Search Results (9,685)

This study investigates the antioxidant and anticorrosive properties of Mentha pulegium L. essential oil (MP EO) as a sustainable and eco-friendly alternative to synthetic oxidation inhibitors. The antioxidant activity of MP EO was evaluated using the ferric reducing antioxidant power (FRAP) assay, which demonstrated a strong electron-donating capacity and effective reduction of ferric ions, indicating promising antioxidant potential. The anticorrosive performance was assessed on mild steel in 0.5 M H₂SO₄ using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed inhibition efficiencies of up to 75.8% at a concentration of 2 g/L. Molecular docking simulations revealed favorable binding interactions between the key oil components (pulegone and menthone) and the ROS-generating enzyme model (PDB ID: 2CDU), providing complementary mechanistic insight into their potential role in oxidative stress modulation. Additionally, quantum chemical calculations highlighted electronic properties favoring adsorption on metallic surfaces. Surface morphology analysis using SEM/EDX confirmed the formation of a protective film on steel in the presence of MP EO. These combined findings position Mentha pulegium essential oil as a potent, biodegradable candidate for both antioxidant applications and corrosion prevention in acidic environments. Full article

The use of cellulosic reinforcement fillers, including cellulose and holocellulose, in the development of sustainable biopolymer composites has become increasingly essential and continues to attract significant attention in the composite industry. This study aimed to improve the structural and morphological characteristics of the polyhydroxybutyrate (PHB) matrix by incorporating cellulosic fillers—namely, α-cellulose and holocellulose produced via a green processing method—and to evaluate the effect of hemicellulose, present in holocellulose and exhibiting compatibilizing capability, on the overall performance of PHB-based blends. For this, the PHB matrix was first dissolved in chloroform, after which the cellulosic fillers were incorporated into the PHB–chloroform mixtures at 1 wt.% to provide the best homogeneous fiber dispersion. The PHB and cellulosic filler mixtures were blended at 500 rpm with a magnetic mixer for 30 min, and the resulting composite was cast onto a Teflon plate. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy were used to characterize the morphological and structural analysis of the obtained biopolymer-based composites. Thermogravimetric analysis (TG-DTG) was used to determine the thermal properties. The results obtained confirmed the presence of cellulosic fillers in the PHB matrix using FTIR, XRD, and SEM. In contrast to holocellulose, α-cellulose in the PHB matrix was shown to create a more organized structure. Both α-cellulose and holocellulose reinforcements were found to have similar effects on the thermal properties of the PHB matrix. Compared with neat PHB, the amount of residual char was found to be more than 36-fold in the sample containing α-cellulose and more than 41-fold in the sample containing holocellulose. Full article

In the contemporary era, nanotechnology has become a central pillar in numerous domains, particularly in cosmetics, nanoelectronics, nanomedicine, and nanobiotechnology. Defined by its focus on materials with dimensions ranging from 0.1 to 100 nm, nanotechnology offers unique physicochemical properties—such as enhanced reactivity, conductivity, and permeability—attributable to the nanoscale. These properties facilitate greater interaction with biological systems, notably improving cellular uptake and functional efficacy. The increasing demand for eco-friendly and biocompatible nanomaterials has driven interest in green synthesis routes, particularly those utilising plant extracts. These methods stand out due to their low toxicity and environmental impact, positioning it as a safer alternative to conventional chemical or microbial methods. Plant-extract-mediated nanoparticles demonstrate promising applications in diagnostics, drug delivery, regenerative medicine, and neurotherapeutics. Their role in precision medicine, including gene and drug delivery and the imaging of neurological disorders, underscores green nanotechnology’s transformative potential. This review highlights recent advances in the synthesis, functionality, and biomedical applications of plant-based nanoparticles, emphasizing their relevance in in vitro models and prospective clinical settings. Full article

To promote sustainable biomass recycling and support food security, Tenebrio molitor (TM) larvae can serve as an eco-friendly source of food and feed. This study compared the survival, growth performance, and nutritional composition of TM larvae fed five diets. The control (CON) diet contained distillers’ dried grains with solubles (DDGS) and wheat bran (WB), while the experimental diets included 10–40% lignocellulose-rich organic products from rewetted peatlands (LPRP) replacing WB, with DDGS adjusted to maintain equivalent protein levels (about 21%). A total of 2500 larvae were divided into five replicates per treatment (100 larvae each). Survival exceeded 90% across all groups. Larvae fed the CON diet had a higher final body weight than those on the 30% and 40% LPRP diets (p < 0.05), with no significant differences among the CON and 10% and 20% LPRP groups. The feed conversion ratio (fresh matter) was significantly lower in the CON and 10% LPRP groups than in the other groups (p < 0.05). Larvae fed the 10% LPRP diet showed slightly higher crude protein content (55.8%) compared to the control group (54.8%) and the other treatment groups, whereas those fed the 30% LPRP diet had the highest numerical total amino acid content. Taken together, these results indicate that incorporating 10% LPRP with DDGS and WB provides the best overall balance between growth performance and nutritional quality for TM larvae, supporting sustainable production and circular economy goals. Full article

This study presents a green bio-upcycling strategy for converting mussel shell biowaste into three value-added products: chitin, chitosan, and calcium lactate. Mussel shells were treated chemically with lactic acid during demineralization, yielding a solid fraction rich in chitin and a liquid fraction containing calcium and lactate ions. The solid fraction was sequentially purified by deproteinization and decolorization, then deacetylated to obtain chitosan, while the liquid fraction was evaporated to obtain calcium lactate. Notably, 2.37 g of raw chitin, 2.15 g of purified chitin, and 275.87 g of calcium lactate were obtained from 100 g of mussel shells, demonstrating the efficiency of the process. FTIR spectra revealed characteristic absorption bands corresponding to α-chitin and chitosan functional groups, while XRD patterns indicated the crystalline α-chitin structure and the formation of calcium lactate pentahydrate. TGA demonstrated the high thermal stability of chitin and chitosan and confirmed the presence of crystallization water in calcium lactate. In conclusion, these results confirmed the successful preparation of α-chitin, chitosan, and calcium lactate pentahydrate, with improved purity compared to previous studies. This approach highlights the potential of the green bio-upcycling process of mussel shell waste as a renewable source for the eco-friendly production of biopolymers and calcium salts, supporting sustainable waste management and the development of the Bio-Circular-Green (BCG) economy. Full article

This study presents a detailed colorimetric evaluation using the CIEL*a*b* system for a novel series of symmetrically structured disazo-stilbene dyes. The synthesis utilized the non-genotoxic 4,4’-diaminostilbene-2,2’-disulfonic acid as the diazotizing component, with the coupling components being N-substituted acetoacetanilide derivatives. The purity of the obtained dyes was confirmed by HPLC analysis. The color analysis was initially conducted on the dyes in solid state (powder) to investigate potential structure–color correlations. Subsequently, these parameters were applied to analyze the performance of the dyes incorporated into acrylic resin films. Titanium dioxide (P.W.6; C.I. 77891) served as the white standard, along with mixtures of dyes in different concentrations that were applied to a cellulosic substrate. The results characterize these compounds as eco-friendly dyes possessing high tinctorial strength and a significant metamerism effect. Full article

Red- and near-infrared (NIR)-emissive quantum dots (QDs) hold great promise in optoelectronic devices, sensors, and biomedicine owing to their advantages of low optical scattering, deep-tissue penetration, and compatibility with advanced photonic technologies. However, the toxicity of conventional cadmium (Cd)- and lead (Pb)-based QDs has led to growing demand for eco-friendly alternatives. Here, we provide a comprehensive review of sustainable classes of red/NIR-emissive QDs, including indium phosphide (InP), I-III-VI chalcogenides (CuInS₂, AgInSe, and so on), group-IV (Si, Ge, and SiGe) nanocrystals, and carbon-based QDs (graphene QDs or carbon dots). InP QDs are leading candidates for display technologies due to their high efficiencies and narrow bandwidths in emission properties, enabled by advanced core/shell engineering. In contrast, I-III-VI chalcogenides, group-IV, and carbon-based QDs offer advantages for biocompatible NIR bioimaging, photothermal therapy, and silicon photonics integration. We discuss synthesis strategies for achieving long-wavelength emission, the mechanisms of red/NIR photoluminescence (PL), and representative applications in displays, sensors, and bioimaging. Finally, we outline the remaining challenges, such as large-scale manufacturing and long-term stability, which should be addressed for commercial and clinical viability. Full article

Water scarcity and pollution from anthropogenic activities are major challenges, increasing the need for sustainable wastewater treatment solutions. Constructed wetlands mimic natural wetland ecosystems using macrophytes and substrates, representing a possible nature-based solution aligned with circular economy principles and the United Nations Sustainable Development Goals. So, this revision integrates recent literature, providing an overview of natural wetlands and examining the design and operation of constructed wetland systems. Also, incorporates a case study that focuses on a constructed wetland implemented at an eco-friendly dog shelter in Portugal—a unique example globally—demonstrating practical wastewater treatment and small-scale water reuse, and offering insights for sustainable management. Performance assessment based on previous work indicates that the system effectively reduces most water quality parameters to levels compliant with national and European irrigation standards. Removal efficiencies exceeded 97% for chemical oxygen demand, total suspended solids, and turbidity, while maintaining low energy consumption and minimal maintenance. Overall, constructed wetlands emerge as a sustainable alternative to conventional wastewater treatment systems; however, several challenges remain to be addressed. Future research should focus on improved aeration strategies, optimized substrate–macrophyte combinations, and long-term monitoring under climate variability, with floating wetlands offering promising opportunities to further enhance treatment efficiency. Full article

This study explored the eco-friendly synthesis of AgNPs using Prosopis laevigata seed mucilage and assessed their antimicrobial, antibiofilm, and biocompatibility effects against foodborne pathogens. The AgNPs were mostly spherical, with sizes ranging from 2.5 to 56 nm (average: 14.69 nm), as confirmed by XRD and DLS analysis. They showed consistent antimicrobial activity, with MICs at 0.5 mg/mL and MBCs at 1.0 mg/mL across all tested strains, and inhibited bacterial growth by over 75% at 0.5–5 mg/mL, similar to or better than gentamicin. The antibiofilm performance was notable, with inhibitions of 76–84% against E. coli (1–10 mg/mL), 96–98% against S. aureus (0.5–10 mg/mL), 76–82% against Salmonella Typhimurium (0.5–10 mg/mL), and 70–84% against P. aeruginosa (1–10 mg/mL), surpassing gentamicin against E. coli and P. aeruginosa. Cell viability remained 100% at 0.25 mg/mL, and no significant changes in immunological parameters were observed, suggesting good biocompatibility at therapeutic doses. This research shows, for the first time, that P. laevigata mucilage is an effective bioreducing agent for green synthesis of AgNPs with antimicrobial and antibiofilm activity against both Gram-negative and Gram-positive foodborne pathogens. Its superior ability to inhibit biofilms compared to traditional antibiotics, along with its safety profile at therapeutic levels, makes these nanoparticles promising for food safety applications, antimicrobial coatings, and topical treatments. Overall, the findings support the use of native plant resources in green nanotechnology to address global challenges of antimicrobial resistance. Full article

Recently, lead-free metal halide perovskite variant nanocrystals (NCs) have emerged as promising alternatives to their lead-based counterparts, with tunable optoelectronic properties achievable through structural and compositional engineering. Their tunable bandgaps, near-unity quantum yields, solution-processable synthesis routes, and intrinsic environmental benignity render them attractive candidates for a broad range of optoelectronic applications. This review comprehensively summarizes recent advances in perovskite-derived NCs, including diverse synthetic strategies, as well as structural and compositional engineering approaches for optimizing their photophysical properties. Additionally, this review critically discusses the emerging applications of lead-free metal halide perovskite variants, such as solid-state lighting, high-sensitivity photodetection, and advanced radiation imaging. This review aims to provide in-depth insight into the structure–composition–performance relationship of lead-free perovskite variant NCs and pave the way for next-generation eco-friendly optoelectronic materials and devices. Full article

Squalene and squalane are widely used cosmetic ingredients valued for their emollient properties and excellent skin compatibility, yet sustainable sourcing remains a challenge. This study presents an integrated and eco-friendly strategy for valorizing wine lees as a renewable source of squalene and converting it into stable, high-performance squalane. Squalene was efficiently recovered from yeast-rich winery waste through optimized ultrasound-assisted extraction, followed by chromatographic purification. Green catalytic hydrogenation using palladium supported on natural clay minerals enabled the selective conversion of squalene into squalane under mild conditions. The functional evaluation via in vitro transport studies across an artificial membrane, using quercetin as a poorly permeable model antioxidant, demonstrated enhanced permeation compared with conventional vehicles, while accelerated aging experiments further confirmed the superior oxidative stability of squalane relative to native squalene. Overall, this work provides a proof of concept for upcycling winery by-products into multifunctional cosmetic ingredients that combine sustainability, stability, and functional performance, supporting circular economy principles and the growing demand for ethically sourced raw materials in the cosmetic industry. Full article

The accumulation of highly alkaline red mud poses serious environmental risks due to land occupation and potential soil/groundwater contamination. Recycling red mud as a secondary resource offers an eco-friendly solution, yet its influence on the performance of high-performance mortar (HPM) remains incompletely understood, particularly in aggressive environments. This study aims to systematically evaluate the effects of red mud on the fresh and hardened properties of HPM, including rheological parameters, setting time, mechanical strength, drying shrinkage, and sulfate dry–wet erosion resistance. The novelty lies in (1) quantifying the nonlinear relationships between red mud content and rheological/setting behaviors, (2) revealing the dual effect of red mud with curing age, and (3) using XRD/SEM-EDS to elucidate the micro-mechanisms related to hydration products and elemental changes (Al and Fe). The results show that increasing red mud content reduces slump flow (max 76.03%), plastic viscosity (46.7%), and yield stress (42.3%) while also shortening initial/final setting times (67.91% and 76.18% max reductions). At curing ages below 7 days, flexural and compressive strength increase (up to 64.53% and 33.35%, respectively), following cubic functions; however, at 7 and 28 days, both strength values decrease (max reductions of 13.43% and 12.98%). Red mud increases drying shrinkage and delays sulfate-induced degradation. Microstructural analysis reveals improved compactness of hydration products at early ages but reduced compactness at later ages, accompanied by increased Al/Fe content and enhanced SiO₂/calcium silicate hydrate crystals. These findings provide valuable insights for applying red mud HPM in marine environments. Full article

Carbon quantum dots (CQDs) and stimuli-responsive hydrogels are advanced functional materials whose hybridization yields CQD-enhanced stimuli-sensitive hydrogels, opening new interdisciplinary avenues for smart material applications. This review systematically summarizes the latest advances in these composites, focusing on synthetic strategies, structure–property modulation mechanisms, and practical applications. Distinct from existing reviews that either investigate CQDs or hydrogels independently or discuss their composites in a single research field, this work features core novelties in integration strategy, application scope and critical analysis: it systematically compares the advantages, limitations and applicable scenarios of three typical CQD–hydrogel integration approaches (physical entrapment, in situ synthesis, covalent conjugation), comprehensively covers the multi-field application progress of the composites and conducts in-depth cross-field analysis of their common scientific issues and technical bottlenecks. By incorporating CQDs, the composites achieve remarkable performance optimizations: 40% improved mechanical toughness, sub-ppm-level heavy metal-sensing sensitivity, and over 80% organic dye photocatalytic degradation efficiency, addressing pure hydrogels’ inherent limitations of insufficient strength and single functionality. These enhancements enable sophisticated applications in biomedical field (real-time biosensing, controlled drug delivery), environmental remediation (pollutant detection/degradation), energy storage, and flexible electronics. The synergistic interplay between CQDs and hydrogels facilitates precise single/multi-stimulus responsiveness (pH, temperature, light), a pivotal advance for precision medicine and intelligent environmental monitoring. Despite promising progress, the large-scale practical application of CQD–hydrogel composites still faces prominent challenges: the difficulty in scalable fabrication with the uniform dispersion of CQDs in hydrogel matrices, poor long-term stability of most composites under physiological cyclic stress (service life < 6 months in practical tests), and low accuracy in discriminating multi-stimuli in complex real-world matrices. Future research should prioritize biomass-based eco-friendly CQD synthesis, machine learning-aided multimodal responsive systems, and 3D bioprinting for scalable manufacturing. Full article

The study focuses on the attempt to produce structural concrete, class C25/30 with exposure class XC3, using recycled aggregates derived from Excavation, Construction and Demolition Waste (ECDW) management. All the necessary properties of the recycled aggregates used were determined and four concrete mix compositions were made with recycled aggregate percentages ranging from 25% to 100%, while two more mix compositions were made with natural aggregates (NAs) to compare the results. A total of 78 cubic specimens, 13 from each mix, were obtained and their compressive strength, dynamic modulus of elasticity, rebound number, maximum deformation and maximum mass loss due to evaporation were determined at ages of 3, 7, 14, 28 and 90 days. The results show that 25–50% replacement with mixed recycled aggregates can satisfy the C25/30 strength class, whereas 100% replacement leads to significant strength and stiffness reductions. Overall, the study demonstrates that structural-grade recycled aggregate concrete is feasible up to moderate replacement levels, provided that the high water absorption and increased deformability associated with recycled aggregates are explicitly accounted for in mix design, curing and serviceability checks. Full article

Agriculture faces escalating challenges from pests, diseases, and climatic stresses that threaten global food security. Green nanotechnology offers a sustainable approach to enhance crop protection and productivity by using plant-based methods to synthesize metallic nanoparticles (NPs), reducing chemical inputs and environmental impacts. This review presents the framework of green nanotechnology in agriculture, focusing on biogenic sources of nanoparticle synthesis (especially plant extracts), mechanisms of nanoparticle formation and stabilization by phytochemicals, and characterization techniques for green-synthesized NPs. We examine the application of plant-derived metallic nanoparticles as nanofertilizers to improve nutrient use efficiency and crop yields, as nanopesticides to manage plant pathogens and pests, and as nano-enabled agents to enhance tolerance to abiotic stresses such as salinity and drought. Recent studies demonstrate that green-synthesized NPs can increase wheat and rice yields by 13–55%, improve nutrient-use efficiency by up to 80–90% compared to conventional fertilizers, and provide effective pathogen control at reduced active ingredient doses, while reducing dependence on conventional agrochemicals. The review also discusses key challenges limiting large-scale adoption, including production scalability, biological variability in synthesis, potential phytotoxicity at high concentrations, regulatory uncertainties, and gaps in knowledge regarding nanoparticle fate and safety. Overall, green-synthesized metallic nanoparticles emerge as promising tools for improving crop productivity and protection in an eco-friendly manner, supporting the transition toward more sustainable agricultural systems. Full article