Search Results (6,257)

Green nanotechnology offers a sustainable and eco-friendly approach for nanoframework synthesis. The present study intended to synthesize a novel eco-friendly encapsulated Zeolitic Imidazolate Framework-8 (ZIF-8) in a one-pot method using metabolites from the mangrove plant Conocarpus erectus (CE). Gas Chromatography–Mass Spectrometry (GC-MS) analysis of the extract revealed the presence of important bioactive metabolites. The synthesized material was evaluated by UV-Vis spectroscopy, X-ray diffraction (XRD), particle size analysis (PSA), zeta potential measurement, high-resolution transmission electron microscopy (HR-TEM), and Fourier transform infrared (FT-IR) spectroscopy studies. The environment-friendly mangrove metabolites aided by Zeolitic Imidazolate Framework-8 was found to be crystalline, rhombic dodecahedron structured, and size dispersed without agglomeration. The nanomaterial possessed a broad antimicrobial effect on drug-resistant microorganisms, including Candida krusei, Escherichia coli, Streptococcus Sp., Staphylococcus aureus, Enterococcus Sp., Pseudomonas aeruginosa, Klebsiella pneumoniae, C. propicalis, and C. albicans. Further, its cytotoxicity against MDA-MB-231 cells was found to be efficient. The morphological alterations exhibited by the antiproliferative impact on the breast cancer cell line were detected using DAPI and AO/EB staining. Therefore, ZIF-8 encapsulated mangrove metabolites could serve as an effective biomaterial with biomedical properties in the future. Full article

Background: Epigallocatechin-3-gallate (EGCG), a potent green tea polyphenol, possesses significant therapeutic potential, but its clinical application is limited by poor gastrointestinal stability and low oral bioavailability. To address this, a novel herbal nanomedicine-based delivery system was developed utilizing D-α-tocopheryl polyethylene glycol succinate (TPGS) and Poloxamer 407. Objectives: This study aims to develop and characterize EGCG-loaded TPGS/Poloxamer 407 micelles, evaluating their physicochemical properties, storage stability, in vitro drug release profile, in vivo oral bioavailability, and preliminary tolerability observation. Methods: The micelles were prepared using the film hydration method followed by lyophilization. Results: The optimized 2:2 TPGS-to-poloxamer 407 weight ratio yielded EGCG-loaded micelles, displaying a mean particle size of 15.4 nm, a polydispersity index (PDI) of 0.16, a zeta potential of −17.7 mV, an encapsulation efficiency of 82.7%, and a drug loading capacity of 7.6%. The critical micelle concentration (CMC) was determined to be 0.00125% w/v. Transmission electron microscopy (TEM) confirmed the micelles’ uniform spherical morphology. In vitro release studies demonstrated a sustained release profile in both simulated gastric and intestinal fluids. EGCG formulation remained stable for at least six months when stored at 4 °C. No adverse clinical signs were noted during the 28-day tolerability observation. In vivo pharmacokinetic evaluation in mice revealed a significant elevation in oral bioavailability, achieving a 2.27-fold increase in area under the curve (AUC) and a 1.8-fold increase in peak plasma concentration (Cmax) compared to free EGCG. Conclusions: Collectively, these findings underscore the potential of the TPGS/poloxamer 407-based micelle system as a promising oral delivery platform for EGCG, enhancing its stability and pharmacokinetic performance. Full article

A tiered approach is presented for evaluating occupational risks during liquid deposition modelling (LDM) using ceramic materials for manufacturing complex geometries in construction. The ceramic paste is comprised of kaolin/zeolite powders mixed with deionised water at a specific ratio. The tiered occupational risk analysis covered (i) the material evaluation and information gathering, (ii) on-site exposure measurements to ultrafine and micro-size particles, and (iii) morphological and toxicological analyses of raw and collected air samples. Results indicated an increase in PM4 (particle diameter < 4 μm) concentrations during powder preparation, reaching up to 1 mg/m³ during powder preparation, although below the corresponding substance-specific and general dust occupational exposure limit and with no increased exposure to ultrafine particles, as supported by morphological analysis. In toxicity assessment, reactive oxygen species production (ROS) reached approximately 300% for 50 μg/mL raw kaolin powder, while inducing high upregulation of TNF-α and IL-6 mRNA expression genes, indicating activation of pro-inflammatory pathways. Airborne samples resulted in cell viability reduction by ~50% at 40 μg/mL, showing significance (p-value < 0.001). Translating these findings to human risk remains difficult, yet the findings highlight an urgent requirement for continuous exposure surveillance, tailored toxicity evaluations, and robust protective strategies throughout ceramic manufacturing. Full article

Field emission scanning electron microscopy (FE-SEM) may be used to visualize the surface morphology of samples that are permeable to electron beams, including biological samples. Probiotics attenuate host physiological functions and are characterized by their three-dimensional surface structures. In this study, we determined the effect of critical point drying (CPD) on FE-SEM observations of the surface of Lacticaseibacillus paracasei strain Shirota (LcS). We also assessed ionic liquid (IL), a non-volatile liquid salt that retains moisture, and NanoSuit^®, which forms a protective polymer membrane around the sample, through FE-SEM observation of these probiotics. The results indicate that dehydration during CPD leads to reticular structures on the probiotic surface, potentially affecting the characteristics observed by FE-SEM. In addition, we examined IL and NanoSuit^®, which do not involve dehydration. The initial examination involving optimal dilution using silica particles revealed that 5–10% IL and 5–20% NanoSuit^® solutions maintained particle size consistency. We examined LcS specimens under these conditions and observed smooth surfaces, not reticulate structures. These results indicate that CPD affects LcS surface morphology, whereas the IL and NanoSuit^® methods preserved it. This suggests their applicability for probiotic preparation before FE-SEM observations. Full article

Allyl isothiocyanate (AITC) has been shown to enhance perceived saltiness in food products; however, it is also associated with a pungent and spicy flavour. The objective of this study was to assess the encapsulation of AITC with maltodextrin (MD) and gum Arabic (GA) using spray-drying (SD) and freeze-drying (FD) techniques, with and without the addition of a surfactant. Furthermore, the different encapsulated formulations were evaluated for their impact on sensory properties when added to soups. In total, twelve different treatments were investigated. The physicochemical characteristics (i.e., encapsulation efficiency, surface oil content, capsule morphology, and moisture content) and sensory properties (i.e., hedonic scales and rate-all-that-apply) of the encapsulated AITC particles were analyzed. Gas chromatography revealed low AITC retention in all FD formulations, while SD formulations with surfactants achieved up to 136.71 mg AITC/g powder. Sensory trials were conducted on eight formulations added to tomato soup (0.500 mg AITC/100 mL) (SD trial: n = 79, and FD trial: n = 93). FD resulted in relatively low AITC retention (with and without surfactants), while SD with surfactants led to higher AITC retention. None of the formulations significantly impacted the saltiness perception of the soups. FD soups significantly enhanced thickness, creaminess, and tomato flavour, increasing overall liking. This is the first study to evaluate the sensory properties and cross-modal interactions of encapsulated AITC. Further studies are needed to continue exploring the sensory properties, its release behaviour, overall stability, and shelf life of encapsulated AITC. Full article

The heterostructures TiOF₂/(0.5–5 wt.%)MnO(OH) attract attention as potential catalysts for pollutant removal from water. In this paper, a novel synthesis route was proposed through the precipitation of MnO(OH) particles out of an alkaline solution on the TiOF₂ particles. The formation of manganese oxyhydroxide was confirmed by X-ray diffraction analysis. The presence of manganese in proportions up to 1 wt.% recalculated to MnO(OH) did not affect the morphology of TiOF₂/MnO(OH) particles. Higher concentrations of Mn caused the appearance of mostly spherical particles of dimensions ca. 100 nm. The effect of calcination temperatures 300–600 °C on the structure and photocatalytic activity of the particles was analyzed. It was found that calcination of the powder formed TiO₂ phase with mainly anatase structure as well as Mn₃O₄. After calcination at 600 °C, the appearance of fluorine was detected, indicating the formation of fluorinated titanium dioxide. For higher manganese concentrations, the fluorine proportion in F-TiO₂ samples decreased. Increased Mn content in TiOF₂/MnO(OH) significantly improved its photocatalytic activity, shortening the degradation time and increasing the degradation degree of methylene blue (MB). However, an increase in the calcination temperature decreased the degradation degree of MB. It was found that the optimal concentration of MnO(OH) was 5 wt.%. Full article

Green synthesis methods of silver nanoparticles have gained great attention because they offer sustainable, eco-friendly, and less-toxic alternatives to traditional methods. This study sheds light on the green synthesis of chitosan silver nanoparticle composites, providing a comparative evaluation of microwave-assisted (M1) and a one-pot (M2) reduction methods. The morphological, crystallinity, and structural uniformity characteristics were evaluated by UV-Visible, Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) with employing image processing pipeline based on deep learning model for segmentation and particles size estimation. The UV-visible spectrum exhibited independent SPR peaks ranging from 400 to 450 nm for all samples; however, microwave assisted-synthesis possessed narrower and more intense peaks indicative of better crystallinity and mono-dispersity. SEM depicted smaller, more uniformly dispersed particles for microwave-assisted (M1), while deep learning segmentation showed lower particle size variability (σ ≈ 24–43 nm), compared to polydisperse (σ ≈ 16–59 nm) in M2 samples. XRD showed crystalline face-centered cubic (FCC) silver with dominant peaks in M1 samples, whereas M2 had broader, less intense peaks with amorphous features. Raman vibrations revealed more structural order and homogenous capping in M1 than M2. Therefore, microwave-assisted (M1) showed better control on nucleation, particle size, crystallinity, and homogeneity due to a faster and uniform energy distribution. The future research would focus on the antimicrobial evaluation of such nanoparticles in agronomy. Full article

The cutting process is accompanied by complex electrical phenomena, which are particularly evident in narrow cutting clearances. To further explore the laws of electrical phenomena in the capillary of the cutting zone, this paper uses a Faraday collector with an external bias electric field to investigate the electrical phenomena in the narrow slit of the cutting zone under different cutting parameters and when different tool and workpiece materials are combined. The results show that there is a stable and continuous electrical phenomenon in the cutting contact area, and the emission intensity of charged particles when cutting insulating materials is significantly higher than that of metals. The emission intensity of negative ions is higher than that of positive ions. The electrical and mechanical properties of materials have a significant impact on the electrical phenomena in the cutting zone. In addition, it was found that there is a linear relationship between the electrical phenomena in the cutting zone and the cutting parameters. Finally, based on the morphology of the capillaries in the cutting zone, the self-excited electric field intensity generated in it during the cutting process was estimated. Full article

With the increasing demand for energy conservation and emission reduction in the automotive industry, optimizing the performance of cylinder liner and piston ring pairs in engines has become crucial. Aluminum–silicon alloy cylinder liners, known for their lightweight and excellent thermal conductivity, have emerged as a new trend in cylinder liner materials. Given the relatively moderate hardness of Al-Si alloys, judicious selection of piston rings is imperative to ensure optimal performance. This study investigates the tribological properties of aluminum–silicon alloy cylinder liners paired with CKS and DLC piston rings. The surface morphology and hardness of the test materials were characterized, and reciprocating friction and wear tests were conducted, using a tribometer to simulate operating conditions. The friction coefficient and wear volume were used as indicators to evaluate the tribological properties of the piston rings. The results show that, when the aluminum–silicon alloy cylinder liner was paired with a DLC piston ring, the friction coefficient was 27.82% lower, and the wear volume of the cylinder liner was 83.52% lower, compared to pairing with a CKS piston ring. When paired with a CKS piston ring, wear was exacerbated because silicon particles were easily dislodged to form abrasive particles. This particle detachment is mainly caused by the collision between the fine ceramic particles embedded in the CKS coating and the silicon particles (≤5 μm) uniformly distributed in the Al-Si alloy cylinder liner during the sliding process. The DLC piston ring, containing both sp² and sp³ hybridized carbon–carbon bonds, combined excellent lubrication properties with high hardness, resulting in minimal wear on both the cylinder liner and piston ring. Specifically, the DLC coating has a hardness of 2300 HV_0.3, which is 2.42 times that of the CKS piston ring (950 HV_0.3); the sp³-hybridized carbon in the DLC coating enhances its wear resistance to resist scratching from silicon particles in the cylinder liner, while the sp²-hybridized carbon forms a graphite-like transfer layer at the friction interface to reduce frictional resistance. In conclusion, the aluminum–silicon alloy cylinder liner paired with a DLC piston ring exhibits superior tribological properties. Selecting an appropriate piston ring can significantly enhance the tribological properties of the cylinder liner–piston ring pair, thereby extending the engine’s service life. Full article

Particles travelling within and interacting with any fluid media are found in both natural phenomena and industrial processes. Through these interactions, the particles experience a drag force, heavily influenced by their morphology, and significantly affecting their dynamics. This study examines the relationship between particle morphology and the drag force exerted on them, using both empirical models and computational simulations. The findings indicate that for regular and irregular particles of diverse morphologies, a combination of existing empirical models can predict the drag force within a 40% error margin. However, these models may fall short of meeting the accuracy demands in certain applications. To address this, the study provides clear guidelines for selecting the most suitable drag model based on particle morphology and flow regime. Full article

In salt lake KCl cold decomposition–direct flotation for K-Na separation, octadecylamine hydrochloride (ODA-H) acts as a collector, reducing product purity and limiting high-end applications of salt lake KCl. To study KCl purification mechanisms and optimize crystal properties, this study investigates ODA-H aqueous systems. By regulating the cooling rate, stirring rate, and ODA-H concentration, the crystallization purification of KCl and precise control of its morphology were achieved, ultimately yielding three typical crystal morphologies: cubic, spherical, and ellipsoidal. Of the three crystal morphologies, spherical crystals have the best flowability but lowest purity. Ellipsoidal crystals have better flowability than cubic ones: their purity exceeds that of cubic crystals before washing but falls below it after washing. Cubic crystals, with poorer flowability, reach the highest purity post-washing. This study provides a theoretical basis for enhancing purity via crystal morphology regulation and industrial-scale purification of salt lake KCl. Full article

The widespread and excessive use of plastic in our daily life has led to serious microplastic pollution in the atmosphere, water, and soil. These microplastics can enter freshwater systems and pose significant risks to the ecosystem and human health via the food chain. This environmental problem deserves proper investigation and mitigation strategies. In this study, the abundance, morphology, color, size and polymer composition of microplastics in surface water of Feiyun River Basin were systematically studied by means of field sampling, microscopy and laser micro-Raman spectroscopy. The result showed that microplastic abundance ranged from 3.7 to 36.4 items/L, with an average of 11.0 ± 2.39 items/L. These microplastics were mainly particles, followed by fragments and fibers, with white, black, and blue being the most common colors. Most of the particles were smaller than 0.1 mm (57%), and a laser micro-Raman spectrometer was used to identify the polymer types of the microplastics. The results showed that the main polymer types identified were PET, PP, and PS. Risk assessment based on PLI, PHI, and PERI indices indicated a low ecological risk of microplastics in the study area. These findings provide further insight into the sources and distribution of microplastics in local watersheds and support future assessments of riverine transport of microplastics to estuarine and marine environments. Full article

This study investigated the production and characterization of avocado oil emulsions generated with a three-fluid nozzle (3FN) and the physicochemical and thermodynamic properties of the resulting microcapsules obtained by spray drying. The emulsions showed a bimodal size distribution with a main peak at 0.893 µm and PDI values below 0.70 indicate a mid-range polydispersity. Despite their shear-thinning behavior, emulsions exhibited limited stability, as indicated by ζ-potential (−23.9 mV) and increasing TSI values. Spray drying with 3FN achieved a yield of 71.7% and an encapsulation efficiency of 57.8%, with moisture content below 4%, meeting commercial requirements. The microcapsules displayed unimodal particle distributions (D[3,2] = 8.38 µm; D[4,3] = 11.14 µm) and irregular spherical morphologies with surface folds and roughness. Adsorption isotherms followed a type II pattern, well described by the GAB model, with monolayer moisture content (0.043–0.060 g H₂O/g solids) defining critical stability conditions. Thermodynamic analyses identified a “minimum entropy zone” corresponding to enhanced structural stability, while glass transition data confirmed that encapsulated oil did not act as a plasticizer. Overall, the use of a three-fluid nozzle enabled the development of avocado oil microcapsules with favorable physical and thermal attributes, supporting their potential for long-term stability in functional food applications. Full article

Lithium-ion batteries (LIBs) are vital for modern energy storage applications. Lithium iron phosphate (LFP) is a promising cathode material due to its safety, low cost, and environmental friendliness compared to the widely used nickel manganese cobalt oxide (NMC), which contains hazardous nickel and cobalt compounds. However, challenges remain in enhancing the performance of LFP cathodes due to their low electronic and ionic conductivity. To improve both the safety and sustainability of the battery, this work presents a water-based LFP cathode utilizing the bio-based binder carboxymethyl cellulose (CMC), eliminating the need for polyvinylidene fluoride (PVDF) and the toxic solvent N-methyl-2-pyrrolidone (NMP). This study investigates the impact of different dispersing methods—dissolver mixing and wet jet milling—on slurry properties, electrode morphology, and battery performance. Slurries were characterized by rheology, particle size distribution, and sedimentation behavior, while coated and calendered electrodes were examined via thickness measurements and scanning electron microscopy (SEM). Electrochemical performance of the electrodes was evaluated by means of C-Rate testing. The results reveal that dispersing methods significantly influence slurry characteristics but marginally affect electrochemical performance. Compared to dissolver mixing, wet jet milling reduced the median particle size by 39% (ΔD50 = 3.1 µm) and lowered viscosity by 96% at 1 s⁻¹, 80% at 105 s⁻¹, and 64% at 1000 s⁻¹. In contrast, the electrochemical performance of the resulting electrodes differed only slightly, with discharge capacity varying by approximately 12.8% at 1.0 C (Δcapacity = 10.7 mAh g⁻¹). This research highlights the importance of optimizing not only material selection but also processing techniques to advance safer and more sustainable energy storage solutions. Full article

In the present study, aluminum matrix composites (AMCs) were fabricated by friction stir processing (FSP) using Ni-Cu particles. Ni-Cu particles were added to the Al matrix in two ways. First, without any treatment and in the form of a mixture of as-received powders. Second, treated through mechanical alloying to form Monel solid-solution particles. The particles were added to a groove to be processed by the FSP tool to produce a local AMC. To investigate the kinetics of intermetallic compounds (IMCs) growth in reinforcement particles, the produced AMCs were annealed at 500 °C for 2 h. To characterize the reinforcing particles, several analyses were performed on the samples. Field-emission scanning electron microscopy (FE-SEM) was used to study the size, morphology, and IMC thickness. TEM was performed to characterize the IMCs through high-resolution chemical analyses. Tensile testing was used to understand the mechanical properties and fracture behavior of AMCs. Tensile testing revealed a noticeable improvement in strength for the as-mixed sample, with a UTS of 90.3 MPa, approximately 22% higher than that of the base aluminum. In contrast, the mechanical alloying sample with annealing heat treatment exhibited a severe drop in ductility, with elongation decreasing from 17.98% in the as-mixed sample to 1.52%. The results showed that heat treatment thickened the IMC layer around the reinforcing particles formed during the FSP process with as-mixed particles. In the AMC reinforced with mechanically alloyed Ni-Cu powders, IMC formation during FSP was significantly suppressed compared to that of as-mixed particles, despite the finer size resulting from milling. Additionally, the heat treatment resulted in only a slight increase in IMC thickness. The IMC layer thickness after heat treatment in both the mechanically alloyed sample and the as-mixed sample was approximately 2 µm and 20–40 µm, respectively. The reason behind this difference and its effect on the fracture behavior of the composite were elaborated in this study, giving insights into metal-matrix production with controlled reaction. Full article