Search Results (2,524)

Developing ultra-high-temperature geothermal resources is challenging, as traditional drilling fluids, including foam systems, lack thermal stability above 160 °C. To address this key technical bottleneck, this study delves into the screening principles for high-temperature-resistant foaming agents and foam stabilizers. Through high-temperature aging experiments (foaming performance evaluated up to 240 °C and rheological/filtration properties evaluated after aging at 200 °C), specific additives were selected that still exhibit good foaming and foam-stabilizing performance under high-temperature and high-salinity conditions. Building on this, the foam drilling fluid system formulation was optimized using an orthogonal experimental design. The optimized formulations were systematically evaluated for their density, volume, rheological properties (apparent viscosity and plastic viscosity), and filtration properties (API fluid loss and HTHP fluid loss) before and after high-temperature aging (at 200 °C). The research results indicate that specific formulation systems exhibit excellent high-temperature stability and particularly outstanding performance in filtration control, with the selected foaming agent FP-1 maintaining good performance up to 240 °C and optimized formulations demonstrating excellent HTHP fluid loss control at 200 °C. This provides an important theoretical basis and technical support for further research and field application of foam drilling fluid systems for deep high-temperature geothermal energy development. Full article

The objectives of this study were to prepare whey protein–quercetin–gellan gum conjugates using the pH-shift method and to evaluate the impacts of varying pH values and quercetin concentrations on the interaction mechanisms and functional characteristics of the complexes. Spectroscopic analyses (fluorescence, UV-vis, and FT-IR) revealed that new complexes formed under alkaline conditions. Notably, an increasing quercetin concentration led to a reduction in complex particle size and an increase in the zeta potential value, with these effects being more pronounced under alkaline conditions. The particle size was 425.7 nm, and the zeta potential value was −30.00 mV at a quercetin addition concentration of 15 umol/g protein. Additionally, the complexes formed under alkaline conditions exhibited superior foaming capacity, emulsification properties, and significantly enhanced free radical scavenging activity. The complex’s DPPH and ABTS radical scavenging rates rose by 41.57% and 57.69%, respectively. This study provides theoretical foundations and practical insights for developing protein—polyphenol systems, offering significant implications for the application of quercetin functional foods and supplements in the food science and pharmaceutical industries. Full article

Environmental protection has become one of the key challenges of our time. This has led to an increase in pro-environmental activities in the field of cosmetics and household chemicals, where manufacturers are increasingly trying to meet the expectations of consumers who are aware of the potential risks associated with the production of cosmetics and household chemistry products. This is one of the most important challenges of today’s industry, given that some of the raw materials still commonly used, such as surfactants, may be toxic to aquatic organisms. Many companies are choosing to use natural raw materials that have satisfactory performance properties but are also environmentally friendly. In addition, modern products are also characterized by reduced consumption of water, resources, and energy in production processes. These measures reduce the carbon footprint and reduce the amount of plastic packaging required. In the present study, seven formulations of environmentally friendly car shampoo concentrates were developed, based entirely on mixtures of bio-based surfactants. The developed formulations were tested for application on the car body surface, allowing the selection of the two best products. For these selected formulations, an in-depth physicochemical analysis was carried out, including pH, density, and viscosity measurements. Comparison of the results with commercial products available on the market was also performed. Additionally, using the multiple light scattering method, the foamability and foam stability were determined for the car shampoos developed. The results obtained indicate the very high application potential of the products under study, which combine high performance and environmental concerns. Full article

This study aims to enhance the performance of an innovative steel slag–ceramsite foam concrete (SSCFC) to advance sustainable green building materials. An eco-friendly composite construction material was developed by integrating industrial by-product steel slag (SS) with lightweight ceramsite. Employing a three-factor, three-level orthogonal experimental design at a fixed density of 800 kg/m³, 12 mix proportions (including a control group) were investigated with the variables of water-to-cement (W/C) ratio, steel slag replacement ratio, and ceramsite replacement ratio. The governing mechanisms of the W/C ratio, steel slag replacement level, and ceramsite replacement proportion on the SSCFC’s fluidity and compressive strength (CS) were elucidated. The synergistic application of range analysis and analysis of variance (ANOVA) quantified the significance of factors on target properties, and partial least squares regression (PLSR)-based prediction models were established. The test results indicated the following significance hierarchy: steel slag replacement > W/C ratio > ceramsite replacement for fluidity. In contrast, W/C ratio > ceramsite replacement > steel slag replacement governed the compressive strength. Verification showed R² values exceeding 65% for both fluidity and CS predictions versus experimental data, confirming model reliability. Multi-criteria optimization yielded optimal compressive performance and suitable fluidity at a W/C ratio of 0.4, 10% steel slag replacement, and 25% ceramsite replacement. Full article

A modular strategy for the molecular design of silicone-based antifoaming agents was developed by precisely controlling the architecture of poly (methylhydrosiloxane) (PMHS). Sixteen PMHS variants were synthesized by systematically varying the siloxane chain length (L1–L4), backbone composition (D₃T₁ vs. D₃₀T₁), and terminal group chemistry (H- vs. M-type). These structural modifications resulted in a broad range of Si-H functionalities, which were quantitatively analyzed and correlated with defoaming performance. The PMHS matrices were integrated with high-viscosity PDMS, a nonionic surfactant, and covalently grafted fumed silica—which was chemically matched to each PMHS backbone—to construct formulation-specific defoaming systems with enhanced interfacial compatibility and colloidal stability. Comprehensive physicochemical characterization via FT-IR, ¹H NMR, GPC, TGA, and surface tension analysis revealed a nonmonotonic relationship between Si-H content and defoaming efficiency. Formulations containing 0.1–0.3 wt% Si-H achieved peak performance, with suppression efficiencies up to 96.6% and surface tensions as low as 18.9 mN/m. Deviations from this optimal range impaired performance due to interfacial over-reactivity or reduced mobility. Furthermore, thermal stability and molecular weight distribution were found to be governed by repeat unit architecture and terminal group selection. Compared with conventional EO/PO-modified commercial defoamers, the PMHS-based systems exhibited markedly improved suppression durability and formulation stability in high-viscosity environments. These results establish a predictive structure–property framework for tailoring antifoaming agents and highlight PMHS-based formulations as advanced foam suppressors with improved functionality. This study provides actionable design criteria for high-performance silicone materials with strong potential for application in thermally and mechanically demanding environments such as coating, bioprocessing, and polymer manufacturing. Full article

Aluminum foam materials have gained significant attention over the past decade, particularly in the automotive industry, due to their excellent stiffness-to-weight ratio and superior energy absorption capabilities. In this study, a multiscale numerical material model was developed to accurately and efficiently simulate the vibrational behavior of aluminum foams. The foam specimens were categorized into four density classes based on their measured mass and calculated volume. Two specimens were selected to conduct CT (computerized tomography) scans and quantify the volume of air in their density class. Based on the CT measurements, a representative volume element (RVE) was built using ANSYS Material Designer (MD). The newly obtained material was employed in conducting normal mode numerical simulations. The resonance frequencies and response amplitudes were compared with physical experiments and showed correlation within 3%. These findings underscore the efficacy of using CT scans in foam to develop material models and accurately predict structural behavior. By conducting comprehensive investigations and numerical simulations, we established a correlation between physical tests and simulation results, highlighting the reliability of the developed models. Full article

Aluminium alloy foams have been widely used due to their excellent strength-to-weight ratio, low density, and outstanding properties such as high energy absorption and effective noise and heat insulation. In this study, aluminium machining chips have been used for foam production as a potential recycling method. The process has involved solution heat treatment followed by artificial ageing. Researchers have been analysing the microhardness of both the foam and the bulk material, as well as examining their microstructures. The maximum microhardness value of the bulk material has been found to be 158 ± 2 HV1 at an ageing temperature of 175 ± 1 °C for 2 ± 0.02 h. For the foams, the highest microhardness of 150 ± 2 HV1 has been achieved after ageing at 150 ± 1 °C for 9 ± 0.02 h. Experimental planning has been carried out using Design Expert software. The optimisation process has identified 150 ± 1 °C for 2 ± 0.02 h as the optimum condition for artificial ageing. Full article

In the context of the growing need to reduce greenhouse gas emissions and to develop sustainable solutions for the construction industry, foamed geopolymers represent a promising alternative to traditional binders and insulation materials. This study investigates the thermal properties of novel low-emission, insulating geopolymer binders made from fly ash with diatomite, chalcedonite, and wood wool aiming to assess their potential for use in thermal insulation systems in energy-efficient buildings. The stability of the foamed geopolymer structure is also assessed. Measurements of thermal conductivity, specific heat, microstructure, density, and compressive strength are presented. The findings indicate that the selected geopolymer formulations exhibit low thermal conductivity, high heat capacity and low density, making them competitive with conventional insulation materials—mainly load-bearing ones such as aerated concrete and wood wool insulation boards. Additionally, incorporating waste-derived materials reduces the production carbon footprint. The best results are represented by the composite incorporating all three additives (diatomite, chalcedonite, and wood wool), which achieved the lowest thermal conductivity (0.10154 W/m·K), relatively low density (415 kg/m³), and high specific heat (1.529 kJ/kg·K). Full article

The acoustic performance of windows significantly influences evaluations of building quality, particularly in urban environments. This study presents the results of laboratory tests on the airborne sound insulation of windows with dimensions greater than those specified in ISO 10140-5:2021-10. The aim was to determine the impact of construction details and installation techniques on sound insulation, specifically R_w and R_w + C_tr values. The experimental variables included mounting methods (expansion tape versus low-pressure polyurethane foam), the presence or absence of a threshold in the lower frame, and the type of mullion (fixed versus movable). The tests involved two types of IGUs characterized by different acoustic properties. The findings indicate that the frame configuration, including threshold and mullion type, has a negligible influence on sound insulation. However, the standard method for estimating acoustic performance (EN 14351-1:2006 + A2:2017), which relies on IGU-based data, proved unreliable for modern window assemblies. The estimated values of R_w and R_w + C_tr were consistently lower than those obtained from direct laboratory measurements. These results highlight the need for verification through full-size window testing and suggest that reliance on simplified estimation procedures may lead to underperformance in real-world acoustic applications. Full article

Due to its lightweight and superior adsorption properties, carbon foam is frequently employed for the removal of heavy metal pollutants from aqueous solutions. In this study, a novel modified carbon foam (M-CF) was successfully synthesized for the effective removal of Pb²⁺ and Cd²⁺ from water. The synthesis involved partially substituting phenol with the liquefaction product of bamboo powder, followed by modification with a silane coupling agent (KH560) and foaming with n-hexane-loaded activated carbon (H/AC). The prepared carbon foam was comprehensively characterized, and its adsorption performance and mechanism for Pb²⁺ and Cd²⁺ in aqueous solution were investigated. The results showed that M-CF possessed a uniform and well-developed spherical pore structure and demonstrated excellent removal capacity for Cd²⁺ and Pb²⁺. The adsorption process conformed to the Sips isotherm model and the pseudo-second-order kinetic equation, with maximum adsorption capacities of 22.15 mg·g⁻¹ and 61.59 mg·g⁻¹ for Cd²⁺ and Pb²⁺, respectively. Mechanistic analysis revealed that the removal of Cd²⁺ and Pb²⁺ was a result of the synergistic effect of physisorption and chemisorption, accompanied by complexation. Furthermore, precipitates formed during the adsorption process were found to be mainly composed of hydroxides, carbonates, and PbS. This research demonstrates the efficacy of carbon foam prepared from bamboo powder waste as a partial phenol substitute for the efficient removal of Pb²⁺ and Cd²⁺ from water, thus expanding the preparation pathways for novel heavy metal adsorption materials. Full article

Polyurethane foam is widely used as a primary filling material in car seats. While it provides good damping and energy absorption, the mechanical properties are complex but play a vital role in vibration attenuation and vehicle ride comfort. This study proposes a comprehensive experimental and analytical method to characterize the visco-hyperelastic properties of seat-grade polyurethane foam. Quasi-static and dynamic compression tests were conducted on foam blocks to obtain load–deflection curves and dynamic stiffness. A visco-hyperelastic material model was developed, where the hyperelastic response was derived via the hereditary integral and difference-stress method, and viscoelastic behavior was captured using a Prony series fitted to dynamic stiffness data. The model was validated using finite element simulations, showing good agreement with experimental results in both static and dynamic conditions. The proposed method enables accurate characterization of the visco-hyperelastic material properties of seat-grade polyurethane foam. Full article

Lightweightness and durability are key consumer demands for footwear. To address the issues of deformation and poor durability in foamed sole materials, this study integrates natural fibers into the formulation of foamed rubber. The effects of natural fiber incorporation on density, mechanical properties, creep behavior, anti-slip performance, and aging resistance were comprehensively analyzed. Additionally, the study explored the mechanisms underlying the improved performance of the modified rubber materials. The results revealed that natural fiber integration significantly enhanced the structural stability, strength, and aging resistance of natural rubber (NR). Among the fibers compared, collagen fibers (CF) proved to be the most effective modifier for foamed NR. The density, tensile strength, tear strength, and coefficient of friction of CF-modified foamed NR (CF-NR) were found to be 0.72 g/cm³, 10.1 MPa, 48.0 N/mm, and 1.105, respectively, meeting the standard requirements for sole materials. Furthermore, CF-NR demonstrated a recoverable deformation of 4.58% and a negligible irreversible deformation of 0.10%, indicating a successful balance between comfort and durability. This performance enhancement can be attributed to the supportive role of CF in the pore structure, along with its inherent flexibility and recoverability. This work presents a novel approach for the development of high-quality, lightweight footwear in the sole material industry. Full article

Incorporating health-promoting resveratrol into food products is challenging, primarily due to its poor solubility. Covalent conjugation is a promising, low-energy, and environmentally friendly strategy to overcome this limitation. This study compared the effectiveness of free radical grafting and alkaline methods for covalently conjugating whey protein isolate (WPI) with resveratrol. Conjugates were evaluated for molecular weight, structural characteristics, functional properties, and antioxidant activities. Both methods yielded conjugates with enhanced solubility relative to native resveratrol, with fold increases from 7.6 to 21.7 for the free radical grafting and from 8.1 to 23.6 for the alkaline method. Conjugates prepared via free radical grafting exhibited greater increases in molecular weight (10–100 kDa range), higher resveratrol incorporation (up to 17.6%), and superior functional properties compared to the alkaline conjugates (p < 0.05). Specifically, emulsifying activity, foaming capacity, and foaming stability improved by up to 64.7%, 45.8%, and 220.9%, respectively, compared to WPI. The antioxidant activities of the free radical grafting conjugates were 1.3- to 3.6-fold higher than those of alkaline conjugates. These findings highlight free radical grafting of WPI as a promising approach for incorporating resveratrol and improving the functionality of protein-based ingredients in functional food products. Full article

Mycelium-based composites (MBCs) are an emerging category of cost-effective and environmentally sustainable materials that are attracting significant research and commercial interest across various industries, including construction, manufacturing, agriculture, and biomedicine. These materials harness the natural growth of fungi as a low-energy bio-fabrication method, converting abundant agricultural by-products and waste into sustainable alternatives to energy-intensive synthetic construction materials. Their affordability and eco-friendly characteristics make them attractive for both research and commercialisation. Currently, mycelium-based foams and sandwich composites are being actively developed for applications in construction. These materials offer exceptional thermal insulation, excellent acoustic absorption, and superior fire safety compared to conventional building materials like synthetic foams and engineered wood. As a result, MBCs show great potential for applications in thermal and acoustic insulation. However, their foam-like mechanical properties, high water absorption, and limited documentation of material properties restrict their use to non- or semi-structural roles, such as insulation, panelling, and furniture. This paper presents a comprehensive review of the fabrication process and the factors affecting the production and performance properties of MBCs. It addresses key elements such as fungal species selection, substrate choice, optimal growth conditions, dehydration methods, post-processing techniques, mechanical and physical properties, termite resistance, cost comparison, and life cycle assessment. Full article

Room-temperature vulcanizing (RTV) silicone foams are used in many industrial applications that require the material to perform over long time periods. However, mechanical properties tend to deteriorate when these foams age under a compressive load. The chemical aging is attributed to the presence of unreacted functional groups of the prepolymers, residues from acid, and catalytically active tin (II) species. Here, an optimized thermal treatment of an RTV foam that achieves completion of curing reactions and deactivation of reactive species is proposed. Foams that were thermally aged for three months under compressive load showed no signs of compression set, indicative of the effectiveness of the implemented post-curing approach. In addition, the effects of fillers (diatomaceous earth, fumed silica, and carbon nanofibers) on thermomechanical properties were investigated. Tensile strength, tear strength, and thermal conductivity increased when these fillers were added to the unfilled RTV formulation, with carbon nanofibers (CNFs) being the most effective filler. Rheological studies of RTV formulations indicated that 2.5 wt.% of CNFs is the upper limit that can be added to the RTV formulation. Full article