Search Results (5,373)

Efficient detection of toxic and flammable vapors remains a major technological challenge, especially for environmental and industrial applications. This paper reports on the fabrication technology and gas-sensing properties of nanostructured Ga₂O₃/GaS_0.98Se_0.02. The β-Ga₂O₃ nanowires/nanoribbons with inclusions of Ga₂S₃ and Ga₂Se₃ microcrystallites were obtained by thermal treatment of GaS_0.98Se_0.02 slabs in air enriched with water vapors. The microstructure, crystalline quality, and elemental composition of the obtained samples were investigated using electron microscopy, X-ray diffraction, and Raman spectroscopy. The obtained structures show promising results as active elements in gas sensor applications. Vapors of methanol (CH₃OH), ethanol (C₂H₅OH), and acetone (CH₃-CO-CH₃) were successfully detected using the nanostructured samples. The electrical signal for gas detection was enhanced under UV light irradiation. The saturation time of the sensor depends on the intensity of the UV radiation beam. Full article

The coffee-ring effect, while harnessed in diverse fields such as biosensing and printing, poses challenges for achieving uniform particle deposition. Controlling this phenomenon is thus essential for precision patterning. This study proposes a novel method to regulate coffee-ring formation by tuning surface wettability via integrated nanoporous and hexagonal microstructures. Four distinct surface types were fabricated using UV nanoimprint lithography: planar, porous planar, hexagonal wall, and porous hexagonal wall. The evaporation behavior of colloidal droplets and subsequent particle aggregation were analyzed through contact angle measurements and confocal microscopy. Results demonstrated that nanoscale porosity significantly increased surface wettability and accelerated evaporation, while the hexagonal pattern enhanced droplet stability and suppressed contact line movement. The porous hexagonal surface, in particular, enabled the formation of connected dual-ring patterns with higher particle accumulation near the contact edge. This synergistic design facilitated both stable evaporation and improved localization of particles. The findings provide a quantitative basis for applying patterned porous surfaces in evaporation-driven platforms, with implications for enhanced sensitivity and reproducibility in surface-enhanced Raman scattering (SERS) and other biosensing applications. Full article

This study developed phospholipid-based liposomes loaded with extract from wild thyme (Thymus serpyllum L.) tea processing residues to enhance polyphenol stability and delivery. Liposomes were prepared with phospholipids alone or combined with 10–30 mol% cholesterol or β-sitosterol. The effect of different lipid compositions on encapsulation efficiency (EE), particle size, polydispersity index (PDI), zeta potential, stability, thermal properties, diffusion coefficient, and diffusion resistance of the liposomes was investigated. Liposomes with 10 mol% sterols (either cholesterol or β-sitosterol) exhibited the highest EE of polyphenols, while increasing sterol content to 30 mol% resulted in decreased EE. Particle size and PDI increased with sterol content, while liposomes prepared without sterols showed the smallest vesicle size. Encapsulation of the extract led to smaller liposomal diameters and slight increases in PDI values. Zeta potential measurements revealed that sterol incorporation enhanced the surface charge and stability of liposomes, with β-sitosterol showing the most pronounced effect. Stability testing demonstrated minimal changes in size, PDI, and zeta potential during storage. UV irradiation and lyophilization processes did not cause significant polyphenol leakage, although lyophilization slightly increased particle size and PDI. Differential scanning calorimetry revealed that polyphenols and sterols modified the lipid membrane transitions, indicating interactions between extract components and the liposomal bilayer. FT-IR spectra confirmed successful integration of the extract into the liposomes, while UV exposure did not significantly alter the spectral features. Thiobarbituric acid reactive substances (TBARS) assay demonstrated the extract’s efficacy in mitigating lipid peroxidation under UV-induced oxidative stress. In contrast, liposomes enriched with sterols showed enhanced peroxidation. Polyphenol diffusion studies showed that encapsulation significantly delayed release, particularly in sterol-containing liposomes. Release assays in simulated gastric and intestinal fluids confirmed controlled, pH-dependent polyphenol delivery, with slightly better retention in β-sitosterol-enriched systems. These findings support the use of β-sitosterol- and cholesterol-enriched liposomes as stable carriers for polyphenolic compounds from wild thyme extract, as bioactive antioxidants, for food and nutraceutical applications. Full article

Biogenic silver nanoparticles (AgNPs) were synthesized via a green chemistry strategy using wheat extract and subsequently functionalized with a carboxymethyl chitosan–cinnamaldehyde (CMC=CIN) conjugate through covalent imine bonding. The resulting nanohybrid (AgNP–CMC=CIN) was extensively characterized to confirm successful biofunctionalization: UV–Vis spectroscopy revealed characteristic cinnamaldehyde absorption peaks; ATR-FTIR spectra confirmed polymer–terpene bonding; and TEM analysis evidenced uniform nanoparticle morphology. Dynamic light scattering (DLS) measurements indicated an increase in hydrodynamic size upon coating (from 59.46 ± 12.63 nm to 110.17 ± 4.74 nm), while maintaining low polydispersity (PDI: 0.29 to 0.27) and stable surface charge (zeta potential ~ −30 mV), suggesting colloidal stability and homogeneous polymer encapsulation. Antifungal activity was evaluated against Fusarium oxysporum, Penicillium citrinum, Aspergillus niger, and Aspergillus brasiliensis. The minimum inhibitory concentration (MIC) against F. oxysporum was significantly reduced to 83 μg/mL with AgNP–CMC=CIN, compared to 708 μg/mL for uncoated AgNPs, and was comparable to the reference fungicide tebuconazole (52 μg/mL). Seed priming with AgNP–CMC=CIN led to improved germination (85%) and markedly reduced fungal colonization, while maintaining a favorable phytotoxicity profile. These findings highlight the potential of polysaccharide-terpene-functionalized biogenic AgNPs as a sustainable alternative to conventional fungicides, supporting their application in precision agriculture and integrated crop protection strategies. Full article

The development of sustainable and functional nanocomposites has attracted considerable attention in recent years due to their broad spectrum of potential applications, including wood preservation. Also, a global goal is to reuse the large volumes of waste for environmental issues. In this context, the aim of the study was to obtain soda lignin particles, to graft ZnO nanoparticles onto their surface and to apply these hybrids, embedded into a biodegradable polymer matrix, as protection/preservation coating for oak wood. The organic–inorganic hybrids were characterized in terms of compositional, structural, thermal, and morphological properties that confirm the efficacy of soda lignin extraction and ZnO grafting by physical adsorption onto the decorating support and by weak interactions and coordination bonding between the components. The developed solution based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and lignin-ZnO was applied to oak wood specimens by brushing, and the improvement in hydrophobicity (evaluated by water absorption that decreased by 48.8% more than wood, humidity tests where the treated sample had a humidity of 4.734% in comparison with 34.911% for control, and contact angle of 97.8° vs. 80.5° for untreated wood) and UV and fungal attack protection, while maintaining the color and aspect of specimens, was sustained. L.ZnO are well dispersed into the polymer matrix, ensuring a smooth and less porous wood surface. According to the results, the obtained wood coating using both a biodegradable polymeric matrix and a waste-based preservative can be applied for protection against weathering degradation factors, with limited water uptake and swelling of the wood, UV shielding, reduced wood discoloration and photo-degradation, effective protection against fungi, and esthetic quality. Full article

Background: Transition metal complexes incorporating fluorinated counter anions represent a significant class of compounds with broad applications in industry, pharmaceuticals, and biomedicine. These fluorinated anions are known to enhance the solubility, stability, and reactivity of the complexes, thereby expanding their functional utility in various chemical and biological contexts. Methods: A set of metal(II) complexes of the general formula [MPy₆][B(C₆F₅)₄]₂ where (Py = pyridine, M = Mn (1), Fe (2), Co (3), Ni (4), Cu (5), Zn (6)) have been synthesized by direct reaction of metal halides and pyridine in the presence of Ag[B(C₆F₅)₄]. The complexes were characterized using different techniques to assure their purity, such as elemental analysis (EA), electron paramagnetic resonance (EPR) spectroscopy, thermogravimetric analysis (TGA), ultraviolet–visible (UV–Vis) spectroscopy, ¹¹B-NMR, ¹H-NMR, and FT-IR spectroscopy. The antimicrobial and antifungal properties against different types of bacteria and fungi were studied for all prepared complexes. Results: The synthesized complexes exhibited broad-spectrum antimicrobial activity, demonstrating variable efficacy compared to the reference antibiotic, oxytetracycline (positive control). Notably, complex 6 displayed exceptional antibacterial activity against Streptococcus pyogenes, with a minimum inhibitory concentration (MIC) of 4 µg/mL, outperforming the control (MIC = 8 µg/mL). Complexes 1, 2, and 4 showed promising activity against Shigella flexneri, Klebsiella pneumoniae, and Streptococcus pyogenes, each with MIC values of 8 µg/mL. Conversely, the lowest activity (MIC = 512 µg/mL) was observed for complexes 3, 5, and 6 against Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae, respectively. Regarding antifungal properties, complexes 5 and 6 demonstrated the highest activity against Candida albicans, with MIC values of 8 µg/mL, equivalent to that of the positive control, fluconazole. Density functional theory (DFT) calculations confirmed an overall octahedral coordination geometry for all complexes, with tetragonal distortions identified in complexes 3, 4, and 5. Full article

This study enhanced the self-healing performance of cherry wood furniture coatings by incorporating chitosan gum arabic-coated tung oil (CGA-T) microcapsules (types 1 and 2) into UV topcoats at 3%–15% concentrations. Multi-layer coated samples were systematically evaluated for optical, mechanical, and self-healing properties. Results demonstrated that microcapsules conferred self-healing ability, but concentrations >9% reduced reflectance (min 39.20%), increased color difference (max ΔE = 8.35), decreased gloss (max 35.25% loss at 60°), and raised roughness (max 1.79 μm). Mechanically, impact resistance improved (to grade 3), while adhesion declined (to grade 3) and hardness decreased (4H→2H). Self-healing performance peaked at 9% microcapsule 2 content (31.32% healing rate), with optimal overall performance at 6%. The 6% microcapsule 2 formulation (Sample 7) achieved the best overall balance among optical, mechanical, and self-healing properties, demonstrating its suitability for practical applications. Full article

This study presents a photoresist-free patterning method for solution-processed indium zinc oxide (IZO) thin films using two photochemical exposure techniques, namely pulsed ultraviolet (UV) light and UV-ozone, and a plasma-based method using oxygen (O₂) plasma. Pulsed UV light delivers short, high-intensity flashes of light that induce localised photochemical reactions with minimal thermal damage, whereas UV-ozone enables smooth and uniform surface oxidation through continuous low-pressure UV irradiation combined with in situ ozone generation. By contrast, O₂ plasma generates ionised oxygen species via radio frequency (RF) discharge, allowing rapid surface activation, although surface damage may occur because of energetic ion bombardment. All three approaches enabled pattern formation without the use of conventional photolithography or chemical developers, and the UV-ozone method produced the most uniform and clearly defined patterns. The patterned IZO films were applied as active layers in bottom-gate top-contact thin-film transistors, all of which exhibited functional operation, with the UV-ozone-patterned devices exhibiting the most favourable electrical performance. This comparative study demonstrates the potential of photochemical and plasma-assisted approaches as eco-friendly and scalable strategies for next-generation IZO patterning in electronic device applications. Full article

Access to clean water is a pressing global concern and membrane technologies play a vital role in addressing this challenge. Thin-film composite membranes prepared via interfacial polymerization (IPol) using meta-phenylenediamine (MPD) and trimesoyl chloride (TMC) exhibit excellent separation performance, but face limitations such as fouling and low hydrophilicity. This study investigated the interaction between MPD and sulfonated zinc phthalocyanine, Zn(SO₂⁻)₄Pc, as a potential strategy for enhancing membrane properties. Using Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT), we analyzed the optimized geometries, electronic structures, UV–Vis absorption spectra, FT-IR vibrational spectra, and molecular electrostatic potentials of MPD, Zn(SO₂⁻)₄Pc, and their complexes. The results show that MPD/Zn(SO₂⁻)₄Pc exhibits reduced HOMO-LUMO energy gaps and enhanced charge delocalization, particularly in aqueous environments, indicating improved stability and reactivity. Spectroscopic features confirmed strong interactions via hydrogen bonding and π–π stacking, suggesting that Zn(SO₂⁻)₄Pc can act as a co-monomer or additive during IPol to improve polyamide membrane functionality. A conformational analysis of MPD/Zn(SO₂⁻)₄Pc was conducted using density functional theory (DFT) to evaluate the impact of dihedral rotation on molecular stability. The 120° conformation was identified as the most stable, due to favorable π–π interactions and intramolecular hydrogen bonding. These findings offer computational evidence for the design of high-performance membranes with enhanced antifouling, selectivity, and structural integrity for sustainable water treatment applications. Full article

This work investigates on how Fe incorporation influences the surface, microstructural, and optical properties of solution precursor plasma-sprayed TiO₂ coatings. The Fe-TiO₂ coatings were prepared using titanium isopropoxide and iron acetylacetonate as precursors, with ethanol as the solvent. X-ray diffraction analysis revealed the existence of both anatase and rutile TiO₂ phases, with a predominant rutile phase, also confirmed by Raman spectroscopy. There was an increase in the anatase crystals upon the addition of Fe ions. A longer spray distance further enhanced the anatase content and reduced the average TiO₂ crystallite sizes present in the Fe-added coatings. SEM cross-sectional images displayed finely grained, densely packed deposits in the Fe-added coatings. UV-Vis spectroscopy showed visible-light absorption by the Fe-TiO₂ coatings, with reduced band gap energies ranging from 2.846 ± 0.002 eV to 2.936 ± 0.003 eV. Photoluminescence analysis showed reduced emission intensity at 356 nm (3.48 eV) for the Fe-TiO₂ coatings. These findings confirm solution precursor plasma spray to be an effective method for developing Fe-TiO₂ coatings with potential application as visible-light-active photocatalysts. Full article

In this work, bio-based thermoelectric composites were developed using acrylated epoxidized soybean oil (AESO) as the polymer matrix and bismuth telluride (Bi₂Te₃) as the thermoelectric filler. The materials were formulated for both UV-curing and thermal-curing processes, with a focus on Digital Light Processing (DLP) 3D printing. Although UV curing proved ineffective at high filler concentrations due to the light opacity of Bi₂Te₃, thermal curing enabled the fabrication of stable, homogeneously dispersed composites. The samples were thoroughly characterized through rheology, FTIR, TGA, XRD, SEM, and density measurements. Thermoelectric performance was assessed under a 70 °C temperature gradient, with Seebeck coefficients reaching up to 51 µV/K. Accelerated chemical degradation studies in basic media confirmed the degradability of the matrix. The results demonstrate the feasibility of combining additive manufacturing with sustainable materials for low-power thermoelectric energy harvesting applications. Full article

This work presents the synthesis, characterization and evaluation of physicochemical and biological properties of two new aminoporphyrazine derivatives bearing magnesium(II) cations in their cores and peripheral pyrrolyl groups. The synthesis was carried out in several stages, using classical methods and the Microwave-Assisted Organic Synthesis (MAOS) approach. The obtained compounds were characterized using spectral techniques: UV-Vis spectrophotometry, mass spectrometry, ¹H and ¹³C NMR spectroscopy. The porphyrazine derivatives were tested for their electrochemical properties (CV and DPV), which revealed four redox processes, of which in compound 7 positive shifts of oxidation potentials were observed, resulting from the presence of free phenolic hydroxyl groups. In spectroelectrochemical measurements, changes in UV-Vis spectra associated with the formation of positive-charged states were noted. Photophysical studies revealed the presence of characteristic absorption Q and Soret bands, low fluorescence quantum yields and small Stokes shifts. The efficiency of singlet oxygen generation (Φ_Δ) was higher for compound 6 (up to 0.06), but compound 7, despite its lower efficiency (0.02), was distinguished by a better biological activity profile. Toxicity tests using the Aliivibrio fischeri bacteria indicated the lower toxicity of 7 compared to 6. The most promising result was the strong photodynamic activity of porphyrazine 7 against the Methicillin-resistant Stapylococcus aureus (MRSA) strain, leading to a more-than-5.6-log decrease in viable counts after the colony forming units (CFU) after light irradiation. Compound 6 did not show any significant antibacterial activity. The obtained data indicate that porphyrazine 7 is a promising candidate for applications in photodynamic therapy of bacterial infections. Full article

This review article focuses on the long-term durability challenges associated with bamboo fiber-reinforced polymer composites when subjected to various environmental aging conditions such as water immersion, hygrothermal fluctuations, ultraviolet (UV) radiation, soil burial, and refrigerated storage. The primary issue addressed is the degradation of mechanical and structural performance of bamboo fiber-reinforced polymer composites due to moisture absorption, fiber swelling, and fiber–matrix interface deterioration. To mitigate these aging effects, the study evaluates and compares multiple strategies, including chemical and physical fiber surface treatments, filler additions, and fiber hybridization, which aim to enhance moisture resistance and mechanical stability. These composites are relevant in automotive interiors, construction panels, building insulation, and consumer goods due to their eco-friendly nature and potential to replace conventional synthetic composites. This review is necessary to consolidate current knowledge, identify effective enhancement approaches, and guide the development of environmentally resilient bamboo fiber-reinforced polymer composites for real-world applications. Full article

TiO₂ was synthesized via the sol–gel method and employed as a support material for the deposition of CdS nanofibers using two novel techniques: impregnation and photodeposition. XRD characterization shows that crystallite size decreases when CdS is incorporated into TiO₂. UV-Vis spectroscopy showed that the bandgap of the CdS/TiO₂ heterostructured nanocomposites decreases compared to the raw TiO₂ support, making them very appropriate for photocatalytic applications in the visible region. The photocatalysts were tested for hydrogen production in methanol–water solutions under visible light conditions. It was observed that the TiC20 photocatalyst prepared by the impregnation method improved the photocatalytic activity compared with photodeposition technique (TiC20FD), achieving a maximum hydrogen production of 570.5 µmol H₂ ${\mathrm{g}}_{\mathrm{c}\mathrm{a}\mathrm{t}}^{-1}$ h⁻¹, while the latter attained 383.4 µmol H₂ ${\mathrm{g}}_{\mathrm{c}\mathrm{a}\mathrm{t}}^{-1}$ h⁻¹. Full article

This study explores the development and optimization of TiO₂-based photoactive coatings enhanced with silver (Ag)—to boost photocatalytic performance—for application on glass-fiber-reinforced polyester (GFRP) and epoxy (GFRE) composites. The influence of Ag content on the structural, physicochemical, and functional properties of the coatings was evaluated. The TiO₂-Ag coating showed the best performance and was tested under UV-A irradiation and visible light (Vis), with high efficiency in VOC degradation, self-cleaning, and microbial activity. The tests were repeated in multiple runs, showing high reproducibility in the results obtained. In GFRP, pollutant and microorganism removal ratios of more than 90% were observed. In contrast, GFRE showed a lower adhesion and stability of the coating. This result is attributed to incompatibility problems with the epoxy matrix, which significantly limited its functional performance. The results highlight the feasibility of using the TiO₂-Ag coating on GFRP substrates, even under visible light. Under real-world conditions for 351 days, the coating on GFRP maintained its stability. This type of material has high potential for application in modular building systems using sandwich panels, as well as in facades and automotive components, where self-cleaning and contaminant-control properties are essential. Full article