Effects Of Metal Oxide Nanoparticles Research Articles

A Review on the Effect of Metal Oxide Nanoparticles on Tribological Properties of Biolubricants.

This review provides a comprehensive and accessible literature review on the integration of nanoparticles into biolubricants to enhance wear and friction regulation, thus improving the overall lubricated system performance. Nanotechnology has significantly impacted various industries, particularly in lubrication. Nanobiolubricants offer promising avenues for enhancing tribological properties. This review focuses on oxide nanoparticles, such as zinc oxide (ZnO), aluminum oxide (Al2O3), copper oxide (CuO), titanium dioxide (TiO2), zirconium dioxide (ZrO2), and graphene oxide (GO) nanoparticles, for their ability to enhance lubricant performance. The impact of nanoparticle concentration on biolubricant properties, including viscosity, viscosity index, flash point temperature, and pour point temperature, is analyzed. The review also addresses potential obstacles and limitations in nanoparticle incorporation, aiming to propose effective strategies for maximizing their benefits. The findings underscore the potential of nanobiolubricants to improve operational efficiency and component lifespan. This review aims to provide valuable insights for researchers, engineers, and professionals in exploring and leveraging nanotechnology's potential in the lubrication industry. This review paper explores the basics of tribology along with its significance, green principles, mechanisms, and energy savings because of friction, wear, and lubrication. Condition monitoring techniques are also explored to achieve brief knowledge about maintaining reliability and safety of the industrial components. Recent advances in tribology including superconductivity, biotribology, high-temperature tribology, tribological simulation, hybrid polymer composite's tribology, and cryogenic tribology are investigated, which gives a thorough idea about the subject.

Statement of retraction: Comparison of the effect of metal oxide nanoparticles (copper, zinc, and iron) on the removal of cobalt by electrocoagulation processes from refinery wastewater

Statement of retraction: Comparison of the effect of metal oxide nanoparticles (copper, zinc, and iron) on the removal of cobalt by electrocoagulation processes from refinery wastewater

Exploring the In Vitro Antidiabetic Potential of Metal Oxide Nanoparticles Synthesized Using Lemongrass and Mint Formulation.

Aim This study aimed to compare the antidiabetic effect of metal oxide nanoparticles (CuONPs and ZnONPs)prepared using lemongrass and mint herbal formulations. Introduction The study explores green-synthesized nanoparticles for potential applications in diabetes management, emphasizing sustainable synthesis methods, particularly zinc oxide nanoparticles (ZnONPs) and copper oxide nanoparticles (CuONPs) produced from lemongrass and mint herbal formulations. The study was prompted by the increasing importance of innovative therapeutic strategies, responding to emerging health challenges, and leveraging advancements in nanotechnology and eco-friendly practices to explore the potential of green-synthesized nanoparticles in diabetes management. Methods The methods involve herbal formulation preparation, CuONPs and ZnONPs synthesis, and UV-visible spectrophotometry for characterization. In vitro antidiabetic activity is assessed through α-amylase and β-glucosidase enzyme assays using varied nanoparticle concentrations (10-50 µL). Results Visual observations confirm successful synthesis, with distinct color changes observed in both CuONPs and ZnONPs after 24 hours. UV-visible spectrophotometry reveals absorption peaks at 440 nm and 380 nm for CuONPs and ZnONPs, respectively. In the α-amylase assay, both nanoparticles exhibit concentration-dependent inhibition, with CuONPs ranging from 40% to 77% and ZnONPs ranging from 36% to 80%. The β-glucosidase assay demonstrates similar concentration-dependent inhibition patterns, highlighting significant differences. Conclusion The study concludes that CuONPs and ZnONPs synthesis using lemongrass and mint herbal formulations show concentration-dependent antidiabetic activity. The comparative analysis underscores the need for tailored approaches based on nanoparticle composition. These findings contribute valuable insights into the therapeutic potential of green-synthesized nanoparticles, paving the way for future nanomedicine research and development in diabetes management.

Comparison of the effect of metal oxide nanoparticles (copper, zinc, and iron) on the removal of cobalt by electrocoagulation processes from refinery wastewater

Cobalt is one of the heavy metals that can enter the environment via refinery wastewater due to its wide use. Various methods have been used to remove it. Recently, electrocoagulation has become one of the methods used in the treatment of wastewater. In this work, the best efficiency was achieved at a potential difference of 30 volts and a time of 60 minutes, with an efficiency of 52%. In the next steps, the experiments were carried out using copper, iron, and zinc nanoparticles, each of which was able to reduce the amount of cobalt by 87%, 73%, and 61%, respectively. The results showed that of the metal oxides used, iron oxide nanoparticles were able to remove the largest amount of cobalt from the wastewater, followed by copper and zinc. Using the statistical method of reaction surface, the optimal operating conditions for cobalt removal were determined and a second-order kinetic model was presented according to the laboratory parameters. The predictions of the statistical model resulting from the experimental design show good agreement with the laboratory data for the removal of cobalt in the present work.

Potential Effects of Metal Oxides on Agricultural Production of Rice: A Mini Review

The extensive usage of metal oxide nanoparticles has aided in the spread and accumulation of these nanoparticles in the environment, potentially endangering both human health and the agroecological system. This research describes in detail the hazardous and advantageous impacts of common metal oxide nanomaterials, such as iron oxide, copper oxide, and zinc oxide, on the life cycle of rice. In-depth analyses are conducted on the transport patterns of nanoparticles in rice, the plant's reaction to stress, the reduction of heavy metal stress, and the improvement of rice quality by metal oxide nanoparticles, all of which are of significant interest in this subject. It is emphasized that from the perspective of advancing the field of nanoagriculture, the next stage of research should focus more on the molecular mechanisms of the effects of metal oxide nanoparticles on rice and the effects of combined use with other biological media. The limitations of the lack of existing studies on the effects of metal oxide nanomaterials on the entire life cycle of rice have been clearly pointed out.

Evaluating metal oxide nanoparticle (MeOx NP) toxicity with different types of nano descriptors mainly focusing on simple periodic table-based descriptors: a mini-review

Given the rapid growth of nanotechnology, it is essential to know the hazardous effects of metal oxide nanoparticles (MeOx NPs) posed to living organisms within the ecosystem.

Nickel-Cobalt Oxide Nanoparticle-Induced Biohydrogen Production.

The positive effects of metal oxide nanoparticles (NPs) on dark fermentation (DF) for biohydrogen synthesis have been increased, and the mechanism still needs to be further revealed. In this study, nickel-cobalt oxide (NiCo2O4) NPs were prepared to increase H2 yield via DF. The highest (259.67 mL/g glucose) and the lowest (188.14 mL/g glucose) yields were achieved at 400 and 800 mg/L NiCo2O4 NPs added, respectively, with their corresponding 33.97% increase and 2.93% decrease compared with the control yield (193.82 mL/g glucose). Meanwhile, the microbial community further confirmed that NiCo2O4 NPs increased the abundance of the dominant H2-producing Clostridium sensu stricto 1 by 23.05%. The gene prediction also showed that NiCo2O4 NPs increased the abundance of genes encoding the rate-limiting enzyme pyruvate kinase in glycolysis, thus increasing the substrate conversion. Moreover, the gene abundance of key enzymes directly related to H2 evolution was also increased at different levels.

Comparative toxic effect of bulk zinc oxide (ZnO) and ZnO nanoparticles on human red blood cells

Abstract Metal oxide nanoparticles (NPs) are a member of nanomaterials family that have been produced on a large scale and their toxicity affected by their high surface-to-volume ratio. The hemolytic toxic effects of metal oxide NPs may be completely different from those observed in their bulk counterparts. So, the main purpose of this research was to measure the difference between the hemolytic effects of ZnO (NPs and bulk) on isolated human red blood cells (RBCs). Hemolysis was measured after incubation of human RBCs with 0.01–1 mM of ZnO (bulk and NPs) for 6 h. For measurement of other variables, human RBCs were treated with 0.1 mM of ZnO (NPs and bulk) for 1, 2, and 3 h. Our results demonstrate that bulk ZnO did not show any toxic effects in the concentrations tested, while ZnO NPs caused toxic hemolytic effects through formation of ROS, lipid peroxidation, and glutathione depletion.

Effect of metal oxide nanoparticles and aluminum hydroxide on the physicochemical properties and flame-retardant behavior of rigid polyurethane foam

In this work, we present the influence of zinc oxide (ZnO) and magnesium oxide (MgO) nanoparticles (NPs) combined with aluminum hydroxide (ATH) on the physicochemical properties and flame-retardant behavior of rigid polyurethane (PU) foam. Adding these kinds of NPs and ATH exhibit a significant influence on the morphological, structural, thermal stability, and mechanical properties of PU nanocomposites. Flammability including horizontal, vertical burning, and limiting oxygen index (LOI) tests were performed to evaluate the flame retardancy of PU nanocomposites. It could be observed that the effects of cell structureand density were close to the fire retardancy of PU nanocomposite foam. Whereby, a combination of ZnO and MgO NPs and ATH led to reduce cell size and increase density value of PU foams, thus playing the increased their flame retardancy. The flaming time of PU and its nanocomposites took 71 s and 59–62 s to self-quench the fire, respectively, and lost ∼84 % of their weight. The addition of 125 php ATH to PU nanocomposites led to a decrease in burning time to 9–10 s and a loss of ∼61 % of their weight. LOI value increased to 24 % with the incorporation of 5 php ZnO, MgO NPs, and 125 php ATH NPs into the PU foam.

Surface Roughness, Hardness and FTIR of the Modified Soft Liner with Different Metal Oxide Nanoparticles

Aims: To study the effect of metal oxide nanoparticles (MgO, ZrO2, ZnO) on acrylic based soft liner surface properties and FTIR. Materials and Methods: Acrylic-based soft-liner specimens were prepared by adding three different concentrations (0.5, 1, and 2) %wt of metal oxide nanoparticles (MgO, ZrO2, ZnO). A disk-shaped specimens with 30mm diameter and 3mm thickness were prepared for shore (A) hardness test to evaluate the surface hardness of modified soft liner. The surface roughness of soft-liner samples (10X10X2mm) was tested by a profilometer. FTIR analysis was conducted to evaluate chemical reaction that may occur between acrylic-based soft liner and nanoparticles. Results: there were no chemical reaction carried out between soft liner and metal oxide nanoparticles at different concentration- surface hardness (shore A) was increased as nanoparticles concentration increased in modified resin. Nanoparticles with 1 and 2% concentration incorporated in soft liner had lower surface roughness value. Conclusions: Metal oxide nanoparticles have improved the surface texture of acrylic-based soft liner, while the hardness of modified soft liner was increased with nanoparticles concentration increases.

Effect of ZnO and CuO Nanoparticles on Culturable Bacterial Population, Microbial Biomass, and Enzyme Activities in Two Soil Types

Metal oxide nanoparticles are widely used in many agricultural, medical, and electronic products. This study was conducted to assess the effects of metal oxide nanoparticles on the total culturable soil bacterial population and enzymatic activities – namely, dehydrogenase (DHA), urease (UA), and microbial biomass (MCB) – using Philippine soils. The factors included the two soil types – Lipa clay loam (LCL) and Sariaya sandy loam (SSL) – and five treatments – namely, copper oxide bulk particles (bCuO), zinc oxide bulk particles (bZnO), copper oxide nanoparticles (CuONPs), zinc oxide nanoparticles (ZnONPs), and untreated control. The experiment was laid out in a split-plot completely randomized design over a 28- day incubation period under laboratory conditions. Results showed no significant effect on the culturable bacterial population. The DHA of ZnONPs-, bCuO-, and CuONPs-treated LCL was significantly reduced up to 7, 14, and 28 days after amendment (DAA), respectively. This result was probably due to the strongly acidic property, high level of organic matter (OM), low permeability due to particle size distribution, and low phosphate concentration of LCL. For UA, it was significantly reduced in LCL by CuONPs up to 28 DAA, perhaps due to the inactivation of soil UA. UA, however, was significantly increased by ZnONPs up to 28 DAA, presumably due to the release of intracellular urease from dead cells due to the toxic level of Zn2+. Soil MCB was significantly reduced at 7 DAA in CuONP-amended LCL and ZnONPs- amended SSL, whereas bCuO- and bZnO-amended LCL had a significant increase in MCB. The effect of CuONPs and ZnONPs on the parameters measured was influenced by soil type. In conclusion, CuONPs could pose a threat to soil microorganisms, especially in clayey soils.

Effect of metal oxide nanoparticles on the activity of glutathione reductase, catalase, peroxidase and superoxide dismutase in plants under drought

AbstractThere is no accurate information on the effect of metal oxide nanoparticles (MO NPs) on plant enzymatic activities (EAs) under drought stress (DS). The aim of this work was to study the effect of MO NPs on the EAs of Agropyron cristatum (L.) Gaertn and Sanguisorba officinalis L. under DS. Foliar spray of silver oxide (AgO), iron oxide (FeO), zinc oxide (ZnO) and cadmium oxide (CdO) at levels of 30, 60, 90 and 120 mg L−1 were used on plant aerial parts under DS levels of 25–100% field capacity (FC). Glutathione reductase (GR), catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) were measured after 2 weeks of the experiment. The EAs changes varied depending on the plant species, levels of DS, types and levels of NPs. Application of 30–60 mg L−1 MO NPs under 25–50% FC significantly reduced EAs, especially in S. officinalis (P < 0.01). Higher concentrations of MO NPs significantly increased EAs. Decreases in CAT (20.90%, 18.80%), POD (21.30%, 17.67%) and SOD (23.14%, 16.88%) were observed using 60 mg L−1 ZnO NPs under 25–50% FC in S. officinalis and A. cristatum, respectively. High concentrations of CdO NPs (90–120 mg L−1) increased EAs (max. = 24.0%) in both species under 25% FC.

Effects of Metal Oxide Nanoparticles on Nitrous Oxide Emissions in Agriculture Soil

Metal oxide nanoparticles (NPs) have been widely used in industrial and agricultural production and introduced into soils. The impact of these nanoparticles on soil nitrous oxide (N2O) emission is unclear. We conducted a microcosm experiment to investigate the effects of titanium oxide nanoparticles (TiO2 NPs), copper oxide nanoparticles (CuO NPs), and aluminum oxide nanoparticles (Al2O3 NPs) on soil N2O emissions and the abundance of functional genes related to N2O production/reduction. Compared to the soil without NPs addition, TiO2 NPs applied to the soil produced no significant effect on N2O emissions. The denitrification process in the soil exposed to CuO NPs was inhibited by reducing the functional genes related to nitrite reductase (nirK) and increasing N2O reductase (nosZ), while CuO NPs added to the soil stimulated the cumulative N2O emissions by 92.7%. After the application of Al2O3 NPs to the soil, the nitrification process was inhibited by inhibiting the functional genes of ammonia-oxidizing bacteria (AOB amoA), and soil N2O emission was reduced by 48.6%. Large-scale application of CuO NPs in agricultural soils may stimulate the N2O emissions resulting in potential environmental risks.

Effects of Metal Oxide Nanoparticles in Zebrafish.

Metal oxide nanoparticles (MO NPs) are increasingly employed in many fields with a wide range of applications from industries to drug delivery. Due to their semiconducting properties, metal oxide nanoparticles are commonly used in the manufacturing of several commercial products available in the market, including cosmetics, food additives, textile, paint, and antibacterial ointments. The use of metallic oxide nanoparticles for medical and cosmetic purposes leads to unavoidable human exposure, requiring a proper knowledge of their potentially harmful effects. This review offers a comprehensive overview of the possible toxicity of metallic oxide nanoparticles in zebrafish during both adulthood and growth stages, with an emphasis on the role of oxidative stress.

Exposure of Metal Oxide Nanoparticles on the Bioluminescence Process of Pu- and Pm-lux Recombinant P. putida mt-2 Strains.

Comparison of the effects of metal oxide nanoparticles (NPs; CuO, NiO, ZnO, TiO2, and Al2O3) on different bioluminescence processes was evaluated using two recombinant (Pm-lux and Pu-lux) strains of Pseudomonas putida mt-2 with same inducer exposure. Different sensitivities and responses were observed according to the type of NPs and recombinant strains. EC50 values were determined. The negative effects on the bioluminescence activity of the Pm-lux strain was greater than for the Pu-lux strains for all NPs tested. EC50 values for the Pm-lux strain were 1.7- to 6.2-fold lower (corresponding to high inhibition) than for Pu-lux. ZnO NP caused the greatest inhibition among the tested NPs in both strains, showing approximately 11 times less EC50s of CuO, which appeared as the least inhibited. Although NPs showed different sensitivities depending on the bioluminescence process, similar orders of EC50s for both strains were observed as follows: ZnO > NiO, Al2O3 > TiO2 > CuO. More detailed in-depth systematic approaches, including in the field of molecular mechanisms, is needed to evaluate the accurate effect mechanisms involved in both bioluminescence metabolic processes.

Effect of metal oxide nanoparticles on wax formation, morphology, and rheological behavior in crude oil: An experimental study

In this work, Fe2O3, ZnO, and MgO nanoparticles were synthesized via a chemical precipitation method to investigate their effects on wax formation, morphological characteristics, and rheological behavior in a crude oil sample. For this purpose, differential scanning calorimetry, cross-polarized microscopy, and viscometry have been utilized as the main experimental techniques. It was observed that ZnO and MgO nanoparticles had the most positive effect on the wax appearance temperature (WAT) of the crude oil by reducing the WAT from 25 °C to 19.2 and 17 °C at 500 ppm, respectively. However, Fe2O3 nanoparticles did not have an acceptable efficiency in postponement of WAT. Addition of the nanoparticles into the crude oil caused deformation of wax crystals to more spherical and regular structures. In addition, presence of the synthesized nanoparticles prevented formation of the strong three-dimensional lattice of wax structures at high temperatures. XRD analysis of the wax deposits extracted from the crude oil showed that no chemical bonding occurred between the nanoparticles and wax molecules. However, superior size-dependent properties of the nanoparticles are responsible for controlling the growth of wax crystal nuclei and reduction of the WAT. Field-emission scanning electron microscopy images of the wax deposits showed a smooth and layered surface of the wax with some fine particles, which confirm physical interaction of the nanoparticles with wax. Findings of this work reveal the potential of ZnO and MgO nanoparticles as efficient and low-cost additives for production, storage, and transportation of the waxy crude oil.

Metal Oxides as Soluble Nano Catalyst on Biodiesel: A Review

Nano particles of metal oxide developed as soluble nano additive in liquid fuels to improve fuel quality. One application of nano metal oxide particles is an additive to biodiesel. Biodiesel is an alternative fuel that can reduce dependence on fossil fuels. Pure biodiesel has a relatively lower calorific value compared to fossil fuels. Low calorific value results in increased brake specific fuel consumption. Moreover, biodiesel has a higher density and viscosity compared to fossil fuel. The content of carbon monoxide (CO), unburned hydrocarbons (HC) and nitrogen oxide (NOx) in exhaust gases with biodiesel is higher than fossil fuels. Metal oxide nanoparticles are added to biodiesel between 6 to 80 nm with concentrations about 50 to 500 ppm. Addition of metal oxide nanoparticles to biodiesel can improve brake thermal efficiency, reduce brake specific fuel consumption, carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxide (NOx) and improve carbon dioxide (CO2) emission due to the catalytic effect of metal oxide nanoparticles. Metal oxide acts as an oxidation catalyst thereby reduce the carbon combustion activation temperature and thus enhances hydrocarbon oxidation, promoting complete combustion. Nanoparticles that are often used in various studies are nickel (II) oxide (NiO), cerium (IV) oxide (CeO2), titanium oxide (TiO2), zinc oxide (ZnO), aluminum oxide (Al2O3), and silicon dioxide (SiO2). This review paper describes the progress and development of nano metal oxide applications as additives for biodiesel, and the discussion in this paper is divided into 3 main topics, including the effects of nanoparticles on the properties of biodiesel, engine performance, and emission characteristics.

Protein interaction, monocyte toxicity and immunogenic properties of cerium oxide crystals with 5% or 14% gadolinium, cobalt oxide and iron oxide nanoparticles – an interdisciplinary approach

Metal oxide nanoparticles are widely used in both consumer products and medical applications, but the knowledge regarding exposure-related health effects is limited. However, it is challenging to investigate nanoparticle interaction processes with biological systems. The overall aim of this project was to improve the possibility to predict exposure-related health effects of metal oxide nanoparticles through interdisciplinary collaboration by combining workflows from the pharmaceutical industry, nanomaterial sciences, and occupational medicine. Specific aims were to investigate nanoparticle-protein interactions and possible adverse immune reactions. Four different metal oxide nanoparticles; CeOx nanocrystals with 5% or 14% Gd, Co3O4, and Fe2O3, were characterized by dynamic light scattering and high-resolution transmission electron microscopy. Nanoparticle-binding proteins were identified and screened for HLA-binding peptides in silico. Monocyte interaction with nanoparticle–protein complexes was assessed in vitro. Herein, for the first time, immunogenic properties of nanoparticle-binding proteins have been characterized. The present study indicates that especially Co3O4-protein complexes can induce both ‘danger signals’, verified by the production of inflammatory cytokines and simultaneously bind autologous proteins, which can be presented as immunogenic epitopes by MHC class II. The clinical relevance of these findings should be further evaluated to investigate the role of metal oxide nanoparticles in the development of autoimmune disease. The general workflow identified experimental difficulties, such as nanoparticle aggregate formation and a lack of protein-free buffers suitable for particle characterization, protein analyses, as well as for cell studies. This confirms the importance of future interdisciplinary collaborations.

The Biolog EcoPlate™ Technique for Assessing the Effect of Metal Oxide Nanoparticles on Freshwater Microbial Communities.

The application of Biolog EcoPlate™ for community-level physiological profiling of soils is well documented; however, the functional diversity of aquatic bacterial communities has been hardly studied. The objective of this study was to investigate the applicability of the Biolog EcoPlate™ technique and evaluate comparatively the applied endpoints, for the characterisation of the effects of metal oxide nanoparticles (MONPs) on freshwater microbial communities. Microcosm experiments were run to assess the effect of nano ZnO and nano TiO2 in freshwater at 0.8–100 mg/L concentration range. The average well colour development, substrate average well colour development, substrate richness, Shannon index and evenness, Simpson index, McIntosh index and Gini coefficient were determined to quantify the metabolic capabilities and functional diversity. Comprehensive analysis of the experimental data demonstrated that short-term exposure to TiO2 and ZnO NPs affected the metabolic activity at different extent and through different mechanisms of action. TiO2 NPs displayed lower impact on the metabolic profile showing up to 30% inhibition. However, the inhibitory effect of ZnO NPs reached 99% with clearly concentration-dependent responses. This study demonstrated that the McIntosh and Gini coefficients were well applicable and sensitive diversity indices. The parallel use of general metabolic capabilities and functional diversity indices may improve the output information of the ecological studies on microbial communities.

Comparisons of the Effect of Different Metal Oxide Nanoparticles on the Root and Shoot Growth under Shaking and Non-Shaking Incubation, Different Plants, and Binary Mixture Conditions.

We evaluated the toxicity of five metal oxide nanoparticles (NPs) in single or binary mixtures based on root and shoot growth of two plant species under non-shaking and shaking conditions. The effects of NPs on root and shoot growth differed depending on the NP type, incubation condition, and plant type. The half maximal effective concentration (EC50) of NPs based on root growth were significantly lower, by 2.6–9.8 times, under shaking than non-shaking conditions (p = 0.0138). The magnitude of the effects of NPs followed the order CuO > ZnO > NiO >> Al2O3, TiO2. In addition, Lactuca sativa L. was more sensitive to the tested NPs than Raphanus sativus L., with an EC50 0.2–0.7 times lower (p = 0.0267). The observed effects of 12 combinations of binary NP mixtures were slightly, albeit non-significantly, lower than expected, indicative of an additive effect of the individual NPs in the mixtures. The results emphasize the importance of careful plant model selection, appropriate application of incubation conditions, and consideration of chemical mixtures rather than single compounds when evaluating the effects of metal oxide NPs.