Search Results (3,444)

In this study, we developed new food gel materials, prepared agarose (AG) gels containing chitosan (CHI)-oleic acid (OA) complex particles, and evaluated their structure, mechanical properties, and in vitro digestion characteristics. CHI-OA complex particles, with an average diameter of approximately 0.9 mm, were successfully incorporated into 1–3 wt% AG gels by mixing with an aqueous AG solution and cooling it while maintaining a uniform dispersion state of the complex particles after gelation. The incorporation of CHI-OA complex particles affected the gelation behavior of AG during cooling and altered the mechanical properties of the resulting gel. The digestion properties of the CHI-OA-AG gel were evaluated through in vitro gastric digestion experiments using a flask shaker and a human gastric digestion simulator. After 120 min of flask shaking, the CHI-OA-AG gel maintained its shape, whereas significant disintegration and fragmentation were observed after 120 min in the human gastric digestion simulator. Notably, most CHI-OA complex particles were retained within the gel fragments even after disintegration, with <5% of the total particles released into the simulated gastric juice. In addition, we prepared a CHI-OA-AG gel encapsulating water-insoluble curcumin (CUR) using the hydrophobic domains of the CHI-OA complex particles. CUR was successfully incorporated into the gel at concentrations up to 72 μmol/L, suggesting that CUR contained in the CHI-OA-AG dispersion before gelation was completely encapsulated. These results demonstrate the potential applicability of the CHI-OA-AG composite gel as a next-generation food material with enhanced nutritional value and controlled digestibility. Full article

Limited ionic conductivity and unstable interfaces, primarily caused by poor solid–solid contact, pose significant challenges to the stable cycling of solid-state batteries. In this study, an interfacial in situ polymerization strategy is proposed to construct a poly(1,3-dioxolane) (PDOL) gel electrolyte layer between a poly(vinylidene fluoride) (PVDF)-based solid polymer electrolyte and the electrodes. This approach aims to address interfacial compatibility issues in solid-state lithium metal batteries. By precisely tuning the composition of the gel precursor and employing characterization techniques such as FTIR and NMR, the efficient ring-opening polymerization of 1,3-dioxolane (DOL) was confirmed, achieving a high conversion rate of 90%. The precursor was drop-cast onto the PVDF-based electrolyte/electrode interfaces before cell assembly. Electrochemical evaluations revealed that the in situ formed solidified interlayer significantly enhanced interfacial compatibility and ion transport, yielding a high Li⁺ transference number (0.341), an exceptional critical current density (1.4 mA cm⁻²), and remarkable cycling stability exceeding 1600 h in Li||Li symmetric cells. Furthermore, full cells incorporating LiFePO₄ cathodes demonstrated excellent rate capability and long-term cyclability, retaining 98.7% of their capacity after 1000 cycles. These results collectively underscore the effectiveness of this in situ solidification strategy in optimizing the interface structure and improving the overall performance of PVDF-based solid-state batteries. Full article

Water-based fracturing fluids, which are essential for enhancing oil and gas production, increasingly utilize seawater or produced water as alternatives to freshwater due to scarcity and cost considerations. However, the high salinity of these alternative water sources can compromise fluid stability and induce formation damage. Herein, the rheological behavior of borate-crosslinked hydroxypropyl guar (HPG) fracturing fluids was systematically evaluated in the presence of individual salts to elucidate the effects of ionic composition and concentration. Viscosity measurements at 80 °C and 170 s⁻¹ revealed that Ca²⁺ above 1500 mg/L reduced viscosity to below 50 mPa·s within 50 min, whereas Na⁺, K⁺, Mg²⁺ and SO₄²⁻ up to 10,000 mg/L exhibited no significant influence on viscosity and shear resistance. Among the cations investigated, Fe³⁺ exerted the most severe effect: only 15 mg/L Fe³⁺ caused viscosity to drop below 50 mPa·s within 30 min, far below the requirement for field applications. At elevated concentrations, MgCl₂, CaCl₂ and FeCl₃ compromised gel structural strength, while KCl-containing fluids demonstrated superior elastic resistance compared to NaCl at equivalent high concentrations. Microstructural analysis by SEM revealed that Na⁺, K⁺ and Mg²⁺ enhanced polymer hydration and HPG fiber entanglement, promoting the formation of well-defined network structures. In contrast, Ca²⁺ and Fe³⁺ disrupted the crosslinked gel architecture through complexation and electrostatic interactions with the polymer, resulting in reduced structural integrity. These findings provide critical insights for formulating fracturing fluids using saline or recycled water sources and inform targeted pretreatment strategies for flowback water in hydraulic fracturing operations. Full article

Red mud, as a by-product of alkaline regeneration of alumina, has limited application due to its strong alkalinity, fine particle size, and complex composition. In this work, red mud porous ceramics with uniform pore size distribution and high mechanical strength were prepared using a foam-gel casting method. The effects of solid loading and sintering temperature on the microstructure of porous ceramics were systematically investigated. The porosity of red mud-based porousceramics sintered at 1150 °C with a solid content of 60.4% was 33.7%, and the maximum compressive strength was 54.70 MPa, while the porousceramics prepared with a solid loading of 34.1% and sintered at 1050 °C achieved a maximum porosity of 79.7% and a compressive strength of 2.36 MPa. Increasing the solid loading reduced porosity and enhanced compressive strength, allowing for the tailoring of mechanical properties to meet specific application requirements. Higher sintering temperature promoted the formation of the liquid phase, enhanced particle bonding, and further improved the compressive strength. Additionally, toxicity leaching tests confirmed that the ceramics are environmentally safe, with leachate levels well within regulated limits. These results demonstrate the potential of foam-gel casting as an effective route for transforming red mud into value-added porous ceramics, thereby contributing to sustainable waste utilization and broadening the application prospects of red mud-based materials. Full article

Achieving low hydration heat without sacrificing strength is essential for early-age temperature-crack control in concrete. This study designed a low-heat Portland cement (LHPC)–fly ash (FA)–ground-granulated blast-furnace slag (GGBS)–silica fume (SF) binder system with LHPC fixed at 80 wt.% and total supplementary cementitious materials (SCMs) fixed at 20 wt.%. Compressive strength at 3, 7, and 28 d, 7 d isothermal calorimetry combined with Krstulović–Dabić (K–D) modeling, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to identify a low-heat/high-strength pathway. The mixture containing 20 wt.% FA (F20) reduced the 7 d cumulative heat to 194.060 J·g⁻¹ but lowered the 28 d compressive strength to 44.2 MPa. Replacing FA with GGBS under the same replacement level restored the strength baseline, and the mixture containing 20 wt.% GGBS (G20) reached 56.7 MPa. Introducing SF created an optimum compositional window, and the mixture containing 10 wt.% FA, 3 wt.% GGBS, and 7 wt.% SF (F10G3S7) achieved the highest 28 d strength of 58.2 MPa. Notably, the mixture containing 10 wt.% FA, 9 wt.% GGBS, and 1 wt.% SF (F10G9S1) combined relatively low 7 d heat (203.545 J·g⁻¹) with high 28 d strength (54.2 MPa). K–D fitting showed that FA lowered the heat potential (Qmax = 217.98 J·g⁻¹) relative to LHPC (236.19 J·g⁻¹), whereas GGBS/SF blends increased Qmax to 268.77–271.55 J·g⁻¹, indicating composition-dependent hydration efficiency. TGA revealed higher bound water per unit LHPC at 28 d (21.46–22.97%) than in LHPC alone (17.17%), and bound water correlated more strongly with compressive strength (R² = 0.75–0.78) than calcium hydroxide (CH) content (R² = 0.66–0.67). SEM confirmed a more continuous gel-rich matrix in F10G9S1, suggesting that the low-heat/high-strength route is governed by efficient heat-to-hydrate conversion and microstructural densification rather than heat output alone. These findings provide both mechanistic insight and practical guidance for proportioning low-heat, high-strength binders for concrete applications requiring early-age temperature-crack control. Full article

Studies on the influence of radiotherapy on the structure, thermal properties, and thermo-oxidative decomposition of breast silicone implants were conducted. Additionally, the potential use of breast silicone implant waste as a component in layered composites was investigated. ATR-FTIR, DSC, and TG/DTG/FTIR analyses confirmed that radiation does not affect the structure, thermal properties, or oxidative decomposition behavior of the shell and gel layers of breast silicone implants. The conducted tests demonstrated the successful fabrication of composite materials using a PUM matrix and breast silicone implant waste. The presence of the PUM matrix in the manufactured composites influenced the crystallization and melting behavior of the silicone phase. Moreover, the incorporation of a silicone implant waste layer into the composites increased their thermal stability while decreasing the glass transition temperature, storage modulus and hardness compared to neat PUM. The type of implant waste layer used (shell or gel) in the preparation of the PUM composites did not significantly affect the melting and glass transition temperatures, thermal stability, or oxidative decomposition behavior of the newly developed materials. As demonstrated, new layered composite materials based on silicone implant waste (shell and gel), with properties valuable for practical applications, were successfully developed. Full article

Solar interfacial evaporation is promising for freshwater production, yet thermodynamic energy limits and mass transfer attenuation in high-salinity environments restrict practical applications. To address these challenges, a 3D high-efficiency evaporator is developed by cross-linking a hydrophilic composite gel onto a macroporous sponge scaffold. This spatially decoupled architecture enables fundamental water-state regulation and efficient environmental heat harvesting. Specifically, hydrophilic functional groups in the gel network reduce the equivalent enthalpy of vaporization of water to 1181.8 J g⁻¹. Simultaneously, the 3D columnar structure induces a sidewall cold sink effect to extract additional ambient thermal energy. Through this synergy, the PCPH delivers a remarkable apparent evaporation rate of 8.59 kg m⁻² h⁻¹ under one standard sun. Furthermore, interconnected macropores within the sponge establish excellent convective pathways for rapid ion diffusion. Consequently, the device operated continuously for 8 h in a 10 wt% NaCl solution without significant blockage and decreased key metal ion concentrations in 3.5 wt% simulated seawater by 4 to 5 orders of magnitude. The purified water fully satisfies World Health Organization standards. This study offers an innovative strategy to surpass conventional photothermal bottlenecks and design highly durable water treatment materials. Full article

This study investigates the valorization of dredged sludge as a sustainable subgrade fill material through stabilization with a nano-calcium carbonate–cement composite. Unconfined compressive strength (UCS) tests were systematically conducted to determine the optimal dosage of nano-CaCO₃ as a supplementary additive at a fixed cement content of 8% by dry soil mass. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and quantitative pore structure analysis were employed to elucidate the underlying solidification mechanisms. The results demonstrate that the addition of 2% nano-CaCO₃ yields the highest 28-day UCS of 721 kPa, representing a statistically significant 21% improvement over the cement-only reference (596 kPa) and a more than threefold increase relative to untreated sludge (213 kPa). Conversely, increasing the nano-CaCO₃ dosage to 2.5% leads to a significant strength reduction, attributed to nanoparticle agglomeration and hindered cement hydration. Microstructural characterization reveals that the optimal nano-CaCO₃ dosage accelerates early-age hydration through a nucleation effect, promotes the consumption of portlandite, and enhances the formation of calcium silicate hydrate (C–S–H) gel. Semi-quantitative XRD analysis further confirms the conversion of less stable monosulfate (AFm-SO₄) into stable monocarboaluminate (AFm-CO₃) phases. These synergistic mechanisms—nucleation, physical pore filling, and chemical reaction—result in a densified matrix with a refined pore structure, reduced total porosity, and a more homogeneous pore-size distribution. The findings provide a robust theoretical basis for the resource-oriented utilization of dredged sludge and the design of low-carbon composite stabilizers for soft soil treatment. Full article

Mg-doped ZnO (Zn_1−xMg_xO, x = 0.00–0.05) thin films were successfully grown on glass substrates with a c-axis orientation at 600 °C using the sol–gel dip-coating technique. The structural features, defect-related photoluminescence, and optical constants of the films were systematically investigated as a function of Mg concentration. X-ray diffraction (XRD) patterns confirmed a single-phase hexagonal wurtzite structure with a preferential (₀₀₂) orientation for all compositions, indicating the successful substitution of Mg²⁺ ions into the ZnO lattice. The crystallite size (D₀₀₂) was found to vary between 28.49 and 41.18 nm, while microstrain and stress exhibited non-monotonic behavior depending on Mg content. This behavior reveals a transition from compressive to tensile stress due to lattice distortion and defect formation. Photoluminescence (PL) spectra showed a dominant near-band-edge (NBE) ultraviolet emission, along with broad visible emissions extending from violet to red. Optical constants were accurately extracted using a double-facet-coated substrate (DFCS) model, combined with nonlinear curve fitting using the Nelder–Mead optimization algorithm. The films showed a strong absorption edge at about 370 nm and exceptional optical transparency (≈60–80%) in the visible spectrum. The systematic blue shift in the extinction coefficient with increasing Mg content confirms bandgap engineering in Zn_1−xMg_xO thin films. The refractive index dispersion was successfully modeled using the Cauchy relation, demonstrating composition-dependent tunable optical properties. Depending on the Mg content, the optical bandgap values ranged from approximately 3.265 to 3.315 eV. The band-edge states and optical constants are strongly affected by the combined effects of defect development, Mg-induced lattice distortion, and changes in optical dispersion. These results indicate that sol–gel-derived Mg-doped ZnO thin films with composition-dependent stress states, defect states, and tunable optical properties are promising candidates for UV photodetectors, optical coatings, and transparent optoelectronic devices. Full article

Rapid urbanization has intensified challenges regarding urban waterlogging and vehicle exhaust pollution. While permeable asphalt mixtures mitigate waterlogging and nano-TiO₂ offers photocatalytic exhaust degradation capabilities, the direct application of nano-TiO₂ is hindered by agglomeration and low photocatalytic efficiency. This study developed a composite modified nano-TiO₂ via metal ion doping and support treatment to enhance its performance in asphalt pavements. Specifically, nano-TiO₂ was doped with Fe³⁺, Ag⁺, and La³⁺ via the sol–gel method, and supported on activated carbon (AC) or Al₂O₃. The exhaust degradation performance was evaluated using a custom-built system, while dispersion properties were assessed via fluorescence microscopy and UV-Vis spectrophotometry. Furthermore, X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy were conducted to investigate the microstructural mechanisms underlying the doping modification and support treatment. Photocatalytic permeable asphalt mixtures were prepared by partially replacing mineral powder with the composite modified nano-TiO₂ to validate exhaust degradation and pavement performance. The results indicated that metal doping substituted Ti⁴⁺ in the lattice, inducing defects and reducing crystallite size to boost photocatalytic activity. The optimal doping concentrations are determined to be 1.0% for Fe³⁺, 1.5% for Ag⁺, and 1.0% for La³⁺. Among these, Fe³⁺-doped nano-TiO₂ at 1.0% content exhibits superior exhaust degradation, achieving 46.7% efficiency for hydrocarbons (HC) and 33.5% for nitrogen oxides (NO). Regarding dispersion, while AC performs better at low support content, Al₂O₃ at 40% content provides superior dispersion properties by increasing active sites and surface hydroxyl groups. For photocatalytic permeable asphalt mixtures, replacing 40–50% of mineral filler with the composite modifier is recommended. The optimized mixture demonstrates superior exhaust degradation performance while maintaining the required high-temperature stability, low-temperature cracking resistance, water stability, and fatigue life. Specifically, compared to the control group, these indicators for the mixture with 50% of the mineral filler replaced by the composite modifier increases by 7.0%, 12.5%, 13.4%, and 22.9%, respectively. This study presents a viable technical solution for developing multifunctional asphalt mixtures with photocatalytic functionality as the core innovation and mechanical performance as the application baseline. Full article

Silica fume (SF) is a valuable industrial by-product for low-carbon cementitious systems, but it weakens early-age strength due to slow pozzolanic activation. To overcome this limitation and, crucially, to elucidate the influence of pore system geometry on macroscopic performance, graphene oxide (GO) was introduced as a modifying agent. Concurrently, the fractal dimension (D) of the pore network was adopted as a pivotal descriptor linking microstructure to macroscopic strength. Results show that GO compensates for the early strength loss caused by SF and further amplifies long-term gains by accelerating hydration and promoting gel continuity. SF reduces total porosity through filler and pozzolanic reactions, while GO dramatically increases geometric complexity of pores, producing the highest fractal dimension and the most refined pore structure in the matrix. Critically, the proposed log–log interaction model demonstrates that compressive strength is jointly controlled by porosity and fractal dimension, rather than porosity alone. Higher fractal dimension intensifies strength gains in low-porosity matrices by reflecting improved pore connectivity control and energy-dissipation pathways. This establishes fractal dimension as a powerful, mechanistically interpretable index for predicting performance and guiding structural design in SF–GO modified cementitious composites. Full article

The development of protective coatings that integrate self-healing and environmental tolerance is vital for extending substrate lifespan. In this study, a multifunctional hydrogel composite coating is developed based on a waterborne polyacrylate dynamic covalent network containing oxime–carbamate bonds. The functional monomer MEOC, which contains an oxime–carbamate dynamic bond, was synthesized and incorporated into the waterborne polyacrylate matrix to form a hydrogel network (OC-PA) with intrinsic self-healing capability. Prussian blue (PB) and nano-SiO₂ were incorporated to form a photothermal functional layer, imparting hydrophobicity and converting light into heat for de-icing, while also activating dynamic bond rearrangement within the substrate. When the MEOC content was 7 wt% and the PB content was 2 wt%, the coating temperature rose to 110 °C within 2 min under 0.6 W/cm² irradiation, and the scratch healed within 5 min. After 1 h of fracture repair, the tensile strength reached 6.68 MPa, with a repair rate as high as 92.91%, and de-icing time was reduced from 343 s to 183 s. The coating achieved a water contact angle >100°. At −20 °C, the icing delay time increased by 215%. The hydrogel coating also exhibited excellent abrasion resistance, chemical stability, UV aging resistance, and anti-fouling properties, offering a durable solution for demanding environments. Full article

Due to their availability and environmental friendliness, alginate polymers are widely used in pharmaceuticals and cosmetics. The most common type of alginate is derived from seaweed and is used to develop topical dosage forms, among other things. However, variability in the seaweed material can lead to instability in the physicochemical parameters. Biotechnologically produced alginate minimizes this drawback through controlled synthesis. However, unlike algal alginates, the safety profile of such polymers has not been well studied. When developing dosage forms intended for wound surfaces, safety is of primary importance. In this study, we developed enzybiotic compositions based on bacterial alginate as an excipient and a novel recombinant modified endolysin, LysSi3-LK, as an antibacterial agent, and assessed their antibacterial properties and safety profile. The study included an in vitro evaluation of the activity spectrum, as well as the cytotoxicity and biocompatibility, of gel and hydrogel compositions. It was demonstrated that bacterial alginate is acceptable for the encapsulation of endolysin. It exhibited medium cytotoxic effects on the HaCaT cells, which were significantly reduced by the LysSi3-LK addition. The migration of cells was diminished following exposure to the gel and hydrogel formulations. However, an improvement in biocompatibility was observed in the cell proliferation assay. Full article

Conventional powdered biochar encounters severe bottlenecks in practical water treatment, such as difficult separation, easy loss, and potential secondary pollution. This work aimed to develop recyclable and high-performance adsorbents by preparing iron-doped biochar/sodium alginate composite microspheres (BC/MBC500-ALF) through Fe³⁺ cross-linking. Using corn stalk biochar and KMnO₄-modified biochar as adsorbent components and sodium alginate (SA) as a green shaping matrix, SA formed a stable egg-box hydrogel network to convert powdered biochar into uniform microspheres. Batch adsorption experiments revealed that the optimal pH for oxytetracycline (OTC) adsorption was 9, with adsorption capacities of 136.28 mg/g for BC500-ALF and 182.91 mg/g for MBC500-ALF. Kinetic analysis showed that BC500-ALF followed pseudo-first-order kinetics (R² = 0.983) dominated by physisorption, while MBC500-ALF fitted pseudo-second-order kinetics (R² = 0.994) dominated by chemisorption. The maximum Langmuir adsorption capacities at 308 K were 220.75 mg/g and 495.05 mg/g, respectively. Thermodynamic parameters confirmed a spontaneous and endothermic process. The adsorption mechanisms involved hydrogen bonding, π–π stacking, electrostatic attraction, metal-bridging complexation, and Fe–Mn oxide-mediated redox reactions. SA exerted dual functions in structure stabilization and adsorption enhancement. This composite provides an efficient and eco-friendly approach for tetracycline antibiotic pollution control in aqueous environments. Full article

To address the environmental sensitivity and low bioavailability of riboflavin, this study constructed a soybean protein isolate fibril (SPF)/κ-carrageenan (κC) composite gel delivery system. This study systematically investigated the effects of two independent variables (protein type: SPI/SPF; κC concentration: 2, 4, 6, 8 mg/mL) on the gel structural stability, riboflavin encapsulation performance, and in vitro digestive delivery characteristics of the system. Thioflavin T (ThT) fluorescence and ultraviolet (UV) absorption spectroscopy confirmed the successful preparation of SPF and verified specific intermolecular interactions between SPF and κC. Intermolecular forces, protein leaching rates, and differential scanning calorimetry (DSC) results indicated that compared with SPI-κC composite gels, κC regulates SPF molecular conformation via hydrogen bonding and hydrophobic interactions to exert a synergistic effect. This conformational regulation significantly reduced the protein leaching rates in SPF-κC composite gels, elevated the thermal denaturation temperatures (up to 79.82 °C), and enhanced the gel structural stability. As the κC concentration increased, the environmental stability of SPF-κC riboflavin-loaded composite gels were markedly enhanced, which effectively delayed the gel degradation during simulated gastrointestinal digestion. This was manifested as a reduced protein loss rate (reduced to 22.23%). At a κC concentration of 8 mg/mL, the in vitro release mechanism of riboflavin shifted from Fickian to non-Fickian diffusion. Full article