Search Results (213)

Functional hydrogels are a growing class of soft materials. Functional hydrogels are characterized by their three-dimensional (3D) polymeric network and high water-retention capacity. Functional hydrogels are deliberately engineered with specific chemical groups, stimuli-responsive motifs, or crosslinking strategies that impart targeted biomedical or environmental roles (e.g., drug delivery, pollutant removal). Their capacity to imitate the extracellular matrix, and their biocompatibility and customizable physicochemical properties make them highly suitable for biomedical and environmental applications. In contrast, non-functional hydrogels are defined as passive polymer networks that primarily serve as water-swollen matrices without such application-oriented modifications. Recent progress includes stimuli-responsive hydrogel designs. Stimuli such as pH, temperature, enzymes, light, etc., enable controlled drug delivery and targeted therapy. Moreover, hydrogels have shown great potential in tissue engineering and regenerative medicine. The flexibility and biofunctionality of hydrogels improve cell adhesion and tissue integration. Functional hydrogels are being explored for water purification by heavy metal ion removal and pollutant detection. The surface functionalities of hydrogels have shown selective binding and adsorption, along with porous structures that make them effective for environmental remediation. However, hydrogels have long been postulated as potential candidates to be used in clinical advancements. The first reported clinical trial was in the 1980s; however, their exploration in the last two decades has still struggled to achieve positive results. In this review, we discuss the rational hydrogel designs, synthesis techniques, application-specific performance, and the hydrogel-based materials being used in ongoing clinical trials (FDA–approved) and their mechanism of action. We also elaborate on the key challenges remaining, such as biocompatibility, mechanical stability, scalability, and future directions, to unlocking their multifunctionality and responsiveness. Full article

Grout propagation is a critical aspect of fracture grouting. This study investigated grout propagation at fracture intersections under flowing conditions using a simplified two-dimensional (2D) fracture network. Transparent soil technology was employed to simulate the porous filling material within the fractures. The results showed that the penetration velocity of grout decreased significantly after passing through an intersection, and the velocity in the main fracture was consistently higher than that in the branch fractures. In the unfilled fracture network, the diffusion ratio between branch and main fractures ranged from 0.35 to 0.88, whereas after filling, it ranged from 0.71 to 0.86. For each intersection, the ratio of grout length in the downstream branch to that in the main fracture (RDM) was positively correlated with branch width. This trend was especially evident in unfilled fractures, whereas in filled fractures, the increase in RDM was much less pronounced. Regarding the upstream ratio (RUM), it was consistently lower than RDM. RUM increased with branch width in unfilled fractures but decreased in filled fractures. Additionally, higher fluid velocity amplified these anisotropic propagation behaviors. Based on the simplified filled fracture model, it was concluded that porous filling materials reduce permeability differences between fractures with different aperture widths. Furthermore, increased flow rate intensified the anisotropic diffusion of grout. This study provides valuable insight into the mechanism of anisotropic grout propagation and offers guidance for engineering grouting applications. Full article

Water pollution by organic dyes poses serious environmental and health challenges, demanding efficient and selective remediation methods. In this study, we engineered tailored organo-clay nanocomposites by modifying montmorillonite with hexadecyltrimethylammonium bromide (HTAB) and intercalating polyethylene glycol (PEG) chains of two distinct molecular weights (PEG200 and PEG4000). Comprehensive characterization techniques (XRD, FTIR, SEM, zeta potential, and TGA) confirmed the successful modification of the composites. Notably, PEG4000 promoted significant interlayer expansion, as evidenced by the shift of the (00l) reflection corresponding to the basal spacing d, indicating an increase in basal spacing. This expansion contributed to the formation of a well-ordered porous framework with uniformly distributed pores. In contrast, PEG200 produced smaller pores with a more uniform distribution but induced less pronounced interlayer expansion. Adsorption tests demonstrated rapid kinetics, achieving equilibrium in under 15 min, and impressive capacities: 420 mg/g of methylene blue (MB) adsorbed on PEG200/MMT@HTAB, and 385 mg/g of Congo red (CR) on PEG4000/MMT@HTAB. The crucial role of PEG chain length in adsorption selectivity was assessed, showing that shorter PEG chains favored methylene blue adsorption by producing narrower pores and faster kinetics, while longer PEG chains enhanced CR uptake via a stable, interconnected pore network that facilitates diffusion of larger dye molecules. Thermodynamic and Dubinin–Radushkevich analyses confirmed that the adsorption was spontaneous, exothermic, and predominantly driven by physical adsorption mechanisms involving weak van der Waals and dipole interactions. These findings highlight the potential of PEG-modified montmorillonite nanocomposites as cost-effective, efficient, and tunable adsorbents for rapid and selective removal of organic dyes in wastewater treatment. Full article

SiC nanowires (SiC_nw), due to their excellent dielectric properties, are promising high-temperature absorbing materials. However, the mechanism of their high-temperature absorption still requires further research. Therefore, porous SiC_nw/Si₃N₄ and SiC/Si₃N₄ ceramics with different SiC phase morphologies were fabricated using a simple precursor impregnation and pyrolysis method. The Fe impurity content of the Si₃N₄ powder raw material significantly affects the generation of SiC nanowires. When SiC exists in the form of nanowires, the excellent conductivity brought by the conductive network of the nanowires causes a significant response of the material’s permittivity to temperature. When the test temperature is room temperature, SiC_nw/Si₃N₄ has excellent absorption performance with a minimum reflection loss of −29.75 dB at 2.16 mm and an effective absorption bandwidth of 3.72 GHz at 2.54 mm. As the test temperature increases to 300 °C, the effective absorption bandwidth of SiC_nw/Si₃N₄ covers the entire X-band. The porous SiC_nw/Si₃N₄ ceramics exhibit excellent electromagnetic wave absorption performance, demonstrating significant application potential for high-temperature environments. Full article

In many scientific and engineering fields, such as hydrogeology, petroleum engineering, geotechnical research, and developing renewable energy solutions, fluid flow modeling in porous media is essential. In these areas, optimizing extraction techniques, forecasting environmental effects, and guaranteeing structural safety all depend on an understanding of the behavior of single-phase flows—fluids passing through connected pore spaces in rocks or soils. Darcy’s law, which results in an elliptic partial differential equation controlling the pressure field, is usually the mathematical basis for such modeling. Analytical solutions to these partial differential equations are seldom accessible due to the complexity and variability in natural porous formations, which makes the employment of numerical techniques necessary. To approximate subsurface flow solutions, traditional methods like the finite difference method, two-point flux approximation, and multi-point flux approximation have been employed extensively. Accuracy, stability, and computing economy are trade-offs for each, though. Deep learning techniques, in particular convolutional neural networks, physics-informed neural networks, and neural operators such as the Fourier neural operator, have become strong substitutes or enhancers of conventional solvers in recent years. These models have the potential to generalize across various permeability configurations and greatly speed up simulations. The purpose of this study is to examine and contrast the mentioned deep learning and numerical approaches to the problem of pressure distribution in single-phase Darcy flow, considering a 2D domain with mixed boundary conditions, localized sources, and sinks, and both homogeneous and heterogeneous permeability fields. The result of this study shows that the two-point flux approximation method is one of the best regarding computational speed and accuracy and the Fourier neural operator has potential to speed up more accurate methods like multi-point flux approximation. Different permeability field types only impacted each methods’ accuracy while computational time remained unchanged. This work aims to illustrate the advantages and disadvantages of each method and support the continuous development of effective solutions for porous medium flow problems by assessing solution accuracy and computing performance over a range of permeability situations. Full article

This study utilizes high-resolution X-ray computed tomography (CT) to evaluate the reservoir characterization in heterogenous carbonate rocks. These rocks show a diagenetic alteration that influences the reservoir quality in the Cretaceous Qamchuqa–Bekhme formations in outcrop and subsurface sections (Gali-Bekhal, Bekhme, and Taq Taq oilfields, NE Iraq). The scanning of fifty-one directional line analyses was conducted on three facies: marine, early diagenetic (non-hydrothermal), and late diagenetic (hydrothermal dolomitization, or HTD). The facies were analyzed from thousands of micro-spot analyses (up to 5250) and computed tomographic numbers (CTNs) across vertical, horizontal, and inclined directions. The surface (outcrop) marine facies exhibited CTNs ranging from 2578 to 2982 Hounsfield Units (HUs) (Av. 2740 HU), with very low average porosity (1.20%) and permeability (0.14 mD) values, while subsurface marine facies showed lower CTNs (1446–2556 HU, Av. 2360 HU) and higher porosity (Av. 8.40%) and permeability (Av. 1.02 mD) compared to the surface samples. Subsurface marine facies revealed higher porosity, lower density, and considerably enhanced conditions for hydrocarbon storage. The CT measurements and petrophysical properties in early diagenesis highlight a considerable porous system in the surface compared to the one in subsurface settings, significantly controlling the quality of the reservoir storage. The late diagenetic scanning values coincide with a saddle dolomite formation formed under high temperature conditions and intensive rock–fluid interactions. These dolomites are related to a hot fluid and are associated with intensive fracturing, vuggy porosities, and zebra-like textures. These textures are more pronounced in the surface than the subsurface settings. A surface evaluation showed a wide CTN range, accompanied by an average porosity of up to 15.47% and permeability of 301.27 mD, while subsurface facies exhibited a significant depletion in the CTN (<500 HU), with an average porosity of about 14.05% and permeability of 91.56 mD. The petrophysical characteristics of the reservoir associated with late-HT dolomitization (subsurface setting) show two populations. The first one exhibited CTN values between 1931 and 2586 HU (Av. 2341 HU), with porosity ranging from 3.10 to 18.43% (Av. 8.84%) and permeability from 0.08 to 2.39 mD (Av. 0.31 mD). The second one recorded a considerable range of CTNs from 457 to 2446 HU (Av. 1823 HU), with porosity from 6.38 to 52.92% (Av. 20.97%) and permeability from 0.16 to 5462.62 mD (Av. 223.11 mD). High temperatures significantly altered the carbonate rock’s properties, with partial/complete occlusion of the porous vuggy and fractured networks, enhancing or reducing the reservoir quality and its storage. In summary, the variations in the CTN across both surface and subsurface facies provide new insight into reservoir heterogeneity and characterization, which is a fundamental factor for understanding the potential of hydrocarbon storage within various geological settings. Full article

Flexible hydrogel sensors demonstrate emerging applications, such as wearable electronics, soft robots, and humidity smart devices, but their further application is limited due to their single-responsive behavior and unstable, low-sensitivity signal output. This study develops a dual-responsive starch-based conductive hydrogel via a facile “one-pot” strategy, achieving mechanically robust pressure sensing and ultra-sensitive humidity detection. The starch-Poly (2,3-dihydrothieno-1,4-dioxin)-poly (styrenesulfonate) (PEDOT:PSS)-glutaraldehyde (SPG) hydrogel integrates physical entanglement and covalent crosslinking to form a porous dual-network architecture, exhibiting high compressive fracture stress (266 kPa), and stable electromechanical sensitivity (ΔI/I₀, ~2.3) with rapid response (0.1 s). In its dried state (D-SPG), the film leverages the starch’s hygroscopicity for humidity sensing, detecting minute moisture changes (ΔRH = 6.6%) within 120 ms and outputting 0.4~0.5 (ΔI/I₀) signal amplitudes. The distinct state-dependent responsiveness enables tailored applications: SPG monitors physiological motions (e.g., pulse waves and joint movements) via conformal skin attachment, while D-SPG integrated into masks quantifies respiratory intensity with 3× signal enhancement during exercise. This work pioneers a sustainable candidate for biodegradable flexible electronics, overcoming trade-off limitations between mechanical integrity, signal stability, and dual responsiveness in starch hydrogels through synergistic network design. Full article

Polymers containing biocidal moieties (e.g., amino or ammonium groups) are considered promising materials that can help combat the growing resistance of pathogens to commonly used antimicrobials. Searching for new polymeric biocides, in this work, non-porous and porous poly(hydromethylsiloxane) (PHMS) networks were prepared and post-functionalized by N-allylaniline (Naa). Non-porous networks were obtained by cross-linking PHMS in the bulk and porous—in W/O high-internal-phase emulsion (HIPE). Linear divinyldisiloxane (M₂^Vi) or cyclic tetravinyltetrasiloxane (D₄^Vi) were used as cross-linkers. Studies confirmed the expected non-porous and open macroporous microstructure of the initial networks. They also showed that functionalization by Naa was more efficient for the non-porous networks that swelled to lower extents in toluene and contained higher amounts of Si-H groups than the porous ones. In the reactions with benzyl chloride or 1-bromoctane, some amino groups present in these materials were transformed to ammonium groups. It was found that activity against Gram-positive S. aureus and Gram-negative E. coli bacteria depended on the functionalization degree, cross-linking level and the microstructure of the modified materials. Full article

The permeability of porous asphalt pavements is a critical skid resistance indicator that directly influences driving safety on wet roads. To ensure permeability (water infiltration capacity), it is necessary to assess the degree of clogging in the pavement. This study proposes a permeability evaluation model for porous asphalt pavements based on 3D laser imaging and deep learning. The model utilizes a 3D laser scanner to capture the surface texture of the pavement, a pavement infiltration tester to measure the permeability coefficient, and a deep residual network (ResNet) to train the collected data. The aim is to explore the relationship between the 3D surface texture of porous asphalt and its permeability performance. The results demonstrate that the proposed algorithm can quickly and accurately identify the permeability of the pavement without causing damage, achieving an accuracy and F1-score of up to 90.36% and 90.33%, respectively. This indicates a significant correlation between surface texture and permeability, which could promote advancements in pavement permeability technology. Full article

Effective bone tissue regeneration remains pivotal in implant dentistry, particularly for edentulous patients with compromised alveolar bone due to atrophy and sinus pneumatization. Biomaterials are essential for promoting regenerative processes by supporting cellular recruitment, vascularization, and osteogenesis. This study presents the development and characterization of a novel lithography-printed ceramic β-TCP scaffold, with a macro/micro-porous lattice, engineered to optimize osteoconduction and mechanical stability. Morphological, structural, and biomechanical assessments confirmed a reproducible microarchitecture with suitable porosity and load-bearing capacity. The scaffold was also employed for maxillary sinus augmentation, with postoperative evaluation using micro computed tomography, synchrotron imaging, histology, and Fourier Transform Infrared Imaging analysis, demonstrating active bone regeneration, scaffold resorption, and formation of mineralized tissue. Advanced imaging supported by deep learning tools revealed a well-organized osteocyte network and high-quality bone, underscoring the scaffold’s biocompatibility and osteoconductive efficacy. These findings support the application of these 3D-printed β-TCP scaffolds in regenerative dental medicine, facilitating tissue regeneration in complex jawbone deficiencies. Full article

Batteries are used as energy storage devices in various equipment. Today, research is focused on solid-state batteries (SSBs), replacing the liquid electrolyte with a solid separator. The solid separators provide electrolyte stability, no leakage, and provide mechanical strength to the battery. Separators are mostly manufactured by either traditional processes or 3D printing technologies. These processes involve making a slurry of plastic, active and conductive material and usually adding a plasticizer when making thin films or filaments for 3D printing. This study investigates the additive manufacturing of solid-state electrolytes (SSEs) by employing fused deposition modeling (FDM) with recyclable, bio-derived polylactic acid (PLA) filaments. Precise control of macro-porosity is achieved by systematically varying key process parameters, including raster orientation, infill percentage, and interlayer adhesion conditions, thereby enabling the formation of tunable, interconnected pore networks within the polymer matrix. Following 3D printing, these engineered porous frameworks are infiltrated with lithium hexafluorophosphate (LiPF₆), which functions as the active ionic conductor. A tailored thermal sintering protocol is then applied to promote solid-phase fusion of the embedded salt throughout the macro-porous PLA scaffold, resulting in a mechanically robust and ionically conductive composite separator. The electrochemical ionic conductivity and structural integrity of the sintered SSEs are characterized through electrochemical impedance spectroscopy (EIS) and standardized mechanical testing to assess their suitability for integration into advanced solid-state battery architectures. The solid-state separator achieved an average ionic conductivity of 2.529 × 10⁻⁵ S·cm⁻¹. The integrated FDM-sintering process enhances ion exchange at the electrode–electrolyte interface, minimizes material waste, and supports cost-efficient, fully recyclable component fabrication. Full article

To enhance the antibacterial activity of cefquinome (CEF) against Escherichia coli, a Carboxymethylcellulose sodium (CMCNa)/D-Mannosamine hydrochloride (DMH)-based nanogels delivery system capable of protecting CEF from gastric acid degradation while enabling intestinal sustained release and targeted antibacterial enhancement was developed. Systematic research was conducted on the best formulation, physicochemical characteristics, stability, gastrointestinal fluid-responsiveness, and antibacterial activity of the optimal formulation. The results showed that the optimized CEF nanogels demonstrated an enhanced loading capacity (13.0% ± 1.7%) and encapsulation efficiency (52.2% ± 1.0%). CEF nanogels appeared as uniform transparent spheres with a smooth surface under transmission electron microscopy and exhibited a three-dimensional porous network via scanning electron microscopy. More importantly, stability studies revealed that the CEF nanogels hold satisfactory stability. In addition, the formed CEF nanogels could effectively avoid the destruction of CEF by gastric acid in simulated gastric juice. In addition, they had the effect of slow and targeted release in the simulated intestinal tract. Compared to the free CEF, CEF nanogels have stronger antibacterial activity against Escherichia coli. In short, the prepared CEF nanogels had stronger antibacterial activity than CEF through sustained and targeted release. Full article

Recently, a new class of materials with very high porosity and ultra-lightweight, namely, semiconductor aero-materials, has attracted the attention of many researchers. Semiconductor aero-materials, due to their special properties, can be used in the development of devices applied in biomedical, electronics, optoelectronic, energy conversion and storage, sensors, biosensors, catalysis, automotive, and aeronautic industries. Although aero-materials and aerogels are similar, different methods of obtaining them are used. Aerogels are synthesized from organic, inorganic, or hybrid precursors, the main characteristic being that they are gel-like solids with a high air content (99.9%) in the structure. Thus, three-dimensional (3D) interconnected porous network chains are formed, resulting in light solid-state structures with very high porosity due to the large number of air pores in the network. On the other hand, to obtain aero-materials with controlled properties such as morphology, shape, or the formation of 3D hollow structures, sacrificial templates are used. Thus, sacrificial structures (which can be easily removed) can be obtained depending on the morphology of the 3D structure to be obtained. Therefore, this review paper offers a comprehensive coverage of the synthesis methods of different types of semiconductor aero-materials that use ZnO tetrapod, ZnO(T), as a sacrificial template, related to the present and future perspectives. These ZnO(T) sacrificial substrates offer several advantages, including diverse synthesis processes and easy removal methods that occur simultaneously with the growth of the desired aero-materials. Full article

In situ-grown SiC nanowires (SiCnws) on SiC porous material (SiCnws@SiC) were prepared using sol–gel and carbothermal reduction methods, which substantially improves the electromagnetic wave absorption property of composite material. The crystallinity and purity of SiCnws are the best when the sintering temperature is 1600 °C. When the ratio of the carbon source (C) to the silicon source (Si) is 1:1, SiCnws@SiC composite exhibits excellent electromagnetic wave absorption performance, the minimum reflection loss is −56.95 dB at a thickness of 2.30 mm, and the effective absorption bandwidth covers 1.85 GHz. The optimal effective absorption bandwidth is 4.01 GHz when the thickness is 2.59 mm. The enhancement of the electromagnetic wave absorption performance of SiCnws is mainly attributed to the increase in the heterogeneous interface and multiple reflection and scattering caused by the network structure, increasing dielectric loss and conduction loss. In addition, defects could occur during the growth of SiCnws, which could become the center of dipole polarization and increase the polarization loss of composite materials. Therefore, in situ growth of SiCnws on SiC porous ceramics is a promising method to improve electromagnetic wave absorption. Full article

The effect of oil incorporation (soybean oil [SO] and coconut oil [CO] at 0, 1, 3, and 5 g/100 g) on the rheological, structural, and 3D printing properties of fish myofibrillar protein (MP, also known as surimi) paste and gel was investigated. Small-amplitude oscillatory shear (SAOS) tests showed that increasing oil concentration reduced the storage modulus (G′), weakening the gel network. Large-amplitude oscillatory shear (LAOS) analysis revealed strain-stiffening shifts and nonlinearity at γ = 5%. CO-containing gels exhibited higher hardness and gumminess, particularly at lower concentrations, due to enhanced protein–lipid interactions. In contrast, SO-containing gels showed reduced strength at higher concentrations, indicating phase separation. SEM confirmed that CO promoted a denser network, while SO led to a more porous structure, especially at 5% oil. Three-dimensional printing analysis demonstrated that both oils improved extrusion flowability by reducing nozzle friction. However, CO-containing samples maintained post-extrusion stability at 85% moisture, whereas SO-containing samples collapsed after multiple layers due to excessive softening. These findings highlight oil’s dual role in MP gels, enhancing lubrication and flowability while compromising rigidity. The results offer valuable insights for developing soft, texture-controlled foods using 3D printing, especially for personalized nutrition applications such as elderly care or dysphagia-friendly diets. Full article