Search Results (760)

To enhance the fire suppression performance of Class A foam, this study identifies sodium dodecyl sulfate (SDS) as the primary foaming agent and develops a high-efficiency foam system comprising primary and auxiliary foaming agents, wetting agents, and foam stabilizers. It interprets these macroscopic findings at the molecular level through molecular dynamics simulations. Sixteen formulations were designed using orthogonal experiments and evaluated in terms of surface tension, viscosity, wetting performance, and foam expansion ratio. The results demonstrated that the formulated systems exhibited superior foaming characteristics compared to conventional aqueous film-forming foam (AFFF), while other physicochemical properties were inferior. Two high-performing foam systems were further investigated using molecular dynamics simulations. Analysis of the spatial concentration distributions, diffusion coefficients, and the hydrogen-bonding networks of water molecules revealed 14.3% and 14.2% increases in the peak values of the radial distribution function (RDF) for the two systems modified with auxiliary foaming agents, respectively. The auxiliary foaming agents exhibited synergistic effects with SDS, enhancing its water activation capability. The incorporation of wetting agents reduced the water diffusion coefficients by 4.7% and 21.9%, indicating that sodium bis(2-ethylhexyl) succinate sulphonate (T) interferes less with the primary foaming agent than alcohol ethoxylate (AEO). The selected formulations also demonstrated 4.4% and 3.5% reductions in water hydrogen bonding compared to SDS-only solutions, indicating decreased molecular cohesion and improved water activation. By integrating physicochemical evaluation with molecular simulation, the optimized formulation was determined to be SDS (primary foaming agent), sodium fatty alcohol ether sulfate (auxiliary foaming agent), alcohol ethoxylate (wetting agent), lauryl hydroxysultaine (foam stabilizer), and ethylene glycol butyl ether (cosolvent). Full article

Background/Objectives: Increasing the bioavailability of poorly absorbed drugs is a continuous challenge in modern pharmaceutical technology. This is due to the problematic nature of BCS class IV active pharmaceutical ingredients: these drugs possess poor solubility and membrane permeability. Moreover, many undergo immediate efflux and/or rapid systemic metabolism after absorption. This project aimed to improve the bioavailability of BCS class IV drugs by formulating gastroretentive self-emulsifying systems using curcumin as a model drug. Methods: The base of the systems was created by melting emulsifying agents, dissolution retardants, and PEGs together. Curcumin was added after the mixture was cooled slightly. Aqueous dispersions of several compositions were characterized by dynamic light scattering. After screening these results, the viscosities of the selected formulations were evaluated. Dissolution retardants were selected and added to the most superior samples, and their dissolution profiles were compared. Gastroretention of the final formulation was achieved by dispersing air in the molten system through melt foaming; internal structure was assessed by microCT, and physicochemical properties by PXRD and DSC. Cytotoxicity was measured in Caco-2 cells using MTT and Neutral Red assays, and transcellular transport was also studied. Results: Based on these results, a homogeneous gastric floating system was developed. We observed an advantageous cytotoxic profile and increased bioavailability. Conclusions: Overall, we were able to create a self-emulsifying gastroretentive formulation displaying extended release and gastric retention with a low amount of cost-efficient excipients. Full article

Hierarchically porous polymers can unite macro-scale architected voids with micro-scale pores, enabling unique combinations of low density, high surface area, and controlled transport properties that are difficult to achieve with traditional methods. This review outlines the current advancements in creating such multiscale architectures using fused filament fabrication (FFF), the most widely used polymer additive manufacturing technique. Unlike earlier reviews that consider lattice architectures and foaming chemistries separately, this work integrates both within a single analysis. It begins with an overview of FFF fundamentals and how process parameters affect macropore formation. Design strategies for achieving macroporosity (≳100 µm) with a single thermoplastic are presented and categorized: 2D infill patterns, strut-based lattices, triply periodic minimal surfaces (TPMS), and Voronoi structures, along with functionally graded approaches. The discussion then shifts to functional filaments incorporating chemical or physical blowing agents, thermally expandable or hollow microspheres, and sacrificial porogens, which create microporosity (≲100 µm) either in situ or through post-processing. Each material approach is connected to case studies that demonstrate its application. A comparative analysis highlights the advantages of each method. Key challenges such as viscosity control, thermal gradient management, dimensional instability during foaming, environmental concerns, and the absence of standardized porosity measurement techniques are addressed. Finally, emerging solutions and future directions are explored. Overall, this review provides a comprehensive perspective on strategies that enhance FFF’s capability to fabricate hierarchically porous polymer structures. Full article

This study systematically analyzes the influencing factors and optimization strategies of foam stability and performance for CO₂-soluble foaming agents in high-temperature and high-pressure (HTHP) complex reservoir environments. By constructing a HTHP experimental system and utilizing dynamic foam testing, interfacial tension analysis, and microscopic observation of liquid films, the effects of chemical factors (e.g., pH, foaming agent concentration, stabilizer synergy) and physical factors (e.g., temperature, pressure) on foam behavior are investigated. The results show that the nonionic surfactant E-1312 exhibits optimal foam performance in neutral to mildly alkaline environments. The foam performance tends to saturate at around 0.5% concentration. High pressure enhances the foam stability, whereas elevated temperature significantly reduces the foam lifetime. Moreover, the addition of nano-sized foam stabilizers such as silica (SiO₂) can significantly delay liquid film drainage and strengthen interfacial mechanical properties, thereby improving foam durability. This study further reveals the key mechanisms of CO₂-soluble foaming agents in terms of interfacial behavior, liquid film evolution, and foam formation in porous media, providing theoretical guidance and optimization pathways for the molecular design and field application of CO₂ foam flooding technology. Full article

This study develops a high-performance water-based mold release agent for polyurethane (PU) foaming applications. We demonstrate that incorporating octamethylcyclotetrasiloxane (D4) into a dimethyl silicone oil emulsion (5 vol% fixed concentration) significantly enhances key performance metrics. By systematically varying D4 content (0–15 vol%), we characterize droplet morphology, particle size distribution, contact angle, and viscosity to elucidate the underlying enhancement mechanism. Our findings reveal the following: (i) Optimal emulsion stability: At 5 vol% D4, the mold release agent exhibits a narrow particle size distribution (6–9 μm). (ii) Efficient processing: Film formation completes within 10 min, reducing demolding force and yielding PU foam with defect-free, non-adherent surfaces. (iii) Storage stability: After 60 days in ambient conditions, performance remains unchanged, with no phase separation observed under thermal stress (60 °C) or refrigeration (2–6 °C). This work explores an alternative pathway to mitigate key limitations—slow film formation and poor shelf-life—offering a prototype for next-generation release agents. Full article

The role of science and technology in enhancing beer quality is crucial amid growing market demands. This pilot study assessed the clarity and physicochemical stability of laboratory beers treated post fermentation with three clarifying (fining) agents: two chitosan-based and one collagen-based (fish bladder/isinglass). The beers were brewed with Polish barley malt and hops (alpha acids 7.5% and 14.5%). The measured parameters included pH, colour, turbidity, viscosity, surface tension, and foam volume. Within this small-scale, low-power dataset, both the collagen- and chitosan-based agents improved clarity, with the collagen agent showing the lowest turbidity in this sample. The clarifying agents also influenced the colour and surface tension, while the pH was largely unchanged. The foam volume increased with fining. Shelf-life checks suggested improved stability in clarified beers, with no clear differences between agents under these conditions. These findings are preliminary. The results should be interpreted cautiously due to the limited number of replicates. Larger scale studies with adequate replication are required before translating these observations into brewing practice. Chitosan’s effectiveness as a clarifying agent aligns with its high charge density and ability to coagulate suspended particles. This study underscores the importance of selecting appropriate clarifying agents to optimize beer clarity and stability while maintaining essential physicochemical properties. These findings contribute to the brewing industry’s efforts to meet consumer expectations for high-quality, stable beer products. Full article

Foam acidification is often employed as a clean and efficient method to remove blockages from wells and promote oil and gas production. In order to effectively control the diffusion of H⁺ in the acid solution into the rock surface, reduce the acid–rock reaction rate, and achieve deep acidification, a foam-retarding acid with foam stability, temperature and salt resistance, and excellent retarding performance was prepared by studying the synergistic effect of the foaming agent and foam stabilizer. ZG-A was used as the foaming agent, and ZG-B was added as a foam stabilizer to achieve foam stabilization. When the ZG-A/ZG-B ratio was 0.67%/0.33%, the foam exhibited the best comprehensive performance. By measuring and comparing the acid–rock reaction rate under different conditions, the results showed that the average acid–rock reaction rate of the 10% compound acid was 1.412 × 10⁻³ mg/(cm²·s), while the average acid–rock reaction rate of the foam-retarding acid system was reduced to 6.622 × 10⁻⁵ mg/(cm²·s), representing a reduction of two orders of magnitude, and the slow rate reached 95.31%. Foam fluid diversion experiments were carried out on cores with different permeabilities. The results showed that the foam could increase the diversion flow rate of low-permeability cores and reduce the diversion flow rate of high-permeability cores. Thus, the foam fluid could be uniformly propelled in cores with different permeabilities. Based on this principle, foam acid acidification can increase the amount of acid injection into the low-permeability layer and reduce the amount of acid absorption in the high-permeability layer, thereby improving the acidification effect. Full article

The internal mammary arteries (IMAs) and coronary arteries share many common characteristics. The inner layer (tunica intima, or intima) of both arteries is lined with a smooth, longitudinally orientated monolayer of endothelial cells (ECs), connective tissue, and an internal elastic lamina that separates the tunica intima from the tunica media (middle layer). The intima of IMAs is lined with an additional protective layer, the neointima, containing vascular smooth muscle cells (VSMCs). The neointima, located between the intima and internal elastic lamina, protects IMAs from damage by assisting in the remodeling of VSMCs. Coarse longitudinal folds in the internal elastic lamina of IMAs partially prevent the infiltration of VSMCs into damaged IMAs, and intimal thickening is thus less likely to occur. Inflamed IMAs resist the migration of monocytes across the endothelial layer and prevent the formation of lipid-rich macrophages (foam cells) within the subintimal or medial layers of arteries. IMAs are thus less likely to form plaques and develop atherosclerosis (AS). Higher levels of prostacyclin (PGI2) in IMAs prevent blood clotting. The anti-thrombotic agents, and production of tumor necrosis factor α (TNF-α), interferon-γ (INF-γ), and visfatin render IMAs more resistant to inflammation. An increase in the production of nitric oxide (NO) by ECs of IMAs may be due to small ubiquitin-like modifier (SUMO) proteins that alter the nuclear factor kappa B (NF-κB) and TLR pathways. The production of reactive oxygen species (ROS) in IMAs is suppressed due to the inhibition of NADPH oxidase (NOX) by a pigment epithelium-derived factor (PEDF), which is a serine protease inhibitor (SERPIN). In this review, a comparison is drawn between the anatomy of IMAs and coronary arteries, with an emphasis on how ECs of IMAs react to immunological changes, rendering them more suited for coronary artery bypass grafts (CABGs). This narrative review covers the most recent findings published in PubMed and Crossref databases. Full article

To address the issues of numerous influencing factors on material quality, difficulty in determining the optimal mix proportion, and the need to clarify the formation mechanism when foam concrete is used as an internal mold for prefabricated components, this study conducted orthogonal tests to investigate the influence laws of fly ash content, foam content, foaming agent dilution ratio, and water–binder ratio on the dry density and compressive strength of foam concrete, and determined the optimal mix proportion via analysis of variance (ANOVA). Additionally, scanning electron microscopy (SEM) tests were performed to analyze the effects of these four factors on the microscopic pore morphology of foam concrete from a microscopic perspective, thereby revealing its formation mechanism, and engineering applications were carried out. The results show that the primary-to-secondary order of factors affecting the dry density and compressive strength of foam concrete is as follows: foam content (B) > water–binder ratio (D) > foaming agent dilution ratio (C) > fly ash content (A). The optimal mix proportion is 5% fly ash content, 18% foam content, a 30-fold foaming agent dilution ratio, and a water–binder ratio of 0.55. Under this mix proportion, the pore size of foam concrete ranges from 200 μm to 500 μm with uniform distribution, and the pore spacing is between 20 μm and 30 μm, with almost no connected pores. When the foam concrete slurry sets and hardens, hydration products such as calcium silicate hydrate (C-S-H) gel, calcium hydroxide, ettringite (AFt), and monosulfate aluminate (AFm) are generated around the bubbles. The mechanical properties of foam concrete are afforded by the combined action of these hydration products and the pore structure. Full article

The increasing demand for critical raw materials such as copper and cobalt highlights the need for efficient beneficiation of low-grade ores. This study investigates a copper–cobalt sulfide ore (0.99% Cu, 0.028% Co) using froth flotation to produce high-grade concentrates. Various types of surfactants are applied in different ways, each serving an essential function such as acting as collectors, frothers, froth stabilizers, depressants, activators, pH modifiers, and more. A series of flotation tests employing different collectors (SIPX, PBX, AERO, DF 507B) and process conditions was conducted to optimize recovery and selectivity. Methyl isobutyl carbinol (MIBC) was consistently used as the foaming agent, and 700 g/L was used as the slurry density at 25 °C. Dosages of 30 and 100 g/t¹ were used in all tests. Notably, adjusting the pH to ~4 using HCl significantly improved cobalt concentrate separation. The optimized flotation conditions yielded concentrates with over 15% Cu and metal recoveries exceeding 80%. Mineralogical characterization confirmed the selective enrichment of target metals in the concentrate. The results demonstrate the potential of this beneficiation approach to contribute to the European Union’s supply of critical raw materials. Full article

Foam cement, as a building insulation material, encounters a major problem in practical application, which is the difficulty in achieving a balance between its strength and insulation performance. To achieve multi-objective optimization of foamed cement mix design, this study first determined the optimal ranges of nano-silica aerogel (NSA), foaming agent, and polypropylene (PP) fiber dosage through single-factor experiments. Then, response surface methodology (RSM) was employed to construct a quadratic polynomial regression model, systematically investigating the influence of different NSA contents, foaming agent contents, and PP fibers contents on the thermal conductivity and compressive strength of foamed cement. Finally, the optimal mix ratio was further predicted and experimentally validated. The results demonstrate that the regression model developed using RSM exhibits high accuracy and reliability. The correlation coefficients R² of the regression models established by the response surface method are 0.9756 and 0.9684, respectively, indicating good prediction accuracy. The optimized mix ratio was determined as follows: NSA content, 9.548%; foaming agent content, 0.533%; and PP fiber content, 0.1%. Under this mix, the model predicted a thermal conductivity of 0.123 W/(m·K) and a 28-day compressive strength of 1.081 MPa. Experimental verification confirmed that the errors between predicted and measured values for all performance indicators were within 5%, demonstrating the high reliability of the predictive model. This study provides support for the practical application of foam cement as a thermal insulation material in construction projects and offers guidance for optimizing its mixture composition. Full article

This study identified the optimal enzymatic treatment for improving the foaming characteristics of oat globulin, and alkaline protease was found to be the most effective enzyme. The impact of alkaline protease on the foaming properties and structural changes in oat globulin was explored. The results show that the foaming capacity of oat globulin hydrolysates is negatively correlated with surface hydrophobicity and positively correlated with the degree of hydrolysis. The results of circular dichroism (CD) and size-exclusion chromatography (SEC) indicate that hydrolysis generated smaller, disordered peptides. Under equilibrium conditions at a 2% concentration, a reduction of 1.62 mN/m in surface tension and an increase of 3.82 μm in foam film thickness were observed. These peptides reduce surface tension between air and water, forming larger, thicker, and more stable foams. Compared to untreated oat globulin, the foaming capacity of hydrolyzed ones increased by 87.17%. Under comparable conditions, these findings demonstrate that limited hydrolyzed oat globulin exhibits potential as an effective plant-based foaming agent up to a degree of hydrolysis of 15.06%. Full article

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

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

Hydrogen energy is a pivotal carrier for achieving carbon neutrality, requiring green and efficient production via water electrolysis. However, the anodic oxygen evolution reaction (OER) involves a sluggish four-electron transfer process, resulting in high overpotentials, while the prohibitive cost and complex preparation of precious metal catalysts impede large-scale commercialization. In this study, we develop a FeCo-based bimetallic deep eutectic solvent (FeCo-DES) as a multifunctional reaction medium for engineering a three-dimensional (3D) coral-like FeOOH-Co₂(OH)₃Cl/NF composite via a mild one-step impregnation approach (70 °C, ambient pressure). The FeCo-DES simultaneously serves as the solvent, metal source, and redox agent, driving the controlled in situ assembly of FeOOH-Co₂(OH)₃Cl hybrids on Ni(OH)₂/NiOOH-coated nickel foam (NF). This hierarchical architecture induces synergistic enhancement through geometric structural effects combined with multi-component electronic interactions. Consequently, the FeOOH-Co₂(OH)₃Cl/NF catalyst achieves a remarkably low overpotential of 197 mV at 100 mA cm⁻² and a Tafel slope of 65.9 mV dec⁻¹, along with 98% current retention over 24 h chronopotentiometry. This study pioneers a DES-mediated strategy for designing robust composite catalysts, establishing a scalable blueprint for high-performance and low-cost OER systems. Full article