Search Results (533)

As a novel carbon material, multi-walled carbon nanotubes (MWCNTs) have attracted significant research interest in energetic applications due to their high aspect ratio and exceptional physicochemical properties. However, their inherent structural characteristics and poor dispersion severely limit their practical utilization in solid propellant formulations. To address these challenges, this study developed an innovative reverse-engineering strategy that precisely confines MWCNTs within a three-dimensional Fe₂O₃ gel framework through a controllable sol-gel process followed by low-temperature calcination. This advanced material architecture not only overcomes the traditional limitations of MWCNTs but also creates abundant Fe-C interfacial sites that synergistically catalyze the thermal decomposition of glycidyl azide polymer-based energetic thermoplastic elastomer (GAP-ETPE). Systematic characterization reveals that the MWCNTs@Fe₂O₃ nanocomposite delivers exceptional catalytic performance for azido group decomposition, achieving a >200% enhancement in decomposition rate compared to physical mixtures while simultaneously improving the mechanical strength of GAP-ETPE-based propellants by 15–20%. More importantly, this work provides fundamental insights into the rational design of advanced carbon-based nanocomposites for next-generation energetic materials, opening new avenues for the application of nanocarbons in propulsion systems. Full article

The inferior electrical conductivity and elevated hardness of AgSnO₂ electrical contact materials have impeded their development. To investigate the effects of Co, Bi, and La doping on the stability and electrical properties of AgSnO₂, this study established interfacial models of doped AgSnO₂ based on first-principles calculations initiated from the atomic structures of constituent materials, subsequently computing electronic structure parameters. The results indicate that doping effectively enhances the interfacial stability and bonding strength of AgSnO₂ and thereby predicted improved electrical contact performance. Doped SnO₂ powders were prepared experimentally using the sol–gel method, and AgSnO₂ contacts were fabricated using high-energy ball milling and powder metallurgy. Testing of wettability and electrical contact properties revealed reductions in arc energy, arcing time, contact resistance, and welding force post-doping. Three-dimensional profilometry and scanning electron microscopy (SEM) were employed to characterize electrical contact surfaces, elucidating the arc erosion mechanism of AgSnO₂ contact materials. Among the doped variants, La-doped electrical contact materials exhibited optimal performance (the lowest interfacial energy was 1.383 eV/Ų and wetting angle was 75.6°). The mutual validation of experiments and simulations confirms the feasibility of the theoretical calculation method. This study provides a novel theoretical method for enhancing the performance of AgSnO₂ electrical contact materials. Full article

The dramatic increase in urban construction waste poses severe environmental challenges. Utilizing waste concrete to produce recycled aggregates (RA) for manufacturing recycled concrete (RC) represents an effective strategy for resource utilization. However, inherent defects in RA, such as high porosity, microcracks, and adherent old mortar layers, lead to significant performance degradation of the resulting RC, limiting its widespread application. Traditional methods for enhancing RA often suffer from limitations, including high energy consumption, increased costs, or the introduction of new pollutants. MICP offers an innovative approach for enhancing RC performance. This technique employs the metabolic activity of specific microorganisms to induce the formation of a three-dimensionally interwoven calcium carbonate gel network within the pores and on the surface of RA. This gel network can improve the inherent defects of RA, thereby enhancing the performance of RC. Compared to conventional techniques, this approach demonstrates significant environmental benefits and enhances concrete compressive strength by 5–30%. Furthermore, embedding mineralizing microbial spores within the pores of RA enables the production of self-healing RC. This review systematically explores recent research advances in microbial mineral gel network for improving RC performance. It begins by delineating the fundamental mechanisms underlying microbial mineralization, detailing the key biochemical reactions driving the formation of calcium carbonate (CaCO₃) gel, and introducing the common types of microorganisms involved. Subsequently, it critically discusses the key environmental factors influencing the effectiveness of MICP treatment on RA and strategies for their optimization. The analysis focuses on the enhancement of critical mechanical properties of RC achieved through MICP treatment, elucidating the underlying strengthening mechanisms at the microscale. Furthermore, the review synthesizes findings on the self-healing efficiency of MICP-based RC, including such metrics as crack width healing ratio, permeability recovery, and restoration of mechanical properties. Key factors influencing self-healing effectiveness are also discussed. Finally, building upon the current research landscape, the review provides perspectives on future research directions for advancing microbial mineralization gel techniques to enhance RC performance, offering a theoretical reference for translating this technology into practical engineering applications. Full article

As a bridge for human–machine interaction, the performance improvement of sensors relies on the in-depth understanding of ion transport mechanisms. This study focuses on the surface effect of resistive gel sensors and designs a polyacrylic acid/ferric ion hydrogel (PAA/Fe³⁺) gas flow sensor. Prepared by one-pot polymerization, PAA/Fe³⁺ forms a three-dimensional network through the entanglement of crosslinked and uncrosslinked PAA chains, where the coordination between Fe³⁺ and carboxyl groups endows the material with excellent mechanical properties (tensile strength of 80 kPa and elongation at break of 1100%). Experiments show that when a gas flow acts on the hydrogel surface, changes in surface humidity alter the density of the network structure, thereby regulating ion migration rates: the network loosens to promote ion transport during water absorption, while it tightens to hinder transport during water loss. This mechanism enables the sensor to exhibit significant resistance responses (ΔR/R₀ up to 0.55) to gentle breezes (0–13 m/s), with a response time of approximately 166 ms and a sensitivity 40 times higher than that of bulk deformation. The surface ion transport model proposed in this study provides a new strategy for ultrasensitive gas flow sensing, showing potential application values in intelligent robotics, electronic skin, and other fields. Full article

New stable three-dimensional hydrogels were obtained in an inert gas atmosphere in light in an aqueous dispersion of the main components: cod collagen, methyl methacrylate, polyethylene glycol, RbTe_1.5W_0.5O₆ complex oxide, and modifying additives. The analysis of the new hydrogels’ cytotoxicity using the MTT assay showed that the cytotoxicity of the sample extracts was observed in a number of examples, but was decreased with increasing dilution of the extracts. The decrease in cell viability at high concentrations of the extract is likely caused by a decrease in the number of specific components of the complete culture medium used to produce extracts. It is related to the well-known adsorption of medium proteins by the gel component, high-molecular compounds included in the matrix. The stimulating effect of the substances included in its composition was observed with a significant dilution of the extract, i.e., the proliferative activity of the cells increased. The extract of the hydrogel hydrolysate sample and all its dilutions did not show cytotoxicity in the MTT assay examples. It determines the prospect of its use on the wound surface, since hydrogel destruction occurs under the action of body enzymes. The new hydrogel is a promising material for creating wound coverings or scaffolds. Full article

In order to solve various problems in traditional roads and extend their service life, new road materials have become a research hotspot. Polyurethane prepolymers (PUPs) and ceramic fibers (CFs), as materials with unique properties, were chosen due to their synergistic effect: PUPs provide elasticity and gel-like behavior, while CFs contribute to structural stability and high-temperature resistance, making them ideal for enhancing asphalt performance. PUPs, a thermoplastic and elastic polyurethane gel material, not only enhance the flexibility and adhesion properties of asphalt but also significantly improve the structural stability of composite materials when synergistically combined with CF. Using response surface methodology, an optimized preparation scheme for PUP/CF composite-modified asphalt was investigated. Through aging tests, dynamic shear rate (DSR) testing, bending rate (BBR) testing, microstructure scanning (MSCR), scanning electron microscopy (SEM), atomic force microscopy (AFM), and infrared spectroscopy (IR), the aging performance, rheological properties, permanent deformation resistance, microstructure, and modification mechanism of PUP/CF composite-modified asphalt were investigated. The results indicate that the optimal preparation scheme is a PUP content of 7.4%, a CF content of 2.1%, and a shear time of 40 min. The addition of the PUP and CF significantly enhances the asphalt’s aging resistance, and compared with single-CF-modified asphalt and base asphalt, the PUP/CF composite-modified asphalt exhibits superior high- and low-temperature rheological properties, demonstrating stronger strain recovery capability. The PUP forms a gel network structure in the material, effectively filling the gaps between CF and asphalt, enhancing interfacial bonding strength, and making the overall performance more stable. AFM microscopic morphology shows that PUP/CF composite-modified asphalt has more “honeycomb structures” than matrix asphalt and CF-modified asphalt, forming more structural asphalt and enhancing overall structural stability. This study indicates that the synergistic effect of PUP gel and CF significantly improves the macro and micro properties of asphalt. The PUP forms a three-dimensional elastic gel network in asphalt, improving adhesion and deformation resistance. Using response surface methodology, the optimal formulation (7.4% PUP, 2.1% CF) improves penetration (↓41.5%), softening point (↑6.7 °C), and ductility (↑9%), demonstrating the relevance of gel-based composites for asphalt modification. Full article

In this study, curdlan was investigated as a substitute for egg-white protein, and the effects of different concentrations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%) on lipid oxidation and the physicochemical properties of a novel low-salt surimi gel containing transglutaminase (TGase) and lysine were evaluated. The results indicated that adding appropriate curdlan concentrations (0.2%–0.4%, especially 0.4%) significantly inhibited lipid oxidation in the surimi gel, achieving the highest L* and whiteness values. The fracture strength, WHC, hardness, and chewiness of the gel increased by 23.87%, 6.70%, 32.80%, and 13.49%, respectively, compared to the control gel containing egg-white protein (p < 0.05). At 0.4% curdlan, the gel also enhanced the crosslinking within the surimi, improved its resistance to shear stress, significantly increased the G’ value, and shortened the T₂₁, T₂₂, and T₂₃ relaxation times, inhibiting the conversion of immobilized to free water in the gel and promoting a denser three-dimensional network structure. However, excessive curdlan amounts (0.6%–1.0%) led to a notable deterioration in the gel performance, causing a more irregular microstructure, the formation of larger cluster-like aggregates, and a negative effect on color. In conclusion, the combination of 0.4% curdlan with TGase and Lys is effective for preparing low-salt surimi products. 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

Soft or flexible electronics is a rapidly growing and pioneering research field, as it makes devices comfortable to use, especially in biomedical engineering. Both single- and multi-network hydrogels have diverse applications where the most significant one is in the building of soft electronics, including soft circuits, displays, sensors, batteries, and supercapacitors, electronic storage, electric skin, health monitoring devices, soft robots, and automotive. Three-dimensional printing of conductive gels/hydrogels facilitates the construction of soft electronics. This review illustrates the design, mechanism, and application of hydrogel in soft electronics. The current progress, scope of improvement, and future prospects of hydrogel-based soft electronics are also discussed. This review will provide a clear concept of the topic to researchers. Full article

Background: Endothelial dysfunction triggers atherosclerosis pathogenesis. This study aimed at developing a 3D scaffold model able to reproduce in vitro the human vascular intima and study the endothelial damage induced by oxidative low-density lipoproteins (ox-LDLs) and shear stress. (2) Methods: Three-dimensional sandwich-like scaffolds were fabricated using electrospinning technology, functionalized with type I collagen and laminin, and subsequently coated with methacrylated gelatin hydrogel (GelMa) to achieve the final composite structure. Human umbilical vein endothelial cells (HUVECs) were used as the cell model for testing the suitability of 3D supports for cell culture exposed to ox-LDL both under static and shear stress conditions. Cell viability, ultrastructural morphology, and nitric oxide (NO) levels were analyzed. (3) Results: Electrospun mats and their functionalization were optimized to reproduce the chemical and physical properties of the vascular intima tunica. The 3D supports were suitable for the cell culture. Ox-LDL did not affect the HUVEC behavior in the 3D models under a static environment. Conversely, high shear stress (500 µL/min, HSS) significantly decreased the cell viability, also under the ox-LDL treatment. (4) Conclusions: Endothelial cell cultures on electrospun supports exposed to HSS provide a candidate in vitro model for investigating the endothelial dysfunction in atherosclerosis research. Technical improvements to the experimental setting are necessary for validating and standardizing the suggested 3D model. Full article

Tomato spotted wilt virus (TSWV) is a highly destructive plant pathogen and transmitted by several thrips including the western flower thrips, Frankliniella occidentalis. A structural N protein encoded in the viral genome represents the nucleocapsid protein by binding to the viral RNA genome. However, it remains unknown how the RNA-binding protein specifically interacts with the viral RNA from host RNAs in the target cells. To study the molecular basis of N function, we produced the protein in Escherichia coli and the resulting purified recombinant protein was used to investigate the protein–RNA interactions. The recombinant N protein migrated on agarose gel to the anode in the electric field due to its high basic isoelectric point. This electrostatic property led N protein to bind to DNA as well as RNA. It also bound to both single-stranded (ssRNA) and double-stranded RNA (dsRNA). However, when the total RNA was extracted from plant tissues collected from TSWV-infected host, the RNA extract using the recombinant N protein was much richer in the TSWV genome compared to that without the protein. To investigate the specificity of N protein to ssRNA, the three-dimensional structure was predicted using the AlphaFold program and showed its trimeric oligomerization with the binding pocket for ssRNA. This was supported by the differential susceptibility of N protein with ssRNA and dsRNA against RNase attack. Furthermore, a thermal shift assay to analyze the RNA and protein interaction showed that ssRNA strongly interacted with N protein compared to dsRNA. In addition, the N gene was expressed along with the multiplication of the viral RNA genome segments from the segment-specific fluorescence in situ hybridization analysis in different tissues during different developmental stages of the virus-infected F. occidentalis. These results suggest that the functional trimeric N proteins bind to the viral RNA to form a basic nucleocapsid structure at a specific virus-replicating compartment within the host cells. Full article

Gels are semi-solid colloidal systems characterized by three-dimensional networks capable of retaining up to 99% of liquid while exhibiting both solid-like and liquid-like properties. A novel biphasic system, the bigel, consists of hydrogel and oleogel, enabling the encapsulation of hydrophilic and lipophilic compounds. Their structure and functionality are influenced by the distribution of gel phases (e.g., oleogel-in-hydrogel or hydrogel-in-oleogel). This study aims to review current trends in polysaccharide-based bigels derived from seeds, vegetable oils and waxes, highlighting their biocompatibility, sustainability and potential food applications. A bibliometric analysis of 157 documents using VOSviewer identified four key thematic clusters: structured materials, delivery systems, pharmaceutical applications, and physicochemical characterization. Principal component analysis revealed strong correlations between terms, while also highlighting emerging areas such as 3D printing. This analysis demonstrated that seed-derived polysaccharides, including chia seed mucilage and guar gum, improve bigel structure and rheological properties, offering sustainable plant-based alternatives. Additionally, innovations such as extrusion-based 3D printing, functional food design, controlled drug release, bioactive compound delivery, and fat replacement are helping to support the further development of these systems. Finally, bibliometric tools remain instrumental in identifying research gaps and guiding future directions in this field. Full article

Glioblastoma (GBM, isocitrate dehydrogenase wild-type) is the most common primary malignant brain tumor in adults and is associated with a severely low survival rate. Treatments offer mere palliation and are ineffective, due, in part, to a lack of understanding of the intricate mechanisms underlying the disease, including the contribution of the tumor microenvironment (TME). Current GBM models continue to face challenges as they lack the critical components and properties required. To address this limitation, we developed innovative and practical three-dimensional (3D) GBM models with structural and mechanical biomimicry and tunability. These models allowed for more accurate emulation of the extracellular matrix (ECM) and vasculature characteristics of the native GBM TME. Additionally, 3D bioprinting was utilized to integrate these complexities, employing a hydrogel composite to mimic the native environment that is known to contribute to tumor cell growth. First, we examined the changes in physical properties that resulted from adjoining hydrogels at diverse concentrations using Fourier-Transform Infrared Spectroscopy (FTIR), compression testing, scanning electron microscopy (SEM), rheological analysis, and degradation analysis. Subsequently, we refined and optimized the embedded bioprinting processes. The resulting 3D GBM models were structurally reliable and reproducible, featuring integrated inner channels and possessing tunable properties to emulate the characteristics of the GBM ECM. Biocompatibility testing was performed via live/dead and AlamarBlue analyses using GBM cells (both commercial cell lines and patient-derived cell lines) encapsulated in the constructs, along with immunohistochemistry staining to understand how ECM properties altered the functions of GBM cells. The observed behavior of GBM cells indicated greater functionality in softer matrices, while the incorporation of hyaluronic acid (HA) into the gelatin methacryloyl (gelMA) matrix enhanced its biomimicry of the native GBM TME. The findings underscore the critical role of TME components, particularly ECM properties, in influencing GBM survival, proliferation, and molecular expression, laying the groundwork for further mechanistic studies. Additionally, the outcomes validate the potential of leveraging 3D bioprinting for GBM modeling, providing a fully controllable environment to explore specific pathways and therapeutic targets that are challenging to study in conventional model systems. Full article

Soil stabilizers are environmentally friendly engineering materials that enable efficient utilization of local soil-water resources. The application of nano-modified stabilizers to reinforce loess can effectively enhance the microscopic interfacial structure and improve the macroscopic mechanical properties of soil. This study employed nano-SiO₂ and nano-CaCO₃ to modify cement-based soil stabilizers, investigating the enhancement mechanisms of nanomaterials on stabilizer performance through compressive and flexural strength tests combined with microscopic analyses, including SEM, XRD, and FT-IR. The key findings are as follows: (1) Comparative analysis of mortar specimen strength under identical conditions revealed that nano-SiO₂ generally demonstrated superior mechanical enhancement compared to nano-CaCO₃ across various curing ages (1–3% dosage). At 1% dosage, the compressive strength of both modified stabilizers increased with curing duration. Early-stage strength differences (3 days) remained below 3% but showed a significant divergence with prolonged curing: nano-SiO₂ groups exhibited 10.3%, 11.3%, and 7.2% higher compressive strengths than nano-CaCO₃ at 7, 14, and 28 days, respectively. (2) The strength enhancement effect of nano-SiO₂ on MBER soil stabilizer followed a parabolic trend within 1–3% dosage range, peaking at 2.5% with over 15% strength improvement. (3) The exceptional performance of nano-SiO₂ originates from its high reactivity and ultrafine particle characteristics, which induce nano-catalytic hydration effects and demonstrate strong pozzolanic activity. These properties accelerate hydration processes while promoting the formation of interlocking C-S-H gels and hexagonal prismatic AFt crystals, ultimately creating a robust three-dimensional network that optimizes interfacial structure and significantly enhances strength characteristics across curing periods. These findings provide scientific support for the performance optimization of soil stabilizers and their sustainable applications in eco-construction practices. Full article