Stability Of ZnO Nanoparticles Research Articles

Synthesis of ZnO Nanoparticle using Lidah Mertua (Sansevieria trifasciata) Extract through Sol-Gel Method and Its Application for Methylene Blue Photodegradation

Methylene blue is widely used in the textile industry and is difficult to degrade naturally because of its heterocyclic aromatic structure. One technique that can be used to degrade methylene blue is through a photocatalytic process using ZnO nanoparticles. This study aims to synthesize ZnO nanoparticles using Lidah mertua extract (Sansevieria trifasciata) as a capping agent by the sol-gel method, and determine the characteristics and stability of ZnO nanoparticles in methylene blue photodegradation. The synthesis of ZnO nanoparticles begins with drying Lidah mertua, grinding it, and then extracting it using distilled water. Furthermore, the extract was reacted with Zn(CH3COO)2.2H2O 0.15 M at pH 8. The extract was characterized using Fourier Transform Infrared (FTIR), and the ZnO nanoparticles were characterized using X-Ray Diffraction (XRD), ultraviolet-visible (UV-Vis) DRS, and Scanning Electron Microscopy (SEM). Lidah mertua extract has OH (hydroxyl), CN, CH, and C=C functional groups. The obtained ZnO nanoparticles have a crystal size of 19.324 nm. The crystalline phase is hexagonal; the morphology is spherical, with a particle size of 79.153 nm and a band gap energy of 3.21 eV. ZnO nanoparticles exhibited a methylene blue decolorization of 98.50% through 43.41% by adsorption and 55.09% by photocatalytic mechanism. ZnO nanoparticles showed good stability for a three-cycle reaction. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

Cosmetic nanomaterials in the environment: nano-zinc oxide and zinc-influence on soil microorganisms

This study aimed to investigate the impact of water-containing sunblock products with different residual quantities of bulk ZnO or ZnO nanoparticles (NPs) on soil microorganisms using a bioassay toxicity experiment. The two forms of ZnO were studied at different concentrations ranging from 0 to 10 mg L−1, and leachates obtained from the water disposal during a handwashing simulation experiment were also evaluated, along with raw sunblocks containing both bulk ZnO and ZnO NPs (at 50% and 100%). The key characteristics of each type of ZnO material were analyzed using multiple analytical techniques, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and ultraviolet–visible spectroscopy (UV–Vis). The outcomes revealed that the stability of ZnO nanoparticles was considerably high, with the highest dissolution rate estimated after 36 h as 0.19% of the sunblock's overall ZnO NPs concentration. The different forms of pure ZnO used in the bacterial bioassay demonstrated that the Zn concentration of 10 mg L−1 exhibited the largest inhibition zone area compared to the other treatments. The disc diffusion bioassay findings confirmed that ZnO NPs are active components with greater toxicity than bulk ZnO. These results demonstrated that the antimicrobial effect was exclusively due to the nano-specific influence at higher concentrations. However, additional research is needed to understand better the environmental effects of different types of ZnO particles disposed of by sunblock users. Examining how such substances react in actual environmental conditions is crucial, as they contain various diverse ingredients that may cause varying reactions compared to bulk ZnO particles.

Experimental studies on ethanol solubility and nanoparticle (NP) stability in diesel fuel

The main objective of the study was to prepare the most soluble and stable diesel-ethanol-nanoparticle blend for CI engine and investigate the influence of different mixing parameters on ethanol’s solubility in diesel and the nanoparticle stability in diesel-ethanol blends. Total 22 DE10, and DE15 samples were prepared, using various stirring speeds (1500–2000, 2500–4000 rpm) and times (30, 60, 120, 180, 240, 360 min), ultrasonication times (15, 30, 60, 90, 120 min) with and without surfactants (SPAN 80, TWEEN 80). The result revealed that ultrasonication, stirring speed and time influenced the ethanol solubility in diesel fuel and ethanol solubility was better with DE10 blend (Sample G) prepared using low ultrasonication (15 min) and high stirring time (min. 60 min) and speed (min. 2500–4000 rpm) without surfactant. Increase in ultrasonication time (>15 min) resulted in negligible effect on solubility. The effect of ultrasonication, surfactant and dispersion approach on the stability of Al2O3 and ZnO nanoparticles in sample G was also studied. Stability of ZnO nanoparticles was much higher than the Al2O3 nanoparticles at same ultrasonication time (120 min) and surfactant proportion (0.5 %). It displayed lower agglomeration, and 50 %, 33 %, and 52 % reduction in sedimentation index, height and weight, respectively, compared to Al2O3 nanoparticle.

Bioactive properties of ZnO nanoparticles synthesized using Cocos nucifera leaves.

The online version contains supplementary material available at 10.1007/s13205-022-03110-9.

Polyphenol Enriched Extract of Pomegranate Peel; A Novel Precursor for the Biosynthesis of Zinc Oxide Nanoparticles and Application in Sunscreens

Background: Green synthesized nanoparticles (NPs) from agricultural wastes is an area of great interest due to it is eco-friendly and profitable. Zinc oxide is an inorganic UV-filter commonly used as UV-blocker in a different industry. Methods: Zinc oxide nanoparticles (ZnO NPs) were successfully biosynthesized using Zn(NO3)2 as a substrate by polyphenol enriched fraction (PEF) of pomegranate peel. The biological activity of ZnO NPs was evaluated using MBC and MIC tests for antibacterial and DPPH assay for antioxidant potential. Sunscreen potential of NPs was determined after applying them in water-in-oil emulsions. Results: UV-Vis and FT-IR spectroscopy techniques confirmed the formation of ZnO NPs. FE-SEM characterized the morphology and purity of the biosynthesized NPs with EDAX and XRD data. The average crystalline size of ZnO NPs was found to be 22 nm. FT-IR spectroscopy revealed the role of phenolic compounds in the formation and stability of ZnO NPs. The antibacterial activity of PEF and its biosynthesized ZnO was evaluated against Staphylococcus aureus and Escherichia coli. The prepared NPs showed a higher antibacterial effect than the commercial ZnO NPs. Interestingly, the antioxidant activity was also detected for obtained NPs. The PEF powder also exhibited higher antibacterial and antioxidant activity than the standards. Furthermore, the in vitro sun protection factors were estimated after applying NPs in water-in-oil emulsions. Conclusion: This study highlighted the possibility of using PEF of pomegranate peel for the biosynthesis of ZnO NPs as well as applying its NPs in sunscreens to achieve a safe alternative to harmful chemical UV-filters commonly used in cosmetics.

One step synthesis of ZnO nanoparticles with zinc acetate dehydrates and potassium

In this study, pure ZnO nanoparticles have been synthesised by one-step method where zinc acetate dehydrates and potassium use as a precursor. The (ultraviolet-visible) UV-vis absorption spectrum was indicated that the reduction and stabilisation of ZnO nanoparticles in aqueous medium. The peaks in X-ray diffraction (XRD) pattern were revealed that the formation of ZnO in nanoscale and it good treaty with that of crystalline hexagonal structure. It was observed that ZnO elicited in form of nanoparticles and nanoflowers in spherical shape as well as homogeneous dispersion. The grain size were found to be 18 nm–40 nm. Thermo gravimetric analysis and diffractive thermal analysis results were showed the thermal stability of ZnO nanoparticles in the temperature region of room temperature to 1,00°C. Fourier transform infrared (FTIR) measurement revealed that the synthesised Zn ion have potential interaction towards organic aqueous fluid to form of ZnO nanoparticles.

The effect of humic acid and bovine serum albumin on the adsorption and stability of ZnO nanoparticles on powdered activated carbon

Abstract Natural organic matter (NOM) can influence the properties and behavior of metal nanoparticles (MNPs) in aquatic environments. Thus, understanding the effect of NOM on MNPs’ physiochemical properties is critical for identifying an effective water treatment processes, and controlling the potential risk they pose to ecological and human health. In this study, adsorption and leaching experiments were performed with powder activated carbon (PAC), to investigate the effect of humic acid (HA) and bovine serum albumin (BSA) on the removal of ZnO nanoparticles (ZnONPs) from an aqueous environment and their stability on the adsorbed PAC. The different ZnONPs forms— particulate, colloidal, and dissolved Zn fractions, were respectively considered. The adsorption experiments demonstrated that both colloidal and dissolved Zn fractions can adsorb on the PAC’s surface. As the HA concentration increased from 0 to 20 mg/L, the colloidal Zn fraction’s adsorption efficiency decreased from 74.49% to 61.24%. However, BSA did not significantly influence the colloidal Zn fraction’s adsorption. The leaching experiments showed that the colloidal Zn fraction would release from the PAC’s surface, and most of them transferred to the dissolved Zn fraction. As the HA concentration increased from 0 to 20 mg/L, the Zn concentration leached from the PAC adsorbed ZnONPs reduced from 0.956 to 0.694 mg/g. Comparatively, the leached Zn concentration varied only slightly with an equal increase in BSA concentration.

Ultrasonication‐Assisted Synthesis of 3‐Substituted Indoles in Water Using Polymer Grafted ZnO Nanoparticles as Eco‐Friendly Catalyst

AbstractIndole based heterocyclic molecules are important and valuable structural unit that are present in various biologically active natural products, pharmaceuticals and agrochemicals. In this paper, zinc oxide nanoparticles were explored as catalyst for the synthesis of 3‐substituted indoles in water via ultra‐sonication. The stability of ZnO nanoparticles and their dispersion in water was enhanced by grafting it with a biodegradable polymer (poly lactic acid). The proposed methodology is capable of providing desired products in good yield (83‐97%) and 25 derivatives of indoles were synthesized. The green reaction metrics such as E‐factor (0.16) and atom economy (97%) show that the present protocol is sustainable and economical. Also, the reactions were carried out in water under environmentally benign conditions that avoids use of any additives or hazardous solvents.

Facile and green synthesis of zinc oxide particles by Stevia Rebaudiana and its in vitro photocatalytic activity

Stevia rebaudiana leaves is a well-known medicinal plant for its non-caloric bio-sweetener. To enhance its value addition, employed first time for synthesis and stabilization of ZnO nanoparticles. The characterization using UV-Spec, FE-TEM, XRD, DLS revealed that SR-ZnO (ZnO particles obtained from S. rebaudiana) were flower-shape, 500–1,000 nm sizes, hydrodynamic diameter Z-average of polydisperse SR-ZnO was 582.35 ± 52.40 nm with a PDI of 0.33 ± 0.002. Furthermore, 76% degradation of methylene blue dye within 30 min exposure to SR-ZnO and plant extract under UV light indicates that it could be utilized as an efficient photocatalyst for wastewater treatment.

Corrigendum to "Synthesis and stabilization of ZnO nanoparticles on a glass plate to study the removal efficiency of acid red 18 by hybrid advanced oxidation process (ultraviolet/ZnO/ultrasonic) published in vol. 170 (2019) pp. 325–336 (doi:10.5004/dwt.2019.24728)

Corrigendum to "Synthesis and stabilization of ZnO nanoparticles on a glass plate to study the removal efficiency of acid red 18 by hybrid advanced oxidation process (ultraviolet/ZnO/ultrasonic) published in vol. 170 (2019) pp. 325–336 (doi:10.5004/dwt.2019.24728)

Synthesis and stabilization of ZnO nanoparticles on a glass plate to study the removal efficiency of acid red 18 by hybrid advanced oxidation process (ultraviolet/ZnO/ultrasonic)

Synthesis and stabilization of ZnO nanoparticles on a glass plate to study the removal efficiency of acid red 18 by hybrid advanced oxidation process (ultraviolet/ZnO/ultrasonic)

Optical excitation-enhanced sensing properties of acetone gas sensors based on Al2O3-doped ZnO

PurposeThe purpose of this research is to synthesize Al2O3-ZnO thick films, study the effect of doping and optical excitation on their sensing properties and introduce an attractive candidate for acetone detection in practice.Design/methodology/approachZnO nanoparticles doped with Al2O3 were prepared by sol-gel method and characterized via X-ray diffraction and field-emission scanning electron microscopy. The sensing properties to acetone were investigated with an irradiation of UV. The sensing mechanism was also discussed with UV-Vis spectroscopy.FindingsThe doping of Al2O3 promoted the sensing response and stability of ZnO nanoparticles. The optimum performance was obtained by 4.96 Wt.% Al2O3-ZnO. The response to acetone (1,000 ppm) was significantly increased to 241.81, even just at an operating temperature of 64°C. It was also demonstrated that optical excitation with UV irradiation greatly enhanced the sensing response and the sensitivity can reach up to 305.14.Practical implicationsThe sensor fabricated from 4.96 Wt.% Al2O3-ZnO exhibited excellent acetone-sensing characteristics. It is promising to be applied in low power and miniature acetone gas sensors.Originality/valueIn the present research, the optimum performance was obtained by 4.96 Wt.% Al2O3-ZnO at a low operating temperature of 64°C. The sensing properties were enhanced significantly with optical excitation, and the sensing mechanism was discussed with UV-Vis spectroscopy which has been reported rarely before.

Influence of EDC/NHS coupling chemistry on stability and cytotoxicity of ZnO nanoparticles modified with proteins

The toxicity of ZnO nanoparticles (NPs) is a growing concern due to its increasing use in several products including sunscreens, paints, pigments and ceramics for its antibacterial, antifungal, anti-corrosive and UV filtering properties. The toxicity of ZnO NPs is mostly attributed to the Zn2+ release causing an increase in the intracellular reactive oxygen species (ROS) level. The surface modification with a biocompatible ligand or a polymer can be a good strategy to reduce dissolution based toxicity. In two previous studies, the conflicting results with EDC/NHS coupling chemistry for ZnO NPs were reported. In this study, the same surface modification strategy with an emphasis on the stability of ZnO NPs is clarified. First, the density of –OH groups on the ZnO NPs is increased with hydrogen peroxide (H2O2) treatment, and then a silica coating on the ZnO NPs (Si-ZnO) surface is performed. Finally, a covalent attachment of bovine serum albumin (BSA) on three different concentrations of ZnO-Si is carried out by EDC/NHS coupling chemistry. ZnO NPs have a very high dissolution rate under acidic conditions of EDC/NHS coupling chemistry as determined from the ICP-MS analysis. In addition, the amount of ZnO NPs in coupling reaction has an important effect on the dissolution rate of Zn2+ and dependently BSA attached on the ZnO NP surfaces. Finally, the cytotoxicity of the BSA modified Si-ZnO NPs on human lung cancer (A549) and human skin fibroblast (HSF) is evaluated. Although an increased association of BSA modified ZnO NPs with cells was observed, the modification significantly decreased their cytotoxicity. This can be explained with the decreased active surface area of ZnO NPs with the surface modification. However, an increase in the mitochondrial depolarization and ROS production was observed depending on the amount of BSA coverage.

Aloe vera extract functionalized zinc oxide nanoparticles as nanoantibiotics against multi-drug resistant clinical bacterial isolates

ZnO nanoparticles (ZnONPs) were synthesised through a simple and efficient biogenic synthesis approach, exploiting the reducing and capping potential of Aloe barbadensis Miller (A. vera) leaf extract (ALE). ALE-capped ZnO nanoparticles (ALE-ZnONPs) were characterized using UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) analyses. XRD analysis provided the average size of ZnONPs as 15nm. FTIR spectral analysis suggested the role of phenolic compounds, terpenoids and proteins present in ALE, in nucleation and stability of ZnONPs. Flow cytometry and atomic absorption spectrophotometry (AAS) data analyses revealed the surface binding and internalization of ZnONPs in Gram +ve (Staphylococcus aureus) and Gram −ve (Escherichia coli) cells, respectively. Significant antibacterial activity of ALE-ZnONPs was observed against extended spectrum beta lactamases (ESBL) positive E. coli, Pseudomonas aeruginosa, and methicillin resistant S. aureus (MRSA) clinical isolates exhibiting the MIC and MBC values of 2200, 2400μg/ml and 2300, 2700μg/ml, respectively. Substantial inhibitory effects of ALE-ZnONPs on bacterial growth kinetics, exopolysaccharides and biofilm formation, unequivocally suggested the antibiotic and anti-biofilm potential. Overall, the results elucidated a rapid, environmentally benign, cost-effective, and convenient method for ALE-ZnONPs synthesis, for possible applications as nanoantibiotics or drug carriers.

Effects of cyanobacterial extracellular polymeric substances on the stability of ZnO nanoparticles in eutrophic shallow lakes

Extracellular polymeric substances (EPS) from bloom-forming cyanobacteria exist ubiquitously in eutrophic waters, while their effects on the aggregation/stabilization of nanoparticles remain unknown. In this study, the stability of ZnO nanoparticles (ZNPs) upon adsorption of cyanobacterial EPS was investigated by using two dimensional ATR-FTIR correlation spectroscopy, XPS and DLVO theory. Results showed that the adsorption process followed the Langmuir isotherm and pseudo-second-order kinetics both for the total organic contents as well as the individual parallel factor-derived components. The physicochemical and spectroscopic techniques revealed the mechanism of both electrostatic attraction and surface complexation in EPS adsorption. Further analysis showed increased absorbance and turbidity of ZNPs solutions with EPS addition, demonstrating the enhanced colloidal stability. The DLVO theory explained that the increased energy barriers and values of second energy maximum were responsible for the stability enhancement. This study facilitates a deeper insight into the environmental behavior of nanoparticles in eutrophic algae-rich waters.

Stability of ZnO Nanoparticles in Solution. Influence of pH, Dissolution, Aggregation and Disaggregation Effects

In this study, the zeta potential and z-average hydrodynamic diameter of zinc oxide (20 nm, 99.5% purity) were investigated as a function of pH and time. The nanoparticles readily formed aggregates and could not be disintegrated to its primary size eventhough ultrasonication was applied. In zinc oxide suspensions (25 mgL and 100 mg/L) the nanoparticles were examined for electrophoretic mobility and aggregation behaviour within the pH range of 3 to 11 and time duration of 60 minutes. In this study, the particle size and zeta potential were measured by dynamic light scattering technique. The application of nanoparticle tracking analysis was demonstrated as well to observe the aggregation and disaggregation of zinc oxide nanoparticles at various pH values. The NTA results obtained in this work were compared and validated by the DLS. The z-average hydrodynamic diameter of the particles was 389 d.nm with an average zeta potential value of +23 mV using the DLS compared to mean particle size of 365 d.nm by NTA. DLS analysis also identified the pH of the point of zero charge (pHPZC) and the isoelectric point (IEP) at pH 9.4 and pH 6.4 respectively. It was found that the zeta potential remained unaffected by the concentration of the suspension. However, results show that pH does have a pronounced effect on the stability of zeta potential, pH and particle size as a function of time in pH regions where dissolution (< pH 6.4 and 8.3 < pH < 10.5) and aggregation (pH 6.4 and 9.4) occurs. It is apparent that the pH of the suspension strongly influences the zeta potential of ZnO nanoparticles without external factors which will consequently govern their behaviour, agglomeration state and their interactions with each other and surfaces in the environment.

The effect of cations on the aggregation of commercial ZnO nanoparticle suspension

Nanoscale ZnO materials have been largely used in many products due to their distinct properties. However, ZnO nanoparticles (NPs) are hazardous to human health and the ecosystem. The characteristics and the stability of ZnO NPs are relevant to their fate in the environment and their potential toxicities. In this study, a stable commercial ZnO NP suspension was chosen to investigate its aggregation under various salt additions. Different concentrations of NaCl, KCl and CaCl2 were chosen to represent various environmental conditions. Under pH 8–9, the surface charge of commercial ZnO NPs was negative. The behavior of the stabilized ZnO NPs in water was affected by ionic combinations and ionic strength; that is, divalent cations were more effective than monovalent ones in promoting aggregation formation. The attachment efficiencies of ZnO aggregates were calculated based upon the aggregation kinetics. The critical coagulation concentration values for this commercial ZnO NPs were higher than previous reported for ZnO NPs, indicating this ZnO NP could be stable in the aquatic environment and might have increased hazardous potentials. Based upon the Derjaguin–Landau–Verwey–Overbeek theory, interactions between ZnO NPs in the presence of different ions were evaluated to illustrate the aggregation mechanism. Our results indicated that critical ionic type and concentration promote the aggregation of stable ZnO NPs. These understandings also can facilitate the design of the precipitation treatment to remove NPs from water.

Hyperbranched Polymers for the Formation and Stabilization of ZnO Nanoparticles

The synthesis and characterization of a new family of dendritic polymers comprising a hyperbranched polyamidoamine core and polyethyleneglycol-derivative units is reported. The mentioned polymers have either core−shell or core−multishell architectures. Their intrinsic properties (solubility in a wide range of solvents, ability to interact with hydrophilic or hydrophobic compounds, etc.) allows the one-step in situ synthesis of water-soluble ZnO quantum dots via decomposition of an organometallic precursor. The effect of structural properties of the polymer (nature of the shell, core molecular weight, etc.), as well as external stimuli (temperature, ionic strength, etc.) on the formation and/or stabilization of nanoparticles has been evaluated. The as-synthesized nanoparticles could be easily redispersed in various solvents and presented stable photoluminescent properties.