Production Of Zinc Oxide Nanoparticles Research Articles

Biogenic production of eco-friendly Arjuna-ZnO NPs for sunlight-activated efficient degradation of organic dyes of high commercial usage

The present study describes an environmentally benign biological method for the production of zinc oxide nanoparticles (ZnO NPs) by blending water-based leaf extract from a sustainable bio-source, the Arjuna tree, under ambient conditions. Aqueous leaf extract comprised of different reducing agents appeared as the precursor for phytofabrication, and zinc nitrate hexahydrate (ZnNO3·6H2O) acted as a zinc source. The phytofabricated Arjuna-ZnO NPs had a hexagonal shape with an average size of 31.14 nm, as revealed by HR-TEM, FE-SEM micrographs, and XRD patterns. The FESEM-EDS micrograph and the XRD patterns also revealed the elemental composition, phase purity, and crystalline nature of phytofabricated Arjuna-ZnO NPs. The initial formation of ZnO NPs was confirmed by absorption maxima at approximately 376 nm and Zn-O stretching vibrations at 520 cm−1 using UV–VIS and an FT-IR spectrophotometers, respectively. The aqueous extract of Arjuna leaf was also analysed using FT-IR spectrophotometer to identify the functional groups of bioactive substances that participated in the reduction and encapsulation processes. The efficacy of the Arjuna-ZnO NPs was assessed in terms of their ability to photocatalyzed on three noxious dyes, methylene blue (MB), methyl orange (MO), and congo red (CR), for high commercial and industrial usage. The phytofabricated Arjuna-ZnO NPs were photoactive and proved highly efficient and effective nano-photocatalysts for the photodegradation of three dyes, MB, MO, and CR, under natural sunshine, underscoring their potential for effective remediation of environmental pollutants. The degradation process adhered to pseudo-first-order kinetics in terms of adsorption kinetics.

Green synthesis of ZnONps using Horse gram seed aqueous extract and its in vitro evaluation on antioxidant, antidiabetic, anticancer and DNA binding potential

The goal of this study was to access the green production of zinc oxide nanoparticles (G-ZnO NPs) using aqueous extract of horse gram seeds (Macrotyloma Uniflorum). The precursor to the extract ratio (2.5:1) and pH value (8.5), along with the zinc nitrate concentration (0.5 M), had an impact on the particle size and the green synthesized ZnO nanoparticles. UV Spectroscopy inspection revealed formation of G-ZnO NPs with absorption at 320 nm which is the characteristic absorption of G-ZnO NPs. FTIR, XRD, SEM, EDX and TEM were used to characterize the green synthesized ZnO NPs. The findings demonstrated that the presence of secondary metabolites in the seed extractstabilize and contribute in the production of G-ZnO NPs. A dose-dependent increase in antibacterial activity was seen in evaluation of these NPs against Klebsiella, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa. The antioxidant activity and antidiabetic activity for G-ZnO NPs was also noted to be concentration dependent. The synthesized nanoparticles are found to interact with CT-DNA to produce a hypochromic shift. Further the studies on the G-ZnONPs in MCF-7 cells using the MTT test demonstrated greater cellular inhibition. The results validate that the green synthesized ZnO-NPs from horse gram seed possess good biological activities and can be an excellent biologically derived potential material which could be used in the drug discovery from natural products.

Anticancer approach of zinc oxide nanocomposite prepared by gamma radiation via induction of apoptosis and PGC‐1α pathways in hepatocellular carcinoma in rats

Zinc oxide nanoparticles (ZnO NPs) are attracting the interest of researchers due to their potential applications in cancer treatment. It was recently shown that ZnO NPs specifically destroy cancer cells. However, the underlying molecular processes that drive ZnO NPs' anticancer activity are unclear. Radical polymerization was used for synthesizing zinc oxide nanoparticles using gamma radiation. Polyvinylpyrrolidone (PVP) was employed as a stabilizer in the production of zinc oxide nanoparticles using zinc nitrate. PVP@ZnO nanostructures were characterized using a number of techniques, including high‐resolution transmission electron microscopy (HRTEM) and UV–visible spectroscopy. Fourier‐transform infrared spectroscopy (FTIR) was used to study the functional groups of the produced nanostructures. Moreover, the surface morphology of prepared zinc oxide nanoparticles (ZnO NPs) and PVP@ZnO nanostructures was shown using SEM. In addition, the crystalline structure of the aforementioned samples was identified and investigated via XRD. The current work examined the anticancer effect of ZnO nanocomposite against rat hepatocellular carcinoma (HCC). The results demonstrated that ZnO nanocomposite exert distinct effects on apoptosis and PGC‐1α pathways in hepatocellular carcinoma in rats. mRNA levels of tumor suppressor gene p53 and antiapoptotic gene BCL‐2 were downregulated, while the apoptotic gene Bax was upregulated and Caspase‐3 activity increased in diethylnitrosamine (DEN) + ZnO nanocomposite‐treated rats in comparison with DEN‐treated rats. ZnO nanocomposite were also found to have an effect on liver function (ALT, AST, ALP, and GGT) and total antioxidant capacity (TAC). Treatment with DEN manifested a significant decrease in the expression of mtTFA and PGC‐1α (mtTFA: 0.54 fold and PGC‐1α: 0.31 fold in respect to the normal control), while ZnO nanocomposite treatment induced a remarkable increase in their expression. In conclusion, the present data demonstrated that ZnO nanocomposite showed anticancer activity via induction of apoptosis and PGC‐1α pathways. In addition, improvements in liver function and antioxidant capacity.

Design of reactor for the production of zinc oxide nanoparticles

This study aims to design a continuous stirred tank reactor (CSTR) type reactor to produce zinc oxide (ZnO) nanoparticles. Mass balance calculations were carried out in this study as a benchmark to determine whether the reactor was working properly by knowing the flow of incoming raw materials and the products produced by the reactor. Furthermore, the reactor's design and the stirrer used in the reactor are calculated manually using Microsoft Excel. Based on the calculation results of the reactor design, the reactor volume is 8224.359 liters, with a vessel diameter of 73.298 in, a cylinder height of 166.090 in, and a cylinder thickness of 73.444 in. The top cover of the reactor measures 12.387 inches with a thickness of 0.072 inches, while the bottom cover measures 21.185 inches with a thickness of 0.083 inches, so the overall height of the reactor is 37.552 in. The reactor is equipped with one stirrer with an impeller diameter of 36.722 in, impeller height from the bottom of the tank is 24.433 in, impeller width is 7.344 in, and impeller length is 9.180 in. Turbulent stirring flow conditions with a standard motor power for the stirrer is 6.849 HP. This design will be a reference for building more economical, efficient, and highly demanding reactors.

Zinc oxide nanoparticles synthesized using Oldenlandia Umbellata leaf extract and their photocatalytic and biological characteristics

The aim of this study was to examine the environmentally friendly green production of zinc oxide nanoparticles (ZnO NPs) utilizing Oldenlandia Umbellata (OU) leaves extract, as well as to study the photo catalytic and biological activities of these particles. XRD, UV-Visible, FT-IR, SEM, EDAX, TEM and Zeta potential studies were used to investigate the purity and properties of as synthesized ZnO NPs. From the FT-IR investigations presenting functional groups were verified. The hexagonal form and wurtzite crystal nature were confirmed by SEM and XRD photographs. The decreasing zeta potential of −23.7 mV suggested the stability of OU-ZnO NPs, which was validated by Zeta potential and EDAX measurements. The OU-ZnO NPs' photo catalytic activity was also examined using their methylene red dye degradation potential. It also has a DPPH test that revealed it had a 66% radical scavenging activity. Furthermore, this substance was proven to be an effective anti-fungal agent against Candida albicans, which demonstrated a maximum mycelial inhibition of 12.5 ± 0.7. Additionally, the biosynthesized nanoparticles had high antibacterial activity verses all of the microbiological strains tested to varying degrees.

Self-cooling mortar production with zinc oxide nanoparticles additive and investigation of the DC application when early-age hydration

In this study, mortars with 300 dosages (weight of cement in mortar for 1 m3 production) were prepared by adding 0%, 0.25%, 0.50%, 0.75%, and 1.00% by weight ZnO instead of cement. To investigate the effect of direct current (DC) on the flexural and compressive strength of the mortars, 22.5 V DC was applied to some of the specimens for one day while they were fresh. To investigate the effect of ZnO and DC on the hydration temperature, the hydration temperature values of the cement-based mortars were measured by placing a thermocouple (temperature meter) in the middle of the samples for one day. Various comparisons were made by recording the internal temperature values (°C) of the mortars using a data logger for each minute that electrical current was applied, and the electrical current was not applied. It was concluded that as the ZnO ratio in the mortars increased, the hydration temperature decreased. As a result, the setting time can be delayed by adding ZnO nanoparticles to mortars. Another result obtained from this research is that the final setting time can be shortened by increasing the ZnO ratio and applying DC to the mortars. HIGHLIGHTS Production of zinc oxide nanoparticles added mortar. The effect of direct current (DC) on mechanical, and microstructure features of the mortar. Delaying the setting time by using nano technology product (ZnO) Accelerating the setting time by using ZnO and DC application

ZnO Nanoparticles for Photocatalytic Methyl Orange Degradation: Hydrothermal Synthesis, Characterization, and Optimization

This study investigates the production of zinc oxide nanoparticles (ZnO NPs) utilizing an efficient and surfactant-free hydrothermal method for use as a photocatalytic agent in the purification of organic polluted water. The structural features, optical properties and photocatalytic performance of ZnO NPs have been investigated. XRD, SEM, HR-TEM, FTIR and UV–vis absorption spectroscopy were used as analytical and characterization techniques. The ZnO NPs prepared with hexagonal structure and interesting applied properties was obtained by adjusting the processing time at a low treatment temperature of 75 °C. The crystallite size and energy band gap are reaction time-dependent, which in turn affects the photocatalytic performance. ZnO NPs under UV irradiation show an efficiency of 93% in the photocatalytic decomposition of methyl orange (MO) dye. The value of ZnO NPs bandgap (3.38 eV) is suitable for allowing UV light absorption and rapid generation of charge carriers; creating photooxidation reactions for decomposing the organic dye.

Single and Combined Toxicity Effects of Zinc Oxide Nanoparticles: Uptake and Accumulation in Marine Microalgae, Toxicity Mechanisms, and Their Fate in the Marine Environment

Recently, there has been rapid growth in the production of zinc oxide nanoparticles (ZnO-NPs) due to their applications in household and cosmetic products. Over the last decade, considerable research was conducted to reveal the effect of ZnO-NPs on microalgae, which form the base of the aquatic food chain. This review discusses the fate and behavior of ZnO-NPs in the marine environment. Predominately, the toxicity mechanism of ZnO-NPs on marine microalgae could be attributed to three sources: the release of Zn2+ ions; the interaction between ZnO-NPs and algae cells; and the generation of reactive oxygen species (ROS). Most toxicity studies were carried out using single ZnO-NPs under conditions not often observed in natural ecosystems; however, organisms including microalgae are more likely exposed to ZnO-NPs mixed with other types of pollutants. This review highlights the importance of increasing the assessment studies of combined pollutants. Lastly, knowledge, research, gaps, and opportunities for further research in this field are presented.

The toxicity analysis of PVP, PVA and PEG surface functionalized ZnO nanoparticles on embryonic as well as adultDanio rerio.

Globally, the production of zinc oxide nanoparticles (ZnO NPs) increased due to its wide applications including cosmetics, paints etc., and gets accumulated in the environment during their production, use or end-of-life. The toxic effects of the NPs vary with the presence of various surface modification agents. In the current report, toxic effect of bare and capped ZnO NPs with polymeric surface modifying agent including polyvinyl alcohol (PVA), polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP) is studied against adult as well as embryonic zebra fish. The surface capped NPs showed great variation in toxicity levels. It was observed that ZnO-PVA showed highly reduced toxic effects relative to ZnO-PEG and ZnO-PVP. Further, various environmental agents including humic acid can also have an impact on NPs toxicity. ZnO particles showed increased toxic effect in humic acid presence. The uptake of ZnO particles by D. rerio was high in the order of PVP-, PEG- and PVA- followed by bare-ZnO. The current investigation found that ZnO NPs dissolution and uptake are the major factors which cause the toxicity against adult as well as embryonic zebra fishes respectively.

Green Synthesis, Characterization of Zinc Oxide Nanoparticles, and Examination of Properties for Dye-Sensitive Solar Cells Using Various Vegetable Extracts

The production of zinc oxide nanoparticles (ZnO NPs) utilizing different vegetable extracts (onion, cabbage, carrot, and tomato) was performed in this research owing to its excellency over other methods of synthesis, namely, simplicity, environmental friendliness, and the elimination of harmful compounds. Fresh extracted onion, cabbage, carrot, and tomato of ZnO NPs are characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectroscopy. FTIR findings demonstrate that the prepared nanoparticles were observed in the spectrum of 626 cm-1–1219 cm-1 with some other functional groups. Wurtzite hexagonal structure of the prepared ZnO NPs was observed from XRD results. In addition, the prepared nanoparticles were failed into nanoscales (17 nm, 18 nm, 24 nm, and 15 nm) calculated from Scherrer’s equation. Nearly spherical shapes were seen from SEM image for onion and tomato extraction while rod and tube for carrot and cabbage, respectively. Two broad peaks were observed from UV-vis spectroscopy results for each extract. The presence of a wide range of energy bandgaps in the region of 3-4 eV was detected, indicating that ZnO NP material can be employed in metal oxide semiconductor-based systems. The dye-sensitive solar cell based on ZnO NPs has been successfully synthesized, and the efficiency of the device has been evaluated by measuring the current density-voltage behaviour under the presence of artificial sunshine. The increased effectiveness of the manufactured dye-sensitive solar cell is attributable to a large improvement in dye molecular adsorption onto the surface of ZnO NPs. Thus, the usage of the green produced ZnO NPs with creating dye sensitivity solar cell is a simple and viable way for the well-being of our future.

Structural and biochemical modifications of model and native membranes of human immune cells in response to the action of zinc oxide nanoparticles.

The development of nanotechnology has led to the increased production of zinc oxide nanoparticles (ZnO-NPs) and their application in a wide variety of everyday products. It creates the need for a full assessment of their safety for humans. The aim of the study was to assess the toxic effects of ZnO-NPs on model human cells of the immune system: U-937, HL-60, HUT-78, and COLO-720L. Particular attention was paid to the direct interaction of the nanoparticles with membrane lipids and the role of zinc ions in the mechanism of their toxicity. Cell viability, lipid peroxidation, cell membrane integrity, and the amount of zinc ions released from nanoparticles were tested. Disruption in cell metabolism was noted for ZnO-NPs concentrations from 6.25 mg/L. Contact with ZnO-NPs caused lipid peroxidation of all cells and correlated with membrane disruption of HL-60, HUT-78, and COLO-720L cells. Model monolayers (Langmuir technique) were used to assess the interaction of the nanoparticles with the studied lipids. Physicochemical parameters, such as the area per molecule at maximal layer compression, the pressure at which the monolayer collapses, and the static compression modulus, were calculated. The models of the HL-60 and U-937 cell membranes under ZnO-NPs treatment reacted in a different way. It has also been shown that Zn2+ are not the main causative factor of ZnO-NPs toxicity. Investigating the early stages of mechanism of nanoparticles toxicity will allow for a more complete risk assessment and development of methods for a safer synthesis of engineering nanomaterials.

Zinc Oxide Nanoparticles Obtained by Supercritical Antisolvent Precipitation for the Photocatalytic Degradation of Crystal Violet Dye

In this work, the synthesis of zinc oxide (ZnO) photocatalyst from thermal decomposition of zinc acetate (ZnAc) nanoparticles obtained by supercritical antisolvent (SAS) precipitation was investigated. The optimization of calcination conditions of the SAS ZnAc was carried out, studying the effect of temperature (in the range 300–600 °C) on the production of ZnO nanoparticles. In particular, it was demonstrated that the organic residues in ZnO and its particle size, thus the specific surface area, strongly affect the photocatalytic performances. SAS micronization of ZnAc produces regular nanoparticles with a mean diameter of about 54.5 ± 11.5 nm, whereas unprocessed ZnAc is characterized by very large crystals. The experimental results evidenced that ZnAc prepared by SAS process calcined at 500 °C showed a regular nanometric structure (mean diameter: 65.0 ± 14.5 nm) and was revealed to be the best choice for the photocatalytic removal of crystal violet dye (CV). In fact, the photocatalytic activity performances of ZnO nanoparticles prepared by this route were higher with respect to that of ZnO from unprocessed ZnAc calcined at 500 °C (which is characterized by irregular tetrapods with mean size 181.1 ± 65.5 nm). The optimized photocatalyst was able to assure the complete CV decolorization in 60 min of UV irradiation time and a mineralization degree higher than 90% after 120 min of treatment time.

Biocompatibility assessment and photocatalytic activity of bio-hydrothermal synthesis of ZnO nanoparticles by Thymus vulgaris leaf extract

A facile synthetic route and growth mechanism of phytochemicals stabilized zinc oxide (ZnO) nanoparticles have been developed using Thymus vulgaris (Thyme) leaf extract via hydrothermal method. Using thyme leaf extract as a size reducing agent with zinc nitrate as precursor via hydrothermal method is the novelty of this work. Presence of flavonoids, phenols and saponins in Thyme leaf extract has served as both reducing and stabilizing agents that play a critical role in the production of ZnO nanoparticles. The obtained ZnO nanoparticles having 50−60 nm size with an irregular shape. The in-vitro antioxidant activity by DPPH assay showed prominent activity (<75%) for higher concentration (10 mg/ml) of tested ZnO nanoparticles. The antimicrobial activity of ZnO nanoparticles against selected foodborne pathogens revealed that the tested gram-negative bacteria are more pronounced than the tested gram-positive bacteria. The maximum hemolysis percentage for all the samples were less than ∼3% (up to 6 mg/ml) which is much lesser than permissible limit. The results showed the great photocatalytic degradation of methylene blue (MB) as compared to Control (TiO2-P25). Results of this study reveals that Thyme leaf extract containing phytochemicals possess reducing property for ZnO nanosize fabrication and the obtained ZnO nanoparticles could be employed effectively for biological applications and food science.

Environmentally-Friendly Green Approach for the Production of Zinc Oxide Nanoparticles and Their Anti-Fungal, Ovicidal, and Larvicidal Properties

Green synthesis of nanoparticles can be an important alternative compared to conventional physio-chemical synthesis. We utilized Scadoxus multiflorus leaf powder aqueous extract as a capping and stabilizing agent for the synthesis of pure zinc oxide nanoparticles (ZnO NPs). Further, the synthesized ZnO NPs were subjected to various characterization techniques. Transmission electron microscope (TEM) analysis showed an irregular spherical shape, with an average particle size of 31 ± 2 nm. Furthermore, the synthesized ZnO NPs were tested against Aedes aegypti larvae and eggs, giving significant LC50 value of 34.04 ppm. Ovicidal activity resulted in a higher percentage mortality rate of 96.4 ± 0.24 at 120 ppm with LC50 value of 32.73 ppm. Anti-fungal studies were also conducted for ZnO NPs against Aspergillus niger and Aspergillus flavus, which demonstrated a higher inhibition rate for Aspergillus flavus compared to Aspergillus niger.

Sonication-assisted synthesis of a new cationic zinc nitrate complex with a tetradentate Schiff base ligand: Crystal structure, Hirshfeld surface analysis and investigation of different parameters influence on morphological properties

A nanostructured cationic zinc nitrate complex with a formula of [ZnLNO3]NO3 (where L = (N2E,N2′E)-N1,N1′-(ethane-1,2-diyl)bis(N2-((E)-3-phenylallylidene)ethane-1,2-diamine)) was prepared by sonochemical process and characterized by single crystal X-ray crystallography, scanning electron microscopy (SEM), FT-IR and NMR spectroscopy and X-ray powder diffraction (XRPD). The X-ray analysis demonstrates the formation of a cationic complex that metal center is five-coordinated by four nitrogen atom from Schiff base ligand and one oxygen atom from nitrate group. The crystal packing analysis demonstrates the essential role of the nitrate groups in the organization of supramolecular structure. The morphology and size of ultrasound-assisted synthesized zinc nitrate complex have been investigated using scanning electron microscopy (SEM) by changing parameters such as the concentration of initial reactants, the sonication power and reaction temperature. In addition the calcination of zinc nitrate complex in air atmosphere led to production of zinc oxide nanoparticles.

Beta vulgaris aided green synthesis of ZnO nanoparticles and their luminescence, photocatalytic and antioxidant properties

Multifunctional zinc oxide nanoparticles (ZnO Nps) were synthesized by solution combustion synthesis using beetroots (Beta vulgaris). The structure and morphology of the product were studied by powder X-ray diffraction, UV-visible spectroscopy and scanning electron microscopy. XRD studies indicate the formation of Nps with hexagonal wurtzite structure having crystallite sizes in the range of ∼ 52–76 nm. The UV-visible spectrum of Nps shows maximum absorption at 373 nm. The SEM analysis indicates the formation of porous, sponge-like agglomerated structures. Very interesting room temperature luminescence phenomena were observed with violet, green and red emissions upon exciting the ZnO Nps at 378 nm. This phenomenon could be due to oxygen vacancy and ZnO interstitial defects. ZnO Nps effectively degrade malachite green (MG) and methylene blue (MB) dyes in the presence of UV light. Nps show good antioxidant activity by scavenging 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals. The study successfully demonstrates simple, economical and ecofriendly methods of synthesis of multifunctional ZnO Nps. Nps may be used as good color tunable phosphor materials. The method demonstrated in this study is suggested as an effective replacement for the hazardous chemical methods of production of zinc oxide nanoparticles.

Zinc oxide nanoparticles toxicity to Daphnia magna: size‐dependent effects and dissolution

As the production of zinc oxide nanoparticles (ZnO-NPs) and other metal oxides is exponentially increasing, it is important to investigate potential environmental and health impacts of such nanoparticles. Nanoparticles' properties (e.g., size, dissolution rate) may change in different water media, and their characterization is essential to derive conclusions about toxicity results. Therefore, an aquatic model organism, Daphnia magna, was used to investigate the effect of ZnO-NPs with 2 different particle sizes (30 nm and 80-100 nm) and then compare these effects with ZnO microsized particles (>200 nm) and the ionic counterpart (in the form of ZnCl2 ) on immobilization, feeding inhibition, and reproduction endpoints. The 48-h median lethal concentration (LC50) for immobilization ranged between 0.76 mg Zn L(-1) for the ionic zinc and 1.32 mg Zn L(-1) for ZnO-NPs of 80 nm to 100 nm. For the chronic exposures, the reproduction output was impaired similarly among zinc exposures and possibly driven mainly by the zinc ionic form. The concentrations used showed a total dissolution after 48 h. On the other hand, feeding activity was more affected by the 30 nm ZnO-NPs than by the ionic zinc, showing that the particulate form was also playing an important role in the feeding inhibition of D. magna. Dissolution and particle size in the daphnia test media were found to be essential to derive conclusions on toxicity. Therefore, they can possibly be considered critical for evaluating nanoparticles' toxicity and fate.

Association of zinc ion release and oxidative stress induced by intratracheal instillation of ZnO nanoparticles to rat lung

Zinc oxide (ZnO) nanoparticles are one of the important industrial nanoparticles. The production of ZnO nanoparticles is increasing every year. On the other hand, it is known that ZnO nanoparticles have strong cytotoxicity. In vitro studies using culture cells revealed that ZnO nanoparticles induce severe oxidative stress. However, the in vivo influence of ZnO nanoparticles is still unclear. In the present study, rat lung was exposed to ZnO nanoparticles by intratracheal instillation, and the influences of ZnO nanoparticles to the lung in the acute phase, particularly oxidative stress, were examined. Additionally, in vitro cellular influences of ZnO nanoparticles were examined using lung carcinoma A549 cells and compared to in vivo examinations. The ZnO nanoparticles used in this study released zinc ion in both dispersions. In the in vivo examinations, ZnO dispersion induced strong oxidative stress in the lung in the acute phase. The oxidative stress induced by the ZnO nanoparticles was stronger than that of a ZnCl2 solution. Intratracheal instillation of ZnO nanoparticles induced an increase of lipid peroxide, HO-1 and alpha-tocopherol in the lung. The ZnO nanoparticles also induced strong oxidative stress and cell death in culture cells. Intracellular zinc level and reactive oxygen species were increased. These results suggest that ZnO nanoparticles induce oxidative stress in the lung in the acute phase. Intracellular ROS level had a high correlation with intracellular Zn2+ level. ZnO nanoparticles will stay in the lung and continually release zinc ion, and thus stronger oxidative stress is induced.

Production of Zinc Oxide Nanoparticles by Liquid Phase Processing: an Investigation on Optical Properties

In the recent years, many researchers have been interested in nanoparticles because of their unique properties. In this study, a method for producing ZnO nanoparticle colloids is proposed. The colloids were characterized by spectroscopic analyzer. By absorption spectrum study, we found out that colloids were consisted of nanoparticles with less than 10 nanometer size. The quantum confinement effect in these spectrums was recognized through blue shift of onset absorption wavelengths. These wavelengths shift from 370 nm to 340 nm by decreasing the particles size. Transmittion electron micrographs showed formation of zinc oxide nanoparticles.