Oxide Nanoparticles Research Articles

Electrochemical DNA-nano biosensor for the detection of Goserelin as anticancer drug using modified pencil graphite electrode.

Goserelin is an effective anticancer drug, but naturally causes several side effects. Hence the determination of this drug in biological samples, plays a key role in evaluating its effects and side effects. The current studies have concentrated on monitoring Goserelin using an easy and quick DNA biosensor for the first time. In this study, copper(II) oxide nanoparticles were created upon the surface of multiwalled carbon nanotubes (CuO/MWCNTs) as a conducting mediator. The modified pencil graphite electrode (ds-DNA/PA/CuO/MWCNTs/PGE) has been modified with the help of polyaniline (PA), ds-DNA, and CuO/MWCNTs nanocomposite. Additionally, the issue with the bio-electroanalytical guanine oxidation signal in relation to ds-DNA at the surface of PA/CuO/MWCNTs/PGE has been examined to determination Goserelin for the first time. It also, established a strong conductive condition to determination Goserelin in nanomolar concentration. Thus, Goserelin's determining, however, has a 0.21 nM detection limit and a 1.0 nM-110.0 µM linear dynamic range according to differential pulse voltammograms (DPV) of ds-DNA/PA/CuO/MWCNTs/PGE. Furthermore, the molecular docking investigation highlighted that Goserelin is able to bind ds-DNA preferentially and supported the findings of the experiments. The determining of Goserelin in real samples has been effectively accomplished in the last phase using ds-DNA/PA/CuO/MWCNTs/PGE.

Morphostructural studies of pure and mixed metal oxide nanoparticles of Cu with Ni and Zn

Nano-scale interactions between pure metal or metal-oxide components within an oxide matrix can improve functional performance over basic metal oxides. This study reports on the synthesis of monometallic (CuO), bimetallic (CuO–NiO) and trimetallic (CuO–NiO–ZnO) oxide nanoparticles (NPs) via the co-precipitation method and investigation of morphostructural properties. All of the synthesized metal oxide NPs were calcined at 550 °C temperature and annealed under vacuum. In this work, we applied Scherrer formula, modified Scherrer equation, Williamson-Hall plots, and Halder-Wagner plots to calculate the average crystallite size. The XRD data analysis showed that average crystallite sizes of the as-synthesized metal oxide phases were between 4 nm and 76 nm and average diameters calculated from SEM image were between 15 nm and 83 nm. The XRD studies also disclosed that average crystallite size and lattice microstrain of the CuO phases remain almost same (43 nm–46 nm and 2.074×10−3 to 2.665×10−3) for pure CuO and mixed CuO–NiO; but in case of mixed CuO–NiO–ZnO it is found to decrease in size to 11 nm where lattice microstrain increases to 9.653×10−3. Line broadening of diffraction peaks from microstrain contribution was between 0.02 and 0.01. Degree of crystallinity (%) of CuO phases found to decrease from 81 to 71. Dislocation density of CuO phases found to increase from 6.63×10−4nm−2 to 12.68×10−3nm−2. X-ray density of CuO phases increased from 6.48 to 6.53 g/cm3. Where this calculated small dislocation density well agreed with the high crystallinity. Crystal structure and specific surface area were determined from lattice constants and X-ray density. These synthesized nanopowders showed the existence of monoclinic, cubic, and hexagonal phases. The obtained NPs of multi-metal oxide explained more than one phases with different size, shape, and morphology at nano scale.

Interpretable Machine Learning Models for Practical Antimonate Electrocatalyst Performance.

Computationally predicting the performance of catalysts under reaction conditions is a challenging task due to the complexity of catalytic surfaces and their evolution in situ, different reaction paths, and the presence of solid-liquid interfaces in the case of electrochemistry. We demonstrate here how relatively simple machine learning models can be found that enable prediction of experimentally observed onset potentials. Inputs to our model are comprised of data from the oxygen reduction reaction on non-precious transition-metal antimony oxide nanoparticulate catalysts with a combination of experimental conditions and computationally affordable bulk atomic and electronic structural descriptors from density functional theory simulations. From human-interpretable genetic programming models, we identify key experimental descriptors and key supplemental bulk electronic and atomic structural descriptors that govern trends in onset potentials for these oxides and deduce how these descriptors should be tuned to increase onset potentials. We finally validate these machine learning predictions by experimentally confirming that scandium as a dopant in nickel antimony oxide leads to a desired onset potential increase. Macroscopic experimental factors are found to be crucially important descriptors to be considered for models of catalytic performance, highlighting the important role machine learning can play here even in the presence of small datasets.

Chitosan-based hydrogel incorporating mesoporous silica/zinc oxide nanoparticles with controlled swelling and potent antibacterial activity

Staphylococcus aureus (S. aureus) is a notable causative agent of bacterial infections known for its development of antibiotic resistance over time. In response, hydrogels augmented with antibacterial nanoparticles (NPs) and controllable swelling properties have emerged as promising alternatives. In the study, a novel chitosan (CS)-based hydrogel was prepared by combining CS as a main component, zinc oxide NPs (ZnO NPs) as an antibacterial agent, and mesoporous silica NPs (MSN) as the swelling control material. Comprehensive characterization of the prepared novel hydrogels were carried out by dynamic light scattering (DLS), zeta potential (ζ-potential), Brunauer–Emmett–Teller (BET) analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microcopy (SEM), and X-ray diffraction (XRD). The ZnO/MSN/CS-based hydrogel exhibited superior swelling, precisely controllable swelling, and potent antibacterial activity against S. aureus. These hybrid CS-based hydrogels, incorporating both ZnO NPs and MSN, exhibit significant potential as agents for combating antibiotic resistance, offering an alternative strategy to mitigate reliance on conventional antibiotics.

Synthesis of NiO nanoparticles from Paulownia tomentosa plant extracts via a green synthesis method and antibacterial, antibiofilm and cytotoxicity applications

This study revealed the effective production of nickel oxide nanoparticles (NPs) using chelating agents derived from the leaves of Paulownia tomentosa plants and nickel (II) chloride hexahydrate (NiCl2⋅6H2O) as the precursor. Nickel oxide NPs (NiO NPs) have been successfully prepared by a green synthesis method using extracts of P. tomentosa leaves in water. The morphology and crystallinity of the NPs were investigated via X‐ray diffraction (XRD), scanning electron microscopy (SEM), UV–visible spectroscopy (UV–vis), energy‐dispersive X‐ray analysis (EDX), Fourier transform infrared spectroscopy (FT‐IR) and thermogravimetric analysis (TGA). The formation behaviour of NiO NPs and the microstructural and physical properties of the resulting particles were studied. This study additionally investigated the antimicrobial, antibiofilm and cytotoxic effects of NiO NPs. Microstructurally uniform NiO NPs with a nanometre diameter were consistently produced using an eco‐friendly processing approach and exhibited a visible‐range transparency of 89%. The obtained SEM images confirmed the octahedral shape of the NPs. The NiO NPs acquired were found to have potent antimicrobial efficacy against all the other bacterial strains. As a result of their antibiofilm effects on pathogenic Escherichia coli and Pseudomonas aeruginosa bacteria, NiO NPs strongly inhibited these bacteria in a concentration‐dependent manner. In the cytotoxicity study of NiO NPs, a decrease in cell viability was shown to occur depending on the concentration of the cell lines used.

Size, polyglycerol grafting, and net surface charge of iron oxide nanoparticles determine their interaction and toxicity in Caenorhabditis elegans

The widespread application of engineered nanoparticles (NPs) in environmental remediation has raised public concerns about their toxicity to aquatic organisms. Although appropriate surface modification can mitigate the ecotoxicity of NPs, the lack of polymer coating to inhibit toxicity completely and the insufficient knowledge about charge effect hinder the development of safe nanomaterials. Herein, we explored the potential of polyglycerol (PG) functionalization in alleviating the environmental risks of NPs. Iron oxide NPs (ION) of 20, 100, and 200 nm sizes (IONS, IONM and IONL, respectively) were grafted with PG to afford ION-PG. We examined the interaction of ION and ION-PG with Caenorhabditis elegans (C. elegans) and found that PG suppressed non-specific interaction of ION with C. elegans to reduce their accumulation and to inhibit their translocation. Particularly, IONS-PG was completely excluded from worms of all developmental stages. By covalently introducing sulfate, carboxyl and amino groups onto IONS-PG, we further demonstrated that positively charged IONS-PG-NH3+ induced high intestinal accumulation, cuticle adhesion and distal translocation, whereas the negatively charged IONS-PG-OSO3– and IONS-PG-COO– were excreted out. Consequently, no apparent deleterious effects on brood size and life span were observed in worms treated by IONS-PG and IONS-PG bearing negatively charged groups. This study presents new surface functionalization approaches for developing ecofriendly nanomaterials.

Heteroaggregation and sedimentation of natural goethite and artificial Fe3O4 nanoparticles with polystyrene nanoplastics in water

Iron oxide nanomaterials play important roles in biogeochemical processes. This study investigates the effects of representative natural carbonaceous materials (humic acid [HA] and extracellular polymeric substances [EPS]) and cations on the heteroaggregation and sedimentation of engineered and natural iron oxide nanomaterials with montmorillonite and sulfate- and amine-modified polystyrene (PS) nanoparticles (NPs) (S- and N-PS NPs, respectively) in water, assessing their environmental behavior and differences in colloidal stability parameters. In addition, a novel extended Derjaguin–Landau–Verwey–Overbeek theory (XDLVO) was developed to describe the mechanism of colloidal behavior that concurrently considers gravitational and magnetic attraction forces. In CaCl2 solution and most natural water samples, negatively charged S-PS NPs promoted heteroaggregation with goethite and iron oxide (Fe3O4) NPs more than positively charged N-PS NPs with increased nanoplastic particle concentration. In seawater, the introduction of S- and N-PS NPs increased the maximum net energy (barrier) (ΦMAX) of heteroaggregation and sedimentation with goethite and Fe3O4 NPs, facilitating dispersal and suspension of the system. The X-ray photoelectron spectroscopy (XPS) and molecular dynamics simulation results suggested that Ca2+ forms bridging interactions between Fe3O4 and S-PS NPs to promote aggregation, while competitive adsorption occurs between the N atoms of N-PS NPs and Ca2+ on the surface of Fe3O4 NPs. The study findings will help to improve the understanding of interfacial processes affecting ions at nanomaterial/water interfaces and assessments of the geochemical behavior and ecological risks of nanoplastics.

Green synthesis of ZnO nanoparticles using the mangosteen (Garcinia mangostana L.) leaf extract: Comparative preliminary in vitro antibacterial study

Abstract In the realm of public health, the rising threat caused by bacteria resistant to many drugs is a critical concern. In this work, we used the aqueous extract of mangosteen leaves to create zinc oxide (ZnO) nanoparticles (NPs) in an environmentally friendly manner. Through various analytical methods, we thoroughly characterized these biogenic ZnO NPs, including UV−visible, Fourier transform infrared, X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray powder diffraction, field emission-scanning electron microscopy with energy dispersive X-ray and high resolution-transmission electron microscopy. ZnO NPs showed distinctive properties among different characterization techniques, including a small energy bandgap of 2.80 eV, a porous, a minimum crystalline size of 16.99 nm, an average particle size of 14.21 nm, and a spherical nanostructure. Additionally, we performed preliminary antibacterial experiments to assess ZnO NPs, copper oxide (CuO) NPs, and ZnO–CuO nanocomposites for antibacterial activity. Interestingly, ZnO NPs showed significant potential in suppressing the growth of Staphylococcus aureus ATCC BAA-1026, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, and Klebsiella pneumoniae ATCC 13883, with decreasing order of minimum inhibitory concentrations: S. aureus = B. subtilis (15.63 μg·mL−1) > E. coli (62.50 μg·mL−1) > K. pneumoniae (125.00 μg·mL−1). These results highlight the potential of biogenic NPs, particularly ZnO NPs, as effective agents against multi-drug-resistant bacteria.

Medicinal Properties of Cobalt and Copper Nanoparticles Synthesized Using Limonia acidissima Leaf Extract

Aim: The present investigation was undertaken to synthesize Cobalt and copper nanoparticles (NPs) using Limonia acidissima L. leaf extract and to test their few medicinal properties like antimicrobial antioxidant and anti-diabetic activities. Methodology: Limonia acidissima plant leaves were collected from the vicinity of the College and the study was completed in 11 months. The hot aqueous leaf extract and soxhlet extract using ethyl acetate as solvent were prepared. Phytochemical analysis of the leaf extract showed the presence of Tannins, Flavonoids, Alkaloids and absence of Phenols. The leaf extract was then used to make Cobalt and copper nanoparticles (NPs) using Cobalt acetate and Copper sulphate respectively. Results: The formation of NPs was checked by color change and confirmed with UV–visible spectrophotometry. The typical peaks of Co-NPs were detected in the range of maximum wavelength between 380-520 nm and that for Cu NPs was detected between 260-580 nm. The antimicrobial activity of the synthesized NPs of both metal oxides was then tested against Gram positive and Gram negative bacteria and also against two Candida sps. Cobalt NPs exhibited strong antimicrobial activity against all tested organisms but Copper NPs showed no antimicrobial activity. The both NPs were also tested for antioxidant and anti-diabetic properties. Comparatively the Copper NPs possessed higher antioxidant and anti-diabetic activity than the cobalt nanoparticles. Conclusion: Thus, this underutilized plant from India can be further exploited for more medicinal properties and bring it into pharmaceutical usage.

Effect of varying concentration of dichroic dye on textural, electro-optical, phase transition and band gap studies of zinc oxide nanoparticles induced vertically aligned liquid crystals

Vertically aligned liquid crystal (VALC) perpetually boosts the advancement for display devices and optoelectronics. Herein, initially, the nanoparticles (NPs) induced VALC (nVALC) cell was prepared via doping of 0.3 (wt./wt.%) of zinc oxide NPs in nematic liquid crystal (LC). After that, a series of orange azo dichroic dye doped nVALC cells were prepared with varying concentrations of dye such as 0.0625, 0.125, 0.25 and 0.5 wt.%. The effect of dye concentrations on LC textures, phase transition, electro-optical and band gap properties were investigated, as well as resulted in a significantly reduced value of the threshold and operating voltages as a function of dye concentrations. The contrast ratio was also enhanced up to 0.25 wt.% dye doped nVALC cells. Additionally, the transition temperature from nematic to isotropic phase and band gap studies were also performed. The present work provides improved properties of nVALC systems for next-generation display technologies.

Synthesis and stabilities of Fe, Ni and Zn oxide incorporated colloidal TiO2

Owing to the unique physical and chemical characteristics of nanoparticles (NPs), their use in the manufacturing of commercial products is on the rise. The future will see an increasing quantity of NPs being discharged into our surroundings. This is precisely why it is important to understand their stability under changing conditions. This research examined the role of added Fe (III), Ni (II) and Zn (II) on the formation and stabilities of aqueous colloids of TiO2 particles. To the best of our knowledge, this is the first attempt to investigate the stability of lab synthesized composite NPs. The study confirmed that both the stability and environmental fate of metal oxide and mixed metal oxide NPs depends on the composition of aqueous environment. This can add more to the general understanding of NPs while paving way for exploring the stability and environmental fate of various mixed metal oxide/composites NPs as previous studies explored only commercially prepared plain NPs. TiO2 and TiO2-Fe2O3, TiO2-NiO, and TiO2-ZnO were synthesized following reported methods. Different characterization techniques including transmission electron microscope (TEM), x-rays diffraction (XRD), energy dispersive X-ray (EDX) analysis, and dynamic light scattering (DLS) were used to confirm the surface morphology, phase, elemental composition, and hydrodynamic (Dh) size of synthesized TiO2 particles. As-synthesized TiO2 and its various forms (TiO2-Fe2O3, TiO2-NiO, and TiO2-ZnO) showed rapid aggregation behavior in solutions, which is a sign of less or no threat to human health and the environment. Among the synthesized composites, TiO2-Fe2O3 showed the highest stability across all the methods utilized in this research. For all the approaches employed in dispersing aggregates of TiO2 NPs and their composites in solution, homogenization method displayed the highest efficiency. Moreover, the addition of an electrolyte i.e., KCl into the particle suspensions has affected the ionic strength of these suspensions resulting in an increased aggregation due to the shifting of ions-particles equilibrium. Thus, the formation of composites on TiO2 can govern both the stability and environmental fate of TiO2 particles under various aqueous environments.

Metal nanoparticle-induced effects on green toads (Amphibia, Anura) under climate change: conservation implications.

The toxicity of aluminum oxide (Al2O3), copper oxide (CuO), iron oxide (Fe3O4), nickel oxide (NiO), zinc oxide (ZnO), and titanium dioxide (TiO2) nanoparticles (NPs) on amphibians and their interaction with high temperatures, remain unknown. In this study, we investigated the survival, developmental, behavioral, and histological reactions of Bufotes viridis embryos and larvae exposed to different NPs for a duration of 10 days, using lethal concentrations (LC25%, LC50%, and LC75% mg/L) under both ambient (AT: 18 °C) and high (HT: 21 °C) temperatures. Based on LC, NiONPs > ZnONPs > CuONPs > Al2O3NPs > TiO2NPs > Fe3O4NPs showed the highest mortality at AT. A similar pattern was observed at HT, although mortality occurred at lower concentrations and Fe3O4NPs were more toxic than TiO2NPs. The results indicated that increasing concentrations of NPs significantly reduced hatching rates, except for TiO2NPs. Survival rates decreased, abnormality rates increased, and developmental processes slowed down, particularly for NiONPs and ZnONPs, under HT conditions. However, exposure to low concentrations of Fe3O4NPs for up to 7 days, CuONPs for up to 72 h, and NiO, ZnONPs, and TiO2NPs for up to 96 h did not have a negative impact on survival compared with the control group under AT. In behavioral tests with larvae, NPs generally induced hypoactivity at AT and hyperactivity at HT. Histological findings revealed liver and internal gill tissue lesions, and an increase in the number of melanomacrophage centers at HT. These results suggest that global warming may exacerbate the toxicity of metal oxide NPs to amphibians, emphasizing the need for further research and conservation efforts in this context.

Nanofiber membranes immobilized with in-situ grown nanoparticles for enhanced wetting resistance in direct contact membrane distillation

Immobilizing nanoparticles (NPs) onto the hydrophobic nanofiber membrane surface is an effective method to enhance its resistance to pore wetting in membrane distillation (MD) due to construction of a hierarchical structure. However, loading NPs onto the fabricated membrane through post-treatment techniques (e.g., electrospray, physical vapor deposition etc.) results in agglomeration of NPs and their weak attachment with membrane surface. To address this issue, we utilize precipitation and crystallization methods to achieve in-situ growth of zinc oxide (ZnO) NPs onto nanofiber surface for intensifying their interaction. Morphological characterization demonstrated that the size and amount of in-situ grown ZnO NPs could be controlled by varying reaction time and concentration of precipitation agent. Furthermore, the resultant nanofiber membrane with higher contact angles (163°) showed stable water flux and effective salt rejection in presence of surfactant and oil. Finally, the kinetics of wetting progression monitored by ultrasonic time-domain reflectometry (UTDR) further confirmed that the early partial wetting induced by surfactants was significantly restrained owing to the hierarchical structure generated by the in-situ grown ZnO NPs. This study suggested the modified nanofiber membrane presented outstanding wetting resistance to low-surface-tension foulants and promise for desalination in MD.

Empirical investigation of the effect of adding nanoparticles to HB-80 gas turbine oil: Evaluation of thermophysical behaviors

The current study aims to conduct an empirical investigation on the performance of copper (II) oxide (CuO), Graphene Oxide (GO), and Molybdenum (VI) Oxide (MoO3) nanoparticles as additives for HB-80 base lubricant and their effects on essential characteristics such as density, flashpoint and flammability, cloud point and pour point, viscosity and viscosity indicators, thermal conductivity coefficient, friction coefficient and wear. The test results show that nanoparticles have minor effects on density and viscosity but managed to improve viscosity indicators. Flashpoint, flammability, cloud point, and pour point all increased after the addition of nanoparticles. The increase in the concentration of nanoparticles also improved and increased the lubricant's thermal conductivity coefficient; the highest increase was 11.3 % compared to the base oil with the addition of 1 wt% CuO. Adding nanoparticles to lubricant decreases wear and friction coefficient by creating a lubricant film, especially at lower nanoparticle concentrations, which leads to a more stable lubricant film by nanoparticles. Copper (II) Oxide nanoparticles had the best performance in reducing friction coefficient and wear at 0.2 wt% with 22.86 % and 63.92 % reduction compared to the base oil, respectively.

Characterization and therapeutic potential of chitosan‐zinc oxide nanostructured particles synthesized using crab shell derived biopolymer

AbstractThe development of novel drug candidates for treating microbial infections and cancer turns into a challenging task. The biopolymer‐based nanomaterials have gained popularity for their effective roles in the pharmaceutical sector. The present investigation aims to valorize crab shell wastes to extract chitosan. The obtained (chitosan) biomass was utilized to synthesize chitosan‐zinc oxide nanoparticles (Ch‐ZnO‐NPs). The nanomaterial characterization was achieved by a variety of physicochemical techniques including UV, Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), elemental analysis, and High‐resolution transmission electron microscopic (HR‐TEM) examination. The synthesized nanomaterials have a particle size range of 35–80 nm and are more stable with a zeta potential value of (−40.78) mv. Additionally, the designed nanomaterials were utilized to evaluate the biological efficiency. The minimal inhibitory concentration value of Ch‐ZnO‐NPs was observed as 10 μg/mL. The designed nanomaterials significantly reduced the growth of Vibrio alginolyticus and Bacillus cereus and inhibited biofilm formation. The synthesized Ch‐ZnO‐NPs unveiled cytotoxic effects on A549 cells with an IC50 (half‐maximal inhibitory concentration) of 20 μg/mL. Furthermore, substantial increase in cell death was noticed in A549 cells treated with Ch‐ZnO‐NPs. Consequently, this investigation concludes that Ch‐ZnO‐NPs may act as a biomedicine.

Cerium Oxide Nanoparticles Role as Antioxidant

Abstract Cerium oxide nanoparticles (NPs), also known as ceria NPs, are particles of cerium oxide with sizes in the nanometer range. Cerium oxide (CeO2) is a compound composed of cerium and oxygen, and when it is reduced to NPs, it exhibits unique properties and applications. Cerium oxide NPs possess excellent catalytic properties. Cerium oxide NPs can switch between different oxidation states, Ce+4 and Ce+3, by gaining or losing oxygen atoms. This redox activity enables them to scavenge and neutralize free radicals and reactive oxygen species through their ability to cycle between these states and reduce oxidative stress in cells and tissues.

In silico assessment of nanoparticle toxicity powered by the Enalos Cloud Platform: Integrating automated machine learning and synthetic data for enhanced nanosafety evaluation

The rapid advance of nanotechnology has led to the development and widespread application of nanomaterials, raising concerns regarding their potential adverse effects on human health and the environment. Traditional (experimental) methods for assessing the nanoparticles (NPs) safety are time-consuming, expensive, and resource-intensive, and raise ethical concerns due to their reliance on animals. To address these challenges, we propose an in silico workflow that serves as an alternative or complementary approach to conventional hazard and risk assessment strategies, which incorporates state-of-the-art computational methodologies. In this study we present an automated machine learning (autoML) scheme that employs dose-response toxicity data for silver (Ag), titanium dioxide (TiO2), and copper oxide (CuO) NPs. This model is further enriched with atomistic descriptors to capture the NPs’ underlying structural properties. To overcome the issue of limited data availability, synthetic data generation techniques are used. These techniques help in broadening the dataset, thus improving the representation of different NP classes. A key aspect of this approach is a novel three-step applicability domain method (which includes the development of a local similarity approach) that enhances user confidence in the results by evaluating the prediction’s reliability. We anticipate that this approach will significantly expedite the nanosafety assessment process enabling regulation to keep pace with innovation, and will provide valuable insights for the design and development of safe and sustainable NPs. The ML model developed in this study is made available to the scientific community as an easy-to-use web-service through the Enalos Cloud Platform (www.enaloscloud.novamechanics.com/sabydoma/safenanoscope/), facilitating broader access and collaborative advancements in nanosafety.

Green synthesis of iron (III) oxide (Fe3O4) Nanoparticles Using Citrus sinensis Peel Extract for the Removal of Ciprofloxacin in Water

Ciprofloxacin is a widely used antibiotic that can contaminate water sources and pose environmental and health risks. Therefore, the objective of this paper is to explore the green synthesis of iron (III) oxide nanoparticles using Citrus sinensis peel extract for the removal of ciprofloxacin in water using standard techniques. The adsorption of ciprofloxacin on the nanoparticles was investigated under different conditions, such as pH, initial concentration of adsorbate, contact time, and different adsorbent doses. The adsorption data were fitted to different isotherm and kinetic models to understand the adsorption mechanism and parameters. The results of characterization revealed the particles to be of nanocrystalline structure with a cubic crystal shape, negative surface charge, and a high thermal stability with elemental composition primarily of Fe and O; it has z- average of 42.60, with Fe-O bond at 693.30cm-1 and UV-Visible absorbance at 221nm. The maximum adsorption capacity with ciprofloxacin was 29.21 mg/g (97.45%) at pH of 7 and room temperature of 25 °C. The results of the adsorption data indicated that the adsorption followed the Langmuir isotherm model and the pseudo-second-order kinetic model, suggesting a monolayer adsorption on a homogeneous surface with a finite number of identical sites. The synthesized nanoparticles showed a high efficiency and selectivity for the removal of ciprofloxacin from water, demonstrating it potential as an eco-friendly and low-cost adsorbent for water purification.

Positron annihilation lifetime spectroscopy of FeCr and FeCrAl oxide dispersion strengthened (ODS) alloys

Positron annihilation lifetime spectroscopy (PALS) was performed to characterize the interfacial nanostructure between the oxide particles and ferritic matrix in two types of oxide dispersion strengthened (ODS) alloys: FeCr dispersed with Y-Ti oxide nanoparticles and FeCrAl dispersed with Y-Al oxide nanoparticles. The spectra were precisely fitted and decomposed into three components with two trapping rates. Bulk lifetime approached the theoretical value of 107 ps by taking into account the positron trapping at two types of defects. Structural characterization was performed by coincidence Doppler broadening and high-resolution transmission electron microscopy (HRTEM), revealing that two-trapping defect clusters were closely associated with Y-Ti or Y-Al oxide particles. Trapping was not detected in the non-ODS alloys. Based on Kuramotos advanced theoretical work, the shorter annihilation lifetime (179–194 ps) could be ascribed to positron trapping at vacancies and divacancies localized under the misfit dislocations associated with Y-Ti or Y-Al oxide particles. The longer annihilation lifetime (301–323 ps) could be attributed to Ar-filled gas bubbles precipitated at the oxide particle-matrix interfaces. These results of PALS analyses were consistent with the HRTEM characterization.

Effects of water-induced aging on iron (oxyhydr)oxides nanoparticles: linking crystal structure, iron ion release, and toxicity

Effects of water-induced aging on iron (oxyhydr)oxides nanoparticles: linking crystal structure, iron ion release, and toxicity