Search Results (148)

This paper investigates the application of non-calcined metal tartrate as a novel alternative pore former to prepare functional ceramic composites to fabricate solid oxide fuel cells (SOFCs). Compared to carbonaceous pore formers, non-calcined pore formers offer high compatibility with various ceramic composites, providing better control over porosity and pore size distribution, which allows for enhanced gas diffusion, reactant transport and gaseous product release within the fuel cells’ functional layers. In this work, nanocrystalline gadolinium-doped ceria (GDC) and Ni-Gd-Ce-tartrate anode powders were prepared using a single-step co-precipitation synthesis method, based on the carboxylate route, utilising ammonium tartrate as a low-cost, environmentally friendly precipitant. The non-calcined Ni-Gd-Ce-tartrate was used to fabricate dense GDC electrolyte pellets (5–20 μm thick) integrated with a thin film of Ni-GDC anode with controlled porosity at 1300 °C. The dilatometry analysis showed the shrinkage anisotropy factor for the anode substrates prepared using 20 wt. The percentages of Ni-Gd-Ce-tartrate were 30 wt.% and 40 wt.%, with values of 0.98 and 1.01, respectively, showing a significant improvement in microstructural properties and pore size compared to those fabricated using a carbonaceous pore former. The results showed that the non-calcined pore formers can also lower the sintering temperature for GDC to below 1300 °C, saving energy and reducing thermal stresses on the materials. They can also help maintain optimal material properties during sintering, minimising the risk of unwanted chemical reactions or contamination. This flexibility enables the versatile designing and manufacturing of ceramic fuel cells with tailored compositions at a lower cost for large-scale applications. Full article

In the synthesis of aerogels, the influence of the drying process on the nanostructure is an issue of utmost relevance for tailoring the final properties of these materials. Among the complex parameters affecting this process, the hydrophobicity of the aerogel structure plays a key role. Thus, herein, four different silica aerogel formulations based on tetraethyl orthosilicate and trimethoxymethylsilane were employed to produce aerogels with different wettability properties (from hydrophilic samples to highly hydrophobic). The synthesized gels were dried by three methods, namely freeze-drying, high-temperature supercritical drying with ethanol, and low-temperature supercritical drying with carbon dioxide, and the influence of each procedure on bulk density, porosity, pore size, and specific surface area of the resulting aerogels was analyzed in detail. The direct correlation between the surface hydrophobicity/hydrophilicity of the silica gels and the effects of each drying technique was analyzed, providing insights into a proper selection of the drying method depending on both the water affinity of the gel and the desired textural properties and structures. Full article

Polymer flooding is one of the critical methods for enhancing oil recovery (EOR) in domestic and international oilfields. Since the large-scale implementation of industrial polymer flooding in Daqing Oilfield in 1996, the overall recovery rate has increased by over 10%. With the advancement of chemical flooding technologies, conventional polymer flooding can no longer meet the practical demands of oilfield development. This study focuses on functional polymers, such as salt-resistant polymers and polymeric surfactants, tailored for Class II and III reservoirs in Daqing Oilfield. A series of experiments, including emulsification experiments, hydrodynamic characteristic size-reservoir compatibility comparison experiments, polymer retention experiments in porous media, and core flooding experiments, were conducted to investigate the differences between functional polymers and conventional polymers in terms of intrinsic properties and application performance. Comparative analyses of molecular chemical structures and micro-aggregation morphologies between functional polymers (branched polymers and polymeric surfactants) and conventional polymers revealed structural composition disparities and distinct viscosity-enhancing properties. From the perspective of aqueous solution viscosity enhancement mechanisms, functional polymers exhibit a three-stage viscosity-enhancing mechanism: bulk viscosity, associative viscosity, and emulsion-induced viscosity enhancement. The hydrodynamic characteristic sizes of polymers were analyzed to evaluate their compatibility with reservoir pore structures, and the seepage resistance mechanisms of both polymeric surfactants and salt-resistant polymers were identified. Core flooding experiments conclusively demonstrated the superior practical performance of functional polymers over conventional polymers. The application of functional polymers in polymer flooding can effectively enhance oil recovery. Full article

This study explored how pore size engineering in Nb-Mn/MCM-41 catalysts affects plasma-catalytic toluene oxidation. Adjusting the pore diameter (2.49–3.98 nm) modulated metal-support interactions and oxygen dynamics, with pore expansion to 3.73 nm (M3) optimizing the Mn⁴⁺/(Mn²⁺ + Mn³⁺) ratio (XPS: 36.8%), the amount of lattice oxygen species (O₂-TPD: 0.222 mmol/g), and crystallite size control (1.5 ± 0.2 nm, TEM). Smaller pores (M1: 2.49 nm) enhanced toluene adsorption but limited active site accessibility, while oversized pores (M4: 3.98 nm) reduced oxygen storage capacity (0.600→0.412 mmol/g). The Nb-Mn/M3 catalyst achieved superior performance with 96.8% toluene conversion, 55.0% CO₂ selectivity, and 85.4% carbon balance, while minimizing organic byproducts (GC-MS). Mechanistic studies revealed pore-mediated oxygen storage-transport cycles as critical for decoupling adsorption and oxidation steps. This study reveals fundamental mechanisms linking pore architecture to plasma-catalytic synergy in toluene oxidation, offering critical insights for the systematic design of energy-efficient, plasma-catalytic systems targeting industrial VOCs remediation. Full article

Superabsorbent polymers (SAPs) are widely employed as an internal curing agent to enhance the durability and shrinkage–cracking resistance of concrete. However, while its macroscopic effects on concrete properties (e.g., strength reduction) have been documented, the nanoscale mechanisms governing the mechanical behavior of calcium silicate hydrate (C-S-H) gel in SAP-modified concrete remain poorly understood. This knowledge gap limits the optimization of SAP content for balancing durability and strength, a critical challenge in high-performance concrete design. In this paper, we address this scientific problem by combining experimental characterization and molecular dynamics (MD) simulations to systematically investigate how SAP-induced pore structure modifications dictate the mechanical performance of C-S-H gel. First, we analyzed the effects of SAP on concrete pore structure and compressive strength, revealing its role in refining capillary pores into gel pores. Next, MD simulations were employed to construct C-S-H gel models with controlled pore size distributions at three SAP contents (0.2%, 0.3%, and 0.5%), to establish a quantitative relationship between pore characteristics and material performance. The results reveal that pores of ~0.74 nm diameter, predominantly located in weak interfacial regions, critically govern the mechanical behavior of C-S-H gel. At 0.2% SAP content, the C-S-H gel exhibits the highest bulk modulus (10.61 GPa) and optimal mechanical properties, whereas 0.3% SAP leads to a dominant pore cluster at 1.12 nm, resulting in significant reductions in bulk modulus (30.8%), shear modulus (29%), and Young’s modulus (22.3%). These findings establish a quantitative pore-property relationship, providing a mechanistic basis for tailoring SAP content to enhance both durability and mechanical performance in concrete, ultimately advancing the design of longer-lasting infrastructure. Full article

Carbon-based aerogels have garnered significant attention for CO₂ capture owing to their low-cost precursors, tunable structures, and high porosity. Their performance in CO₂ adsorption is intricately linked to their microstructural and textural features, including pore size distribution, surface area, and surface chemistry. Micropores (<2 nm) are particularly effective due to their size compatibility with CO₂ molecules, while surface functional groups enhance adsorption through hydrogen bonding and electrostatic interactions. Strategic design approaches have focused on tailoring these properties to optimize CO₂ uptake under realistic conditions. This review provides a comprehensive overview of recent advancements in the structural engineering of carbon aerogels, emphasizing the role of hierarchical porosity and heteroatom doping (nitrogen, oxygen, sulfur, etc.) in enhancing adsorption capacity and selectivity. Experimental and theoretical studies have highlighted how the synergistic control of microstructure and surface chemistry leads to superior adsorption performance. Furthermore, this review identifies current challenges, such as limited structural stability and insufficient mechanistic understanding, which hinder further progress. Future research directions are proposed, including advanced pore architecture control, functional group engineering, and the integration of in situ characterization techniques. Overall, this review serves as a guide for the rational design of next-generation carbon-based aerogels tailored for efficient and scalable CO₂ capture technologies. Full article

Metal Organic Frameworks (MOFs) are a unique family of tailor-made porous materials that have gained significant attention for their properties and their applications in various fields, including agriculture and agrifood. The aim of this review is to explore the potential of MOFs as smart carriers and delivery mediums of essential oils (EOs) and/or aromatic volatiles. Emphasis is given to their potential to be applied in crop protection and fresh food preservation. MOFs indeed present highly promising physicochemical characteristics in order to be applied in such sectors. To name a few, their high surface area, tunable porosity, and customizable functionalities, make them ideal carriers for EOs, which are established for their antimicrobial properties but their wider practical applications are limited by their volatility and chemical sensitivity. The encapsulation of EOs in MOFs enhances their stability, controlled release, and bioavailability, providing effective solutions for sustainable agriculture and food safety. Furthermore, in this review we discuss various MOF types, emphasizing the most recent literature references, including cyclodextrin-based MOFs, Cu²⁺ based MOFs, Zn²⁺ based MOFs as well as Zr⁴⁺ MOFs. In this work, we attempt to highlight the interactions and physicochemical characteristics (e.g., pore size and pore functionality), that contribute to the encapsulation of different EOs within MOFs. We focus on a detailed discussion of the external stimuli that can trigger the targeted release of EOs, such as pH changes caused by pathogenic microbial activity. Additionally, we examine the potential benefits of the EOs encapsulation in MOFs, including the reduction of premature evaporation due to their volatile nature and their improved delivery to targeted sites. These aspects are explored within the frameworks’ food safety enhancement, extended shelf life and the promotion of sustainable food preservation alternatives. Furthermore, we address MOFs’ limitations such as biocompatibility, scalability and chemical stability under field conditions to further comprehend their potential as EO carriers in agrifood applications, emphasizing food preservation and protection. Finally, this work aims to contribute to global challenges in nutrition and sustainable agriculture. Full article

Deep coal seams in the Junggar Basin, China, have demonstrated high gas yields due to enhanced pore structures resulting from hydraulic fracturing. However, raw coal samples inadequately represent these stimulated reservoirs, and acquiring fractured core samples post-stimulation is impractical. To address this, a novel and operable laboratory method has been developed to fabricate porosity-enhanced synthetic coal plugs that better simulate deep coalbed methane reservoirs. The fabrication process involves crushing lignite and separating it into three particle size fractions (<0.25 mm, 0.25–1 mm, and 1–2 mm), followed by mixing with a resin-based binder system (F51 phenolic epoxy resin, 650 polyamide, and tetrahydrofuran). These mixtures are molded into cylindrical plugs (⌀50 mm × 100 mm) and cured. This approach enables tailored control over pore development during briquette formation. Porosity and pore structure were comprehensively assessed using helium porosimetry, mercury intrusion porosimetry (MIP), and micro-computed tomography (micro-CT). MIP and micro-CT confirmed that the synthetic plugs exhibit significantly enhanced porosity compared to raw lignite, with pore sizes and volumes falling within the macropore range. Specifically, porosity reached up to 27.84%, averaging 20.73% and surpassing the typical range for conventional coal briquettes (1.89–18.96%). Additionally, the resin content was found to strongly influence porosity, with optimal levels between 6% and 10% by weight. Visualization improvements in micro-CT imaging were achieved through iodine addition, allowing for more accurate porosity estimations. This method offers a cost-effective and repeatable strategy for creating coal analogs with tunable porosity, providing valuable physical models for investigating flow behaviors in stimulated coal reservoirs. Full article

Antibacterial filter materials have been effectively utilized for controlling biological contaminants and purifying indoor air, with the market for such materials experiencing continuous expansion. Currently, textile antibacterial testing standards are widely adopted to evaluate the antimicrobial efficacy of filter materials, yet no dedicated assessment protocols specifically tailored for filtration media have been established. This study aims to investigate the applicability of textile antibacterial testing methods to high-efficiency glass fiber filter materials (filtration efficiency > 99.9%), as well as to explore the factors that affect the rate of bacterial elution from high-efficiency glass fiber filter materials. By referencing the textile antibacterial testing standard (absorption method), significant discrepancies in bacterial recovery counts were observed between the high-efficiency glass fiber materials and the various textile control samples, with the former exhibiting a markedly lower recovery rate (approximately 10%). Pore structure and wettability analyses revealed the underlying causes of these differences. To ensure the accuracy of the antibacterial evaluation results, the effects of oscillation elution parameters (time and intensity) and material incubation conditions (duration, sealing and humidity) on bacterial recovery rates in glass fiber filter materials were systematically investigated to optimize the elution methodology. The results indicate that specimen type, size, elution method, incubation duration (4 h or 24 h), sealing conditions, and environmental humidity (10% or 30%, 60% and 95% RH) collectively influence bacterial recovery efficiency. The highest recovery efficiency (55%) was achieved when the filter materials were incubated in a sealed environment with humidity maintained at ≥60% RH. These findings emphasize the critical need to establish clear and specialized antibacterial performance testing standards for filter materials. The study provides essential guidance for developing material-specific evaluation protocols to ensure a reliable and standardized assessment of antimicrobial efficacy in high-efficiency filtration systems. Full article

This study explores the influence of various additives on the morphological, chemical, and thermal properties of poly(vinylidene fluoride) (PVDF) membranes prepared via the non-solvent induced phase separation (NIPS) technique. The use of a green solvent such as triethyl phosphate (TEP) was shown to be successful. A particular focus was dedicated to pore formers based on choline chloride–based deep eutectic solvents (DES) in combination with ethylene glycol and glycerol, i.e., ChCl/EG and ChCl/GLY, and its benchmark with traditional counterparts such as poly(ethylene glycol) (PEG) and glycerol (GLY). Comprehensive characterization was conducted using FESEM, FTIR, XRD, and DSC techniques to evaluate changes in membrane morphology, porosity, and crystallinity. PEG acted as a pore-forming agent, transitioning the internal structure from spherulitic to sponge-like with consistent pore sizes, while GLY produced a nodular morphology at higher concentrations due to increased dope solution viscosity. DES induced significant shifts in crystalline phase composition, decreasing α-phase fractions and promoting β-phase formation at higher concentrations. While the overall porosity remained unaffected by the addition of GLY or PEG, it was dependent on the DES concentration in the dope at lower values than those obtained by GLY and PEG. Membrane pore size with ChCl/GLY was lower than with ChCl/EG and GLY. All membranes showed performance at the hydrophobic regime. The findings demonstrate that ChCl/EG and ChCl/GLY can tailor the structural and thermal properties of TEP-driven PVDF membranes, providing a green and versatile approach to customize the membrane properties for specific applications. Full article

The permeability of a porous material is the measure of the ability of fluids to pass through it. The ability to control permeability is valued by tissue engineers who manufacture tissue engineering scaffolds that house cells/tissue and facilitate tissue growth. Therefore, a scaffold design software in which permeability can be entered as a variable in determining the structure and strut topology would be a desirable tool for tissue engineering researchers. The ability to factor permeability directly into the design of scaffolds facilitates more effective bone tissue engineering by enabling optimal nutrient transport and waste removal at regeneration sites. Additionally, having the ability to control the mechanical environment by indicating a region of acceptable porosities for in vitro cell culturing is desirable. This desirability is a result of porosity being a major determining factor in permeability, where increasing porosity will generally mean a higher permeability. Thus, having an upper bound on porosity means that higher-permeability structures can be determined whilst maintaining high values of mechanical strength. In this software, a method is discussed for modifying the Kozeny–Carman equation by incorporating level-set equations for different triply periodic minimal surface (TPMS) structures. Topology analysis is computed on six different TPMS structures in the toolbox, and a relationship between a topological constant and permeability is derived through the Kozeny–Carman equation. This relationship allows for an input of permeability as a factor in the determination of pore size, porosity, and scaffold structure. This novel method allows for scaffold design based on a tailored permeability to assist successful tissue engineering. Full article

This study aimed to evaluate the effect of different concentrations of Tween 20 on various physical properties of agar gel as a model material. The effects of other sources of agar-agar powder on the gel properties were also evaluated. The pure gels were prepared with agar powders obtained from two suppliers. Also, agar gels with Tween 20 in the 0.10 to 0.70% range were produced. The measurement of density, water activity, maximal force at fracture and gelling temperature, and the agar gels’ rheological properties, showed that the gels prepared with different agar powders had similar properties. The syneresis and stability indexes, gas hold-up, mechanical and acoustic attributes, and structure of foamed gels with Tween 20 were measured. The addition of Tween 20 in amounts ranging from 0.10 to 0.35% contributed to a gradual decrease in the stability and mechanical parameters of the gels. Using a concentration of 0.7%, Tween was able to obtain foamed gels with a uniform structure and small pore size, but low hardness and gumminess. Application of a lower concentration of Tween of 0.1% produced more rigid gels with limited gel syneresis. Adding Tween 20 at the appropriate level can be a factor in obtaining gels with a tailored structure and texture. Full article

The electroreduction of CO₂ (CO₂RR) is a promising and environmentally sustainable approach to closing the carbon cycle. However, achieving high activity and selectivity for multicarbon (C₂₊) products remains a significant challenge due to the complexity of reaction pathways. In this study, porous carbon-supported copper catalysts (CuHCS) with pore sizes of 120 nm (CuHCS120) and 500 nm (CuHCS500) were synthesized to tailor the microenvironment at the electrode–electrolyte interface and enhance product selectivity. CuHCS120 achieved a maximum faradaic efficiency (FE) for C₂₊ products of 46%, double that of CuHCS500 (23%). In contrast, CuHCS500 showed a higher FE for CO (36%) compared to CuHCS120 (14%) at the same potential. In-depth ex situ and in situ investigations revealed that smaller pores promote the enrichment and adsorption of *CO intermediates, thereby enhancing C–C coupling and the formation of C₂₊ products. These findings underscore the critical role of structural confinement in modulating the catalytic microenvironment and provide valuable insights for the rational design of advanced catalysts for CO₂RR. Full article

Graphene-based materials, including graphene oxide (GO) and functionalized derivatives, have demonstrated exceptional potential in addressing environmental challenges related to heavy metal detection and wastewater treatment. This review presents the latest advancements in graphene-based electrochemical and fluorescence sensors, emphasizing their superior sensitivity and selectivity in detecting metal ions, such as Pb²⁺, Cd²⁺, and Hg²⁺, even in complex matrices. The key focus of this review is on the use of molecular dynamics (MD) simulations to understand and predict ion transport through graphene membranes, offering insights into their mechanisms and efficiency in removing contaminants. Particularly, this article reviews the effects of external conditions, pore radius, functionalization, and multilayers on water purification to provide comprehensive insights into filtration membrane design. Functionalized graphene membranes exhibit enhanced ion rejection through tailored electrostatic interactions and size exclusion effects, achieving up to 100% rejection rates for selected heavy metals. Multilayered and hybrid graphene composites further improve filtration performance and structural stability, enabling sustainable, large-scale water purification. However, challenges related to fabrication scalability, environmental impact, and cost remain. This review also highlights the importance of computational approaches and innovative material designs in overcoming these barriers, paving the way for future breakthroughs in graphene-based filtration technologies. Full article

Skin tissue engineering scaffolds should possess key properties such as porosity, degradability, durability, and biocompatibility to effectively facilitate skin cell adhesion and growth. In this study, recombinant human collagen (RHC) was used to fabricate porous scaffolds via freeze-drying, offering an alternative to animal-derived collagen where bovine collagen (BC)-based scaffolds were also prepared for comparison. The internal morphology of the RHC scaffolds were characterized by scanning electron microscopy (SEM) and the pore size ranged from 68.39 to 117.52 µm. The results from compression and fatigue tests showed that the mechanical strength and durability of RHC scaffolds could be tailored by adjusting the RHC concentration, and the maximum compressive modulus reached to 0.003 MPa, which is comparable to that of BC scaffolds. The degradation test illustrated that the RHC scaffolds had a slower degradation rate compared to BC scaffolds. Finally, the biocompatibilities of the porous scaffolds were studied by seeding and culturing the human foreskin fibroblasts (HFFs) and human umbilical vein endothelial cells (HUVECs) in samples. The fluorescent images and Cell Counting Kit-8 (CCK-8) assay revealed RHC porous scaffolds were non-cytotoxic and supported the attachment as well as the proliferation of the seeded cells. Overall, the results demonstrated that RHC-based scaffolds exhibited adequate mechanical strength, ideal biodegradability, and exceptional biocompatibility, making them highly suitable for skin-tissue-engineering applications. Full article