Search Results (14,729)

The discharge of synthetic dyes from industries poses severe environmental challenges, necessitating eco-friendly remediation strategies. This study investigated the biosorption of triarylmethane dyes Crystal Violet (CV), and Brilliant Green (BG) using self-immobilized and sponge-immobilized biosorbents of Trametes versicolor (strain CB8, CB8/S2) and Pleurotus ostreatus (strain BWPH, BWPH/S2). Tests were conducted with live and autoclaved biomass under varying conditions of dye concentration (100–400 mg/L), temperature (15–55 °C), and pH (2–10). Sponge-immobilized live biomass (CB8/S2 and BWPH/S2) showed superior performance, removing up to 90.3% and 81.7% of BG and 43.9% and 39.3% of CV, respectively, within 6 h, demonstrating 3–5 times higher efficiency than self-immobilized biomass for both dyes. Maximum sorption of 379.4 mg/g of BG and 48.9 mg/g of CV was achieved by CB8/S2 at 400 mg/L. Principal Component Analysis biplot confirmed immobilization efficacy, where Dim1 (85.9–91.8% variance) dominated dye concentration and contact time. The optimized conditions for BG removal by CB8/S2 was 20.85–32.17 °C and pH 3.4–6, and for CV, at pH 6.5–7.5 and 30 °C. The percentage of dye sorption data fitted well with the quadratic model (p < 0.05). Fourier transform infrared spectroscopy (FT-IR) analysis indicated that hydrogen bonding and electrostatic interactions facilitated dye binding onto fungal mycelium. Notably, sponge-immobilized biosorbents were reusable without additional treatment. The findings support fungal biomass immobilization as a viable strategy to augment the bioremediation potential in treating dye-laden wastewater. Full article

This study aimed to develop a novel biomaterial for neural tissue regeneration by combining chitosan (CS), a natural polymer, with graphene oxide (GO) at concentrations of 3%, 6%, and 9%. The homogeneity, conductivity, three-dimensional characteristics, and ability to support cell viability of the composite materials were systematically evaluated. Fourier-Transform Infrared (FTIR) spectroscopy confirmed the successful incorporation of GO into the CS matrix, while UV-Vis and photoluminescence (PL) spectrometry revealed modifications in the optical properties with increasing GO content. Thermogravimetric analysis (TG-DSC) demonstrated improved thermal stability of the composites, and swelling tests indicated enhanced water absorption capacity. Although some agglomerates were observed, the homogeneity was reasonable at both macroscopic and microscopic level (optical visualization–FTIR and electron microscopy). The composite films exhibited promising physical and electrochemical properties, highlighting their potential for neural tissue engineering applications. Their biological activity was assessed by culturing neuronal cells on the CS-GO scaffolds. Results from MTT, LDH, and LIVE/DEAD assays demonstrated excellent cell viability, moderate-to-good cell attachment, and the promotion of intercellular network formation. Among the tested formulations, the CS-GO 6% scaffold showed the most favorable biological response, with a significant increase in SH-SY5Y cell viability after 7 days (p < 0.05) compared to the CS control. LIVE/DEAD imaging confirmed enhanced cell attachment and elongated morphology, while the LDH assay indicated minimal cytotoxicity. Notably, a critical threshold was identified between 6% and 9% GO, where conductivity increased by approximately 52-fold. Future studies should focus on optimizing the composite parameters, loading them with specific biologically active agents and thus targeting specific neuronal applications. Full article

Continuous crystallizations have promising potential for effectively controlling and modifying the crystal properties of active pharmaceutical ingredients (APIs). In this study, a continuous antisolvent sonocrystallization process was developed to recrystallize a poorly water-soluble API, mefenamic acid, for microparticle production. This method offers advantages such as efficient sonication, enhanced heat removal, and potential for scalability. The effects of operating parameters, such as sonication intensity, crystallization temperature, antisolvent flow rate, and solution flow rate, were investigated and compared. Using continuous antisolvent sonocrystallization, the particle size of mefenamic acid was controlled within the range of 2.6–3.5 μm, achieving a narrower particle size distribution compared to the unprocessed sample. In addition, scanning electron microscopy (SEM) analysis confirmed that the sonocrystallized mefenamic acid exhibited an improved crystal shape. Analytical results from powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) showed that the crystal structure, spectroscopic characteristics, and thermal behavior of mefenamic acid remained unchanged after the sonocrystallization process. Full article

Drilling fluid losses into formation voids are among the major issues that lead to increases in the costs and nonproductive time of operations. Lost circulation materials have been widely used to stop or mitigate losses. In most cases, the size of the loss zone is not known, making conventional lost circulation materials unsuitable for plugging the loss zone. In this study, novel temperature-sensitive LCM (TS-LCM) particles composed of diglycidyl ether of bisphenol A (DGEBA) and 4,4′-diaminodiphenyl methane were prepared. It is a thermal-response shape-memory polymer. The molecular structure was analyzed by Fourier transform infrared spectroscopy. The glass transition temperature (T_g) was tested by Different scanning calorimetry (DSC). The shape-memory properties were evaluated by a bend-recovery test instrument. The expansion and mechanical properties of particles were investigated under high temperature and high pressure. Fracture sealing testing apparatus was used to evaluate sealing performance. The mechanism of sealing fracture was discussed. Research results indicated that the T_g of the TS-LCM was 70.24 °C. The shape fixation ratio was more than 99% at room temperature, and the shape recovery ratio was 100% above the T_g. The particle was flaky before activation. It expanded to a cube shape, and the thickness increased when activated. The rate of particle size increase for D90 was more than 60% under 120 °C and 20 MPa. The activated TS-LCM particles had high crush strength. The expansion of the TS-LCM particles could self-adaptively bridge and seal the fracture without knowing the width. The addition of TS-LCM particles could seal the tapered slot with entrance widths of 2 mm, 3 mm and 4 mm without changing the lost circulation material formulation. The developed TS-LCM has good compatibility with local saltwater-based drilling fluid. In field tests in the Yan’an area of the Ordos Basin, 15 shale oil horizontal wells were plugged with excellent results. The equivalent circulating density of drilling fluid leakage increased by an average of 0.35 g/cm³, and the success rate of plugging malignant leakage increased from 32% to 82.5%. The drilling cycle was shortened by an average of 14.3%, and the effect of enhancing the pressure-bearing capacity of the well wall was significant. The prepared TS-LCM could cure fluid loss in a fractured formation efficiently. It has good prospects for promotion. Full article

Clinical manifestations of salmonellosis in humans typically include acute gastroenteritis, abdominal pain, diarrhea, nausea, and fever. Diarrhea and anorexia may persist for several days. In some cases, the organisms may invade the intestinal mucosa and cause septicemia, even in the absence of significant gastrointestinal symptoms. Most clinical signs are attributed to hematogenous dissemination of the pathogen. As with other microbial infections, disease severity is influenced by the serotype of the organism, bacterial load, and host susceptibility. Serotyping analysis of Salmonella spp. using the White–Kauffmann–Le Minor scheme remains the gold standard for strain typing. However, this method is expensive, time-consuming, and requires significant expertise and visual interpretation by trained personnel, which is why it is typically restricted to regional or national reference laboratories. In this study, we evaluated a spectroscopic technique coupled with chemometrics and multivariate machine learning algorithms for its ability to discriminate the main Salmonella spp. serogroups in a clinical routine setting. We analyzed 95 isolates of Salmonella that were randomly selected, including four strains of S. Typhi. The I-dOne Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) system (Alifax S.r.l., Polverara, Italy) also shows promising potential for distinguishing Salmonella Typhi within the D serogroup. The I-dOne system enables simultaneous identification of both species and subspecies using the same workflow and instrumentation, thus streamlining the diagnostic process. Full article

Biological hydrogels are widely available in terms of raw material sources and can be processed and molded using relatively simple techniques. Hydrogels can offer abundant three-dimensional, water-containing channels that facilitate the reaction between gases and dye, making them the preferred choice for the solid support layer in colorimetric indicators. However, biomass hydrogels exhibit inferior mechanical properties, making them unsuitable for large-scale manufacturing processes. In this study, four dual-network composite hydrogels Agar/Gelatin, Sodium Alginate/Agar, Sodium Alginate/Poly (vinyl alcohol), Sodium Alginate/Gelatin (AG/Gel, SA/AG, SA/PVA and SA/Gel) prepared through hybrid strategies. Furthermore, the influence of the dual-network structure on the mechanical properties and ammonia response was systematically investigated, using microscopy and Fourier transform infrared spectroscopy (FTIR) characterization method. The experimental results demonstrate that the incorporation of SA into original hydrogel matrices can significantly enhance both the mechanical and ammonia response performance due to the secondary topological network structure. The interpenetrating double network structure was effectively regulated through the calcium ion cross-linking process. The color difference threshold of SA/PVA’s response to ammonia gas is 10, it holds promise for rapid detection applications. The SA/Gel composite hydrogel exhibits excellent mechanical robustness and toughness. The tensile strength of the SA/Gel sample is 11 times that of a single gel, and the toughness is 80 times greater, suggesting its suitability for large-scale manufacturing of colorimetric indicator. Full article

This study evaluates the drying kinetics of banana slices sliced at various infrared powers and measurable values, as well as the spectral and microstructural changes that some physical quality parameters present. Banana slices were dried at 300, 400, and 500 W (894, 1190 and 1410 W/m² infrared radiation intensity) medium wavelength infrared (MWIR). In addition, banana samples were sliced to be 6–8 and 10 mm. The drying processes were terminated when the samples reached approximately 30% moisture level. After drying, banana samples’ quality values, such as color, shrinkage, and water loss were evaluated. FT-NIR (Fourier Transform-Near Infrared) spectroscopy and microstructure measurements were performed. For banana slices dried at different powers with medium-wavelength infrared, the shortest drying time is for 6 mm thick products and can be operated in the range of 33–36 min⁻¹. When the color values were examined, it was determined that the lowest total color changes occurred at 500 W drying power. In shrinkage measurements, samples dried at 500 W power were observed at the highest frosting. In water loss analyses, statistically similar results were obtained at 500 W drying power for various thicknesses. While the microstructural configurations of sliced banana samples were observed to be smoother during drying, samples dried at 300 W power were detected in a tighter form during drying and they were combined more regularly at 500 W power. FT-NIR spectral measurements were again expressed independently of the reflection values due to the wide pore range in high-power infrared drying (500 W). Full article

This work presents the synthesis and application of magnetic Fe₃O₄ nanoparticles supported on baobab seed-derived biochar (Fe₃O₄/BSB) for removing Congo red (CR) dye from aqueous solutions through an oxidative process. The biochar support offered a porous structure with a surface area of 85.6 m²/g, facilitating uniform dispersion of Fe₃O₄ nanoparticles and efficient oxidative activity. Fourier-transform infrared (FT–IR) spectroscopy analysis confirmed surface fictionalization after Fe₃O₄ incorporation, while scanning electron microscopy (SEM) images revealed a rough, porous morphology with well-dispersed nanoparticles. Thermogravimetric analysis (TGA) demonstrated enhanced thermal stability, with Fe₃O₄/BSB retaining ~40% of its mass at 600 °C compared to ~15–20% for raw baobab seeds. Batch experiments indicated that operational factors such as pH, nanoparticles dosage, and initial dye concentration significantly affected removal efficiency. Optimal CR removal (94.2%) was achieved at pH 4, attributed to stronger electrostatic interactions, whereas efficiency declined from 94.1% to 82.8% as the initial dye concentration increased from 10 to 80 mg/L. Kinetic studies showed that the pseudo-second-order model accurately described the oxidative degradation process. Reusability tests confirmed good stability, with removal efficiency decreasing only from 92.6% to 80.7% after four consecutive cycles. Overall, Fe₃O₄/BSB proves to be a thermally stable, magnetically recoverable, and sustainable catalyst system for treating dye-contaminated wastewater. Full article

Pharmaceutical formulations, in addition to the medicinal substance(s), contain added excipients that make it possible to create a pharmaceutical product that exhibits required properties in terms of mechanical, physical, chemical, and microbiological stability. Additionally, these substances can act as release modifiers or improve bioavailability parameters. Literature data indicate that excipients, especially polymeric ones, can also affect the polymorphism of the active substance, resulting in drug bioavailability enhancement or reduction. This influence can be evaluated using thermal and spectroscopic methods. In the study, differential scanning calorimetry (DSC), vibrational spectroscopic studies (Fourier transform infrared spectroscopy, FTIR), Raman spectroscopy, and X-ray diffraction (XRD) assay of ibuprofen, naproxen, and naproxen sodium standards and pharmaceutical preparations containing these medicinal substances in their compositions were carried out. DSC results indicated that a sharp melting peak was observed on the DSC curves of the standards, confirming their crystalline form. DSC results obtained for pharmaceutical formulations also indicated that the enthalpy of melting is sometimes lower than calculated from the percentage of active ingredients in the formulations. In addition, the melting peak is often broadened and shifted toward lower temperatures, suggesting the influence of excipients on the polymorphism of drug substances. The FTIR and Raman spectra of pharmaceutical formulations contained all characteristics of the active substances. XRD analysis was also performed. Therefore, possible chemical interactions between the components of the preparations have been excluded. At the same time, FTIR and Raman spectroscopy results as well as XRD assay showed a reduction in the height of signals corresponding to the crystalline API form, confirming the possibility of reducing API crystallinity in pharmaceutical formulations. Full article

To achieve efficient desilication and improve the grade of magnesite, an environmentally friendly surfactant, cocamidopropyl dimethylamine (PKO-H), was employed as a collector for the flotation separation of magnesite and quartz. The flotation performance and adsorption mechanism of PKO-H was systematically investigated through flotation experiments, Fourier-transform infrared spectroscopy (FTIR), contact angle measurements, zeta potential analysis, and molecular simulations. The flotation results demonstrated that PKO-H exhibited excellent selectivity, achieving a MgO recovery rate of 98.8% and a concentrate grade of 45.7% in artificially mixed mineral samples. Contact angle measurements, FTIR spectra, zeta potential analysis, and molecular simulations revealed that the adsorption of PKO-H on quartz is primarily driven by electrostatic attraction. In contrast, due to electrostatic repulsion, the interaction between PKO-H and magnesite is weak, preventing stable adsorption. This study establishes PKO-H as a sustainable and efficient collector for magnesite beneficiation and provides new insights into interfacial mechanisms for the design of eco-friendly flotation reagents. Full article

Hybrid thermosetting terpolymers based on epoxidized linseed oil (ELO), eugenol-based benzoxazine monomer (EPB), and thiols (2SH and 3SH) were synthesized and studied by focusing on the effects of the thiol-bearing functionality over the final performances. The curing dynamics were monitored by differential scanning calorimetry (DSC) and Fourier transform infrared spectrometry (FTIR). FTIR results showed that the curing process takes place in multiple steps and depends on the concentration of thiol used as a crosslinker. At the same time, the complexity of the reactions that take place within each system was highlighted by the curing profiles from DSC. Dynamic mechanical analysis (DMA) and nanoindentation data revealed that the mechanical features of the terpolymers can be modulated to achieve high stiffness, as in the case where 2SH and 3SH thiols were used in 0.25 wt.% or increased flexibility where 1% thiol concentrations were employed. Higher crosslinking density for hybrid terpolymers in comparison with the epoxy/benzoxazine sample indicated a good compatibility between the monomers and the crosslinking agents and the formation of additional chemical bonds within the networks. The ternary samples demonstrated good thermal stability (up to 300 °C) and high residual mass (>25%), which make them suitable candidates as flame-resistant coatings. Full article

This study presents a plant-fabricated nanoparticle system of zirconia (ZrO₂) using Sonchus asper plant extract, compared with conventionally synthesized ZrO_2, for their efficacy in Cr(VI) removal from aqueous solutions. The nanoparticles were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) for elemental composition, Fourier-transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analysis. The plant-fabricated ZrO₂ exhibited mesoporosity and enhanced surface functionality, attributed to bioactive compounds from Sonchus asper, which improved adsorption performance via increased surface area and residual organic functional groups. Batch adsorption experiments showed that Cr(VI) removal was optimized at 100 mg/L Cr(VI), 300 mg/L adsorbent dosage, pH 5, and 30 min reaction time at 25 °C. Adsorption followed the Langmuir isotherm and pseudo-second-order kinetics models. According to Langmuir model fitting, the maximum adsorption capacity (qmax) reached 142.24 mg/g for PF-ZrO₂ NPs and 133.11 mg/g for conventional ZrO₂ NPs, indicating the superior adsorption performance of the green-synthesized material. This work highlights the sustainable potential of plant-fabricated ZrO₂ nanoparticles as cost-effective and environmentally friendly nano-adsorbents for heavy metal remediation, contributing to the achievement of UN SDG No. 6 by providing clean water solutions. Full article

This study presents a comprehensive investigation of a novel graphene oxide/zinc oxide/lignin (GO/ZnO/lignin) nanocomposite for the photocatalytic degradation of methylene blue (MB) and gentian violet (also known as crystal violet, CV) dyes in aqueous solutions. The nanocomposite was synthesized through a hydrothermal method and thoroughly characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). FTIR spectra confirmed the successful incorporation of functional groups from all components, while XRD patterns revealed a well-crystallized structure with characteristic peaks. SEM micrographs showed a uniform, hierarchical morphology and EDX analysis verified the elemental composition and distribution. Under ultraviolet (UV) irradiation, the nanocomposite exhibited remarkable photocatalytic degradation efficiency (~97%) for both MB and CV. Key operational parameters were systematically evaluated, including pH (2–10), catalyst dosage (0.005–0.04 g/20 mL), and initial dye concentration (10–20 ppm). Optimal performance was achieved at pH 10, with a catalyst dosage of 0.03–0.04 g/20 mL and lower dye concentrations. The enhanced photocatalytic activity can be attributed to the synergistic effects coming from GO’s electron transport capabilities, ZnO’s strong photocatalytic activity and lignin’s additional degradation sites. Furthermore, the nanocomposite demonstrated excellent reusability, retaining nearly 60% of its degradation capacity after four cycles, outperforming its individual components. These results highlight the potential of this composite material for sustainable wastewater treatment applications. Full article

Background: The addition of chlorhexidine in dental restorative materials is a promising strategy to reduce the recurrence of tooth decay lesions. However, the main challenge is to develop materials with antimicrobial activity in the long term. Objective: This study analyses the effect of filler type and concentration of resin composites supplemented with chlorhexidine loaded in carrier montmorillonite particles (MMT/CHX) regarding their chemical, physical, and short- and long-term antimicrobial proprieties. Materials: Experimental composites were synthesized with 0, 30, or 60% filler in two ratios, 70/30 and 80/20, of barium glass/colloidal silica, respectively, and 5 wt% MMT/CHX. Conversion was measured using near Fourier-transform infrared spectrometry. Sorption and solubility were determined by specimen weight before and after drying and immersing in water. Flexural strength (FS) and elastic modulus (E) were determined by three bending tests using a universal test machine. Chlorhexidine release was monitored for 50 days. Streptococcus mutans UA159 was used in all microbiological assays. Inhibition halo assay was performed for 12 months and, also, biofilm growth for the specimens and colony-forming unit (CFU). Remineralization assay was used on restored teeth using measurements of microhardness Knoop and CFUs. Results: Conversion, sorption, and solubility were not affected by filler type and concentration. FS and E increase with the filler concentration, independent from filler type. Chlorhexidine was significantly released for 15 days for all experimental materials, and the increase in filler concentration decreased its release. Halo inhibition was observed for a longer time (12 months) in materials with 60 wt% filler at 70/30 proportion. Also, 60 wt% filler materials, independent from the filler ratio, reduced the CFU in relation to the control group from 8 to 12 months. In the remineralization assay, besides the absence of differences in hardness among the groups, after biofilm growth, the CFU was also significantly lower in materials with 60 wt% filler. Conclusions: Materials with 60% filler, preferentially with 70% barium glass and 30% silica, and 5% MMT/CHX particles demonstrated long-term antimicrobial activity, reaching 12 months of effectiveness. Also, this formulation was associated with higher mechanical properties and similar conversion, sorption, and solubility compared to the other materials. Full article

The civil construction and infrastructure sectors are known for their high environmental impact. Most of this impact is related to the carbon dioxide (CO₂) emissions from Portland cement. As a sustainable alternative, alkali-activated binders (AABs) are explored for their potential to replace traditional binders. This research focused on AAB formulations using steel industry byproducts, such as Baosteel’s slag short flow (BSSF), coke oven ash (CA), blast furnace sludge (BFS), and centrifuge sludge (CS), as well as fly ash (FA) from a thermoelectric plant. Byproducts were characterized through laser granulometry, Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM), followed by the formulation of AABs with different precursor ratios. After 28 days, the compressive strength was obtained for each formulation. Based on the compressive strength tests, two binary mixtures were selected for microstructural and chemical analyses through XRF, FTIR, and SEM. CA demonstrated the greatest potential for use in binary AABs based on BSSF, as it presented a higher source of aluminosilicates and smaller particle sizes. The formulations containing BSSF and CA achieved compressive strengths of up to 9.8 MPa, while the formulations with BSSF and FA reached 23.5 MPa. SEM images revealed a denser, more cohesive matrix in the FA-based AAB, whereas CA-based AABs showed incomplete precursor dissolution and higher porosity, which contributed to the lower mechanical strength of CA-based AABs. These findings highlight the critical role of precursor selection in developing sustainable AABs from industrial byproducts and demonstrate how different formulations can be tailored for specific applications. Full article