Search Results (182)

Biomass is one of the most important sources of renewable energy, generating large amounts of ash. This increases the amount of waste, landfill, and air pollution. This work focuses on the sustainable disposal of this ash by producing an innovative binder. The mechanical and microstructural properties of alkali-activated biomass fly ash (BFA) and diatomite (DT) mixtures are currently insufficiently studied. New scientific knowledge of these properties is needed. This study presents the possibility of using BFA and diatomite as aluminosilicate precursors for the production of an alkaline-activated binder. It was found that the reactivity of BFA is relatively low. Based on XRD analysis, the mineral composition of BFA is dominated by quartz and calcite, both of which are non-reactive minerals. Therefore, mixtures with DT were created as precursors. According to Rietveld analysis data, an amorphous part was found in both precursor materials, BFA and DT. Comparing the chemical composition of BFA and DT using XRF and Rietveld analysis data, it was found that the amorphous part of BFA consists of CaO, while the amorphous part of DT consists of SiO₂. Thus, the combination of these precursors should complement each other during the geopolymerisation process. After 28 days of curing, the strength of the binders was dependent on the amount of DT, and the highest strength values, such as 16.4 MPa and 15.3 MPa, were obtained when DT contents were 10% and 30%, respectively. After geopolymerisation, XRD analysis showed that calcium silicate hydrate, hydrotalcite, and calcium aluminium silicate hydrate (zeolite A type) were formed. SEM analysis confirmed the XRD results and showed that DT additives (10% and 30% by weight) improved the microstructure of alkali-activated BFA, which is closely related to compressive strength values. The proposed binder will be useful in the preparation of concrete, which could be used for artificial aggregates or small architectural elements. Full article

The increasing consumption of edible oils has resulted in a parallel rise in waste cooking oil (WCO), a harmful waste stream but one that also represents a promising raw material. In this study, oil-based binders were synthesised from WCO using various reagents: Sulfuric(VI) acid, hydrobromic acid, acetic acid, salicylic acid, glycolic acid, zinc acetate, ethanol, hydrogen peroxide, and their selected mixtures. The manufacturing process was optimised, and the composites were evaluated for physicochemical and mechanical properties, including compressive strength, bending strength, and water absorption. The best performance was observed for composites catalysed with a mixture of sulfuric(VI) acid and 20% hydrogen peroxide, cured at 240 °C, yielding compressive and bending strengths of 5.20 MPa and 1.34 MPa, respectively. Under modified curing conditions, a compressive strength of 5.70 MPa and a bending strength of 0.75 MPa were obtained. The composite modified with glycolic acid showed the lowest water absorption (3%). These findings demonstrate how catalyst type and curing parameters influence composite structure, porosity, and mechanical behaviour. The study provides new insights into the process–structure–property relationships in oil-based materials and supports the development of environmentally friendly composites from waste feedstocks. Full article

Eco-friendly mortars have been manufactured with hybrid binders made of blast furnace slag and a reduced amount of clinker. The objective is to explore new formulations suitable for reinforced structures. Previous studies are mainly focused on activation with sulfates, a salt that is corrosive to reinforcing steel. Sodium nitrate and sodium carbonate, easily implementable in construction, have been used as activators in two different concentrations that involve similar Na content. A Type II PC mortar is used as reference. The dimensional stability of the mortars during curing (at 99% RH) and subsequent drying at 40% RH, has been evaluated, as well as their porosity and mechanical properties. Böhme tests revealed that studied hybrid binders have lower wear resistance than PC mortar. Activation with Na₂CO₃ allows the obtention of mortars with reduced porosity and good compression resistance, but generates microcracking that favors chloride diffusion. Activation with nitrates favors precipitation of AFm phases identified through differential thermal analysis. Nitrates in moderate amounts (4% w/w) allow manufacturing hybrid mortars with good resistance to chloride penetration and reasonably good mechanical properties. Hence, this binder can be a promising option for reinforced structures. Higher amounts of nitrates (8%) for activation give rise to more porous mortars. Full article

USP (usual temperature pitch)-modified asphalt optimizes its rheological properties through reactions between the modifier and the asphalt. This significantly enhances the high- and low-temperature adaptability and environmental friendliness of asphalt. It has now become an important research direction in the field of highway engineering. This article systematically investigates the impact of different dosages of USP warm mix modifier on asphalt binders through rheological and microstructural analysis. Base asphalt and SBS-modified asphalt were blended with USP at varying ratios. Conventional tests (penetration, softening point, ductility) were combined with dynamic shear rheometry (DSR, AASHTO T315) and bending beam rheometry (BBR, AASHTO T313) to characterize temperature/frequency-dependent viscoelasticity. High-temperature performance was quantified via multiple stress creep recovery (MSCR, ASTM D7405), while fluorescence microscopy and FTIR spectroscopy elucidated modification mechanisms. Key findings reveal that (1) optimal USP thresholds exist at 4.0% for base asphalt and 4.5% for SBS modified asphalt, beyond which the rutting resistance factor (G*/sin δ) decreases by 20–31% due to plasticization effects; (2) USP significantly improves low-temperature flexibility, reducing creep stiffness at −12 °C by 38% (USP-modified) and 35% (USP/SBS composite) versus controls; (3) infrared spectroscopy displays that no new characteristic peaks appeared in the functional group region of 4000–1300 cm⁻¹ for the two types of modified asphalt after the incorporation of USP, indicating that no chemical changes occurred in the asphalt; and (4) fluorescence imaging confirmed that the incorporation of USP led to disintegration of the spatial network structure of the control asphalt, explaining the reason for the deterioration of high-temperature performance. Full article

The current economic growth and increasing needs of society have led to developing processes that harm our environment and have severe long-term consequences. For this reason, different attempts have been made to mitigate these effects by substituting conventional toxic materials with environmentally friendly ones. Industry sectors related to energy storage, printed electronics, and wearable technology are moving towards applying sustainable strategies. Renewable biopolymers such as cellulose and its derivatives, as well as carbon-based alternatives, which include carbon nanotubes (CNTs), single-wall carbon nanotubes (SWCNTs), graphite, graphene, and carbon black (CB), are leading the advances in this field. The present research aimed to develop conductive cellulose paper using environmentally friendly components compatible with the paper recycling process. Coating formulations based on carbon black were proposed using three different types of binders: polytetrafluoroethylene (PTFE), latex (styrene butadiene), and sodium carboxymethyl cellulose (CMC). The formulation, composition, and preparation were studied, and they were related to the coating’s electrical resistance and integrity. This last parameter was determined through a new method described in this research, implementing a mechanical/optical technique to measure the coating’s durability. The formulation with the best performance in terms of electrical resistance (0.29 kΩ), integrity, and non-toxicity was obtained using sodium carboxymethyl cellulose (CMC) as a binder and dispersant. Full article

This study aims to address the challenge of backfill compaction in the confined spaces of municipal utility tunnel trenches and to develop an environmentally friendly, zero-cement-based backfill material. The research focuses on the excavation slag soil from a utility tunnel project in Handan. An alkali-activated industrial-solid-waste-excavated slag-soil-based controllable low-strength material (CLSM) was developed, using NaOH as the activator, a slag–fly ash composite system as the binder, and steel slag-excavated slag as the fine aggregate. The effects of the water-to-solid ratio (0.40–0.45) and the binder-to-sand ratio (0.20–0.40) on CLSM fluidity were studied to determine optimal values for these parameters. Additionally, the influence of excavated soil content (45–65%), slag content (30–70%), and NaOH content (1–5%) on fluidity (flowability and bleeding rate) and mechanical properties (3-day, 7-day, and 28-day unconfined compressive strength (UCS)) was investigated. The results showed that when the water-to-solid ratio is 0.445 and the binder-to-sand ratio is 0.30, the material meets both experimental and practical requirements. CLSM fluidity was mainly influenced by the excavated soil and slag contents, while NaOH content had minimal effect. The unconfined compressive strength at different curing ages was negatively correlated with the excavated soil content, while it was positively correlated with slag and NaOH content. Based on these findings, the preparation of “zero-cement” CLSM using industrial solid waste and excavation slag is feasible. For trench backfill projects, a mix of 50–60% excavated soil, 40–60% slag, and 3–5% NaOH is recommended for optimal engineering performance. CLSM is a new type of green backfill material that uses excavated soil and industrial solid waste to prepare alkali-activated materials. It can effectively increase the amount of excavated soil and alleviate energy consumption. This is conducive to the reuse of resources, environmental protection, and sustainable development. Full article

The aim of the article was to test new types of rubber-containing particleboards created from waste materials, which positively contributes to environmental protection, saving primary resources and reducing production costs. This article focuses on the study of three-layer particleboards made from wood particles (spruce non-treated beams) and waste rubber granulates (tires, mixture of seals and carpets, internal flammable cables, external non-flammable cables). Urea–formaldehyde glue, melamine–formaldehyde glue, paraffin emulsion, and ammonium nitrate were used as a binders and excipients in the manufacturing of particleboards. In the core layer of each particleboard, 10% of the weight was made up of rubber granulate. Physical properties (density, water absorption, thickness swelling) and mechanical properties (internal bonding strength, modulus of rupture, modulus of elasticity, screw driving torque) were assessed from this perspective using current EN technical standards. According to the findings, the average densities of all particleboards were comparable to each other in a range from 0.692 to 0.704 g·cm⁻³. The lowest average water absorption and thickness swelling reached particleboards containing 10% of waste internal flammable cables, namely 32.79% for water absorption and 13.21% for thickness swelling. The highest average internal bonding strength reached particleboards without rubber filler and particleboards containing 10% of waste external non-flammable cables, namely 0.52 MPa for both types. The highest average modulus of rupture reached particleboards without rubber filler, namely 12.44 MPa. The highest average modulus of elasticity reached particleboards containing 10% of waste internal flammable cables, namely 2206.29 MPa, and the highest screw driving torque reached particleboards without rubber filler, namely 0.46 N·m for seating torque and 1.44 N·m for stripping torque. The results show that particleboards containing waste external non-flammable cables and particleboards containing waste internal flammable cables achieved comparable results to particleboards without rubber filler, which provides a good basis for a new way of utilizing this type of waste in the form of producing new wood–rubber composites. Full article

Carbon-neutral and carbon-negative construction is gaining significant interest in the home building industry. Accordingly, the development of new materials and innovative redesign of the existing materials are on the rise. This paper presents the results of a review study on hempcrete as a new, emerging construction material, which is crop-based and is accordingly expected to provide a highly sustainable construction system. The paper reviews the mixture design, properties and attributes, different methods for its application in construction, building code requirements for construction of hempcrete homes, mechanical and structural properties for home building, and evaluation of the current state of hempcrete application as a non-load-bearing construction material. The paper also reviews the status of developments toward using hempcrete as a load-bearing system. The study shows a snapshot of the methods used for the construction of hempcrete buildings and touches on efforts that are ongoing to increase the compressive strength of hempcrete toward load-bearing applications. Such an increase would depend on different factors such as curing temperature and humidity, binder type and percentage, hemp-to-binder ratio, water-to-binder ratio, and additives. Full article

The application of slow-release fertilizers is essential for improving fertilizer utilization efficiency and promoting sustainable agricultural development. Unlike traditional single organic polymer-coated or inorganic-coated fertilizers, this study utilized biodegradable modified polyvinyl alcohol (PVA) as a binder and cheap, readily available phosphogypsum–bentonite as an inorganic coating material to develop a novel slow-release potassium magnesium sulfate fertilizer (SRPMSF). This study initially examined the influence of SA dosage on PVA properties. XRD, FTIR, TGA, and water resistance analyses revealed that sodium alginate exhibits good compatibility with polyvinyl alcohol, enhancing its heat and water resistance. Ultimately, PVA–SA-2 (1.2% sodium alginate) was chosen as the optimal binder for SRPMSF production. Furthermore, this study investigated the impact of bentonite on the physical and slow-release properties of the SRPMSF by varying the phosphogypsum-to-bentonite ratio. This experiment included five treatment methods: the treatments consist of SRPMSF-1 (0 g bentonite), SRPMSF-2 (phosphogypsum/bentonite ratio of 4:1), SRPMSF-3 (3:2), SRPMSF-4 (2:3), and SRPMSF-5 (1:4). A control group (PMSF) was also included. The results indicated that, as the bentonite content increased, both the particle size and compressive strength of the coated slow-release fertilizer increased, with the SRPMSF particle sizes ranging from 3.00 to 4.50 mm. The compressive strength of the SRPMSF ranged from 20.85 to 43.78 N, meeting the requirements for industrial production. The soil column leaching method was employed to assess the nutrient release rate of the fertilizers. The experimental results indicated that, compared to the PMSF, the SRPMSF effectively regulated nutrient release. Pot experiments demonstrated that the SRPMSF significantly enhanced garlic seedling growth compared to the PMSF. In conclusion, a new type of slow-release fertilizer with good slow-release performance is prepared in this paper, which can improve the utilization rate of fertilizer and reduce the economic loss and is conducive to the sustainable development of agriculture. Full article

The significantly rising incidence of oral cancer worldwide urgently requires the identification of novel, effective molecular targets to inhibit the progression of malignancy. DNA topoisomerase I (Topo I) is a well-established target for cancer treatment, and many studies have shown that different cancer cell genes could be targeted more selectively with one type of Topo I inhibitor. In this report, a new scaffold pyridothieno[3,2-c]isoquinoline 11,11-dioxide was designed via the combination of the key fragment or bioisoster of Topo I inhibitor azaindenoisoquinolines and G-quadruplex binder quindoline. Thirty-two target derivatives were synthesized, among which compounds 7be, with potent Topo I inhibition, exhibited effective antiproliferative activity against Cal27, one of the oral cancer cell lines highly expressing Topo I protein. Further studies indicated that 7be could also inhibit the activation of PI3K/AKT/NF-κB pathway and downregulate the level of c-MYC, repress the colony formation and the migration of Cal27 cells and trigger apoptosis and autophagy. Molecular docking indicated that 7be could interact with the complex of Topo I and DNA via a mode similar to the indenoisoquinolines. The results of the Cal27 xenograft model confirmed that 7be exhibited promising anticancer efficacy in vivo, with tumor growth inhibition (TGI) of 64.7% at 20 mg/kg. Full article

Structural color-generating materials are expected to replace pigments and dyes as a new type of color-developing materials with good light stability and bright colors. Due to the relatively high refractive index of Cu₂O microspheres, they have strong Mie scattering in the visible region. Herein, various sizes of Cu₂O microspheres were synthesized by a two-step reduction method, and the Cu₂O spheres were firmly bonded to the fabrics by using the PVA binder. Four different fabrics (cotton, silk, polyester, and nylon fabrics) were evaluated to investigate the physical properties and color fastness. It turns out that the tensile and tearing properties of the Cu₂O structured fabrics decreased to a certain extent, and the bursting properties of fabrics increased, except for the cotton structured fabrics. Meanwhile, all the structural colored fabrics showed excellent color fastness to shearing, rubbing, and washing. This study provides experimental data for developing the application of structural colors on different fabrics. Full article

Organic materials have emerged as promising candidates for cathode materials in lithium-ion batteries and supercapacitors, offering unique properties and advantages over traditional inorganic counterparts. This review investigates the use of organic compounds as cathode materials in energy storage devices, focusing on their application in lithium-ion batteries and supercapacitors. The review covers various types of organic materials, organosulfur compounds, organic free radical compounds, organic carbonyl compounds, conducting polymers, and imine compounds. The advantages, challenges, and ongoing developments in this area are examined and the potential of organic cathode materials to achieve higher energy density, improved cycling stability, and environmental sustainability is highlighted. The comprehensive analysis of organic cathode materials provides insights into their electrochemical performance, electrode reaction mechanisms, and design strategies such as molecular structure modification, hybridization with inorganic components, porous architectures, conductive additives, electrolyte optimization, binder selection, and electrode architecture to improve their efficiency and performance. In addition, future research in the field of organic cathode materials should focus on addressing current limitations such as low energy density, cycling stability, poor discharge capability, potential safety concerns and improving their performance. To do this, it will be necessary to improve structural stability, conductivity, cycle life, and capacity fading, explore new redox-active organic compounds, and pave the way for the next generation of high-performance energy storage devices. For organic cathode materials to be commercially viable, it is also essential to develop scalable and economical manufacturing processes. Full article

The backfill binder material is the key to the cost and performance of cemented paste backfill. This study aims to understand the current situation of metal ore backfill binders, identify industry challenges, inspire research ideas, and explore development directions. Current research investigates trends and developments of backfill binders through literature review, experience summary, field research, statistical analysis, and other methods. Firstly, the main backfill binder types are summarized, including cement, metallurgical slag, thermal slag, chemical slag, and tailings binders. Secondly, the research progress regarding reactivity activation, hydration mechanism, harmful ion solidification, energy conservation, and carbon reduction is summarized. Thirdly, three industrial applications of new backfill binders are introduced and summarized. Cement is still the most common, followed by slag powder binder. The cases of steel slag binder and semi-hydrated phosphogypsum backfill have shown significant effects. Solid waste-based backfill binder materials are gradually replacing cement, which is a trend. Finally, further research is discussed, including hydration modeling and simulation, material properties under extreme environments, hardening process control, and technical standards for backfill binders. This work provides a reference and basis for promoting green and efficient paste backfill and sustainable industry development. Full article

In order to eliminate the negative effects caused by traditional pavements, permeable pavements are gradually being used in road construction. In recent years, polyurethane (PU) has been used as a new binder in permeable pavement mixtures. However, compared to traditional pavement mixtures, the adhesion properties between PU and aggregate have not been systematically analyzed. In addition, no clear standards have been established for the performance testing of PU mixtures, posing significant challenges for the selection of materials and the optimization of formulations for PU mixtures. Therefore, this paper proposes new methods for evaluating the performance of PU mixtures from a microscopic point of view, aiming at evaluating the adhesion properties between PU and aggregates. In this study, a PU binder was synthesized. The adhesion properties of this PU binder with aggregate were evaluated by surface free energy measurement and molecular dynamics (MD) simulation. Finally, the effects of different environmental conditions and aggregate types on the PU–aggregate adhesion properties were investigated. The results showed that the adhesion between PU and basalt is consistently better than that with limestone, although the adhesion between PU and aggregate decreased under acidic conditions. It implies that the PU–basalt mixture has better water resistance than the PU–limestone mixture. Furthermore, the results of the surface free energy measurements and MD simulations for the evaluation of adhesion at the PU–aggregate interface showed good correlation with the macroscopic performance experiments, which can be extended to the study of the adhesion properties of other materials. Full article

Artificial sand cementation improves stability, stiffness, and mechanical strength, making it a critical process in geotechnical applications. This study analyzes the capability of the porosity–water/binding agent index $(\eta C_w/B_{iv})$ to predict cemented sands’ unconfined compressive strength $(q_u)$ and stiffness $(G_o)$. Four Colombian sands, i.e., Luruaco, Medellín, Lorica, and Bogotá (stabilized with Portland cement), and were compared with three Brazilian sands: i.e., Osorio, Porto Alegre, and Rio Pardo were evaluated, stabilized with combinations of carbide lime and glass powder, using varying binder contents and a curing period of seven days subjected to ultrasonic pulse velocity (UPV) tests and unconfined compressive strength (UCS) tests. The results indicate that incorporating water content into the index significantly enhances predictive accuracy, achieving R² values above 0.94 for Colombian sands and considerably better fits for Brazilian sands than the traditional porosity/binder index. This new alternative provides an appropriate parameter for representing the small-strain stiffness and unconfined compressive strength of artificially cemented sands stabilized with various types of binders. Furthermore, the new index proved to be more effective in predicting the behavior of uniform and loose-graded sands, such as those from Bogotá and Lorica, which rely more heavily on binder volume and water content to achieve greater strength and stiffness. Lastly, the predictive model, validated against experimental results, achieved reliability indices (R²) of 0.9791 for stiffness and 0.9799 for strength prediction. Full article