Structure Of Oxide Nanoparticles Research Articles

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

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

Green synthesis of MgO nanoparticles and its antibacterial properties.

Magnesium oxide nanostructured particles (NP) were prepared using a simple solution combustion technique using different leaf extracts such as Mangifera indica (Mango - Ma), Azadirachta indica (Neem-Ne), and Carica papaya (Papaya-Pa) as surfactants. The highly crystalline phase of MgO nanostructures was confirmed by PXRD and FTIR studies for 2h 500°C calcined samples. To analyze the characteristics of obtained material-MaNP, NeNP, and PaNP for dosimetry applications, thermoluminescence (TL) studies were carried out for Co-60 gamma rays irradiated samples in the dose range 10-50KGy; PaNP and NeNP exhibited well-defined glow curve when compared with MaNP samples. In addition, it was observed that the TL intensity decreases, with increase in gamma dose and the glow peak temperature is shifted towards the higher temperature with the increase in heating rate. The glow peak was segregated using glow curve deconvolution and thermal cleaning method. Kinetic parameters estimated using Chen's method, trap depth (E), and frequency factor (s) were found to be 0.699, 7.408, 0.4929, and 38.71, 11.008, and 10.71 for PaNP, NeNP, and MaNP respectively. The well-resolved glow curve, good linear behavior in the dose range of 10-50, KGy, and less fading were observed in PaNP as compared with MaNP and NeNP. Further, the antibacterial activity was checked against human pathogens such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. A visible zone of clearance was observed at 200 and 100μg/mL by the PaNP and NeNP, indicating the death of colonies by the nanoparticles. Therefore, PaNP nanomaterial is a potential phosphor material for dosimetry and antibacterial application compared to NeNP and MaNP.

The effect of NAOH and hexamine on the synthesis of titanium oxide nanostructured particles, their photocatalytic degradation effect on malachite green, rodamine B and methylene blue

The effect of NAOH and hexamine on the synthesis of titanium oxide nanostructured particles, their photocatalytic degradation effect on malachite green, rodamine B and methylene blue

Production of nickel oxide nanostructure particles and their photocatalytic degradation of different organic dye

In this study, nickel oxide nanostructured particles were produced by hydrothermal method. X-Ray diffraction (XRD) and transmission electron microscope (TEM) measurements were performed to determine the physical properties of these nanostructured particles. When XRD results are examined, it is seen that NiO nanoparticles are cubic structure. It is understood from the TEM images that these particles are nanostructured. The photocatalytic activities of nanostructured particles were investigated. This examination was carried out by using methylene and methyl blue dyes under the xenon lamp. It has been observed that the photocatalytic degradation rates are high. It was found that the degradation of NiO nanostructured particles on methylene blue was about 59%, the decomposition on methylene blue added H2O2 was about 96% and the degradation on methyl blue was about 92%.

Investigation of Organic Field-Effect Transistor (OFET) based NO2 Sensing Response using Low-Cost Green Synthesized Zinc Oxide Nanoparticles

A low-cost and green-synthesized zinc oxide nanostructured particles are extensively studied owing to their remarkable and ample characteristics with less toxicity and eco-friendly approach. The present work comprehends the green synthesis of ZnO nanostructured particles using bougainvillea leaf extract-arbitrated microwave-assisted synthesis and their use in field effect transistor for nitrogen dioxide sensing at room temperature. The as-synthesized nanoparticles were characterized using analytical techniques; XRD determined the pure crystallite structure with no impurities, SEM confirmed the spherical shape of nanoparticles with ~20 nm (average particle size) and the atomic weight percentage were analyzed using EDAX, notable photophysical properties were revealed from absorption and emission spectra performed using UV-visible spectroscopy. Poly(3-hexylthiophene) and ZnO nanoparticles were employed in the field effect transistor (p-type) for NO2 sensing at room temperature with the mobility (field-effect) of ~10-4 cm2 V-1 s-1. The sensitivity of the fabricated OFET device was extracted from the transistor characteristics (at Vgs = -30 V and Vds = -40 V) found to be ~4.8 × 10-3 nA/ppm. The device exhibited engrossing characteristics such as excellent recoverability (> 95%), with ultrafast response time (< 30 s) and greater sensitivity with high stability as can be assessed from the electrical characteristics.

Production of iron oxide and nickel oxide nanostructural particles, investigation of the supercapacitor and photocatalytic properties

Abstract In this study, iron oxide, nickel oxide, and nickel-iron oxide nanostructured particles were produced by the hydrothermal method. X-ray diffraction (XRD) and SEM measurements were performed to investigate the physical properties of these nanostructured particles. According to the XRD results, the crystal properties of these particles were determined. From the SEM images, these particles understood to be nano-structured. The electrodes were examined for electrochemical properties by using these nanostructured particles. Electrochemical measurements of the produced electrodes were performed, and capacitance values and impedance spectra of the electrodes were determined. The specific capacitance values of the iron oxide, nickel-iron oxide, and nickel oxide nanostructured particles, respectively are 30 F/g, 55 F/g, and 67 F/g. Also, the photocatalytic activities of nanostructured particles were investigated. This examination methylene blue (MB) was used and made under a xenon lamp. In light of our findings, it was observed that high photocatalytic degradation rate. Nickel-iron oxide nanostructured particles, the degradation of MB were found to be about 87%.

Fully Inkjet-Printed CuO Sensor on Flexible Polymer Substrate for Alcohol Vapours and Humidity Sensing at Room Temperature.

This work focuses on an inkjet-fabricated sensor based on copper oxide nanostructured particles on polymer flexible substrate for the sensing of alcohol vapours and humidity at room temperature. Nanoparticles were prepared by a microwave-assisted solvothermal sealed vessel synthesis method. The ink composition was developed on the basis of viscosity and surface tension optimization by the addition of polymeric steric surfactant and dispersant. The printing process was optimized with the help of non-dimensional criteria. Silver nanoink was used for the printing of an interdigitated pattern on a PET substrate which was overprinted by the copper oxide ink, thus obtaining a flexible flat sensor. Material design and all fabrication steps of the sensor respected the temperature limitation given by the thermal stability of the polymer substrate. Printed layers and motifs were characterized microscopically and by resistance measurement. The effectiveness of the prepared sensor was demonstrated and studied by measuring the response to saturated vapours at room temperature. The sensing layer showed the opposite resistance response to stimuli than expected for the well-known p-type sensing mechanism of CuO sensors operated at high temperatures. In addition to vapour sorption, condensation and desorption influencing electron, proton and ionic conductivity, manifestation of another mechanism was observed and an explanation suggested in terms of the electrochemical mechanism.

Simultaneous SWAXS study of metallic and oxide nanostructured particles

A small- and wide-angle X-ray scattering (SWAXS) technique using a laboratory X-ray source is reported in this article. This non-destructive SWAXS technique allows simultaneous measurements of the primary particle or pore size, surface and mass-fractal dimensions, as well as quantitative determination of the crystallite properties, like phase identification, the co-existence of crystallite components, and their fractions. Some selected experimental results of the SWAXS study of the metallic and oxide nanostructured particles (such as pure Silver nanoparticles, commercial AEROXIDE® TiO2 P25, Nickel and Nickel oxide nanoparticles as well as Titanium nanoparticles generated by a laboratory electric discharge generator) are presented and discussed in detail, covering a size range of 1–50 nm. The results obtained by SWAXS are compared to those observed with the transmission electron microscope and scanning electron microscope, as well as the XRD reference patterns from the RRUFF database, showing good agreement. In addition, a comparison between powder and dispersion measurements was carried out for estimating the existence and accessibility of microporous structures inside the synthesized nanoparticles, as well as the fraction of open pores. Because of many advantages, such as the high intensity of the primary beam while using a conventional laboratory X-ray source equipped with unique X-ray focusing optics, a short measurement time can be realized. By noninvasive simultaneous measurement of SAXS and WAXS spectra using a single detector; this unique technique allows for fast and extensive in-situ characterizations of metal and metal oxide nanoparticles, respectively, as well as nanostructured materials in many other potential application fields.

Nanostructural evolution from nanosheets to one-dimensional nanoparticles for manganese oxide

This paper introduces a novel hydrothermal soft chemical synthesis process for manganese oxide nanostructured particles using two-dimensional manganese oxide nanosheets as precursor. In this process, a birnessite-type manganese oxide with a layered structure was exfoliated into its elementary layer nanosheets, and then the nanosheets were hydrothermally treated to transform the two-dimensional morphology of the nanosheets to one-dimensional nanoparticles. The manganese oxide nanofibers, nanotubes, nanobelts, nanoribbons, and fabric-ribbon-like particles constructed from nanofibers or nanobelts were obtained using this hydrothermal soft chemical process. The nanostructural evolution from the two-dimensional nanosheets to the one-dimensional nanoparticles was characterized by XRD, SEM, TEM, and TG-DTA analysis. The morphology and nanostructure of the products are strongly dependent on the molecular dimension of organic amine cations added in the reaction system. The organic amine cations act as a morphology directing agent in the nanostructural evolution process.

Smoke dissipation by solid particles and charged water spray in enclosed spaces

This research investigated the effectiveness of various particles in clearing smoke in enclosed spaces. Metal oxide nanostructured particles, conventional particles (i.e., calcium hydroxide, sodium bicarbonate), or water (electrostatically charged or uncharged) were sprayed into an enclosed experimental chamber filled with combustion smoke. Improvement in visible light transmission through the chamber served as a measure of the effectiveness of the material in clearing smoke. Results showed that the negatively charged water spray was most effective in clearing smoke and improving visibility in the chamber. The smoke treated with charged water spray dissipated approximately 15 times faster than the untreated smoke. Also, compared with the solid particulate materials, the charged water spray resulted in a 3–12-fold increase in the speed of smoke dissipation.

Laboratory evaluation of the effectiveness of nanostructured and conventional particles in clearing smoke in enclosed spaces

The potential of nanostructured and conventional particulate materials in clearing smoke in enclosed spaces was evaluated. Aggregates of metal oxide nanostructured particles or conventional particles were sprayed into an enclosed experimental chamber (2.4 m×2.4 m×3.6 m) filled with glycol smoke. The times required for the light transmission in the room to reach 10% and 20% served as a measure of the effectiveness of the material in clearing smoke. The effects of material type and deployment pressure were considered. Results indicate the potential of some particles in increasing the rate of smoke dissipation and improving the visibility in the smoke-filled chamber.

Bismuth Oxide Nanoparticles by Flame Spray Pyrolysis

Bismuth oxide nanostructured particles were made via the flame spray pyrolysis (FSP) of bismuth nitrate that had been dissolved in a solution of ethanol/nitric acid or in acetic acid. These self‐sustaining spray flames produced tetragonal β‐Bi2O3. The use of ethanol/nitric acid solutions resulted in a mixture of hollow, shell‐like, and solid nanograined particles. The particle homogeneity was improved as the content of acetic acid in the precursor solution increased. Solid bismuth oxide nanoparticles were prepared consistent with percolation theory, accounting for the specific volume of the product and the precursor. Using pure acetic acid as the solvent, the effect of FSP variables on spray flame and product powder characteristics was investigated. The specific surface area of the Bi2O3 particles could be controlled over a range of 20–80 m2/g by the liquid feed and oxygen gas flow rates for powder production rates of 6–46 g/h.

Microstructure and properties of nanostructured oxides

The current knowledge on the microstructure, sintering and creep properties of the nanostructured oxides TiO 2, Y 2o 3 AND zRo 2 synthesized by gas condensation in summarized. Size dependent phase stability in nanostructured oxide particles with average diameter in the range from 3 to 20 nm and phase transformations during particle growth are discussed. The influence of various microstructural parameter of the powder, i.e. grain size and degree of agglomeration, on consolidation and sintering is discussed. Plastic deformation by creep processes under compressive and tensile stresses at temperatures below half the melting point is presented.