Nanosized Zinc Oxide Research Articles

Fabrication and Characterization of Epoxy Matrix Nanocomposites Based on Zinc Oxide Nanoparticles

In this current research, an investigation was carried out on the fabrication of high-performance epoxy matrix nanocomposite for various engineering applications. The nanocomposite samples were synthesized using epoxy matrix, and nano sized zinc oxide particulates. The morphology, particle size and composition of the nano sized zinc oxide particulates were determined using the Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and Energy Dispersive Spectroscopy (EDS). The experimental nanocomposite samples were developed using 0, 1, 2,3,4,5 and 6 wt. % of ZnO nanoparticles by open cast method. Mechanical properties tests were carried out on the samples in accordance with ASTM standards. The results obtained show that tensile strength, flexural strength, and hardness of the nanocomposite samples increased progressively with increasing contents of the nano sized ZnO particulates up to 4 wt. %, after which a slight decrease in hardness, flexural strength, and tensile strength values were observed for samples containing 5 wt. % and 6 wt. % of reinforcement. Also, a similar trend was observed for impact strength results with nanocomposite sample containing 3wt. % reinforcement exhibiting the highest impact strength value of 11.18 KJ/m after which a slight decrease in impact strength value was observed for samples containing 4 wt. %, 5 wt. %, and 6 wt. % of ZnO nanoparticles respectively. Contrarily, the ductility of the nanocomposite samples decreases progressively with increasing contents of the nano sized ZnO particulates. Results obtained from microstructural examination of the nanocomposite samples show that the ZnO nanoparticles were well dispersed in the nanocomposite samples containing 1 wt. % to 4 wt. % of filler contents. However, agglomeration of the ZnO nanoparticles was observed in samples containing 5 wt. % and 6wt. % of filler contents. Keywords: Epoxy, Nanocomposite, Zinc Oxide Nanoparticles, Mechanical Properties.

ZnO Nanoparticles as Potent Inducers of Dermal Immunosuppression in Contact Hypersensitivity in Mice.

Nanosized zinc oxide (nZnO) metal particles are used in skin creams and sunscreens to enhance their texture and optical properties as UV filters. Despite their common use, little is known about the molecular mechanisms of nZnO exposure on damaged skin. We studied the effects of topically applied nZnO particles on allergic skin inflammation in an oxazolone (OXA)-induced contact hypersensitivity (CHS) mouse model. We investigated whether exposure to nZnO during the sensitization or challenge phase would induce immunological changes and modulate transcriptional responses. We followed skin thickness, cellular infiltration, and changes in the local transcriptome up to 28 days after the challenge. The responses peaked at 24 h and were fully resolved by 28 days. Co-exposure to nZnO and hapten did not interfere with the formation of the sensitization process. Conversely, during the hapten challenge, the application of nZnO fully suppressed the development of the CHS response by the inhibition of pro-inflammatory pathways, secretion of pro-inflammatory cytokines, and proliferation of immune cells. In differentiated and stimulated THP-1 cells and the CHS mouse model, we found that nZnO particles and Zn ions contributed to anti-inflammatory responses. The immunosuppressive properties of nZnO in inflamed skin are mediated by impaired IL-1R-, CXCR2-, and LTB4-mediated pathways. nZnO-induced dermal immunosuppression may be beneficial for individuals with contact allergies who use nZnO-containing cosmetic products. Our findings also provide a deeper understanding of the mechanisms of nZnO, which could be considered when developing nanoparticle-containing skin products.

Synthesis, Formulation and Evaluation of Zinc Oxide Nanoparticle of Capparis zeylanica L. Stem

The current study’s focus is on using Capparis zeylanica L. stem extract to produce nanosized zinc oxide (ZnO) biologically in a way that is economical, effective, and environmentally safe. The synthesized nanoparticles were characterized using several techniques such as UV-Vis spectroscopy, TEM, FTIR and UV-vis spectroscopy. UV-vis spectroscopy ranges 200 to 400 nm. Having particle size 248 nm having zeta potential -3.5 mV with different groups. The current work examined by formation of gel, which shows good spreadability.

Optimizing nano-TiO2 and ZnO integration in silica-based high-performance concrete: Mechanical, durability, and photocatalysis insights for sustainable self-cleaning systems

Optimizing nano-TiO2 and ZnO integration in silica-based high-performance concrete: Mechanical, durability, and photocatalysis insights for sustainable self-cleaning systems

A study on soil remediation of hexavalent chromium pollution using nano-sized zinc oxide and Miscanthus lutarioriparius

A study on soil remediation of hexavalent chromium pollution using nano-sized zinc oxide and Miscanthus lutarioriparius

The Application of Micro- and Nano-Sized Zinc Oxide Particles Differently Triggers Seed Germination in Ocimum basilicum L., Lactuca sativa L., and Lepidium sativum L. under Controlled Conditions

Zinc oxide (ZnO) particles have recently received attention in different agriculture sectors as new technologies and practices are entering into force with limited adverse effects on the environment. However, various works have reported both positive or negative effects on plants. The present study focused on an evaluation of the effects of four different new micro- and nano-sized ZnO particles (namely, Desert Roses (DRs), MultiPods (MPs), NanoFlakes (NFs), and NanoParticles (NPs)) on the seed germination traits of Ocimum basilicum L., Lactuca sativa L., and Lepidium sativum L. ZnO particles were applied at concentrations of 12.5 ppm, 25 ppm, and 50 ppm. Seeds moistened with deionized water were used as a control. All the particles were characterized by field emission scanning electron microscopy, and their production of Reactive Oxygen Species (ROS) under seed germination conditions was evaluated through electron paramagnetic resonance spectroscopy. Seeds of each species were put on filter paper under controlled conditions in both dark and light photoperiods. In this bioassay, the final germination percentage (FGP), early root length, and index of germination were evaluated. The results showed a wide variability of response to the type and concentration of ZnO particles and to the applied photoperiod of the three studied species. O. basilicum FGP increased when treated with NPs and DRs already at the lowest concentration and especially in light conditions with values significantly superior to those of the control (71.1%, 69.4%, and 52.2%, respectively). At higher concentrations, phytotoxicity on root length was observed, with a reduction of circa 30% in comparison to untreated seeds. On the contrary, in L. sativum, a phytotoxic effect was seen in radicle length with all the used ZnO particles and concentrations. L. sativa seeds did not show significant effects due to the type of particles, with a reduction in FGP only at higher concentrations and particularly in light conditions. Upon light irradiation, different levels of ROS were counted by the application of ZnO particles. DRs produced the highest amount of DMPO-OH adduct (up to 2.7 × 10−5 M) followed by the NP type (2.0 × 10−5 M). Taking together all these findings, the seeds’ coat morphology, their ability to absorb ZnO particles, and the ROS production in light conditions are indeed crucial players in the application of these formulations in seed germination.

Enhancing Hydrogen Sulfide Gas Detection: Tailoring ZnO Films Through a Novel Sol–Gel Approach with Ultra-Sonication

In this study, nano-sized Zinc Oxide (ZnO) particles were synthesized using a novel sol–gel process with Zn(NO3)2 solutions, specifically tailored for the development of a highly efficient Hydrogen Sulphide (H2S) gas sensing element. The impact of ultra-sonication on the properties crucial for H2S detection was systematically investigated. The resulting ZnO materials exhibited a well-defined crystalline structure along (100), (002), (101), and (102) planes, confirming the formation of the hexagonal wurtzite phase of ZnO. Significantly, an increase in sonication treatment time led to a reduction in particle size. The gas sensing properties for H2S were meticulously analyzed in relation to the varying sizes of ZnO films. Remarkably, the ZnO film fabricated with a 30-minute ultra-sonication treatment demonstrated the highest response to H2S gas at 423 K. The ZnO-thick films exhibited notable sensitivity, coupled with rapid reactivity and recovery times upon exposure to H2S gas. Importantly, our findings establish a direct correlation between the sensitivity of the ZnO sensor and the particle size.

Maximizing the potential of commercial zinc stearate for one-pot esterification and transesterification for high-acidity biodiesel production

Maximizing the potential of commercial zinc stearate for one-pot esterification and transesterification for high-acidity biodiesel production

Investigation of structural, linear, and nonlinear optical properties of nanosized zinc oxide and cadmium oxide particles ingrained in graphitic carbon nitrides

The study aims to evaluate the third-order optical nonlinearity caused by laser irradiation in transition metal oxide incorporated into graphitic carbon nitrides. The work describes the synthesis of nano-sized hybrid g-C3N4/ZnO (14%) and g-C3N4/CdO (14%). Nano-sized transition metal oxides: ZnO and CdO, have been prepared by thermally decomposing the organic precursors; Zinc Acetate Dihydrate, Cadmium Acetate Dihydrate, and Urea at 873 K. Graphitic carbon nitrides are synthesized from urea, which also functions as a reducing agent. The synthesized sample’s structural and morphological characterization are investigated using x-ray diffraction (XRD), Fourier transforms infrared (FTIR), UV–vis. spectra, field emission scanning electron microscopy (FESEM), and energy dispersive x-ray spectroscopy (EDX). The grain size of the ZnO and CdO nanoparticles is observed to be ∼21 nm and ∼28 nm, respectively. The absorption in the samples is found to be 250–450 nm and transmit the light in the visible spectrum as observed in UV–vis. spectra. The bandgap values calculated from Tauc’s plot for the hybrid structure of g-C3N4/ZnO and g-C3N4/CdO are found to be 2.97 eV and 2.30 eV.The z-scan method is adopted to evaluate the nonlinear susceptibility (χ3), intensity-dependent absorption coefficient (β), and nonlinear index of refraction (n2) using a pulsed Nd:YAG laser (∼532 nm). The results of the composite of g-C3N4/ZnO and g-C3N4/CdO show good third-order susceptibility and hence are useful for use as an optical limiter.

Composite core‐double sheath fibers based on some biodegradable polyesters obtained by self‐organization during electrospinning

AbstractObtaining core‐sheath fibers by single‐spinneret electrospinning is a recent and straightforward approach to prepare composite fibers. Fibers of more complex architecture consisting of poly(ethylene oxide) (PEO) core, inner poly(l‐lactide) sheath sd and outer beeswax (BW) sheath may also be obtained using this method. In the present study we report its applicability for a large series of (bio)degradable polyesters such as poly(ε‐caprolactone), poly(d,l‐lactide‐co‐glycolide), poly(butylene succinate), poly(3‐hydroxybutyrate), and poly(l‐lactide‐co‐d,l‐lactide). The fibers have a well‐differentiated PEO core, polyester inner sheath and BW outer sheath. The possibility for targeted location of hydrophilic or hydrophobic substances in the core or in the sheaths of the PEO/polyester/BW fibers has been demonstrated using nanosized zinc oxide with unmodified (hydrophilic) or silanized (hydrophobic) surface. PEO/polyester/BW fibrous materials loaded with a model drug (5‐nitro‐8‐hydroxyquinoline) exhibit antimicrobial activity. The obtained results show that single‐spinneret electrospinning is a novel and versatile method to prepare core‐double sheath composite fibers prospective for various applications such as biomedicine, cosmetics, and food packaging.

Effect of nanosized titanium dioxide and zinc oxide as antimicrobial agents on early compressive strength of high-performance concrete

Incorporation of antimicrobial agents in concrete can enhance the resistance of the concrete to biodeterioration. However, there is lack of adequate knowledge on the effect of antimicrobial agents on performance measures of high-performance concrete (HPC), particularly during early strength development, when the hydration reaction is ongoing, is not well understood. Therefore, the effect of antimicrobial agents on early compressive strength (CS) of HPC was investigated. The cement in HPC samples was partially replaced with nanosized titanium dioxide (TiO2) and zinc oxide (ZnO) by up to 2% by weight of the cement. Using response surface methodology, 21 combinations of TiO2 and ZnO contents were generated. The combinations were adopted for preparation of the samples. Individual and combined effects of TiO2 and ZnO on 7-day CS of the samples were evaluated. The standard form of the second-order response surface model is adopted to develop a model to fit the strength data. Statistics of the data verify that the model can be employed to predict the 7-day CS of HPC that employs nanosized TiO2 and ZnO as antimicrobial agents.

Improving the performance of polyacrylate latex binders for water-based inks through the application of reactive emulsifiers and nanosized zinc oxide

Improving the performance of polyacrylate latex binders for water-based inks through the application of reactive emulsifiers and nanosized zinc oxide

Nanotechnology's Application in Cosmetics: Dermatology and Skin Care Items

Nanotechnology has emerged as a revolutionary force in various fields, and its application in cosmetics has significantly transformed the landscape of dermatology and skin care. This abstract explores the multifaceted impact of nanotechnology on cosmetic products, focusing on its potential to enhance efficacy, improve delivery systems, and address specific dermatological concerns. Integrating nanotechnology into cosmetics offers a notable advantage by enabling precise control of materials at the nanoscale. This capability leads to the creation of formulations that exhibit enhanced bioavailability. The use of nano-sized particles, typically measured in nanometers, improves the penetration of active ingredients into the skin, ensuring precise delivery and increased absorption. This precision has paved the way for the development of highly effective skincare products capable of addressing specific skin conditions such as hyperpigmentation, fine lines, and acne. Furthermore, nanotechnology has revolutionized the formulation of sunscreens, offering transparent and cosmetically elegant options that provide superior protection against both UVA and UVB rays. Nano-sized titanium dioxide and zinc oxide particles scatter light more effectively, offering broad-spectrum coverage without the white residue associated with traditional sunscreens. Enhanced visual appeal motivates consistent application of sunscreen, fostering improved skin well-being and diminishing the likelihood of skin damage caused by sun exposure. In the realm of dermatology, nanotechnology has played a pivotal role in propelling forward groundbreaking therapeutic strategies. Nanoparticles are utilized to encapsulate and transport active components, including vitamins and antioxidants, ensuring their stability and prolonged release. This targeted approach allows for the customization of skincare regimens based on individual skin needs, thereby optimizing treatment outcomes for various dermatological conditions. Despite the remarkable advancements facilitated by nanotechnology, concerns have been raised regarding the safety of nano-sized particles in cosmetics. Addressing these concerns is crucial to ensure consumer confidence and regulatory compliance. Thorough testing and extensive research are crucial for a comprehensive evaluation of the safety characteristics of nanomaterials, taking into account factors such as particle size, surface charge, and potential interactions with the skin. In summary, the integration of nanotechnology into cosmetics marks a new era of innovation in dermatology and skincare. It not only enhances the delivery of active ingredients but also improves the effectiveness of sunscreens, presenting a promising path for the advancement of cutting-edge cosmetic formulations. As research in this field advances, it is essential to find a balance between innovation and safety, ensuring that nanotechnology continues to positively influence the cosmetics industry while prioritizing the well-being of consumers.

Preparation of nano-sized zinc oxide by adjusting the reaction system alkalinity and its antibacterial properties

Preparation of nano-sized zinc oxide by adjusting the reaction system alkalinity and its antibacterial properties

Investigation of the synthesis of nanostructures with increased photoluminescence obtained by depositing ultrathin layers of ZnO to the surface of porous silicon

Determining the features of the formation of hierarchical structures based on the interactions of elementary particles is a promising area of research. The deposition of 20 and 25 layers of zinc oxide by spray pyrolysis on the Si surface with stepped porosity led to the formation of ZnO particles of various sizes. X-ray fluorescence spectroscopy revealed zinc-containing compounds in thin formed layers. The maximum photoluminescence intensity and peaks characteristic of nanosized zinc oxide were found for a sample with 25 film layers. The mechanism of nanocrystal formation includes the capture of charges on oxygen vacancies.

Photocurrent performance and enhancement of opto-electronic properties of spray pyrolysis deposited ZnO thin films via V-doping

This study reports on the deposition of highly transparent conducting n-type zinc oxide (ZnO) thin films on FTO substrates, via an optimized doping process. Our work is focused on doping zinc oxide with vanadium (V) using spray pyrolysis technique and ensure the synthesis of nanoparticles-shaped ZnO, with an improved optical, microstructural and electrical properties for solar cells applications, as optical window material. Undoped and V-doped ZnO thin films, with careful optimized amounts (2, 4, 6 and 8 at.%), were grown at maintained 550∘C pre-heated substrate during the deposition process, which enables us to obtain nano-sized ZnO particles. We proved that 4 at.% is the optimum V content that enhances the crystallinity of the grown thin film noticeably. With an average transmittance of 80%, the deposited thin films revealed high transparency in the visible domain with a slight decrease in optical transmission which might result from additional scattering. UV-Visible analysis showed that increasing V amounts, a resulting decrease in the energy bandgap ([Formula: see text]) is obtained from 3.26[Formula: see text]eV to 3.17[Formula: see text]eV for 4 at.% of V content. Moreover, deep level defects in zinc oxide can be reduced with vanadium doping and consequently strengthen the UV emission. The UV emission peak intensity rises with increasing V-doping amount then decreases slightly at 8% of V content. The electrical properties measurements showed a decrease in resistivity from 2.8 10[Formula: see text][Formula: see text][Formula: see text][Formula: see text]⋅[Formula: see text]cm to 0.9 10[Formula: see text][Formula: see text][Formula: see text][Formula: see text]⋅[Formula: see text]cm when doping with 4 at.% of V. The crucial effect of the V-doping of ZnO was also demonstrated via the enhancement of carrier mobility that attains 38.5[Formula: see text]cm2/V[Formula: see text]⋅[Formula: see text]s at the optimum vanadium content. The photocurrent analysis revealed much higher visible light absorption in the V-doped zinc oxide thin films than that of undoped film. The photocatalytic activity enhancements are attributed to the lower recombination rate of the photogenerated electron-hole pairs, the narrowed bandgap, yielding a higher photocatalytic performance.

Study of the electronic properties of pure nanostructured hexagonal Zinc Oxide by DFT method

(ZnO) Zinc oxide is considered a semiconducting material from the family of transparent conductive oxide materials. Our study aims to study the electronic properties of pure Nano-sized hexagonal zinc oxide using the DFT method using the (GGA-PBE) approximation and the (HSE03) approximation, as we demonstrated through our study on the unit cell In the large cell (3×3×3) and the small cell (1×1×1), zinc oxide has a direct energy gap in the (GGA-PBE) approximation, and its value is (e V) 1.74) and in the (HSE03) approximation, the value of the energy gap is (e V2.79). The difference in the two approximations is very clear, and it is evidence that when using the (GGA-PBE) approximation for the DFT method, it reduces the value of the energy gap for zinc oxide, and when using the (HSE03) approximation, the energy gap increases because it is more mathematically accurate, even though it takes more time to calculate.

Are Physical Sunscreens Safe for Marine Life? A Study on a Coral-Zooxanthellae Symbiotic System.

Limited toxic and ecological studies were focused on physical sunscreen that is considered to have "safer performance", in which nanosize zinc oxide (nZnO) and nanosize titanium dioxide (nTiO2) generally are added as ultraviolet filters. Herein, the common button coral Zoanthus sp. was newly used to assess the toxic effects and underlying mechanisms of physical sunscreen. Results showed that physical sunscreen induced severe growth inhibition effects and largely compelled the symbiotic zooxanthellae, indicating that their symbiotic systems were threatened and, also, that neural and photosynthesis functions were influenced. Zn2+ toxicity and bioaccumulation were identified as the main toxic mechanisms, and nTiO2 particles released from physical sunscreen also displayed limited bioattachment and toxicity. Oxidative stress, determined by increased reactive oxygen species, superoxide dismutase, and malondialdehyde content, was indicated as another important toxic mechanism. Furthermore, when Zoanthus sp. was restored, the inhibited individual coral could be largely recovered after a short (3 d) exposure time; however, a longer exposure time damaged the coral irretrievably, which revealed the latent environmental risks of physical sunscreen. This study investigated the toxic effect of physical sunscreen on Zoanthus sp. in a relatively comprehensive manner, thus providing new insights into the toxic response of sunscreen on marine organisms.

Adsorptive removal of Cr (VI) from aqueous solution using laboratory prepared ZnO nanoparticles

Nano sized zinc oxide (ZnO) been successfully prepared in laboratory by precipitation technique. As prepared ZnO materials were characterized by XRD and SEM analyses. The XRD pattern showed the crystallinity of the material and average crystallite size was found to be 16.61 nm. The SEM images of ZnO nanoparticle revealed that it was flakes like structure having smooth texture. Batch adsorption experiments were performed to investigate the percentage removal of Cr (VI) from aqueous solution. The effects of Cr (VI) concentration, pH of solution, adsorbent dose and contact time variations were studied in order to have adsorptive efficiency of as prepared ZnO nanoparticles. The optimum contact time for maximum adsorption was found to be 90 minutes. The optimum pH was found to be 2.0 at an initial concentration of 20 mg/L. Similarly, the optimum dose of ZnO for the adsorption of Cr (VI) was found to be 0.4 g. The adsorption properties of ZnO were then evaluated by using Langmuir, Freundlich and Temkin isotherm models. The maximum adsorption capacity (Qm) was found to be 3.43 mg/g which is in good agreement with literature value. The correlation value showed that Langmuir isotherm model was found to be more favorable than Freundlich and Temkin adsorption isotherm model, indicating the presence of homogeneous equivalent active sites in ZnO with monolayer adsorption.

Sorption and Photocatalysis of Dyes on an Oil-Based Composite Enriched with Nanometric ZnO and TiO2

Sustainable development and environmental protection are among the most important challenges facing humanity today. One important issue is the problem of groundwater and surface water pollution which can lead to the degradation of aquatic ecosystems and negatively affect human health. As a result, new methods and materials are being sought that can help remove contaminants from water in an efficient and environmentally friendly manner. In recent years, there has been increasing interest in composite materials made from used cooking oil. This paper presents attempts to obtain composite materials with the addition of nano-sized zinc oxide and titanium oxide. The characterization of the composite materials was performed using FTIR, XRD, and SEM-EDS; their sorption and photocatalytic abilities were studied using batch mode experiments. The materials obtained exhibited sorption and photocatalytic properties. The highest value of photodegradation efficiency of more than 70% was recorded for the oil composite containing 20% zinc oxide. Composites containing 10% zinc oxide and titanium oxide had comparable sorption efficiencies of about 45% but different photodegradation efficiencies of 0.52% and 15.42%, respectively.