Search Results (7,437)

Objective: This study aimed to develop eco-friendly zinc oxide nanoparticles (ZnO NPs) using Punica granatum (pomegranate) peel extract and to evaluate their antioxidant, antimicrobial, and photoprotective potential. Method: ZnO NPs were synthesized via a green chemistry route employing polyphenol- and flavonoid-rich peel extract as reducing and stabilizing agents. The nanoparticles were characterized using FTIR, SEM, XRD, DSC, DLS, and UV–Vis spectroscopy. Biological activities were assessed through in vitro assays including antioxidant (DPPH), anti-collagenase, anti-elastase, anti-tyrosinase, antimicrobial activity, and SPF determination. In vivo photoprotective efficacy was further evaluated in UVB-irradiated rat models, with histological analysis to confirm structural skin changes. Results: The optimized ZnO NPs exhibited an average particle size of ~194 nm with a zeta potential of −18.2 mV, indicating good stability. They demonstrated notable antioxidant activity (DPPH IC₅₀ = 52.91 µg/mL), substantial tyrosinase inhibition (72% at 200 µg/mL), and antibacterial activity with inhibition zones up to 19 mm against S. aureus and 17 mm against E. coli. The nanoparticles also showed excellent UV absorption, with an SPF value of 29.8, exceeding the FDA threshold for effective sun protection. In vivo, topical application of ZnO NPs in UVB-exposed rats led to a 69% reduction in epidermal thickness and preservation of collagen fibers compared with UV controls. Conclusions: These findings confirm that P. granatum peel extract–mediated ZnO NPs possess significant antioxidant, antimicrobial, and photoprotective activities. Full article

This research investigated the sustainable biosynthesis of silver nanoparticles (AgNPs) using Zinnia elegans L. extracts to demonstrate the potential of plant-based methods in nanotechnology. The antioxidant and antibacterial properties of the plant extracts were evaluated, and the phytocompounds that react as natural reducing agents in the synthesis of AgNPs were characterized. This approach has demonstrated the potential of Zinnia elegans L. as an environmentally friendly source for the production of AgNPs. The biosynthesized AgNPs were characterized based on their optical, structural, and morphological properties using various techniques, including scanning electron microscopy (SEM), attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR), and thermogravimetric and differential thermal analysis (TGA/DTA). X-ray diffraction (XRD) analysis confirmed the presence of pure silver phases exhibiting a face-centered cubic (FCC) crystalline structure. Ultraviolet–visible (UV–Vis) spectroscopy revealed an absorption peak at 462 nm, which is characteristic of the surface plasmon resonance associated with AgNPs. ATR-FTIR analysis identified several vibrational peaks corresponding to the functional groups of the constituents present in the biosynthesized AgNPs. The size distribution of the AgNPs was found to range from 10 to 30 nm, and both SEM and TEM confirmed their predominantly spherical morphology. Energy dispersive X-ray spectroscopy (EDX) analysis corroborated the predominance of silver as the principal element within the composition of the nanoparticles. This technique provided quantitative elemental analysis, confirming the high purity and concentration of silver in the synthesized AgNPs. The study effectively elucidated the synthesis of AgNPs utilizing plant extracts as natural reducing agents. The synthesized AgNPs exhibited significant antibacterial and antioxidant activities, indicating their potential applicability in diverse biomedical and environmental contexts. Employment of the advanced characterization techniques facilitated a thorough understanding of the multifaceted properties of the synthesized AgNPs, thereby enhancing their viability for future research and application in nanomedicine and bioremediation. Using Zinnia elegans L. for the biosynthesis of plant-synthesized AgNPs is a sustainable and eco-friendly technique that offers a viable alternative to conventional chemical processes. Full article

For optimizing the operational efficiency and productivity within blast furnace processes, a profound understanding of the viscous flow characteristics of CaO–SiO₂–MgO–Al₂O₃–B₂O₃ slag systems is of paramount importance. In this study, we conducted a comprehensive investigation into the influence of the CaO/SiO₂ and MgO/Al₂O₃ ratios on the viscosity, break point temperature (T_Br), and activation energy (E_η) of low boron-bearing high-alumina slag. Concurrently, we elucidated the underlying mechanisms through which these ratios affect the viscous behavior of the slag by employing a combination of analytical techniques, including X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and thermodynamic modeling using the Factsage software. The experimental findings reveal that, as the CaO/SiO₂ ratio increases from 1.10 to 1.30, the slag viscosity at 1773 K decreases from 0.316 Pa·s to 0.227 Pa·s, while both the T_Br and E_η exhibit an upward trend, rising from 1534 K and 117.01 kJ·mol⁻¹ to 1583 K and 182.86 kJ·mol⁻¹, respectively. Conversely, an elevation in the MgO/Al₂O₃ ratio from 0.40 to 0.65 results in a reduction in slag viscosity at 1773 K from 0.290 Pa·s to 0.208 Pa·s, accompanied by a decrease in T_Br from 1567 K to 1542 K. The observed deterioration in slag flow properties can be attributed to an enhanced polymerization degree of complex viscous structural units within the slag matrix. Ultimately, our study identifies that an optimal viscous performance of the slag is achieved when the CaO/SiO₂ ratio is maintained at 1.25 and the MgO/Al₂O₃ ratio is maintained at 0.55, providing valuable insights for the rational design and control of blast furnace slag systems. Full article

Background/Objectives: Primary dysmenorrhea is a prevalent condition that causes severe uterine cramps in women worldwide. The objective of this work was to synthesize and characterize a novel immediate-release system using vitexin and ZIF-8, and to evaluate its pharmacological action in a model of primary dysmenorrhea. Methods: A 2² full factorial design guided the synthesis of the system. Physicochemical characterization was performed by FT-IR, TG, DSC, SEM, XRD, and in vitro release tests. Pharmacological activity was assessed in an oxytocin-induced dysmenorrhea model in mice. In addition, in silico molecular docking and molecular dynamics simulations were conducted to explore the potential mechanism of action of vitexin. Results: Optimal yield and loading capacity were achieved at the high levels of the factorial design. Characterization analyses confirmed the successful formation of the vitexin@ZIF-8 (VIT@ZIF-8) system. The release study demonstrated a markedly enhanced dissolution rate of vitexin. Both isolated vitexin and VIT@ZIF-8 reduced abdominal writhing when administered orally at 3 and 30 mg/kg, while intraperitoneal activity was observed only at 30 mg/kg. Computational analyses revealed favorable interactions of vitexin with aldose reductase (AKR1C3), suggesting this enzyme as a potential molecular target in dysmenorrhea. Conclusions: The VIT@ZIF-8 system represents a promising strategy to improve the dissolution profile of vitexin, although pharmacological activity in this model was not superior to the isolated compound. The combined in vivo and in silico evidence supports vitexin as a potential antidysmenorrheic agent, possibly through modulation of AKR1C3. These findings open avenues for future studies addressing the molecular pathways of vitexin and for the development of novel therapeutic approaches for primary dysmenorrhea. Full article

This study provides a comprehensive analysis of lemon peel (LP) combustion behaviour using combined physicochemical characterization and non-isothermal thermogravimetric kinetics. To achieve this, LP was characterized for its proximate and ultimate composition, with its structure analysed via FTIR, XRD, and SEM. Thermogravimetric analysis (TGA) was then performed at high heating rates (20–80 K min⁻¹) to investigate combustion stages, and kinetic and thermodynamic parameters were determined using six model-free and one model-fitting method. The results revealed a high heating value (23.02 MJ kg⁻¹) and high volatile matter (73.2 wt%), establishing LP’s significant energy potential. TGA displayed four distinct decomposition stages corresponding to dehydration, pectin/hemicellulose, cellulose, and lignin/char combustion. Kinetic analysis yielded activation energies that varied with conversion, peaking at approximately 304 kJ mol⁻¹, and a three-dimensional diffusion (D3) mechanism was identified as the rate-limiting step. In conclusion, while its high energy content and low nitrogen (1.26 wt%) and sulphur (0.20 wt%) content make LP an attractive low-emission biofuel, its viability is challenged by a high potassium concentration in the ash (34.8 wt% K₂O), posing a severe risk of slagging. This study provides the comprehensive combustion kinetic data for LP at high heating rates, which is essential for designing appropriate energy conversion technologies and ash management strategies. Full article

The interfacial properties in carbon fiber (CF)-reinforced polymer composites are substantially limited by the chemically inactive and smooth CF surfaces. In this study, zeolitic imidazolate framework 90 (ZIF90) was chemically grafted onto CF surfaces via polyethyleneimine (PEI) as a coupling agent to construct a hierarchical reinforcement interface in CF/epoxy composite. The successful synthesis of CF grafted with PEI and ZIF90 (CF-PEI-ZIF90) was systematically characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The incorporation of ZIF90 nanocrystals and PEI molecules into CF surfaces effectively improved interfacial adhesion through mechanical interlocking and chemical interactions, thereby optimizing stress transfer efficiency at the fiber–matrix interface and improving the interfacial properties of the composite. Additionally, the resultant CF-PEI-ZIF90/epoxy composite demonstrated significant mechanical enhancement, with the tensile and bending strengths increasing by 33.5% and 21.4%, respectively, compared to unmodified CF/epoxy composites. This work provides a novel strategy for enhancing the interfacial performance of CF composites by leveraging the unique properties of metal-organic frameworks, which is critical for advancing high-performance structural materials in aerospace and automotive applications. Full article

Confronted with increasing global food demands, diminishing arable land, and climate volatility, controlled-environment agriculture with advanced red and far-red LED lighting can enhance photosynthesis and optimize plant growth. This investigation reports the generation of a Mn⁴⁺/Nd³⁺ co-doped Y₂SiO₅ phosphor with a Nd³⁺ concentration ranging from 0.1 to 2.5 mol% via a solid-state synthesis method, aiming to enhance red and far-red emission for plant cultivation LEDs. For the Y₂SiO₅:Mn⁴⁺ (1 mol%), Nd³⁺ (2 mol%) phosphor, the phase integrity, nanostructured morphology, elemental mapping, and vibrational characteristics were examined using XRD, Rietveld analysis, FTIR, SEM, and EDX. Nd³⁺ ions act as near-infrared excitation mediators, ensuring efficient Nd³⁺ → Mn⁴⁺ energy transfer upon 808 nm excitation, and this leads to pronounced red photoluminescence from Mn⁴⁺ ions that covers the range of 640–710 nm, exhibiting strong emission peaks centered at 650nm, 663nm, and 685nm, coinciding with the absorption band of phytochromes and chlorophyll. The optimal emission intensity was accomplished for a Nd³⁺ doping concentration of 2 mol%, beyond which concentration quenching occurred. The material produced a strong, concentrated deep red emission with CIE coordinates near (0.73, 0.27) and a high color purity of 98.96%, making it well-suited for photosynthetic activation. A phosphor-integrated red pc-LED was fabricated, and Tulsi plants were grown under this LED during the winter in Meghalaya, a period critical for plant growth due to the low ambient light. Over a 30-day period, the plants exhibited enhanced height and leaf development, demonstrating the practical potential of Mn⁴⁺/Nd³⁺ co-doped Y₂SiO₅ for energy-efficient, wavelength-optimized horticultural lighting. Full article

The valorization of volcanic ash as a raw material for advanced functional materials offers dual benefits for both the environment and technology. Firstly, it diverts waste from landfills, thereby reducing the environmental footprint of volcanic deposits. Secondly, it contributes to the circular economy by transforming an abundant natural residue into a high-value product. In this study, zeolites were synthesized from the ash of the Ubinas volcano via the hydrothermal method in an alkaline medium. A systematic investigation was conducted to ascertain the influence of NaOH concentration and reaction temperature on synthesis efficiency and final material properties. The crystalline phases and morphology of the products were characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM), while textural and thermal properties were evaluated through the Brunauer–Emmett–Teller (BET) method and Thermogravimetric Analysis (TGA). The results revealed that both temperature and NaOH concentration significantly affected the physicochemical properties of the zeolites. Four zeolite types were obtained; among them, Zeolite Z4 (synthesized with 3 M NaOH at 150 °C) exhibited the highest adsorption capacity, with a specific surface area of 35.60 m²/g, while Zeolite Z1 (synthesized at 120 °C with 1.5 M NaOH and 27.85 m²/g) displayed superior thermal stability and crystallinity. These variations in thermal and textural properties were reflected in the catalytic pyrolysis performance of polypropylene (PP). Zeolite Z3 (synthesized at 150 °C with 1.5 M NaOH) achieved the highest gaseous product yield (80.2%), despite lacking the expected zeolitic crystalline phases. In contrast, Zeolite Z2 (synthesized at 120 °C with 3 M NaOH) yielded 57.7% gaseous products and stood out for its predominant analcime phase, characteristic of zeolitic materials. In summary, this study demonstrates that volcanic ash-derived zeolites not only enhance synthesis efficiency and functional performance but also represent a sustainable strategy for waste valorization, closing material loops and enabling the recovery of high-calorific gaseous products from plastic waste. Full article

This study systematically investigates the effects of individual and combined incorporation of graphene oxide (GO) and nano-silica sol (NS) on the macroscopic properties and microstructure of cement-based grouting materials, with emphasis on their synergistic mechanisms. A series of macroscopic tests including setting time, fluidity, bleeding rate, and mechanical strength were conducted, complemented by multi-scale microstructural characterization techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), mercury intrusion porosimetry (MIP), and Fourier-transform infrared spectroscopy (FTIR). The results demonstrate that both NS and GO effectively reduce setting time and bleeding rate while enhancing mechanical strength; however, NS exhibits a more pronounced adverse effect on fluidity compared to GO. The hybrid system displays a distinct transition from synergy to antagonism: under low-dosage co-incorporation (2 wt% NS + 0.01 wt% GO), the flexural and compressive strengths increased by 13.5% and 45.5%, respectively, relative to the reference group. Microscopic analysis revealed that the synergistic interaction between the pozzolanic effect of NS and the templating effect of GO under this condition optimizes hydrate morphology and pore structure, leading to enhanced performance. Conversely, excessive dosage of either component induces agglomeration, resulting in microstructural deterioration and performance degradation. This study establishes optimal dosage ranges and combination principles for NS and GO in cement-based materials, providing a theoretical foundation for designing high-workability and high-strength cementitious composites. Full article

Silver nanoparticles (AgNPs) are valued for their antimicrobial properties, but conventional synthesis often involves toxic chemicals. Eco-friendly biosynthesis using silver-tolerant microbes from contaminated sites offers a sustainable alternative. This study biosynthesized and characterized AgNPs using a native Bacillus sp. from contaminated soil in the Jazan region, Saudi Arabia, and developed predictive models for optimizing synthesis and antimicrobial activity. AgNPs were synthesized under optimized conditions (1.0 mM AgNO₃, 4.0 mL supernatant, pH 8, 85 °C). Characterization using UV–Vis, SEM, TEM, XRD, and FTIR assessed size, shape, structure, and chemistry. Gaussian and second models evaluated yield and inhibition zones based on AgNP concentration, microorganism type, and MIC. The AgNPs were spherical with diameters of 5–10 nm. The optimal nanoparticle yield occurs when the parameters are at their optimal values; C₀ = 1.0 mM, V₀ = 4.0 mL, pH₀ = 8, T₀ = 85 °C. XRD confirmed their crystalline nature, and FTIR showed biomolecular capping agents for stabilization. The Gaussian model accurately predicted synthesis efficiency, validated by 3D plots matching experimental data. The AgNPs showed strong antimicrobial activity against Gram-positive (Bacillus subtilis) (ATCC6051), Staphylococcus aureus (ATCC12600), Gram-negative bacteria Escherichia coli (ATCC11775) and fungi Candida albicans (ATCC10231); with E. coli having the lowest MIC (1.87 μg/mL). The inhibition zone model closely matched observed data. Biosynthesized AgNPs using silver-tolerant Bacillus sp. demonstrated potent antimicrobial effects and provide a green alternative to chemical synthesis. Integrating modeling optimizes biosynthesis and predicts biological performance, supporting future nanobiotechnology and antimicrobial applications. Full article

This study aimed to evaluate the incorporation of graphene-based additives, graphene nanoplatelets (GNPs) and graphene oxide quantum dots (GOQDs), into polymeric fiber matrices used as biofilm supports in anaerobic digestion systems, determining additive specific effects by benchmarking the impregnated matrices against the same nylon carrier without additives under identical operational conditions. Modified matrices were assessed through BMP assays using the liquid fraction of fruit and vegetable waste (LF-FVW) as substrate. Intermediate GNP and GOQD loadings (FM50 and FMDOT50) achieved the highest methane yields (317.9 ± 20.2 and 348.4 ± 20.0 mL CH₄/g COD_(rem)) compared with the control fiber matrix (301.0 ± 20.1 mL CH₄/g COD_(rem)). Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analyses confirmed nanomaterial retention on the matrix surface and interaction with microbial aggregates. Embedding the nanostructures within the fiber enhanced biofilm formation and methane yield while minimizing nanomaterial washout. Future work will focus on advanced physicochemical characterization (XRD, XPS, BET, and EDX mapping), leaching tests to assess long term stability, and scale up evaluation for full scale anaerobic digestion applications. Full article

A fluorescence sensor was designed based on nitrogen-doped graphene quantum dots confined in a metal–organic framework and molecularly imprinted polymer for the selective determination of 5-hydroxymethylfurfural (HMF). Morphological, structural, and spectroscopic characterizations, such as SEM, STEM, BET, FT-IR, and XRD, verified successful synthesis and imprinting with enhanced surface area and structural durability. The sensor demonstrated intense fluorescence at around 420 nm, which was quenched through photoinduced electron transfer (PET) by HMF, exhibiting a linear relationship up to 35 µmol L⁻¹ and a detection limit of 30 nmol L⁻¹. It offered high imprinting efficiency, selectivity, and stability. The sensing platform also displayed efficient anti-interference performance toward interference species and presented excellent recovery in actual food samples such as honey, juice, and coffee, thus revealing the applicability of the sensing device for real-world HMF measurement in complicated matrices. Full article

The extensive use of petroleum-based plastics has caused serious environmental concerns; thus, the need for biodegradable alternatives is essential. Here, we present eco-friendly bio-based polymers prepared by crosslinking poly(vinyl alcohol) (PVA) and alginate (ALG) with glutaraldehyde, while incorporating cardanol-derived polyols (PCD) to add antibacterial functionality. The synthesized bio-based polymers were characterized by FT-IR, XRD, and TGA. FT-IR confirmed sufficient crosslinking between PVA and ALG, whereas XRD revealed a minor decrease in crystallinity. Thermogravimetric analysis showed enhanced thermal stability with increasing ALG contents, as the residual mass increased from 8 wt% (PVA only) to 19–31% (PVA:ALG = 80:20–60:40). Swelling behavior was strongly governed by ALG, with higher ratios promoting water uptake up to 130%, whereas PCD reduced swelling due to increased hydrophobicity. Antibacterial assays indicated complete inactivation of Escherichia coli and Staphylococcus aureus within 10–60 min depending on the polymer composition. These results demonstrate that tuning the PVA:ALG ratio and PCD content allows precise control of physicochemical properties. Overall, the developed PVA–ALG/PCD bio-based polymers represent a versatile and sustainable platform for eco-friendly packaging, biomedical, and water treatment applications. Full article

In this study, a guar gum-based adsorbent was developed and evaluated for the removal of Ni(II) ions from aqueous solutions through a combined experimental and machine learning (ML) approach. The adsorbent was characterized using FTIR, SEM, XRD, TGA, and BET analyses to confirm surface functionality and porous morphology suitable for metal binding. Batch adsorption experiments were conducted to optimize the effects of pH, adsorbent dosage, contact time, temperature, and initial metal concentration. The adsorption efficiency increased with higher pH and adsorbent dosage, achieving a maximum Ni(II) removal of 97% (qₘ = 86.0 mg g⁻¹) under optimal conditions (pH 6.0, dosage 1.0 g L⁻¹, contact time 60 min, and initial concentration 50 mg L⁻¹). The process followed the pseudo-second-order kinetic and Langmuir isotherm models. Thermodynamic results revealed the spontaneous, endothermic, and physical nature of the adsorption process. To complement the experimental findings, artificial neural network (ANN) and k-nearest neighbor (KNN) models were developed to predict Ni(II) removal efficiency based on process parameters. The ANN model yielded a higher prediction accuracy (R² = 0.97) compared to KNN (R² = 0.95), validating the strong correlation between experimental and predicted outcomes. The convergence of experimental optimization and ML prediction demonstrates a robust framework for designing eco-friendly, biopolymer-based adsorbents for heavy metal remediation. Full article

Melting leakage and low thermal conductivity of stearic acid (SA) restrict its application in thermal storage. In this work, a shape-stabilized phase change material (ECNX/SA) with enhanced thermal storage performance and photothermal conversion is designed based on expanded graphite/chitin-derived carbon (ECNX). Thermal storage performance, including phase change temperature, enthalpy, thermal conductivity and shape stability, of ECNX/SA is investigated. With this, the influence mechanism of ECNX on the thermal storage performance is characterized via N₂ isothermal adsorption–desorption, FTIR, XRD and SEM. Results show that the prepared ECN15/SA has ideal thermal storage performance, where its phase change enthalpy and thermal conductivity are 121.59 J/g and 1.573 W/(m·K), respectively, and possesses superior shape stability. Moreover, the thermal storage performance of ECN15/SA keeps stable even undergoing several thermal cycles, and its photothermal conversion is as high as 89.2%. Characterizations suggest that ECN15 with a hierarchical pore structure and a high graphitization degree to enhance the shape stability and thermal conductivity of SA. Therefore, the prepared ECN15/SA is potential using in thermal storage. Full article