Search Results (10,253)

To easily recover and reuse nano-magnetite (Fe₃O₄) during the catalytic process, Fe₃O₄ is successfully dispersed by coprecipitation of Fe(II, III) salts on anchoring sites of bagasse-sugarcane fibers generated by gliding-arc plasma. Previously, we explored the effect of ascorbic acid (ASC), hydrochloric acid (HCl) and plasma-activated water (PAW) acting as oxidation inhibitors of Fe(II) solution. Prepared materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). The obtained results show that the oxidation inhibitor agent influences the morphology, texture and activity of the synthesized bulk-magnetite, where Fe₃O₄-nanorods, Fe₃O₄-nanospheres and Fe₃O₄-nanosheets were, respectively, obtained with PAW, HCl and ASC. The Fenton-plasmacatalytic treatment of amaranth red dye used as a model pollutant for 30 min revealed degradation rates of 53, 79 and 80%, respectively, for Fe₃O₄-ASC, Fe₃O₄-HCl, and Fe₃O₄-PAW each coupled to plasma. The deposition of nano-magnetite on the plasma-activated bagasse-sugarcane fibers (BM) using PAW as the best oxidation inhibitor agent exhibited characteristic FTIR-absorption bands of -OH, -CH₂ and Fe-O, attesting the bagasse-sugarcane-Fe₃O₄ linkage. The supported magnetite revealed a pollutant degradation rate of 99%, which deeply highlights an activity improvement after Fe₃O₄ deposition on plasma-activated bagasse sugarcane. The reusability of supported-Fe₃O₄ catalyst revealed a pollutant degradation rate of 95% after the fourth cycle, thus highlighting its easy recovery and catalytic stability (reuse). Full article

In this work, the use of biodiesel derived from Acacia sieberiana (commonly referred to as “Bagaruwa”) seed oil is presented as a potential renewable fuel for compression ignition engines. The biodiesel was produced using transesterification and characterized using Fourier transform infrared spectroscopy (FTIR) and gas chromatography–mass spectrometry (GC–MS). The FTIR analysis confirmed the presence of functional groups, including C=O stretching at 1740 cm⁻¹, and C–O ester bands at 1244 and 1170 cm⁻¹. The GC–MS analysis showed that linoleic acid methyl ester was the dominant compound (54.77%), followed by 11-octadecenoic acid methyl ester (22.91%) and palmitic acid methyl ester (11.71%). The physicochemical properties of biodiesel–diesel blends were evaluated according to the ASTM standards. Increasing the biodiesel content reduced the density, viscosity, cetane number, and calorific value, while the flash point was found to increase. B10 and B15 blends showed the highest density values within ASTM limits. The results indicated that Acacia sieberiana seed oil is a promising non-edible feedstock for sustainable biodiesel production and applications. Full article

Due to its excellent electrical and thermal performance, glass packaging demonstrates significant potential in heterogeneous integration of chiplets advanced packaging system, but limited by its poor interfacial adhesion strength between glass and metals. This article studies the mechanisms of glass–metal bonding interface at the microscale level, and the adhesion strength at the macroscale level. In detail, the changes of the adhesion strength after glass surface activation, annealing and micro-etching processes were characterized, and the correlation between the microscale mechanisms and the macroscale adhesion variations of each process was studied. X-ray photoelectron spectroscopy (XPS) results indicate that the increase in Si-OH bond is the key to glass surface activation. Fourier transform infrared spectroscopy (FTIR) was applied to quantitatively correlate the dynamic evolution of surface polar hydroxyl groups on glass substrates with the subsequent glass–metal interfacial bonding strength, and verified the conclusion above. The adhesion strength increased by 2.3 times after surface activation, and by 4.1 times after annealing, while it decreased slightly after etching. Furthermore, the glass–Ti seed layer interface was studied at the atomic level to better analyze the changes in macroscopic adhesion. XPS depth profiling confirmed the formation of Si-O-Ti bonds at the glass–Ti interface, which may contribute to the enhanced adhesion. After annealing, X-ray diffractometer (XRD) characterization revealed the great change in grain structure caused a reduction in residual stress within the plated layer. Full article

Sulfated polysaccharides (SPs) from green seaweed species have been scarcely studied for the development of novel pharmaceutical, cosmetic or nutraceutical products. The present study aimed to investigate the physico-chemical characteristics of the sulfated polysaccharidic fractions isolated from Cladophora vagabunda green seaweed and to evaluate their anti-aging properties in vitro. SPF1 and SPF2 fractions were separated from the purified polysaccharidic extract by size exclusion chromatography. The content of neutral carbohydrates, uronic acids and sulfate was assessed, while Fourier transform infrared spectroscopy (FT-IR) analysis confirmed the presence of a functional group characteristic for sulfated polysaccharides. Capillary zone electrophoresis indicated the monosaccharides profile and the presence of bioactive fucose and uronic acids. The two fractions differed in sulfate content (22.59% and 29.44%). SF2 showed stronger collagenase inhibition (95.69%), whereas SF1 exhibited greater elastase inhibition (84.2%) in comparison with EGCG. Both fractions exhibited antioxidant, anti-collagenase and anti-elastase activities and also a good biocompatibility and capacity to modulate the cell cycle progression in human dermal fibroblast culture. They showed anti-inflammatory potential by inhibition of interleukin-1 beta (IL-1β), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) production in lipopolysaccharide (LPS)-inflamed THP-1-derived macrophages. Also, the level of matrix metalloproteinase-1 (MMP-1) and MMP-9 secretion was reduced after treatment with C. vagabunda fractions with MMP-1 reduced by ~95% in both fractions and MMP-9 reduced by ~79% in SF2 compared with the control. Both fractions stimulated the growth of probiotic cultures Lactobacillus acidophilus and L. rhamnosus. All these results demonstrated, for the first time, the anti-aging potential of sulfated polysaccharides isolated from C. vagabunda green seaweed. Full article

Rice protein peptides, abundant byproducts of rice processing, represent a sustainable source for developing novel nutritional delivery systems. To address the low bioavailability of traditional calcium supplements, this study aimed to fabricate a high-performance calcium-chelating complex (RPP-Ca) and elucidate its functional mechanism. The synthesis process was systematically optimized, yielding a maximum calcium-binding capacity of 93.98 ± 1.99 mg/g under optimal conditions (pH 10, 70 °C, 50 min reaction time, peptide-to-calcium mass ratio of 2:1). Physicochemical characterization utilizing scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) confirmed successful chelation, revealing significant microstructural reorganization and enhanced thermal stability compared to native peptides. Functional validation via in vitro Caco-2 cell models and in vivo calcium-deficient mouse models demonstrated that RPP-Ca significantly promotes intestinal calcium absorption and osteogenesis. Mechanistically, these effects were mediated through the activation of the TRPV6-Calbindin9k signaling axis. These findings underscore the potential of industrial rice protein peptides as an effective and bioavailable calcium fortification ingredient, providing a theoretical basis for the high-value utilization of rice byproducts in functional foods. Full article

This study comprehensively investigates the thermal and mechanical degradation behavior of molded glass-fiber-reinforced plastic (GFRP) grating composites subjected to temperatures ranging from 80 °C to 320 °C. Three types of industrially produced GFRP gratings—open-type (OG), thin closed-skin (CG), and thick closed-skin (TCG)—were evaluated using mechanical, microstructural, chemical, and crystallographic analyses. Three-point bending tests revealed that TCG-type specimens exhibited superior thermal resistance, experiencing only a 43.9% loss in strength at 320 °C, whereas OG-type specimens showed significant resin degradation, fiber–matrix decomposition, and microcrack formation at temperatures above 200 °C. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) analyses revealed significant resin degradation, fiber–matrix decomposition, and microcrack formation. Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC) confirmed substantial mass loss and structural disintegration at temperatures above 200 °C. Dynamic Mechanical Analysis (DMA) results revealed that the glass transition temperature (Tg) occurred at approximately 115–120 °C. The second-order regression model developed to estimate flexural strength under increasing temperature provided high accuracy (R² > 0.99) for all grating types. It should be noted that this investigation focuses on the short-term thermo-mechanical response under fundamental flexural loading to provide an accurate baseline for preliminary engineering design. The findings emphasize that the effect of temperature should be considered a critical parameter in the structural design of GFRP systems, especially in industrial environments with temperatures above 120 °C. Accordingly, tables for material selection and load-carrying capacity should be recalibrated to account for short-term temperature effects. Full article

In order to solve the bottleneck problems of zinc anode in aqueous zinc-ion batteries, such as dendrite disorder growth, hydrogen evolution corrosion, and interface passivation, lard derivative coating (LDC) was fabricated on zinc anode using a coating–calcination process. The microstructure, surface physical, and chemical properties of LDC and its influence on zinc deposition behavior and interface stability were investigated using a combination of techniques, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The LDC-modified Zn anode (LDC@Zn) delivers stable cycling for over 3500 h at 1 mA·cm⁻²/0.5 mAh·cm⁻². In Zn||Cu asymmetric cells, an average coulombic efficiency of 99.8% is achieved over 2400 cycles, confirming highly reversible Zn plating/stripping behavior. Furthermore, the full cell maintains a reversible capacity of ~400 mAh·g⁻¹ after 800 cycles at 5 A·g⁻¹, demonstrating excellent rate capability and long-term stability. Overall, this work innovatively demonstrates that the LDC interphase integrates hydrophobic suppression of side reactions and zincophilic regulation of Zn²⁺ deposition within a single architecture, enabling a synergistic balance between interfacial stability and controlled ion transport, and providing a scalable strategy for stable Zn anodes and new insights into interfacial engineering. Full article

Climate change and population growth are intensifying global food security challenges by reducing agricultural productivity and increasing reliance on fertilizers. In this context, developing sustainable and economically efficient agricultural solutions becomes essential. The study presents the synthesis of an interpenetrating polymer network (IPN) of hydrogels by combining bacterial cellulose (BC) with poly(acrylic acid) crosslinked with N, N-methylene-bis-acrylamide (PAA–co–MBA) via free radical copolymerization. To explore their potential as bioactive compound carriers, an ethanolic hydroalcoholic phytoextract (EHP) obtained from Hypericum perforatum L. and Melissa officinalis L. was directly encapsulated within the IPN hydrogels. The EHP is valued for its rich bioactive profile and antifungal, antimycobacterial, and antioxidant properties. The results of rheology measurements and thermal gravimetric analysis (TGA) revealed that incorporating BC into the IPN hydrogels significantly enhanced the mechanical stiffness, thermal resistance, and overall stability of the resulting IPN structures. Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) confirmed the structural organization and the porosity of the developed composite, as well as the successful fabrication of IPN hydrogels in the EHP medium. Under optimal conditions, the IPN hydrogels exhibited a reduced swelling capacity, thereby slowing the diffusion of the bioactive agents, reducing the application frequency, and enhancing the utilization efficiency. Taken together with the controlled-release performance, these findings demonstrate the potential of BC (PAA-co-MBA) IPN hydrogels as biodegradable and sustainable carrier systems for controlled delivery applications and suggest that they may be promising candidates for hydrogel-based agricultural delivery systems. Full article

This article presents the results of a study investigating the influence of surface-modified montmorillonite nanoclay and environmental exposure on the mechanical and surface properties of composites based on orthophthalic unsaturated polyester resin. A series of samples containing 0.02 to 0.1 wt.% of nanoclay, as well as a reference sample, were prepared. Following synthesis, the samples were incubated for one week in aqueous solutions with pH values of 4, 7, and 9. Mechanical testing included tensile strength, flexural strength, impact resistance, and surface roughness (Ra). Additionally, fracture surface analysis was performed using scanning electron microscopy (SEM) and digital optical microscopy. The effect of the additive on hardness was also assessed, and Fourier transform infrared (FT-IR) spectroscopy was carried out. The results indicated that nanoclay addition increased the material’s stiffness (Young’s modulus), although higher filler concentrations led to decreased impact strength and flexural performance, likely due to particle agglomeration. Incubation in chemically aggressive environments caused mechanical degradation and significant increases in surface roughness, especially after exposure to neutral and alkaline media. Microscopic observations confirmed the presence of microstructural changes and nanoclay agglomerates in selected samples. The findings confirm that the effectiveness of nanoclay modification depends not only on concentration but also on dispersion quality and the environmental conditions to which the material is exposed. Full article

In recent years, hybrid materials have been widely applied in the cultural heritage conservation field, especially to preserve color pigments. Among these, one of the most problematic (in terms of conservation science) is the red pigment cinnabar/vermilion. The challenge of this work was to prepare a hybrid coating consisting of a fluorinated polymer (known to protect cinnabar/vermilion), further modified with an inorganic filler based on anatase TiO₂. The latter is suitable because it is functionalized with quenchers, the particles are well above the nanoscale (≥200 nm in diameter), and it was added to the polymer matrix in small quantities. These characteristics made it suitable as a hybrid coating for protecting natural cinnabar, as demonstrated by the results obtained through a multi-analytical approach, based on multispectral imaging, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray analysis (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence (XRF), contact angle, spectrophotometry and mechanical tests, which were applied to evaluate the performances of the hybrid coating on laboratory specimens (after aging) and original samples. The experimental results provide insight into both the physicochemical decomposition mechanism of natural cinnabar under laboratory-simulated aging conditions and the benefits of the coating. In particular, the treatment did not induce electrochemical changes in the mercury, which remained in its oxidized state (+2) rather than being further reduced to elemental mercury (Hg⁰), the species responsible for the blackening of cinnabar/vermilion (also combined with meta-cinnabar). In the oxidized form (Hg²⁺), the protein binder was altered, yet the application of the hybrid coating did not cause further physicochemical changes (i.e., red shift) to the Hg²⁺/egg-based binder system. This was also reflected in the color properties, which underwent no significant alteration. Finally, the mechanical tests yielded satisfactory results, particularly regarding water vapor permeability and treatment efficiency (even eight months after the initial application, although studies on the same samples are still ongoing). The hybrid coating was ultimately applied to original samples collected at Poggio Spaccasasso (Tuscany, Italy), which could be representative of prehistoric artworks based on natural cinnabar and traces of prehistoric adhesives made from beeswax, natural oils, and plant resins. Full article

Background: Effective management of bone defects remains a major clinical challenge, driving continuous efforts to develop bioactive, localized delivery systems that support bone regeneration. Gold nanoparticles (AuNPs) have gained attention in regenerative medicine for their capacity to modulate cellular activity. Yet, their application in functional delivery systems for bone repair is still limited. Chitosan (CS), a naturally derived biopolymer, exhibits notable osteoinductive properties, particularly when used to modify nanoparticulate carriers. Objectives: In this study, AuNPs and chitosan-coated gold nanoparticles (CS-AuNPs) were formulated, characterized, and incorporated into gel preparations to evaluate their physicochemical properties and therapeutic potential in a rat tibial bone defect model. Methods: AuNPs were synthesized and either left uncoated or coated with CS to enhance biological activity. Both formulations were examined for particle size, zeta potential, X-ray diffraction, and Fourier-transform infrared spectroscopy (FTIR). The resulting nanoparticles were integrated into gel bases, which were assessed for gel strength, swelling index, viscosity, and pH. The in vivo study involved surgically induced bone defects in the tibias of albino rats treated with either formulation. Healing outcomes were assessed via histological analysis, quantification of newly formed bone, immunohistochemical staining, radiographic imaging, and measurement of bone-related markers using RT-qPCR. Results: The CS-AuNP gel formulation demonstrated significantly improved bone regeneration compared to the uncoated counterpart, as evidenced by histological findings, increased bone volume in radiographs, stronger immunohistochemical expression of the VEGF angiogenic protein marker, and increased genetic expression of osteogenic markers. Conclusions: Incorporating CS-AuNPs into gel formulations offers a promising approach for enhancing bone healing. The superior performance of the CS-coated system highlights its potential as a promising localized therapy for managing bone defects. Full article

In this study, the effects of the type and content of phosphorus-based flame retardants, namely melamine polyphosphate (MPP) and aluminum diethylphosphinate (AlDPi), as well as their hybrid systems (MPP:AlDPi ratios of 1:1, 1:3, and 3:1), on the fire performance of acrylonitrile-butadiene-styrene (ABS) composites were investigated. The obtained results indicate that the synergistic action of MPP and AlDPi, including simultaneous inhibition of combustion in the gas phase and action in the condensed phase, leads to a significant improvement in the fire-retardant properties of ABS composites. For unmodified ABS, the peak Heat Release Rate (pHRR) and Total Heat Released (THR) values were 808.7 kW/m² and 86.5 MJ/m², respectively, while for the ABS/MPP_15/AlDPi_5, these values decreased to 292.9 kW/m² and 32.3 MJ/m². Simultaneously, the Effective Heat of Combustion (EHC) decreased from 22.3 to 15.5 MJ/kg, indicating inhibition of combustion processes in the gas phase. Fourier Transform Infrared Spectroscopy (FTIR) analysis of post-combustion residues (peaks 1280 and 1168 cm⁻¹) confirmed the contribution of additives to the formation of phosphorous derivatives in the condensed phase. The hybrid system ABS/MPP_15/AlDPi_5 exhibited the most favorable fire performance in cone calorimeter tests, characterized by reduced heat release and fire growth parameters. This was confirmed by the calculated fire performance indicators, including Fire Growth Rate Index (FIGRA), Maximum Average Rate of Heat Emission (MARHE), Fire Potential Index (FPI), and Flame Retardancy Index (FRI). Full article

Non-destructive diagnostic approaches play a crucial role in cultural heritage studies by enabling the assessment of artworks’ conservation conditions without causing damage. This work presents the case study of the tempera painting Cristo in Trono, by Domenico Morelli and Paolo Vetri, located in Amalfi (SA, Italy). A multi-analytical approach combining portable and non-invasive techniques was employed. Hygrometric tomography revealed anomalous surface moisture values (up to 23 units) along the edges and wooden joints, identifying areas requiring particular attention during conservation. Infrared reflectography (IR-R) detected preparatory drawings, compositional changes, and evidence of previous restoration interventions. X-ray fluorescence spectroscopy (XRF) identified the elemental composition of the pigments, indicating the use of cinnabar (or vermilion), ultramarine (or lapis lazuli), ochres, lead white (Biacca), and brass (Orone) for the golden background. Multivariate statistical analysis of the XRF data (PCA and HCA) revealed compositional heterogeneity and chemically distinct areas within apparently similar chromatic regions. Micro-invasive analyses complemented these results by providing information on the stratigraphy and material composition. Fourier-transform infrared (FT-IR) spectroscopy identified polyvinyl acetate (PVA), attributed to previous restoration treatments and associated with the yellowing of lead white, together with protein-based binders. Microscopic observations revealed the woven structure of the support, pigment-layer cracking, and degradation features, while the interaction of the brass with atmospheric agents and marine chlorides was found to be responsible for the alteration of the original golden background to a greenish-gold hue. The lower part of the canvas exhibited the most severe deterioration, resulting from higher moisture levels, unsuitable past restoration treatments, and prolonged exposure to humidity, atmospheric pollutants, and marine aerosols, highlighting the importance of integrated diagnostic investigations for planning effective conservation and restoration strategies. Full article

This study presents the development of a proof of concept, functional hydrogel interface designed for the acquisition of physiological signals, such as electrocardiogram (ECG) and electromyography (EMG). The hydrogel is synthesized using chitosan extracted from the shells of Tenebrio molitor larvae through a sustainable acid–alkaline protocol, blended with glycerol, polyvinyl alcohol (PVA), and ionized with NaCl to enhance conductivity. The resulting hydrogel membranes were cast and cut into circular shapes to provide a uniform contact geometry. The fabrication process yielded flexible membranes exhibiting ionic conductivity and partial surface conformity and handling stability. The extracted chitosan was characterized by Fourier-transform infrared spectroscopy (FTIR), degree of deacetylation (DDA), and molecular weight determination. Mechanical characterization included compression and tensile testing, while electrical characterization was performed through impedance spectroscopy and comparison with a commercial hydrogel interface. Functional evaluation was conducted through ECG and EMG signal acquisition under controlled experimental conditions. Preliminary in situ ECG and EMG recordings demonstrated successful signal acquisition using the proposed hydrogel interface. Future work may further investigate the mechanical and electrical behavior of the hydrogel under broader experimental conditions, as well as the optimization of the hydrogel formulation and extended physiological signal acquisition. Studies may help further characterize its potential as a chitosan-based bio interface material for bioelectrical sensing applications. Full article

In this study, composite nanofibrous membranes composed of poly(vinyl alcohol) (PVA), gelatin, and zein loaded with different contents of dihydromyricetin (DMY) were fabricated via electroblowing spinning (EBS). The effects of DMY content on the microstructure, physicochemical properties, mechanical strength, and functional performance of the membranes were evaluated. Scanning electron microscopy (SEM) analysis showed that the average fiber diameter increased from 174 ± 29 nm to 221 ± 35 nm with increasing DMY content, followed by a slight decrease at higher loading levels, indicating that DMY incorporation influences fiber morphology. Fourier transform infrared spectroscopy (FTIR) results suggested the presence of hydrogen bonding interactions between DMY and the polymer matrix. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) results indicated changes in the physical state of DMY within the nanofibrous system as the loading content increased. All samples exhibited a typical two-stage release behavior, and the highest cumulative release (nearly 55%) was observed at a DMY loading of 22.5%, while further increasing the loading reduced the release efficiency to approximately 45%. The release profiles were well described by a first-order kinetic model. The composite membranes exhibited improved surface hydrophilicity, appropriate water vapor permeability, antioxidant activity, and antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This study demonstrates the successful fabrication of DMY-loaded PVA/gelatin/zein nanofibrous membranes and provides preliminary insights into their structure–property–function relationships, release behavior, antioxidant activity, and antibacterial activity against representative bacteria, although further application-oriented validation is still required. Full article