation between membrane thickness and stiffness, indicating that increased thickness enhances stiffness. This comprehensive study provides valuable insights into the structural and compositional properties of PBLG NfMs, laying the groundwork for future investigations into their potential applications in the field of tissue engineering.

Effect of PLA-Nanochitosan Films on the Shelf-Life Extension of Fresh Rainbow Trout Fillets

Fish-packaging technology is essential in maintaining the quality and shelf life of fish as a valuable and perishable food. This research was performed to evaluate the influence of polylactic acid-nanochitosan (PLA-NC) films containing Bunium persicum essential oil (BPEO) (0, 0.3, 0.6, and 0.9%) on microbial, chemical, and organoleptic characteristics of rainbow trout fillets during storage under refrigeration for 13 days. On the last day of the storage period, in the rainbow trout fillets wrapped with PLA-NC films containing BPEO, the microbial population declined by at least 1 log CFU/g in comparison with control samples. The initial value of the total volatile base nitrogen (TVB-N) of fillets was 10.28 mg/100 g and it reached 31.75 mg/100 g in the control group on day 4, while in rainbow trout fillets wrapped with PLA-NC films and complemented with BPEO, TVB-N contents were below 25 mg/100 g, until the 10th day of storage. Regarding the results of the current study, the peroxide value (PV) on day 0 was 1.7 meq/kg and reached 13.66 meq/kg in the control samples on the 13th day, while this parameter was lower than 10 meq/kg in samples wrapped with PLA-NC films complemented with BPEO on the final day of the study. The findings of this study illustrated that wrapping rainbow trout fillets in PLA-nanochitosan films complemented with BPEO prolonged the shelf life of rainbow trout fillets without any undesirable organoleptic attributes during storage under refrigeration for 10 days. The topography and surface composition of the prepared films was further confirmed using scanning electron microscope (SEM) and field scanning electron microscope (FESEM) analyses.

Optical and Electrochemical Analysis of Surface‐Enhanced ZnZrO3:Eu3+ Nanostructures for Forensic Applications

AbstractThe surface‐enhanced local crystal structure of a series of ZnZrO3:Eu3+(1 to 5 mol.%) (ZZE) orange–red nanophosphors synthesized using a sol‐gel combustion process is investigated. X‐ray diffraction (XRD) with the Rietveld refinement analysis reveals a monoclinic ZnZrO3:Eu3+ structure with a space group 14. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) analyses reveal the honeycomb alignment of nanoparticles in structure formation. The UV–vis‐diffuse reflectance spectroscopy (UV–vis‐DRS) analysis reveals strong absorption in the UV region, with an increase in the energy bandgap upon the addition of Eu3+ ions (1 to 5 mol.%). The optimized ZnZrO3:Eu3+(2 mol.%) nanophosphor exhibits high‐intensity orange‐red emission at 615 nm, as revealed by photoluminescence (PL) spectroscopy. Cyclic voltammetry (CV) analysis confirms the surface‐modified ZnZrO3:Eu3+ (2 mol.%) nanophosphor and hence reveals its electrochemical stability and selectivity to form stable suspensions with liquids or solids. ZnZrO3:Eu3+ (1 to 5 mol.%) exhibits fluorophore (Eu3+) embedded, surface‐enhanced Raman scattering, which opens new bioimaging applications. Further, the optimized ZnZrO3:Eu3+ (2 mol.%) nanophosphor investigated for the identification of latent fingerprint patterns (LFP) under visible light indicates its potential as a strong LFP‐revealing material in forensics without alternate light sources or chemical reagents.

Development and Evaluation of Poly(Lactic‐Co‐Glycolic Acid) Encapsulated Betulinic Acid Nanocarrier for Improved Anti‐Tumor Efficacy

AbstractBetulinic acid (BA) is a promising natural anti‐tumor agent renowned for its activity against various tumor cell types. Despite its favorable profile of low cytotoxicity to normal cells, BA's inherent hydrophobic nature and relatively short systematic half‐life impose hurdles for clinical application. This study introduces a strategy to surmount these obstacles by developing a drug delivery system employing poly(lactic‐co‐glycolic acid) (PLGA)‐encapsulated BA nanoparticles (PLGA‐BA NPs). Rigorous characterization techniques such as dynamic light scattering (DLS), x‐ray diffraction (XRD), and scanning electron microscopy (SEM) analyses are employed to confirm the integrity of the drug within the nanocarriers. The PLGA‐BA NPs demonstrated a mean particle size of 196 ± 6.80 nm. XRD analysis demonstrated the amorphous state of the PLGA‐BA formulation, a characteristic vital for sustained drug release and enhanced bioavailability. The PLGA‐BA NPs exhibited spherical morphology with encapsulation and loading efficiency of 83 ± 9.24% and 7.0 ± 0.4%, respectively, highlighting efficient encapsulation of the drug within the PLGA NPs. In vitro, cytotoxicity assessments demonstrated enhanced anti‐proliferative efficacy against breast and lung tumor cells when utilizing PLGA‐BA NPs in comparison to free BA. This research underlines the potential of employing the developed PLGA‐based nanocarrier to optimize the therapeutic efficacy of BA.

EVALUATION OF ZINC IN LASER BEAM BRAZE WELDING OF GALVANIZED STEEL SHEETS

For more than a decade, the automotive industry has employed the laser welding-brazing process in the manufacturing of vehicle bodies, where the quality of the brazed seam is an important requirement, especially when exposed to the customer. One aspect that compromises the quality of the seam is the presence of zinc in the coating of galvanized steel sheets. In this context, a comparative study was conducted between two wire feeding methods in laser welding-brazing (pulling and pushing) to mitigate the presence of zinc in the brazed seam region and to evaluate the thickness of the iron-silicon intermetallic layer, which can impact the mechanical strength of the joint. A single laser beam was used for the welding-brazing, with silicon-copper wire addition and two sheet thicknesses. Scanning electron microscopy analyses with attached EDS showed that, despite the low detection, for the thinner sheet, there is a difference in the amount of zinc in the fused zone between the feeding techniques. Additionally, EDS mapping confirmed the presence of an intermetallic layer composed of iron and silicon, whose thickness is greater for the pushing wire addition method, considering the higher heat input compared to the pulling method.

Fracture Failure Analysis of Compressor Valve Spring

Compressor valve spring failure and rapid fracture occurred in a petrochemical enterprise. To find the cause of the failure, and to ensure the safe, stable, and continuous operation of the device, the failure of the spring is analyzed. In this paper, through the macro inspection, chemical composition analysis, metallographic analysis, scanning electron microscopy analysis, energy spectrum analysis, hardness analysis, and other tests, it is concluded that the main reason for the spring fracture is the fatigue fracture caused by unqualified materials. Suggestions are given to avoid similar problems in the future, and it is hoped that this failure analysis will provide valuable experience for similar failure problems in petrochemical enterprises.

ZnO–Polyaniline Nanocomposite Functionalised with Laccase Enzymes for Electrochemical Detection of Cetyltrimethylammonuium Bromide (CTAB)

The direct discharge of cationic surfactants into environmental matrices has exponentially increased due to their wide application in many products. These compounds and their degraded products disrupt microbial dynamics, hinder plant survival, and affect human health. Therefore, there is an urgent need to develop electroanalytical assessment techniques for their identification, determination, and monitoring. In our study, ZnO-PANI nanocomposites were electrodeposited on a glassy carbon electrode (GCE), followed by the immobilization of laccase enzymes and the electrodeposition of polypyrrole (PPy), to form a biosensor that was used for the detection of CTAB. A UV-Vis analysis showed bands corresponding to the π-π* transition of benzenoid and quinoid rings, π-polaron band transition and n-π*polaronic transitions associated with the extended coil chain conformation of PANI, and the presence and interaction of ZnO with PANI and type 3 copper in the laccase enzymes. The FTIR analysis exhibited peaks corresponding to N-H and C-N stretches and bends for amine, C=C stretches for conjugated alkenes, and a C-H bend for aromatic compounds. A high-resolution scanning electron microscopy (HRSEM) analysis proved that PANI and ZnO-PANI were deposited as fibres with hairy topography resulting from covalent bonding with the laccase enzymes. The modified electrode (PPy-6/GCE) was used as a platform for the detection of CTAB with three linear ranges of 0.5–100 µM, 200–500 µM, and 700–1900 µM. The sensor displayed a high sensitivity of 0.935 μA μM−1 cm−2, a detection limit of 0.0116 µM, and acceptable recoveries of 95.02% and 87.84% for tap water and wastewater, respectively.

Fabrication of ferulic acid‐cellulose nanocrystal enhanced stretchable and antibacterial hydrogels

Hydrogels are widely utilized in biomaterials, medicine, and food science due to their versatile properties. This study developed a ferulic acid (FA) and cellulose nanocrystals (CNC) hydrogel within a polyacrylamide matrix, polymerized using ammonium persulfate and crosslinked with N‐methylenebisacrylamide. The FA@CNC hydrogel demonstrated exceptional tensile ductility and elasticity. Antibacterial evaluations against Escherichia coli and Staphylococcus aureus revealed significant efficacy, with activity increasing proportionally to FA concentration. Swelling studies indicated a maximum equilibrium swelling ratio of 1210% after 36 h, showcasing the hydrogel’s ability to undergo substantial expansion while maintaining its original shape and structural integrity. It was indicated that the synthesized hydrogels were capable of absorbing large volumes of exudate while preserving a moist environment conducive to accelerated wound healing. Scanning electron microscopy analysis confirmed a regular and dense microstructure, which contributes to the hydrogel’s mechanical stability and robustness. The optimized preparation process developed in this study resulted in hydrogels with significantly enhanced performance. These findings underscore the hydrogel’s superior mechanical and functional properties, paving the way for innovative applications across biomaterials, medical, and food‐related industries.

Evaluating the anti-Candida effects of selenium nanoparticles impregnated in acrylic resins: An in vitro study

Background. Candida albicans in the oral cavity causes denture-induced stomatitis, but current treatments have side effects and contribute to drug resistance. Selenium nanoparticles (SeNPs) show promise as an antimicrobial agent, but their effectiveness against C. albicans is unknown and warrants further research. Methods. Acrylic resins containing different concentrations of SeNPs (0.2, 2, and 10 g/mL) were formulated and evaluated against C. albicans isolates. The minimum inhibitory concentration (MIC) of SeNPs was determined, and a fungal biofilm was developed on acrylic samples. The quantity of biofilm was assessed using scanning electron microscopy (SEM) and optical density (OD) at 570 nm after staining with crystal violet. Statistical analysis was performed using STATA software, with Kruskal-Wallis and Mann-Whitney tests to establish significance (P<0.05). Results. The MIC of SeNPs was 25%. The OD in the group with 10% SeNPs was 0.477 and 0.547 in the group with 0.2%. Kruskal-Wallis test results showed that at least two groups among those studied had significant differences (P=0.0273). In pairwise comparisons, the differences between all the groups were statistically significant (P=0.049). SEM analysis confirmed the destruction of C. albicans cell walls, leading to reduced colonization, with the 10% group showing the highest efficacy. Conclusion. The study demonstrated that SeNPs are effective against C. albicans colonization when combined with acrylic resin. Specifically, SeNPs exhibited enhanced antifungal properties at a concentration of 10%. These findings confirm that SeNPs are a promising alternative to traditional antifungal agents for treating oral candidiasis and denture-induced stomatitis.

Performance Analysis of TiAlN/TiN PVD Coated Carbide Tools in High-Speed and Dry Machining of AISI 1070 Alloy Steel

This study investigates the performance of TiAlN/TiN PVD-coated carbide tools in high-speed, dry machining of AISI 1070 alloy steel. AISI 1070 is a high-carbon steel known for its exceptional hardness, making tool wear a significant challenge. The research focuses on evaluating tool wear, wear mechanisms, and optimal cutting parameters. Quantitative assessments of flank wear (VB) were conducted, alongside detailed Scanning Electron Microscopy (SEM) analyses to identify the primary wear mechanisms, such as abrasion and adhesion. The study determined that the optimal cutting conditions for minimal tool wear include a cutting speed of 231 m/min, a feed rate of 0.1 mm/rev, and a depth of cut of 1 mm. The TiAlN/TiN coatings significantly enhanced the tools' wear resistance and longevity, maintaining their cutting-edge sharpness under strenuous conditions. Additionally, the coatings effectively minimized the formation of white layers on the machined surface, preserving the mechanical properties and surface integrity of the alloy. These findings demonstrate the coatings' superiority in reducing friction and heat generation during high-speed machining. The study provides valuable insights for industrial applications, highlighting the potential of TiAlN/TiN-coated carbide tools to improve tool performance, operational efficiency, and overall productivity in high-speed machining environments.

INNOVATIVE BLENDS OF GGBFS, METAKAOLIN, AND ALCCOFINE FOR ENHANCED MECHANICAL PROPERTIES IN GREEN CONCRETE

This research aims to improve the sustainability and mechanical properties of concrete by using partial replacement of cement with Ground Granulated Blast Furnace Slag (GGBFS), Alccofine (AL), and Metakaolin (MK). The study compares the effects of different proportions of GGBFS (0-50%), Alccofine (0-20%), and Metakaolin (0-15%) on the compressive, tensile, and flexural strength and at curing ages of 7th, 28th, 56th, and 90th days. The effective proportions of the replacements were determined to be 30% GGBFS, 15 % Alccofine, and 10% Metakaolin in ratios, which considerably improved the structural characteristics of conventional concrete. A ternary blend of these optimal levels was subsequently studied to determine its synergistic effect on the mechanical properties and microstructure. The ternary blend of these optimal levels demonstrated a 67.1% increase in compressive strength at 28 days and a 51.2% increase at 90 days compared to the control mix. Scanning Electron Microscopy (SEM) analysis suggested that increased pozzolanic activities, an increase in densities of the microstructure, and packing densities of the particles were the key factors for the improved performance. The results highlight that through the application of supplemental cementitious materials (SCMs), there exist promising opportunities in attaining high performance at the same time as a low environmental footprint that could help in concrete innovation for more sustainable solutions.

Exploring the Use of Water-Extracted Flaxseed Hydrocolloids in Three-Dimensional Cell Culture.

Plant-derived hydrocolloids offer promising prospects in biomedical applications. Among these, Flaxseed hydrocolloid (FSH) can form a soft, elastic, and biocompatible hydrocolloid with tunable viscosity and superior swelling capacity, making it an attractive scaffold. This study introduces a green extraction method for FSH, employing a single-step aqueous extraction process and fabrication of FSH scaffold. Despite growing interest, the pristine form of FSH has not been investigated for sustainable long-term three-dimensional (3D) cell culture. Here, FSH scaffolds were thoroughly characterized for their morphological, chemical, mechanical, and biological properties. 3D cell culture experiments were conducted using NIH-3T3 mouse fibroblast cells, and cell viability was assessed using live/dead and Alamar Blue assays. High cell viability was sustained for long term compared with 2D cell culture. Cell adhesion and 3D cellular morphology on FSH scaffold for 30 days were monitored by scanning electron microscopy analysis. Also, collagen type-I and F-actin expressions were analyzed by immunostaining after 30 days of culture, resulting in 5- and 4-fold increments of fluorescence intensity, respectively. Results indicate sustained cell viability in the long term and favorable cell-material interaction, demonstrating the potential of FSH as a scaffold. This study emphasizes the importance of the green extraction approach, improving the biocompatibility and functionality of FSH tissue engineering applications.

Ecodesign Enhancement of Polymeric Resins: Reinforcing with Synthetic and Natural Fibers Using Theory of Inventive Problem Solving-Algorithm of Inventive Problem Solving for Sustainable Composite Design

This study examines the enhancement of the mechanical strength of polymer resins through reinforcement with synthetic (glass) and natural (hemp, jute) fibers, using the TRIZ-ARIZ methodology to optimize composite design for improved mechanical properties, sustainability, and economic efficiency. Mechanical testing, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were conducted to evaluate the properties of the composite materials. Regarding tensile strength testing, the results showed the following: jute fiber achieved the best results, with a maximum tensile values of 43.75 MPa (partial reinforcement) and 43.53 MPa (complete reinforcement); glass fiber recorded maximum tensile values of 34.55 MPa (partial reinforcement) and 34.52 MPa (complete reinforcement); and hemp fiber yielded maximum tensile values of 24.98 MPa (partial reinforcement) and 24.86 MPa (complete reinforcement). The mechanical performance of partial reinforcements (in the area of maximum stress) was similar to that of complete reinforcements, enabling a reduction in material usage by up to 60%. The thermal analysis (TGA) results demonstrated that glass fiber-reinforced composites exhibit high thermal stability, with mass loss starting at 320 °C and a residual mass of 8.02%; for other composite materials, thermal degradation begins at 305 °C, with a residual mass of 3.69%; in jute fiber-reinforced composites, thermal degradation starts at 300 °C, with a residual mass of 3.71%. SEM analysis generally revealed good fiber–matrix adhesion, while defects such as voids or detached fibers contributed to reduced mechanical strength. These results demonstrate that natural fiber-reinforced composite materials, particularly those reinforced with jute, can be used in sustainable engineering applications. They also show that localized reinforcement provides high performance with minimal resource consumption.

Effects of steel fibers and carbon nanotubes on the flexural behavior of hybrid GFRP/steel reinforced concrete beams

BackgroundGlass fiber-reinforced polymer (GFRP) bars offer a superior alternative to steel bars in concrete reinforcement but are associated with wider cracks and higher deformation rates. This study introduces a novel approach by combining steel fibers (SFs) and carbon nanotubes (CNTs) to address these drawbacks and enhance the performance of GFRP-reinforced concrete beams. The unique contribution of this study lies in the simultaneous use of SFs and CNTs, which has not been extensively investigated, particularly in the context of GFRP-reinforced concrete. The study involved testing three sets of nine specimens with different concrete mixtures and reinforcement forms.ResultsThe results showed that adding 0.04% CNTs by cement weight and 0.6% SFs by volume fraction significantly improved the mechanical performance of GFRP and steel reinforced beams. GFRP reinforced beams with CNTs and SFs exhibited a reduction in crack width, a 20% increase in load-carrying capacity, and a 25% reduction in deflection compared to reference specimens. Scanning electron microscope analysis further revealed that CNTs effectively enhanced tensile load transfer, improving flexural behavior of the beams. The finite element analysis using ANSYS confirmed the experimental findings, highlighting the improved stress distribution in the modified concrete mixtures.ConclusionsIncorporating SFs and CNTs in concrete significantly improves the mechanical performance of GFRP-reinforced beams, making them more durable and resilient. These findings suggest that the proposed approach can enhance the longevity and sustainability of concrete structures, particularly in dynamic load applications such as bridges and high-rise buildings. Further experimental and analytical studies are recommended to assess the practical implications and cost-effectiveness of these materials in large-scale construction projects.

Effects of discrete fibre reinforcements on the wear resistance behaviour of polyamide-based spur gears

Abstract In many situations, the polymer gears are the perfect replacement for traditional metal gears. Compared to metal gears, the polymer gears will generate more heat at the gear tooth contact surface and more wear loss. Hence, this study aims to decrease the wear loss and increase the load-carrying capacity of the polymer gears. To achieve this, the reinforcement materials were added to the base polymer gear material. In this study, Nylon-66 was chosen as the polymer matrix material and an isolated glass fibre and steel grid were used as the reinforcement materials. Three different types of polymer spur gears such as Polyamide Gear (Nylon-66), Reinforced Polyamide Gear (Nylon-66+Glass Fibre), and Hybrid Glass Fiber Steel Grid Gear (Nylon-66+Glass Fibre+Steel Grid) named PG, RPG and HGFSGG were fabricated using injection moulding machine and each type of gears were compared for wear loss and specific wear rate under the similar testing conditions. The wear test was performed in the Forschungsstelle fur Zahnrader und Getriebebau (FZG) test rig at 1500 rpm with an applied load of 20 N for 12.5 hours continuously. From the test results, it was identified that HGFSGG polymer spur gears have exhibited a lower surface temperature and better wear properties compared to the other two types of spur gears. From the Scanning Electron Microscope (SEM) analysis, it was noticed that the PG spur gear exhibited deep and uniform wear at the gear tooth surface. In contrast, RPG spur gear exhibited glass fibre distortion and abrasive-type wear. The SEM micrograph of HGFSGG spur gear reveals the presence of very few surface flaws in the gear tooth surface.

Predicting and optimizing the wear behavior of centrifugal cast β-TCP/ Mg–2Zn–1Mn alloys: A hybrid artificial neural network—Grey relational analysis approach

This study investigates the wear behavior of temporary implant such as plates and screws made by Mg–2Zn–1Mn alloy reinforced with β-tricalcium phosphate (β-TCP) under both dry and wet sliding conditions. Grey relational analysis (GRA) and an artificial neural network (ANN) model were utilized to predict wear and optimize performance, considering process parameters such as β-TCP content (0%, 2.5%, 5%), load (20, 40, 60 N), sliding speeds (2, 4, 6 m/s), and sliding distances (800, 1600, 2400 m). The wear rate ( Ws) and coefficient of friction (COF) were evaluated using an orthogonal array L27 to optimize both dry and wet conditions. The optimal process parameters obtained through GRA for dry conditions are 5% β-TCP, 20 N, 4 m/s, and 1600 m, while for wet conditions, they are 0% β-TCP, 20 N, 2 m/s, and 2400 m. The experiment was conducted to calculate Ws and COF using the above process parameters. The values of Ws and COF are 0.010149 mm³/m and 0.109 for dry conditions, and 0.001143 mm³/m and 0.128 for wet conditions. The ANN predicted values for dry conditions are 0.010471 mm³/m for Ws and 0.11045 for COF, with error percentages of 3.17% and 1.33%, respectively. Similarly, for wet conditions, the predicted values are 0.001107 mm³/m for Ws and 0.125 for COF, with error percentages of 3.13% and 2.77%. The ANOVA results for the Grey relational grade (GRG) show that load was the most significant factor influencing wear performance, contributing 51.91% in dry conditions and 34.69% in wet conditions. The close alignment of predictions from both models, with overall error percentages below 3.17%, demonstrates their reliability and effectiveness. Field emission scanning electron microscope (FESEM) analysis of worn surfaces under optimal conditions provided insights into the wear mechanisms. This study confirms that GRA and ANN models are highly effective for predicting and optimize the wear behavior.

Miscibility, thermal, and mechanical properties of recycled waste tire rubber-modified polystyrene sustainable composites

Waste tires represent an important source of polymer waste. The ground tire rubber derived from waste tires is a recycled product that can be combined with polystyrene (PS) to produce high-performance PS and waste rubber composites. To improve composite material performance, surface grafting modification of waste tire rubber with styrene to enhance properties of PS composites as a novel approach was investigated. The surface morphology and structure of polystyrene grafted waste tire rubber powder via a conventional free radical polymerization were confirmed successfully using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy analyses in addition to the Fourier-transform infrared spectroscopy (FTIR). The comparative mechanical and thermal property analysis of PS sustainable composites with recycling waste tire rubber powder with and without surface grafting modifications indicated an approximate 4-fold increase in the impact strength of polystyrene grafted waste tire rubber reinforced PS sustainable composites in addition to enhanced interfacial miscibility. The development of sustainable composite materials from recycled waste tire provides a novel avenue to achieve close-loop polymer recycling, which is of significance in the development of the circular economy and an environmentally friendly society.

Analysis of engineering performance of concrete comprising recycled crushed plastic waste and fly ash

This study investigated the attributes of blending of recycled crushed polypropylene plastic coarse aggregates (PPCA) and fly ash (FA) towards the fresh and hardened properties of concrete. Natural coarse aggregate was partially replaced with PPCA at volumetric replacement levels up to 30% and cement was replaced with FA up to 20%. Initially, the performance of PPCA and FA in concrete was investigated distinctly. The incorporation of 30% of PPCA in concrete rather impaired the workability (from 95 mm – 50 mm: 47%) and the compressive strength (from 44.6 MPa to 31.4 MPa: 29.7%). By appropriate using of a superplasticizer, the loss in the workability could be recovered. Microstructural investigation was conducted employing scanning electron microscope analysis; it showed that the formation of a weak interfacial transition zone between PPCA and cement paste to be the reason for strength reduction in PPCA concrete. In contrast, the addition of 10 – 20% of FA in concrete improved the workability by 63.2% – 100%, but yet again, the 28-day compressive strength reduced by 15.8 – 35.6%. Meanwhile, thermal conductivity results and constitutive relationships proved that the use of PPCA enhanced the thermal insulation property and ductility of PPCA concrete, respectively. Eventually, a total of six concrete batches with binary blended PPCA and FA were cast to find the optimum replacement levels. The optimum binary combination with reasonable strength and workability at a minimal cost was achieved to be 10% PPCA and 20% FA.