Search Results (4,674)

The treatment of olive mill wastewater (OMW) remains a major environmental challenge due to its high organic load and phenolic content. This study investigates a combined approach using lime pretreatment and limestone (LS)-based adsorption for cost-effective and sustainable OMW remediation. Locally sourced limestone was used in both micro- and nanoscale forms, while lime (CaO) was produced by calcination. The materials were characterized using X-ray Diffraction pattern (XRD), Scanning Electron Microscopy (SEM), Brunauer–Emmett–Teller (BET), and Point of Zero Charge (pH_PZC) analyses to evaluate surface properties relevant to adsorption. Lime pretreatment achieved notable reductions in total suspended solids (TSS, 99%), chemical oxygen demand (COD, 43%), and total phenolic content (TPC, 48%). Subsequent adsorption with nano-limestone (particles obtained through high-energy ball milling, followed by sieving, with a size distribution 400–500 nm) further enhanced pollutant removal, achieving up to 72% COD and 89% TPC reduction in batch experiments. Column studies confirmed the synergistic effect of mixed particle sizes, yielding 65% COD and 76% TPC removal. The combined process demonstrates the potential of lime–limestone composites as locally available and eco-friendly materials for OMW treatment. While promising, the results represent laboratory-scale findings; further optimization and long-term assessments are recommended for field applications. 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

Titanium alloys are widely used in orthopedic and dental implants, yet their limited bioactivity and bacterial resistance remain critical challenges. This study aimed to enhance the surface performance of a Ti-13Zr-13Nb alloy through the formation of a porous oxide layer and the application of a bioactive, drug-loaded coating. Porous oxide layers composed of Ti, Zr, and Nb oxides with fluoride incorporation were fabricated using a novel anodizing process. The fluoride-assisted electrochemical mechanism controlling oxide growth was elucidated through SEM and EDS analyses. The anodized surface exhibited reduced microhardness, beneficial for minimizing stress-shielding effects. Subsequently, chitosan–tetracycline composite coatings were produced via EPD and compared with dip-coating method. Characterization by ATR-FTIR, optical microscopy, SEM, and UV-VIS spectroscopy confirmed the formation of uniform, adherent, and moderately porous coatings with sustained drug release when produced by EPD, while dip-coated layers were less homogeneous and released the drug faster. Microhardness testing revealed improved mechanical integrity of EPD coatings. The developed chitosan–tetracycline–oxide layer system provides tunable nano/microgram-scale drug release and enhanced surface functionality, offering promising perspectives for acute and medium-term regenerative and antibacterial biomedical applications. Full article

Today, the engineering of load-bearing bone tissue after severe trauma still relies on metal-based (Ti, CoCrMo alloys or stainless steel) permanent implants. Such artificial scaffolds are typically applied in the body and come into direct contact with the recipient’s cells, whose adhesion affects the patient’s implant acceptance or rejection. The present study aims to create a nano-rough texture by means of ultra-short femtosecond laser (fs)-induced periodicity in the form of laser induced periodic surface structures (LIPSS) on the surface of a stainless steel implant model, which is additionally functionalized via magnetron-sputtering with a thin Cu layer, thus providing the as-created implants with a stable antimicrobial interface. Calcium phosphate (CaP) crystal growth was additionally applied due to the strong bioactive interface bond that CaPs provide to the bone connective tissue, as well as for the strong interface bond they create between the artificial implant and the surrounding bone tissue, thereby stabilizing the implanted structure within the body. The bioactive properties in the as-created antimicrobial hybrid topographical design, achieved through femtosecond laser-induced nanoscale surface structuring and micro-sized CaP crystal growth, have the potential for subsequent practical applications in bone tissue engineering. Full article

The advent of nanotechnology has revolutionized the field of medicine, particularly in the development of targeted therapeutic strategies. Among these, radiolabeled nanomaterials have emerged as promising tools for both diagnostic and therapeutic applications, offering precise delivery of radiation to diseased tissues while minimizing damage to healthy ones. Notably, Lutetium-177 (¹⁷⁷Lu) has gained significant attention due to its favorable emission properties and availability that render it suitable for imaging and therapeutic purposes. When integrated with magnetic nano-formulations, ¹⁷⁷Lu-labeled systems combine the benefits of targeted radiation therapy (TRT) with the unique properties of magnetic nanoparticles (MNPs), such as magnetic resonance imaging (MRI) contrast enhancement and magnetically guided drug delivery to address challenges in diagnosis and treatment of diseases, such as cancer. By examining the latest advancements in their design, particularly surface functionalization and bioconjugation strategies, this study aims to highlight their efficacy in targeted therapy, imaging, and theranostic applications. Furthermore, we discuss the current challenges, such as scalability, biocompatibility, and regulatory hurdles, while proposing future directions to enhance their clinical translation. This comprehensive review underscores the transformative potential of ¹⁷⁷Lu-labeled magnetic nano-formulations in precision medicine and their role in shaping the future of therapeutic interventions. Full article

The pursuit of advanced energy technologies has intensified the focus on innovative functional materials. Low-melting-point liquid metals (LMs), particularly Ga-based alloys, have emerged as a promising platform due to their unique combination of metallic conductivity, fluidity, and biocompatibility. Nanoscaling LMs to create nano-liquid metals (nano-LMs) further unlocks extraordinary properties, including electrical duality, enhanced surface reactivity, tunable plasmonics, and remarkable deformability, surpassing the limitations of their bulk counterparts. This review provides a comprehensive overview of the recent progress in nano-LM-based energy technology. We begin by delineating the fundamental properties of LMs and the novel characteristics imparted at the nanoscale. Subsequently, we critically analyze mainstream synthesis strategies, such as sonication, mechanical shearing, and microfluidics. The core of the review focuses on innovative applications in energy storage devices, energy harvesting system, and catalysis for energy conversion. Finally, we discuss persistent challenges in stability, scalable synthesis, and mechanistic understanding, while offering perspectives on future research directions aimed at realizing the full potential of nano-LMs in next-generation intelligent and sustainable energy systems. Full article

In this study, mulberry tree stems were used as raw material to prepare magnetic modified biochar, Fe-BC-500, using the co-precipitation method. The structure of Fe-BC-500 was systematically characterized and tested for arsenic (As) adsorption in batch experiments by varying parameters such as solution pH (3–11), the concentrations of co-existing anions (2–20 mg/L), and ionic strength (0–0.5 mol/L NaNO₃). The results indicate that Fe-BC-500 exhibited optimal adsorption capacity at pH 4 and an initial As(V) concentration of 20 mg/L. The influence of co-existing anions on As(V) adsorption followed the order PO₄³⁻ > SO4²⁻ > NO₃⁻. Kinetic analysis showed that adsorption of Fe-BC-500 on As(V) followed a pseudo-second-order kinetic model, with a correlation coefficient of 1.00, indicating chemical adsorption. The Langmuir model accurately described the isothermal adsorption results, indicating monolayer adsorption. Mechanistic analysis showed that As(V) was fixed on the Fe-BC-500 surface through complexation reactions, demonstrating adsorption specificity. This study provides a theoretical basis and highlights the application potential of magnetically modified biochar for removing As(V) from water. Full article

Micro-nano bubbles (MNBs) have been widely used in water treatment due to their large specific surface area, long retention time, and high zeta potential. This study investigated the degradation of bisphenols by activating persulfate (PDS, an oxidizing agent) with air MNBs (MNBs/PDS). The removal rate of bisphenol A (BPA) in the MNBs/PDS process was 98.3% within 25 min, while there was almost no degradation observed by PDS or MNBs alone. This enhancement was attributed to the huge amount of energy released during the collapse of MNBs, sufficient to break the O–H bonds of water molecules or the O–O bond of PDS to induce the formation of reactive oxygen species (ROS, such as HO^• and SO₄^•−). To qualitatively analyze ROS generated in this system, electron paramagnetic resonance and quenching experiments were conducted, and the HO^• and SO₄^•− were detected in MNBs/PDS. Furthermore, the degradation percentages of bisphenols after 25 min of MNBs/PDS treatment followed the order of bisphenol B (100%) > BPA (98.3%) > bisphenol E (87.9%) > bisphenol F (86.5%) > bisphenol AF (84.9%) > bisphenol S (51%). Higher PDS dosage, higher gas flow rate, and lower pH values were preferred for the degradation. Moreover, the MNBs/PDS treatment reduced the TOC of secondary effluent containing BPA by 45.8% in one hour, indicating the application potential of MNBs/PDS in the advanced treatment of wastewater. Full article

Anodic aluminum oxide (AAO) is a well-known nanomaterial template formed under specific electrochemical conditions. By adjusting voltage, temperature, electrolyte type, and concentration, various microstructural modifications of AAO can be achieved within its hexagonally arranged pore array. To enable broader applications or enhance performance, post-treatment is often employed to further modify its nanostructure after anodization. Among these post-treatment techniques, AAO membrane detachment methods have been widely studied and can be categorized into traditional etching methods, voltage reduction methods, reverse bias voltage detachment methods, pulse voltage detachment methods, and further anodization techniques. Among various delamination processes, the mechanism is highly related to the selectivity of wet etching, as well as the Joule heating and stress generated during the process. Each of these detachment methods has its own advantages and drawbacks, including processing time, complexity, film integrity, and the toxicity of the solutions used. Consequently, researchers have devoted significant effort to optimizing and improving these techniques. Furthermore, through-hole AAO membranes have been applied in various fields, such as humidity sensors, nanomaterial synthesis, filtration, surface-enhanced Raman scattering (SERS), and tribo-electrical nano-generators (TENG). In particular, the rough and porous structures formed at the bottom of AAO films significantly enhance sensor performance. Depending on specific application requirements, selecting or refining the appropriate processing method is crucial to achieving optimal results. As a versatile nanomaterial template, AAO itself is expected to play a key role in future advancements in environmental safety, bio-applications, energy technologies, and food safety. Full article

In this work, polylactic acid (PLA)/poly(butylene adipate-coterephthalate) (PBAT) composites containing nanomagnetite particles were developed for electromagnetic shielding. The nanomagnetite particles acted not only as a conductive filler but also as a reinforced agent and compatibilizer for PLA/PBAT blends. The effect of surface treatments by the silicon coupling agent (SCA) under different pH conditions and with other substances (silica and dopamine (DA)) were investigated in particular. The composites were prepared by thermal mixing and characterized by Fourier-transform infrared spectroscopy (FTRI), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transparency electron microscopy (TEM) and tensile testing. The results show that the interface between the PBAT spheres and the PLA matrix was improved after the addition of magnetite particles treated with SCA or PDA. It is interesting to find that under acidic conditions, SCA acted more efficiently due to the chemical reaction of SCA with the hydroxyl groups on the surface of the magnetite particles, which resulted in chemical improvement. Tensile strength increased about 20%, while elongation also increased about 15%. The fracture surface under SEM clearly showed plastic deformation, which contributed to an improvement in mechanical properties, especially toughness. Full article

The rapid advancement of micro/nano-electromechanical systems (MEMS/NEMS) and precision manufacturing has fundamentally challenged traditional friction theories at the nanoscale. Classical continuum models fail to capture energy dissipation mechanisms at the atomic level, which are influenced by interfacial phenomena such as electron transfer, charge redistribution, and energy level realignment. Density functional theory (DFT), renowned for its accurate description of ground-state properties in many-electron systems, has emerged as a key tool for uncovering quantized friction mechanisms. By quantifying potential energy surface (PES) fluctuations, the evolution of interfacial charge density, and dynamic electronic band structures, DFT establishes a universal correlation between frictional dissipation and electronic behavior, transcending the limitations of conventional models in explaining stick–slip motion, superlubricity, and non-Amonton effects. Research breakthroughs in the application of DFT include characterizing frictional chemical potentials, designing heterojunction-based superlubricity, elucidating strain/load modulation mechanisms, and resolving electronic energy dissipation pathways. However, these advances remain scattered across interdisciplinary studies. This article systematically summarizes methodological innovations and cutting-edge applications of DFT in computational tribology, with the aim of constructing a unified framework for carrying out the “electronic structure–energy dissipation–frictional response” predictions. It provides a state of the art of using DFT to help design high-performance lubricants and actively control interfacial friction. Full article

Tin-based materials have emerged as promising anode candidates for advanced lithium-ion batteries (LIBs) due to their high theoretical capacity (e.g., 994 mAh·g⁻¹ for Li₄.₄Sn), moderate operating potential, and natural abundance. However, Tin-based materials suffer from severe volume expansion (>300%) and rapid capacity decay during cycling. To mitigate these challenges, a composite composed of tin-based materials and porous carbon (PC), i.e., SnO₂/SnS₂@PC, was prepared by calcining a mixture of SnO₂, petroleum asphalt and calcium carbonate at high temperature, where petroleum asphalt acted as the carbon and sulfur resource, and calcium carbonate acted as a pore-forming template. The prepared SnO₂/SnS₂@PC composite had a specific surface area of 190 m²·g⁻¹ with total pore volume 0.386 cm³·g⁻¹, and delivered an initial specific capacity of 1431 mAh·g⁻¹ and retained 722 mAh·g⁻¹ at 100th cycle at 0.2 A·g⁻¹, which is nearly three folds that of the actual capacity (~260 mAh·g⁻¹) of commercial graphite. The novelty of this work lies in that the abundant sulfur element in petroleum asphalt was fully utilized to react in situ with nano SnO₂ to generate SnS₂ and form a composite with high specific capacity and good structural stability, along with greatly reducing the emission of the harmful element sulfur into the atmosphere. Full article

This paper investigates the laws governing the evolution of nanostructures on pre-patterned fused silica surfaces by energetic ion erosion. First, regular nanostructures are fabricated with the Focused Ion Beam (FIB) operating at optimized processing parameters. Then, as a function of the different ion fluences, the surface morphology evolution is studied on a surface with newly formed nanostructures. An experimental phenomenon of inter-transformation between nano-ripples and random dot-like structures is observed. In addition, the principles of the development of the nanostructures are analyzed theoretically. The simulation results fit well with the experiments. This work deeply studies the influence of the initial surface micro-morphology on the evolution of nanostructures, and is of great significance for the control of surface nanostructures generated by energetic ion sputtering. Full article

Since mechanical processing can introduce stress in the sample, electrochemical dissolution has been utilized to attain shape accuracy in certain materials. However, this technique is rarely applied to laser-repaired Ni-based single-crystal superalloys. In this work, the transpassive dissolution behaviors of an additive manufacturing-repaired Ni-based single crystal superalloy in a 10% NaNO₃ solution were investigated by comparison with the substrate. A significant disparity in dissolution rates was found between the dendritic and interdendritic regions of the substrate, resulting in a rough surface. Conversely, the dissolution of the dendritic and interdendritic regions in the cladding structure occurred nearly simultaneously, leading to a high-quality, smooth surface. This behavior was attributed to the differences in phase dissolution preferences between the substrate and the cladding structure. It indicates that electrochemical dissolution is a promising method for achieving shape accuracy in laser-clad Ni-based single-crystal superalloys. Full article

Graphite, with its layered structure and weak van der Waals bonding between graphene nano layers, exhibits excellent self-lubricating properties. Natural graphite, characterized by high crystallinity, and artificial graphite, with relatively low crystallinity, exhibit distinct friction behaviors and structural differences, which significantly influence the performance of graphite–resin composites as solid lubricants. This study investigates the effects of natural/artificial graphite ratios and hydrophobic silane coupling treatment on the oil impregnation behavior, friction coefficient, wear stability, and microstructural changes in graphite–resin composites. Under a vertical load of 88,260 N and surface pressure of 50 MPa, the impregnated graphite–resin composites demonstrated low friction coefficients and stable wear behavior. SEM analysis revealed well-preserved microstructures, and Raman spectroscopy confirmed the formation of stable lubrication films through the I_D/I_G ratio, indicating graphene exfoliation. The results indicate that natural graphite provides dense structures and stable friction, while artificial graphite enhances oil impregnation but leads to unstable friction behavior. Full article