Search Results (3,057)

The integration of recycled materials into cementitious systems presents a sustainable path to reducing environmental impact in construction. This study investigates the mechanical and durability performance of self-compacting mortars (SCMs) incorporating finely ground mortar waste powder (MWP) as a partial cement substitute, reinforced with aluminum oxide (Al₂O₃) and iron oxide (Fe₂O₃). Eleven mixes were designed with MWP replacing cement at 0–50% by volume. Fresh-state tests showed that slump flow decreased moderately (from 259 mm to 240 mm), while V-funnel times improved (from 10.51 s to 7.01 s), indicating acceptable flowability. The optimum performance was observed in SCM2 (5% MWP + oxides), which achieved 75.62 MPa compressive and 13.74 MPa flexural strength at 28 days, outperforming the control mix. Durability under high temperature and freeze–thaw cycling revealed that oxide-reinforced mixes exhibited superior strength retention, with SCM2 maintaining over 87 MPa after 300 °C exposure and minimal degradation after 100 freeze–thaw cycles. Porosity remained low (16.1%) at optimal replacement levels but increased significantly beyond 25% MWP. The results confirm that low-level MWP replacement, when reinforced with reactive oxides, provides a viable strategy for producing durable, high-performance, and eco-efficient SCMs. Full article

Conventional protective coatings based on petroleum raw materials have certain limitations in terms of their availability, environmental pollution, and sustainability. Therefore, this research successfully investigates the potential of sheep wool-derived biochar to develop a sustainable, high-performance protective coating. Two variants of biochar, namely SW800 and SW1000, were developed by pyrolyzing sheep wool at 800 °C and at 1000 °C for 1 h, respectively. The prepared samples were characterized using FTIR, FESEM-EDX, and XRD analyses to confirm the structural and elemental differences between both biochar samples. Furthermore, biochar-based epoxy coatings were developed by varying the concentration of prepared biochar from 1% to 5%. The coating performance was evaluated for its aesthetic, mechanical, chemical resistance, and hydrophobicity. Crucially, this study demonstrated that biochar inclusion did not compromise critical mechanical and chemical properties like adhesion (5B), flexibility (7 mm), scratch hardness (3500 gms), pencil hardness (3H), acid-alkali resistance, and solvent rub test (rating 5). However, a key finding of this research is that the incorporation of biochar into an epoxy coating resulted in a significant improvement in hydrophobicity, which is measured using water contact angle. The incorporation of SW800 and SW1000 into coating formulations at varying concentrations resulted in an increase in water angle of approximately 18% and 20%, respectively. The outcomes of this project establish biochar-based coatings as a promising solution for eco-friendly and high-performance protective applications. Full article

Advanced engineering materials are in high demand for a combination of tailored properties in a single material. Titanium with aluminum alloys is widely used to prepare pistons and knee joints due to its high strength and abundant availability. The primary focus of the study was to utilize an eco-friendly composite material with low cost and a simple production process. Ti–48Al–2Cr–2Nb with molybdenum disulfide was added as reinforcement in varying percentages, fabricated using the squeeze casting production technique. The dry sliding wear test was performed. Adding 4% molybdenum disulfide to Ti–48Al–2Cr–2Nb enhanced its mechanical properties and wear resistance by 57%. Full article

This study examined how different lighting characteristics of conventional and eco-friendly lighting and environmental conditions, particularly snow cover, influenced the luminous environment and, in relation to that, pedestrian perception of faces on footpaths. The analysis was based on a dataset comprising both subjective evaluations and objective measurements. The spatial and directional light field above a footpath was measured for the two types of road lighting, of which the “eco-centric” luminaire had a lumen output of 4820 lm and reduced blue-light component (correlated color temperature (CCT) of 2200 K) compared to the conventional luminaire with 14,000 lm and 4000 K. The luminaires were analyzed under snowy and non-snowy conditions. Snow cover significantly increased light diffuseness and density (directionally averaged illuminance at a point), resulting in more uniform light and higher subjective ratings. Also, face visibility ratings were generally higher and more uniform, while non-snowy conditions led to more pronounced differences between positions and luminaire types. Regression analysis revealed that vertical illuminance at eye height was the strongest predictor of perceived facial friendliness and well-lighted-ness and contributed to more favorable ratings for the environment lighting too. The eco-centric luminaire was found to positively influence face lighting ratings but received lower ratings for environmental visibility. Increased horizontal illuminance did not consistently result in enhanced subjective evaluations, which points to limitations of traditional illuminance-based lighting standards, often considering horizontal illuminance at ground level as one of the main metrics. The “social light field” concept emphasizes a holistic approach to urban lighting design that integrates social perception and environmental sustainability by considering the distribution of the actual, resulting light throughout the urban space, especially vertical illuminance at the face and its effects on visual appearance, as well as contributing interactions with the environment and materials in it. Full article

Despite extensive research on green consumption, consumer purchase intentions for bamboo products under China’s “replacing plastic with bamboo” policy remain underexplored, given growing plastic pollution concerns. Research remains focused on established green products (e.g., green agriculture, energy-efficient appliances, new energy vehicles), overlooking consumer behavior and cognition toward emerging bamboo alternatives. This study employs eye-tracking technology to examine purchase intentions and visual attention allocation mechanisms for bamboo versus plastic products, analyzing the role of green consumption values (GCVs). Using a 2 (material: bamboo/plastic) × 2 (GCVs: high/low) mixed design, we recorded fixation duration, fixation count, and heatmaps from 70 participants. Behavioral results revealed significantly higher purchase intention for bamboo products, particularly among high-GCV consumers. Eye-tracking data showed greater visual attention (fixation duration/count) to bamboo products, with high-GCV participants exhibiting significantly stronger attentional bias toward bamboo. Findings demonstrate that bamboo’s eco-friendly attributes enhance both purchase intention and visual attention allocation, validating material salience in green decision-making. High GCVs strengthen automatic attentional bias toward sustainable materials, reinforcing purchase inclinations. This research provides empirical support for VBN theory at the cognitive level and offers policy-relevant insights for promoting “Bamboo Instead of Plastic” initiatives. Full article

The majority of the polymeric materials used in the industry are derived from petroleum and decompose slowly, resulting in waste that poses environmental issues. As a result, there has been a concerted effort to find alternative materials that cover their engineering performance. Biopolymers have emerged as leading contenders because they can mimic the properties of synthetic polymers while being derived from natural and renewable sources. Several projects are focused on developing biomaterials for these applications. This study presents a modification of the mechanical properties of a gelatin-based material with the crosslinking agent sodium tripolyphosphate (NaTPP) by reinforcement with agar. The gelatin–agar (G-Ax) samples exhibited a homogeneous color and flexibility, sharing similar crystalline structures and functional groups. However, the transversal section of the gelatin-only film was modified by the addition of agar, from a porous morphology to a lamellar morphology at nanometric scale thickness. Notably, the agar samples demonstrated greater stress resistance, yield stress, and strain than the gelatin-only sample. These findings highlight the potential of biopolymers such as gelatin and agar as viable alternatives to conventional materials, contributing to the research on eco-friendly solutions for different engineering applications. Full article

Reinforced concrete structures in harsh environments are highly vulnerable to structural damage caused by rebar corrosion. However, there remains a critical shortage of high-performance, environmentally friendly repair materials that integrate both structural restoration and long-term corrosion protection functionalities to address this issue. To meet this demand, this study innovatively developed an eco-friendly, high-performance repair material using lotus leaf extract (LLE)-modified mortar and systematically evaluated its corrosion protection performance and mechanisms under chloride attack conditions. The primary chemical constituents of LLE include alkaloids and flavonoids, rich in polar functional groups such as O–H, N–H, and C–O. The LLE modifier increased the fluidity of fresh cement paste, thereby improving its construction workability. A low dosage of LLE modifier promoted cement hydration. When the LLE dosage was 0.2 wt%, the 7-day and 28-day flexural strengths of the LLE-modified mortar increased by 16.8% and 7.48%, respectively, compared to those of unmodified mortar, while the compressive strengths increased by 30.6% and 14.5%, respectively. The LLE-modified mortar demonstrated significant protection against chloride corrosion, effectively inhibiting rebar corrosion. Electrochemical corrosion results indicated that compared to unmodified mortar, the modified mortar containing 0.5 wt% LLE exhibited an 80% improvement in protection efficiency against chloride corrosion. These results demonstrate that an appropriate dosage of LLE modifier can simultaneously optimize the fundamental properties of mortar and provide excellent chloride corrosion protection. Therefore, LLE-modified mortar shows promising application potential in integrated repair and corrosion protection engineering for reinforced concrete structures. Full article

The present study explores the sustainable potential of volcanic ash sourced from the active Sakurajima volcano (Japan) as an eco-friendly alternative to Portland cement—a binder known for its high carbon emissions—in concrete and mortar production. The abundant pyroclastic material, currently a waste burden for the residents of Sakurajima and the Kagoshima Bay region, presents a unique opportunity for valorization in line with circular economy principles. Rather than treating this ash as a disposal problem, the research investigates its transformation into a valuable supplementary cementitious material (SCM), contributing to more sustainable construction practices. The investigation focused on the material characterization of the ash (including chemical composition, morphology, and PSD) and its pozzolanic activity index, which is a key indicator of its suitability as a cement replacement. Mortars were prepared with 25% of the commercial binder replaced by volcanic ash—both in its raw form and after mechanical activation—and tested for compressive strength after 28 and 90 days of water curing. Additional assessments included workability of the fresh mix (flow table test), apparent density, and flexural strength of the hardened composites. Tests results showed that the applied volcanic ash did not influence the workability of the mix and showed negligible effect on the apparent density (changes of up to 3.3%), although the mechanical strength was deteriorated (decrease by 15–33% after 7 days, and by 25–26% after 28 days). However, further investigation revealed that the simple mechanical grinding significantly enhances the pozzolanic reactivity of Sakurajima ash. The ground ash achieved a 28-day activity index of 81%, surpassing the 75% threshold set by EN 197-1 and EN 450-1 standards for type II mineral additives. These findings underscore the potential for producing low-carbon mortars and concretes using locally sourced volcanic ash, supporting both emissions reduction and sustainable resource management in construction. Full article

The electrochemical reduction of CO₂ (eCO2RR) has emerged as a promising route for carbon-neutral fuel and chemical production, offering a sustainable alternative to fossil-based processes. This article begins with an overview of conventional CO₂ conversion methods, highlighting their limitations and the advantages of electrochemical approaches under ambient conditions. We focus on recent advancements in electrocatalyst development for the eCO2RR, including metal-based, Cu-based, and metal-free catalysts. Metal-based catalysts are categorized by product selectivity (formate, CO, and multicarbon products), emphasizing their structures and practical performance. Cu-based catalysts are discussed in detail due to their unique capability to produce multicarbon products, with emphasis on design strategies, material types, and performance trends. Additionally, we review emerging metal-free catalysts, including their synthesis, mechanisms, and potential applications. This article provides a comparative analysis to guide future research toward efficient, selective, and durable catalysts for CO₂ electroreduction, aiming to accelerate the deployment of carbon capture and utilization technologies. Full article

Currently, electrochemical devices and portable electronic equipment play a significant role in people’s daily lives. Zinc-ion batteries (ZIBs) are growing rapidly due to their excellent safety, eco-friendliness, abundance of resources, and cost-effectiveness. The application of biomass as a polymer separator is gradually expanding in order to promote a circular economy and sustainable materials. This research focuses on the usage of cellulose fibers obtained from coffee parchment (CP) waste. The extracted cellulose fibers are produced via both mechanical and chemical methods. The sustainable separators are fabricated through vacuum filtration using a polymer filter membrane. The impact of incorporating silica particles and varying silica content on the physical and electrochemical properties of a cellulose-based separator is examined. The optimum amount of silica integrated into the cellulose separator is determined to be 5 wt%. This content led to an effective distribution of the silica particles, enhanced wettability, and improved fire resistance. The ZIBs incorporating cellulose/recycled silica at 5 wt% demonstrate exceptional cycle stability and the highest capacity retention (190% after 400 cycles). This study emphasizes the promise of sustainable polymers as a clean energy resource, owing to their adaptability and simplicity of processing, serving as a substitute for synthetic polymers sourced from fossil fuels. Full article

Hybrid thermoelectric generators (HTEGs) play a pivotal role in sustainable energy conversion by harnessing waste heat through the Seebeck effect, contributing to global efforts in energy efficiency and environmental sustainability. In practical sustainable energy systems, HTEG output performance is significantly influenced by uncertainties in the operational parameters (such as temperature differences and load resistance), material properties (including Seebeck coefficient and resistance), and structural configurations (like the number of series/parallel thermoelectric components), which impact both efficiency and system stability. This study employs the Sobol-sequence-sampling method to characterize these parameter uncertainties, analyzing their effects on HTEG output power and conversion efficiency using mean values and standard deviations as evaluation metrics. The results show that higher temperature differences enhance output performance but reduce stability, a larger load resistance decreases performance while improving stability, thermoelectric materials with high Seebeck coefficients and low resistance boost efficiency at the expense of stability, increasing series-connected components elevates performance but reduces stability, parallel configurations enhance power output yet decrease efficiency and stability, and greater contact thermal resistances diminish performance while enhancing system robustness. This research provides theoretical guidance for optimizing HTEGs in sustainable energy applications, enabling the development of more reliable, efficient, and eco-friendly thermoelectric systems that balance performance with environmental resilience for long-term sustainable operation. Full article

This study investigates sustainable mortars using lightweight synthetic sand (LSS), made from dune sand and recycled PET bottles, to replace natural sand (0–100% by volume). This aligns with circular economy principles by valorizing plastic waste into a construction aggregate. LSS is produced via controlled thermal treatment (250 ± 5 °C, 50–60 rpm), crushing, and sieving (≤3.15 mm), leading to a significantly improved interfacial transition zone (ITZ) with the cement matrix. The evaluation included physico-mechanical tests (density, strength, UPV, dynamic modulus, ductility), thermal properties (conductivity, diffusivity, heat capacity), porosity, sorptivity, alkali–silica reaction (ASR), and SEM. The results show LSS incorporation reduces mortar density (4–23% for 25–100% LSS), lowering material and logistical costs. While compressive strength decreases (35–70%), these mortars remain suitable for low-stress applications. Specifically, at ≤25% LSS, composites retain 80% of their strength, making them ideal for structural uses. LSS also enhances ductility and reduces dynamic modulus (18–69%), providing beneficial flexibility. UPV decreases (8–39%), indicating improved acoustic insulation. Thermal performance improves (4–18% conductivity reduction), suggesting insulation applicability. A progressive decrease in sorptivity (up to 46%) enhances durability. Crucially, the lack of ASR susceptibility reinforces long-term durability. This research significantly contributes to the repurposing of plastic waste into sustainable cement-based materials, advancing sustainable material management in the construction sector. Full article

Hemp stalk, a widely available agricultural waste, is an ideal eco-friendly raw material for biochar production. Carbonization experiments were conducted as a novel approach for the scalable and value-added utilization of hemp stalk under oxygen-exclusion conditions. The effects of feedstock types—Hibiscus cannabinus (KS), Corchorus spp. (JS), and Boehmeria spp. (RS)—and pyrolysis temperatures on biochar properties were analyzed through the measurements of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy. The pH and electrical conductivity (EC) of biochars increased with increasing pyrolysis temperature. Notably, EC was significantly higher for RS (940–2278 μS/cm) than for KS (517–879 μS/cm) and JS (583–863 μS/cm). The C content in these three biochars increased as the temperature increased, whereas the H/C atomic ratio decreased, most notably in JS (by 0.33%). According to FTIR and XRD data, with the pyrolysis temperature increasing, the acidic oxygen-containing groups on biochar surfaces reduced. KS700, with superior aromatic structure and stability, may be able to effectively adsorb heavy metal ions. RS700, with relatively high pH and EC, was suitable for alleviating soil acidification and nutrient deficiency. The feedstock and pyrolysis temperature significantly affected the element content, pore structure, and stability of biochars derived from hemp stalk. Full article

This study investigates the effect of rice husk content (0–60 wt.%) on the thermal, mechanical and rheological properties of polypropylene composites prepared by extrusion and injection molding. A temperature-invariant approach was applied to analyze the viscoelastic properties, allowing the combination of data obtained at different temperatures. The results show that as the husk content increases, the elastic modulus and hardness rise linearly, while the impact strength and elongation at break significantly decrease. Composites with 40–50% filler exhibit a balanced combination of strength and stiffness, as confirmed by the summary data in the table (provide references). The application of the temperature-invariant viscosity method confirmed its effectiveness in evaluating the flow properties of composite melts. The obtained results have practical significance for the development of eco-friendly polymer materials with natural fiber fillers. Full article

Industrial wastewater pollution has reached acute levels in the environment; consequently, scientists are developing new sustainable treatment methods. Lignocellulosic biomass (LB) stands as a promising raw material because it originates from agricultural waste, forestry residues, and energy crop production. This review examines the application of nanomaterials derived from lignocellulosic resources in wastewater management, highlighting their distinctive physical and chemical properties, including a large surface area, adjustable porosity structure, and multifunctional group capability. The collection of nanomaterials incorporating cellulose nanocrystals (CNCs) with lignin nanoparticles, as well as biochar and carbon-based nanostructures, demonstrates high effectiveness in extracting heavy metals, dyes, and organic pollutants through adsorption, membrane filtration, and catalysis mechanisms. Nanomaterials have benefited from recent analytical breakthroughs that improve both their manufacturing potential and eco-friendly character through hybrid catalysis methods and functionalization procedures. This review demonstrates the ability of nanomaterials to simultaneously turn waste into valuable product while cleaning up the environment through their connection to circular bioeconomic principles and the United Nations Sustainable Development Goals (SDGs). This review addresses hurdles related to feedstock variability, production costs, and lifecycle impacts, demonstrating the capability of lignocellulosic nanomaterials to transform wastewater treatment operations while sustaining global sustainability. Full article