Search Results (695)

Hierarchical super-hydrophilic surfaces were realized by forming porous anodic aluminum oxide (AAO) and boehmite [AlO(OH)] on micro-textured Si wafers. One-step anodization of e-beam-deposited Al followed by controlled pore-widening, thermal annealing, or hot-water treatment produced oxide architectures exhibiting near-zero water contact angles (aqueous regime) and pronounced H₂O adsorption–desorption responses (vapor regime). Thermogravimetric analysis, moisture isotherms, and FT-IR indicate that increased porosity and anion incorporation (O⁻/O²⁻/oxalate) enrich surface hydroxyl functionality, enhancing affinity to H₂O. The results delineate two complementary regimes—rapid capillary wetting and multilayer vapor adsorption—supporting the use of these oxide/Si hierarchies as interactive water-affine interfaces with potential relevance to moisture gettering and chemosensing. Full article

The growing demand for sustainable alternatives to animal and synthetic leathers has accelerated interest in mycelium-based materials as an eco-friendly solution for the fashion industry. This study explores the potential of mushroom mycelium to create leather-like materials that align with circular fashion principles. Five species of edible and medicinal mushrooms were cultivated on sawdust substrates and evaluated for their growth performance, physical properties, and suitability as leather substitutes. Growth analysis revealed distinct species-specific behaviors: Cubamyces flavidus and Lentinus squarrosulus exhibited rapid colonization, achieving full substrate coverage within five days and forming dense mycelial networks at 14 days. In contrast, despite growing more slowly, Sanghuangporus vaninii and Ganoderma gibbosum formed thicker, more compact mats that might be suitable for strong leather-like materials. Visual and structural assessments showed diverse textures, colors, and hyphal architectures resembling natural leather. Physical characterization revealed shrinkage ranging from 13.17% to 24.09%, higher than for cow tanned leather (>5%) and PU microfiber (0.1–1.2%), suggesting a need for stabilization treatments. Apparent densities ranged from 0.13 g/cm³ to 0.30 g/cm³, lower than those of cow leather (0.49 g/cm³) and PU leather (0.38 g/cm³), highlighting species-specific hyphal structures that influence flexibility, porosity, and strength. SEM imaging confirmed the presence of interwoven hyphal mats resembling the fibrous architecture of natural leather, with S. vaninii showing the most uniform and continuous structure. Water absorption was significantly higher in mycelium sheets, consistent with their microporous nature, though S. vaninii showed the lowest uptake, reflecting possible natural water absorption. Thermogravimetric analysis revealed three-stage degradation profiles, with S. vaninii and G. gibbosum retaining >35% mass at 400 °C, indicating strong thermal stability for processing techniques such as hot pressing and finishing. Overall, the results demonstrate mycelium-based leathers as a biodegradable, low-impact alternative that can replicate the visual and functional characteristics of traditional leather, with opportunities for further improvement in substrate optimization, eco-tanning, surface coating, and scalable production toward a sustainable fashion future. Full article

Tambatinga (Colossoma macropomum × Piaractus brachypomus), a hybrid Amazonian fish recognized for its superior growth performance, represents a valuable and sustainable source of collagen-rich raw material. Due to its tropical origin, the species’ skin may contain higher levels of amino acids, which can enhance the functional and structural properties of gelatin derived from it. The valorization of fish processing residues for biopolymer production not only mitigates environmental impacts but also reinforces the principles of the circular economy within aquaculture systems. This study explores the development of biopolymer films from Tambatinga skin, an abundant by-product of Brazilian aquaculture. The skins were cleaned and subjected to a hot water–acid extraction process to obtain gelatin. The extracted gelatin exhibited high proline and hydroxyproline contents (12.47 and 9.84 g/100 g of amino acids, respectively) and a Bloom strength of 263.9 g, confirming its suitability for film formation. Films were prepared using 2 g of gelatin per 100 g of film-forming solution, with glycerol added at 10 and 20 g/100 g of gelatin. The resulting films were transparent, flexible, and showed uniform surfaces. Increasing the glycerol concentration reduced tensile strength (from 59.4 to 37.9 MPa) but improved elongation at break (from 116% to 159.1%) and modified the films’ thermal behavior. Moreover, Tambatinga gelatin films demonstrated excellent UV-blocking performance (below 300 nm) and lower water vapor permeability compared to other gelatin-based films reported in the literature. These findings highlight the potential of fish skin—typically regarded as industrial waste—as a renewable and high-value raw material for the production of sustainable biopolymers. This approach supports resource efficiency, waste reduction, and the broader goals of sustainable development and circular bioeconomy. Full article

Coral reefs are increasingly impacted by marine heatwaves and global warming, with the 2023–2024 El Niño–Southern Oscillation (ENSO) event causing unprecedented thermal stress across the Eastern Tropical Pacific. This study assessed the effects of this event on coral reefs in the Gulf of Papagayo, Costa Rica. Sea surface temperatures exceeded the bleaching threshold for seven months, reaching a record 10.2 Degree Heating Weeks—twice the levels recorded during the 1997–1998 ENSO. Benthic and fish community surveys revealed severe coral mortality, particularly in Pocillopora-dominated reefs, with some sites losing over 90% of live coral cover. Resilience varied across sites, likely influenced by factors such as local water circulation, coral genetic diversity, symbiont type, and heterotrophic capacity. Reefs with higher genetic diversity and thermally tolerant Durusdinium symbionts showed partial recovery. Seasonal upwelling appeared to buffer thermal stress in some areas, potentially acting as a natural climate refuge. Bleaching also impacted reef fish communities, with a notable decline in invertebrate-feeding species on degraded reefs. These findings highlight the interplay between prolonged thermal stress, coral biology, and local oceanographic processes in shaping reef resilience. Identifying and protecting such climate refugia will be critical for coral conservation under future climate change scenarios. Full article

The problem of water pollution by various xenobiotics has gained a lot of interest due to their persistence, bioaccumulation potential, and toxic effects on ecosystems and humans. Electrochemical sensors offer a rapid, sensitive, and cost-effective method for on-site monitoring. In this research, an electrochemical sensor for xenobiotics based on a biochar–alumina composite is developed. The biochar–alumina composites were obtained by the air-limited pyrolysis of oak sawdust in the presence of alumina. Two types of alumina were mixed with oak sawdust in three ratios and subjected to thermal treatment. The resulting composites were characterized by SEM, N₂ adsorption isotherm, XRD, and electrochemical characterization. The detection of the herbicide pendimethalin and the antibiotic ciprofloxacin was investigated, and the composite with the optimal biochar/alumina ratio was selected for each of the xenobiotics studied. A linear current response was obtained for pendimethalin in the concentration range 0.7 μM to 70.0 μM with an LOD of 0.5 μM. A linear current response was obtained for ciprofloxacin in the concentration range 1.6 μM to 55.4 μM with an LOD of 0.63 μM. A comparison of the characterization results with the electroanalytical performance implied the importance of the hydrophobic/hydrophilic nature of the electrode surface for detecting the analyte under investigation. Full article

The present study evaluates a surface dielectric barrier discharge (SDBD) plasma system utilizing porous metal electrodes to enhance the performance of non-thermal plasma (NTP)-based water treatment. A custom high-voltage, variable-frequency power driver was developed to operate SDBD reactors featuring novel porous electrode configurations aimed at enhancing plasma–liquid interaction. Three types of porous metal electrodes—copper (60 ppi), copper (20 ppi), and nickel (60 ppi)—were investigated as ground electrodes to evaluate their impact on discharge behavior and treatment performance. Electrical characterization via Lissajous plot analysis and optical emission spectroscopy (OES) was used to assess plasma power and reactive species generation. Ozone measurement and hydroxyterephthalic acid (HTA) dosimetry confirmed the formation of O₃ and hydroxyl radicals (·OH), while methylene blue (MB) removal experiments quantified pollutant removal percentage and energy yield. Among the tested electrodes, the copper (20 ppi) configuration achieved the highest MB removal percentage of 95.07%, followed by nickel (60 ppi) with 90.53%, and copper (60 ppi) with only 27.55%. Correspondingly, the energy yield ($EY$) reached 0.349 g/kWh for copper (20 ppi) at 15 min of plasma exposure, 0.19 g/kWh for nickel (60 ppi) at 20 min, and 0.049 g/kWh for copper (60 ppi) at 15 min. These results highlight the potential of porous metal electrodes as effective design choices for optimizing plasma–liquid interaction in SDBD systems. The findings support the development of compact, energy-efficient plasma water purification technologies using air-fed, surface DBD configurations. Full article

Footwear is traditionally manufactured using non-biodegradable polymers and leather, raising well-documented environmental and health concerns related to their production and disposal. This study explores polyhydroxyalkanoates (PHAs) as sustainable alternatives for bio-based footwear components. A stable aqueous suspension of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) was successfully formulated and applied to cotton fabrics via knife-coating. Various formulations, with and without additives and employing natural or synthetic thickeners, were evaluated in terms of surface morphology, wettability, permeability, and durability. The 10% PHBHHx formulation provided the best balance between material efficiency, coating uniformity, and surface performance. Additives and thermal treatment both influenced wettability, reducing contact angles and enhancing water vapor permeability. Notably, coatings with additives and hot pressing exhibited the highest permeability (68.0 ± 3.1 L/m²/s; 651.0 ± 5.4 g/m²/24 h), while additive-free, non-pressed coatings showed significantly lower values (19.5 ± 4.4 L/m²/s; 245.6 ± 66.2 g/m²/24 h), likely due to excessive compaction. Abrasion resistance remained excellent across all samples, especially with thermal treatment, withstanding 51,200 cycles. Washing resistance results revealed a synergistic effect between additives and heat, promoting long-term hydrophobicity and coating adhesion. Overall, PHBHHx coatings demonstrated potential to enhance water resistance while maintaining breathability, representing a sustainable and effective solution for functional and technical footwear applications. Full article

With increasing attention to health, plant protein products have gained significant market potential due to their growing consumer demand. This study researches the influence of ultrasonic treatment on the structure and function of pea–oat composite protein gel (POPG) to enhance its elasticity and thermal stability. The ultrasonic treatment parameters were regulated to power (200–600 W for 30 min) and ultrasonic time (20–40 min at 400 W) during the preparation of POPG, and the properties and structure, including gel strength, rheological analysis, water-holding capacity (WHC), thermal characteristics, fluorescence performance, and microstructure, were further evaluated. The results showed that the POPG samples exhibited optimal values in WHC, gel strength, surface hydrophobicity, free sulfhydryl amount, and endogenous fluorescence at 400 W ultrasonic for 30 min compared with the untreated POPG. Rheological analysis indicated that POPG displayed the highest storage modulus and improved viscoelasticity. Ultrasonication resulted in an augmentation in β-sheet content, hence creating a more compact network structure. DSC and TGA revealed improved thermal stability, while SEM and CLSM exhibited a homogeneous and firm gel structure of POPG. This research offers the theory that ultrasonic technology can improve the performance of plant-based composite gels. Full article

Hydrogels have attracted considerable attention as biomedical materials owing to their distinctive properties; however, improvements in mechanical strength, biodegradability, and biocompatibility remain essential for advanced clinical applications. This study developed a new dual-crosslinked hydrogel based on gelatin (Gel) and dextran (Dex) via sequential aldimine condensation and photopolymerization. Natural Gel and Dex were functionalized to synthesize methacrylated Gel (GelMA) and oxidized Dex (ODex), respectively. An imine-linked network was initially formed between GelMA and ODex via aldimine condensation, followed by a second crosslinked network generated through blue-light-induced free-radical polymerization of GelMA, yielding dual-crosslinked hydrogels (GMODs). ¹H NMR and FT–IR analyses confirmed the successful functionalization and formation of dual-crosslinked structure. The dual-crosslinked network enhanced the thermal stability and water-retaining capacity of the freeze-dried hydrogels (DGMODs) while reducing the surface wettability and equilibrium swelling ratio of GMODs. The maximum compressive strength (σₘ) increased with crosslinking density; GMOD−2, with moderate crosslinking density, remained intact under 85% compressive strain and achieved σₘ of 108.0 kPa. The degradation rate of GMODs was tunable by adjusting the crosslinking density, thereby modulating their drug-release behavior. GMOD−3, possessing the highest crosslinking density, exhibited effective drug-sustained release for up to five weeks. Biological evaluations, including cytotoxicity assays, live/dead cell staining, and hemolysis tests, verified excellent cytocompatibility (cell survival rate > 92%) and minimal hemolysis ratio (<5%). Furthermore, inhibition zone tests preliminarily revealed moderate antibacterial activity for GMOD−1. The GMOD hydrogels exhibited superior compressive robustness, adjustable biodegradability, and excellent biocompatibility, holding great potential for biomedical applications such as sustained drug-delivery system. Full article

Ti–6Al–4V (TC4) dual-phase titanium alloy is widely used in aerospace components owing to its excellent strength-to-weight ratio and high-temperature stability. However, conventional machining often generates a wide heat-affected zone (HAZ) and oxide or recast layers, which deteriorate the microstructure and reduce long-term reliability. In this study, the water-jet-guided laser (WJGL) process was applied to investigate how coupled laser–water interactions influence the groove morphology, elemental distribution, and crystallographic evolution of TC4 alloy. Under optimized parameters, the WJGL process reduced the HAZ width to less than 1 $\mathsf{\mu }$m, effectively removed the resolidified layer, and suppressed surface oxidation. SEM, EDS, and EBSD analyses confirmed that the $\alpha$ + $\beta$ dual-phase structure remained stable, with no significant phase transformation or grain coarsening. Compared with conventional laser cutting, WJGL achieved smoother surfaces, improved interfacial integrity, and reduced thermal damage. These findings highlight the potential of WJGL for precision machining of high-performance titanium alloys and provide theoretical and experimental support for enhancing the microstructural control and service reliability of aerospace TC4 components. Full article

This study explores chitosan (CS)-based materials for water purification, assessing their disinfection and contaminant degradation capabilities. A reproducible protocol was developed to fabricate homogeneous, stable CS films, validated through permeability testing and characterized using thermal (TGA), mechanical (tensile strength, elongation), and physico-chemical (FTIR-ATR, water contact angle, SEM-EDX) analyses. A catalyst was employed to complex iron ions and crosslink CS chains via acrylamide functions, stabilizing the CS structure and reducing washout in water. Disinfection tests showed that pure CS exhibited strong antimicrobial activity under varying contamination levels, attributed to direct contact and slight dissolution. Functionalized CS materials acted as catalytic surfaces, requiring hydrogen peroxide (H₂O₂) to generate reactive oxygen species (ROS). This ROS-mediated process effectively disinfected high bacteria loads and degraded phenol. Electron paramagnetic resonance (EPR) confirmed hydroxyl radicals as the primary active species when H₂O₂ was present. Under lower contamination levels, residual CS within the functionalized material contributed to direct antimicrobial effects, demonstrating a synergistic action between CS and ROS. These findings highlight CS as a reliable disinfectant and functionalized CS as a versatile material for ROS-driven antimicrobial action and contaminant degradation. The results suggest potential for scalable, sustainable water treatment applications. Future work will focus on optimizing the catalyst structure to enhance ROS production and improve contaminant removal efficiency. Full article

This study investigates the adsorption behavior of natural sepiolite for the removal of cadmium (Cd²⁺), copper (Cu²⁺), and nickel (Ni²⁺) ions from aqueous solutions under batch conditions. The sepiolite was extensively characterized prior to adsorption experiments. Mineralogical analysis confirmed the presence of crystalline sepiolite, while DTG-TGA revealed thermal stability with distinct weight loss linked to surface and structural water. BET analysis indicated a high surface area of 194 m²/g and a mesoporous structure favorable for adsorption. Batch experiments evaluated the effects of contact time, pH, adsorbent dosage, and initial metal concentration. Adsorption was highly pH-dependent, with maximum removal near-neutral pH values. Higher adsorbent dosages reduced in a lower adsorption capacity per unit mass, primarily because the fixed amount of solute was distributed over a larger number of available sites, leading to unsaturation of the adsorbent surface and possible particle agglomeration. Isotherm modeling revealed that the Langmuir model provided the best fit, indicating monolayer adsorption with maximum adsorption capacities of 15.95 mg/g for Cd(II), 37.31 mg/g for Cu(II), and 17.83 mg/g for Ni(II). Langmuir constants indicated favorable interactions. Kinetics showed rapid adsorption within the first hour, reaching equilibrium at 240 min through surface adsorption and intraparticle diffusion. Cu(II) exhibited the fastest uptake, while Ni(II) adsorbed more slowly, suggesting differences in diffusion rates among the metal ions. Desorption using 0.1 N HCl achieved over 80% efficiency for all metals, confirming sepiolite reusability. Overall, raw sepiolite is an effective, low-cost adsorbent for removing potentially toxic elements from water. Full article

This study investigates the development of biodegradable, scented bio-composite filaments incorporating industrial residues, specifically spent coffee grounds (SCG) and lignin (LI), into a PLA matrix for FDM 3D printing. Two fragrance additives, essential oil (EO) and microencapsulated fragrance powder (FP), were introduced (3%) to enhance sensory properties. The research investigates the effects of filler content (5%, 10%, and 15%) and fragrance additives on the surface chemistry (FTIR), thermal stability (TGA and DSC), mechanical properties (Tensile, flexural and impact), microstructure, and dimensional stability (Water absorption test and thickness swelling). Incorporating industrial residues and additives into PLA reduced the thermal stability, the degradation temperature and the glass transition temperature but increased the residual mass and the crystallinity. The effect of lignin was more pronounced than that of SCG, significantly influencing these thermal properties. Increasing the filler content of spent coffee grounds and lignin also led to a progressive decrease in tensile, flexural, and impact strength due to poor interfacial adhesion and increased void formation. However, lignin-based biocomposites exhibited enhanced stiffness at lower concentrations (≤10%), while biocomposites containing 15% SCG doubled their elongation at break compared to pure PLA. Adding fragrance reduced the mechanical strength but improved ductility due to plasticizer-like interactions. Microstructural analysis revealed heterogeneity in the biocomposites’ fracture surface characterized by the presence of pores, filler agglomeration, and delamination, indicating uneven filler dispersion and limited interfacial adhesion, particularly at high filler concentrations. The water absorption and dimensional stability of 3D-printed biocomposites increased progressively with the addition of residues. The presence of essential oil slightly improved water resistance by forming hydrogen bonds that limited moisture absorption. This article adds significant value by extending the potential applications of biocomposites beyond conventional engineering uses, making them particularly suitable for the fashion and design sectors, where multi-sensory and sustainable materials are increasingly sought after. Full article

Culinary herbs and spices are highly valued for their contribution to aroma, color, and overall flavor in traditional foods. Microbial inactivation in fresh herbs and spices is challenging due to their complex surface structures and dense natural microflora, which limit the effectiveness of conventional methods. Atmospheric cold plasma (ACP) is an innovative non-thermal technology with potential applications in the fresh spice industry. This study investigates the efficacy of ACP, generated using a practical, simple, and original system that allows uniform treatment without complex equipment, on microbial inactivation and quality attributes of fresh spices. Treatments of 1 and 3 min were applied, and their effects on natural microflora, Escherichia coli, and Pseudomonas syringae spp. were evaluated on the first day and after 7 days of storage. Results showed that 3 min treatments achieved higher reductions in natural microflora (2.91 log CFU g⁻¹), E. coli (2.76 log CFU g⁻¹), and P. syringae spp. (2.24 log CFU g⁻¹) compared to 1 min treatments (1.87, 1.93, and 1.65 log CFU g⁻¹, respectively). Different herbs exhibited varying responses to ACP, reflecting differences in leaf structure and chemical composition, which highlights the need for tailored treatment strategies. ACP treatment did not significantly affect water activity, color, or moisture content (except for rosemary, bay leaf, and thyme), nor total anthocyanin content (TAA), total phenolic content (TPC), total antioxidant capacity (TAC), or total flavonoid content (TFC). However, total chlorophyll content (TCC) and pH increased significantly in most samples (except rosemary and dill). Scanning electron microscopy (SEM) revealed that the tissue integrity of rosemary and mint was affected by ACP, although more than 50% of carvone in mint was preserved, and its concentration increased. The observed microbial reductions and 3–8-day shelf-life extension suggest meaningful improvements in safety and storage stability for industrial applications. Overall, ACP demonstrates promise as a safe, efficient, and scalable alternative to conventional decontamination methods, with broad potential for enhancing the quality and shelf life of fresh spices. Full article

Background/Objectives: Lidocaine hydrochloride (LD-HCl) is the most commonly used local anesthetic in dentistry, often administered with epinephrine to extend its duration and reduce systemic absorption. However, its relatively short duration of action, the need for repeated injections, and the unpleasant taste may limit patient compliance and procedural efficiency. This study aimed to develop and evaluate a novel injectable nanoemulsion-based in situ gel depot system of LD to provide prolonged anesthetic activity. Methods: LD-loaded nanoemulsions were formulated by high-shear homogenization followed by probe sonication, employing Miglyol 812 N (oil phase), a combination of Tween 80 and soy lecithin (surfactant–co-surfactant), glycerin, and deionized water (aqueous phase). The selected nanoemulsion (S1) was dispersed in a thermoreversible poloxamer solution to form a nanoemulgel. The preparation was evaluated for globule diameter and uniformity, zeta potential, surface morphology, pH, drug content, stability, rheological behavior, injectability, and in vitro drug release. Analgesic efficacy was assessed via tail-flick and thermal paw withdrawal latency tests in Wistar rats. Cardiovascular safety was monitored using non-invasive electrocardiography and blood pressure measurements. Results: The developed nanoemulsions demonstrated a spherical shape, nanometer size (206 nm), high zeta-potential (−66.67 mV) and uniform size distribution, with a polydispersity index of approximately 0.40, while the nanoemulgel demonstrated appropriate thixotropic properties for parenteral administration. In vitro release profiles showed steady LD release (5 h), following the Higuchi model. In vivo studies showed significantly prolonged analgesic effects lasting up to 150 min (2.5 h) compared to standard LD-HCl injection (p < 0.001), with no adverse cardiovascular effects observed. Conclusions: The developed injectable LD in situ nanoemulgel offers a promising, patient-friendly alternative for prolonged anesthetic delivery in dental and operative procedures, potentially reducing the need for repeated injections and enhancing procedural comfort. Full article