Search Results (150)

While crumb rubber powder has demonstrated effectiveness in enhancing the mechanical properties of asphalt binders, its viscoelastic behavior under freeze–thaw conditions in clean water and de-icing salt, typically urban road conditions in winter, remains insufficiently explored. This study systematically investigated the microstructural evolution, compositional changes, and mechanical behavior of asphalt modified with rubber under the influence of freeze–thaw conditions in clean water and de-icing salt. The findings revealed that rubber powder incorporation accelerates the precipitation of oil, enhancing material stability in both aqueous and saline environments. Notably, asphalt containing 10% crumb rubber powder (Asphalt-10% RP) and 20% crumb rubber powder (Asphalt-20% RP) exhibit creep recovery rates 50.53% and 28.94% higher, respectively, under de-icing salt freeze–thaw cycles than under clean water freeze–thaw cycles. Therefore, in regions with extremely low temperatures and frequent snowfall, rubber powder exhibits significant research potential, providing theoretical support for the design of asphalt pavements in cold climates. Full article

In this study, a Zn(CN)₂–V₂O₃–C composite cathode was synthesized via AC electrophoretic deposition (EPD) and evaluated for application in aqueous zinc-ion batteries (ZIBs). Here, we report for the first time a binder-free Zn(CN)₂–V₂O₃–C composite cathode, using AC-EPD to create an ultrathin architecture optimized for probing the electrode–electrolyte interface without interference from additives or bulk effects. The composite combines Zn(CN)₂ for structural support, V₂O₃ as the redox-active material, and carbon for improved conductivity. X-ray diffraction confirmed the presence of Zn(CN)₂ and V₂O₃ phases, while scanning electron microscopy revealed a uniform, ultrathin film morphology. Electrochemical analysis demonstrated a hybrid charge storage mechanism with a b-value of 0.64, indicating both capacitive and diffusion-controlled contributions. The electrode delivered a high specific capacity (~250 mAh/g at 500 mA/g) with stable cycling performance. These results highlight the potential of metal–organic framework-derived composites for high-performance ZIB cathodes. The composite is especially effective when prepared via AC-EPD, which yields ultrathin, uniform films with strong adhesion and low agglomeration. This enhances energy storage performance and provides a reliable platform for focusing on interfacial charge storage, excluding the effect of binders on electrochemical performance. Full article

The development of polymer binders with tailored functionalities and green manufacturing processes is highly needed for high-performance lithium–sulfur batteries. In this study, a readily hydrolyzable 3,9-divinyl-2,4,8,10-tetraoxaspiro-[5.5]-undecane is utilized to prepare a water-based binder. Specifically, the acrolein produced by hydrolysis undergoes in situ polymerization to form a linear polymer, while the other hydrolyzed product, pentaerythritol, physically crosslinks these polymer chains via hydrogen bonding, generating a network polymer (BTU). Additionally, gallic acid (GA), a substance derived from waste wood, is further introduced into BTU during slurry preparation, forming a biphenol-containing binder (BG) with a multi-hydrogen-bonded structure. This resilience and robust cathode framework effectively accommodate volumetric changes during cycling while maintaining efficient ion and electron transport pathways. Furthermore, the abundant polar groups in BG enable strong polysulfide adsorption. As a result, sulfur cathode with a high mass loading of 5.3 mg cm⁻² employing the BG (7:3) binder still retains an areal capacity of 4.7 mA h cm⁻² after 50 cycles at 0.1 C. This work presents a sustainable strategy for battery manufacturing by integrating renewable biomass-derived materials and eco-friendly aqueous processing to develop polymer binders, offering a green pathway to high-performance lithium–sulfur batteries. Full article

Despite their inherently lower energy density than lithium-ion batteries (LIBs), aqueous zinc metal batteries (AZMBs) have recently attracted interest as rechargeable energy storage devices due to their low cost and high operational and environmental safety. They are composed of metallic zinc as the anode, an aqueous zinc salt electrolyte and a cathode capable of (de)intercalating Zn²⁺ ions upon its (oxidation) reduction reaction. In this work, we studied a hybrid AZMB in which a dual-ion electrolyte containing both Zn²⁺ and Li⁺ ions was used in conjunction with a Li⁺ ion intercalation cathode, i.e., LiFePO₄ (LFP), one of the most common, reliable, and cheap cathodes for LIBs. In this study, we present evidence that, thanks to its insolubility in water, ethyl cellulose (EC) can be effectively utilized as a binder for cathode membranes in AZMBs. Furthermore, its solubility in alcohol provides a significant advantage in avoiding the use of toxic solvents, contributing to a safer and more environmentally friendly approach to the formulation process. Full article

The development of efficient, sustainable, and cost-effective catalysts is crucial for energy storage technologies, such as zinc–air batteries (ZABs). These batteries require bifunctional catalysts capable of efficiently and selectively catalyzing oxygen redox reactions. However, the high cost and low selectivity of conventional catalysts hinder the large-scale integration of ZABs into the electric grid. This study presents binder-free Fe-based bifunctional electrocatalysts synthesized via a sol–gel method, followed by thermal treatment under ammonia flow. Supported on nickel foam, the catalyst exhibits enhanced activity for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), essential for ZAB operation. This work addresses two critical challenges in the development of ZABs: first, the replacement of costly cobalt or platinum-group-metal (PGM)-based catalysts with an efficient alternative; second, the achievement of prolonged battery performance under real conditions without passivation. Structural analysis confirms the integration of iron nitrides, oxides, and carbon, resulting in high conductivity and catalytic stability without relying on precious or cobalt-based metals. Electrochemical tests reveal that the catalyst calcined at 800 °C delivers superior performance, achieving a four-electron ORR mechanism and prolonged operational life compared to its 900 °C counterpart. Both catalysts outperform conventional Pt/C-RuO₂ systems in stability and selective bifunctionality, offering a more sustainable and cost-effective alternative. The innovative combination of nitrogen, carbon, and iron compounds overcomes limitations associated with traditional materials, paving the way for scalable, high-performance applications in renewable energy storage. This work underscores the potential of transition metal-based catalysts in advancing the commercial viability of ZABs. Full article

Alkali-activated binders are gaining importance in the construction industry because of their environmental and mechanical advantages. This paper focuses on selective limestone activation (SLA) using aqueous sodium hydroxide solutions to be used as a non-hydraulic binder material. This study investigates the mechanical performance of 3D-printed specimens cured at 45 °C produced with different NaOH concentrations. Varying the NaOH concentration is significant for analyzing its role in optimizing the reactivity and mechanical behavior for additive manufacturing applications. The results show that mechanical strength and physical properties are influenced by the NaOH concentration, with the strength decreasing at higher sodium hydroxide loads. Although porosity and density are consistent in all concentrations, microstructure examination showed non-homogeneous grainy texture. Full article

Paint loss is one of the main forms of deterioration in historical wall paintings, generally restored by the application of chromatic reintegration. In the specific case of outdoor exposed paintings, it is essential to find a binder that will withstand diverse weather conditions. Since chromatic reintegrations have to be compatible with the original painting, fresco paint mock-ups were manufactured and compared to chromatic reintegrations made with an aqueous colloidal dispersion of silica nanoparticles as binder. The physical compatibility was studied by colour spectrophotometry and measurements of static contact angle, gloss, and roughness values, together with a peeling test, stereomicroscopy, and polarised light microscopy. They were also characterised from a mineralogical, chemical, and molecular point of view using X-ray diffraction, X-ray fluorescence and Fourier-transform infrared spectroscopy. The microtexture was studied by scanning electron microscopy with energy-dispersive X-ray spectroscopy. Chromatic reintegrations showed similar roughness and lower gloss values than frescoes, and the nano-silica binder ensured the natural breathability of the wall. Overall, the chemical nature of pigments was highly influential. The reintegrations with silicate-based pigments were more homogenous, with hardly any fissures, while those carried out with sulphide- or oxide-based pigments were severely cracked. The use of verdigris is discouraged due to the lack of affinity between the binder and the pigment. Full article

The pursuit of electrochemical carbon dioxide reduction reaction (CO₂RR) as a means of energy generation and mitigation of global warming is of considerable interest. In this study, a novel RuO₂-incorporated SnO₂-fabricated glassy carbon electrode (GCE) with a Nafion binder was used for the electrochemical reduction of CO₂ in an aqueous alkaline imidazole medium. The electrode fabrication process involved the drop-casting method, where RuO₂.SnO₂ was incorporated onto the surface of the GCE. Electrochemical studies demonstrated that the GCE-RuO₂.SnO₂ electrode facilitated CO₂ reduction at −0.58 V vs. the reversible hydrogen electrode (RHE) via a diffusion-controlled pathway with the transfer of two electrons. Importantly, the first electron transfer step was identified as the rate-determining step (RDS). A Tafel slope of 144 mV dec⁻¹ confirmed the association of two-electron transfer kinetics with CO₂RR. Moreover, the standard rate constant (k_o) and formal potential (E°′) were evaluated as 2.89 × 10⁻⁵ cm s⁻¹ and 0.0998 V vs. RHE, respectively. Kinetic investigations also reveal that the deprotonation and electron release steps took place simultaneously in the CO₂RR. Based on the reported results, the GCE-RuO₂.SnO₂ electrode could be a promising candidate for CO₂ reduction, applicable in renewable energy generation. Full article

In the last decade, the task of developing environmentally friendly and cost-effective methods for obtaining stable superhydrophobic coatings has become topical. In this study, we examined the effect of the concentrations of filler and polymer binder on the hydrophobic properties and surface roughness of composite coatings made from organic–aqueous compositions based on hexyl methacrylate (HMA) and glycidyl methacrylate (GMA) copolymers. Silicon dioxide nanoparticles were used as a filler. A single-stage “all-in-one” aerosol application method was used to form the coatings without additional intermediate steps for attaching the adhesive layer or texturing the substrate surface, as well as pre-modification of the surface of filler nanoparticles. As the ratio of the mass fraction of polymer binder (Wn) to filler (Wp) increases, the coatings show the lowest roll-off angles among the whole range of samples studied. Coatings with an optimal mass fraction ratio (Wn/Wp = 1.2 ÷ 1.6) of the filler to polymer binder maintained superhydrophobic properties for 24 h in contact with a drop of water in a chamber saturated with water vapor and exhibited roll-off angles of 6.1° ± 1°. Full article

Lithium-ion batteries are currently one of the most important energy storage devices for various applications. However, it remains a great challenge to achieve both high energy density and high-power density while reducing the production costs. Cells with three-dimensional electrodes realized by laser ablation are proven to have enhanced electrochemical performance compared to those with conventional two-dimensional electrodes, especially at fast charging/discharging. Nevertheless, laser structuring of electrodes is still limited in terms of achievable processing speed, and the upscaling of the laser structuring process is of great importance to gain a high technology readiness level. In the presented research, the impact of different laser structuring strategies on the electro-chemical performance was investigated on aqueous processed Li(Ni₀.₆Mn₀.₂Co₀.₂)O₂ cathodes with acid addition during the slurry mixing process. Rate capability analyses of cells with laser structured aqueous processed electrodes exhibited enhanced performance with capacity increases of up to 60 mAh/g at high current density, while a 65% decrease in ionic resistance was observed for cells with laser structured electrodes. In addition, pouch cells with laser structured acid-added electrodes maintained 29–38% higher cell capacity after 500 cycles and their end-of-life was extended by a factor of about 4 in contrast to the reference cells with two-dimensional electrodes containing common organic solvent processed polyvinylidene fluoride binder. Full article

Environmental impacts and resource availability are significant concerns for the future of lithium-ion batteries. This study focuses on developing novel fluorine-free electrolytes compatible with aqueous-processed cobalt-free cathode materials. The new electrolyte contains lithium 1,1,2,3,3-pentacyanopropenide (LiPCP) salt. After screening various organic carbonates, a mixture of 30:70 wt.% ethylene carbonate and dimethyl carbonate was chosen as the solvent. The optimal salt concentration, yielding the highest conductivity of 9.6 mS·cm⁻¹ at 20 °C, was 0.8 mol·kg⁻¹. Vinylene carbonate was selected as a SEI-stabilizing additive, and the electrolyte demonstrated stability up to 4.4 V vs. Li+/Li. LiFePO₄ and LiMn_0.6Fe_0.4PO₄ were identified as suitable cobalt-free cathode materials. They were processed using sodium carboxymethyl cellulose as a binder and water as the solvent. Performance testing of various cathode compositions was conducted using cyclic voltammetry and galvanostatic cycling with the LiPCP-based electrolyte and a standard LiPF6-based one. The optimized cathode compositions, with an 87:10:3 ratio of active material to conductive additive to binder, showed good compatibility and performance with the new electrolyte. Aqueous-processed LiFePO₄ and LiMn_0.6Fe_0.4PO₄ achieved capacities of 160 mAh·g⁻¹ and 70 mAh·g⁻¹ at C/10 after 40 cycles, respectively. These findings represent the first stage of investigating LiPCP for the development of greener and more sustainable lithium-ion batteries. Full article

This article presents the results of research work devoted to improving the characteristics of paint and varnish coatings based on aqueous dispersions of polyacrylates; it is proposed to modify them by introducing mineral raw materials as fillers and hydrated lime, with subsequent processing in a vortex layer apparatus. The introduction of activated diatomite does not cause the deterioration of covering power, adhesion or an increase in the porosity of the paint material. The modification of coatings contributes to an increase in their operational properties, which can be associated with a reduction in the free volume in the composite and the formation of polymer boundary layers with modified physical and chemical properties. The aim of this study is to obtain a water-dispersion paint and varnish composition containing modified diatomite on a polyacrylate basis and, subsequently, study its main physical and mechanical parameters. The work has been carried out by the following method: determination of porosity, adhesion, elasticity and covering power of the control composition; determination of porosity, adhesion, elasticity and covering power of the obtained composites using modified filler; investigation of the influence of radiation on the infrared spectrum of the paint coating surface using a FLIRB620 thermal imager. As a result of this research work, it was noticed that the modification of water dispersions with silica-activated diatomite helps to eliminate the main disadvantages of materials and coatings based on acrylate binders—low water resistance and low physical and mechanical characteristics. The introduction of modified diatomite into water-emulsion paint on an acrylate base does not lead to the deterioration of the main performance characteristics of paint coatings—porosity, adhesion, elasticity and covering. Full article

The energy release process of the Mg-based hydroreactive fuels directly affects the performance of water ramjet engines, and the burning rate is one of the key parameters of the Mg-based hydroreactive fuels. However, there is not enough in-depth understanding of the combustion process of Mg-based hydroreactive fuels within the chamber of water ramjet engines, and there is a lack of effective means of prediction of the burning rate. Therefore, this paper aims to examine the flame structure of Mg-based hydroreactive fuels with a high metal content and analyze the impact of the water injection velocity and droplet diameter on the combustion property. A combustion experiment system was designed to replicate the combustion of Mg-based hydroreactive fuels within water ramjet engines, and the average linear burning rate was calculated through the target line method. On the basis of the experiment, a combustion–flow coupling solution model of Mg-based hydroreactive fuels was formulated, including the reaction mechanism between Mg/H₂O and the decomposition products from an oxidizer and binder. The model was validated through experimental results with Mg-based hydroreactive fuels at various pressures and water injection velocities. The mean absolute percentage error (MAPE) in the experimental results was less than 5%, proving the accuracy and validity of the model. The resulting model was employed for simulating the combustion of Mg-based hydroreactive fuels under different water injection parameters. The addition of water injection resulted in the creation of a new high-temperature region, namely the Mg/H₂O non-premixed combustion region in addition to improving the radial diffusion of the flame. With the increasing water injection velocity, the characteristic distance of Mg/H₂O non-premixed combustion region is decreased, which enhances the heat transfer to burning surface and accelerates the fuel combustion. The impact of droplet parameters was investigated, revealing that larger droplets enhance the penetration of the fuel-rich gas, which is similar to the effect of injection velocity. However, when the droplet size becomes too large, the aqueous droplets do not fully evaporate, resulting in a slight decrease in the burning rate. These findings enhance the understanding of the mechanisms behind the burning rate variation in Mg-based hydroreactive fuels and offer theoretical guidance for the optimal selection of the engine operating parameters. Full article

This article introduces a new type of carbon paste electrode prepared from black raw shungite. In powdered form, this carbonaceous material was mixed with several nonpolar binders. The resulting shungite pastes were microscopically and electrochemically characterized. Mixtures of several pasting liquids with different contents of shungite powder were tested to select the optimal composition and compared with other types of carbon paste-based electrodes made of graphite and glassy carbon powder. In terms of physical and mechanical properties, shungite paste electrodes (ShPEs) formed a composite mass being like dense pastes from glassy carbon microspheres, having harder consistency than that of traditional graphitic carbon pastes. The respective electrochemical measurements with ShPEs were based on cyclic voltammetry of ferri-/ferro-cyanide redox pairs, allowing us to evaluate some typical parameters such as electrochemically active surface area, double-layer capacitance, potential range in the working media given, heterogeneous rate constant, charge-transfer coefficient, exchange current density, and open-circuit potential. The whole study with ShPEs was then completed with three different examples of possible electroanalytical applications, confirming that the carbon paste-like configuration with powdered shungite represents an environmentally friendly (green) and low-cost electrode material with good stability in mixed aqueous-organic mixtures, and hence with interesting prospects in electroanalysis of biologically active organic compounds. It seems that similar analytical parameters of the already established variants of carbon paste electrodes can also be expected for their shungite analogues. Full article

The preparation of pellets using a high-shear granulator in a rapid single-step is considered a good economic alternative to the extrusion spheronization process. As process parameters and material attributes greatly affect pellet qualities, successful process optimization plays a vital role in producing pellet dosage forms with the required critical quality attributes. This study was aimed at the development and optimization of the pelletization technique with the Pro-CepT granulator. According to the quality by design (QbD) and screening design results, chopper speed, the volume of the granulating liquid, binder amount, and impeller speed were selected as the highest risk variables for a two-level full factorial design and central composite design, which were applied to the formula of microcrystalline cellulose, mannitol, and with a binding aqueous polyvinylpyrrolidone solution. The design space was estimated based on physical response results, including the total yield of the required size, hardness, and aspect ratio. The optimized point was tested with two different types of active ingredients. Amlodipine and hydrochlorothiazide were selected as model drugs and were loaded into an optimized formulation. The kinetics of the release of the active agent was examined and found that the results show a correlation with the electrokinetic potential because amlodipine besylate can be adsorbed on the surface of the MCC, while hydrochlorothiazide less so; therefore, in this case, the release of the active agent increases. The research results revealed no significant differences between plain and model drug pellets, except for hydrochlorothiazide yield percent, in addition to acceptable content uniformity and dissolution enhancement. Full article