Nanotechnology
I. Benammar; R. Salhi; J. -L. Deschanvres; R. Maalej
Abstract
This work describes the systematic preparation of doped and undoped TiO2 with Er and/or Yb nanoparticles by hydrothermal-assisted sol-gel method with supercritical drying of ethanol, followed by systematic calcination steps at 500°C, 800°C and 1000°C for 2 h. Structural investigation of these ...
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This work describes the systematic preparation of doped and undoped TiO2 with Er and/or Yb nanoparticles by hydrothermal-assisted sol-gel method with supercritical drying of ethanol, followed by systematic calcination steps at 500°C, 800°C and 1000°C for 2 h. Structural investigation of these powders by XRD shows that our samples are crystalline with a tetragonal structure and an anatase phase well crystallized at 500°C. Annealing at 800°C shows a transformation of the anatase phase into the rutile phase, which is well crystallized at 1000°C. XRD analysis shows that the dopants are incorporated into the TiO2 network without phase separation in these nanoparticles. The study of the grain sizes has shown that they have a nanometric size of about 8-12 nm and that their size decreases with Er and/or Yb doping. The elemental analyzes with micro-EDX using SEM confirmed the presence of chemical elements in the TiO2 nanoparticles with the expected atomic ratios. Examination of the SEM images confirmed the XRD observations. They also prove that the nanoparticles are spherical. Optical analysis with excitation at 488 nm shows the presence of three emission bands in the green and red regions. The heat treatment improves the optical, structural and spectroscopic properties and removes impurities due to the preparation conditions.
Applied Physics
Nwar A. Yousif; Selma M. Al-Jawad; Ali A. Taha; Haralambos Stamatis
Abstract
In recent years, extensive studies have been devoted to iron oxide nanoparticles (IONPs). Iron oxides are chemical compounds that have various polymorphic forms, including maghemite (γ-Fe2O3), magnetite (Fe3O4), and Hematite (α-Fe2O3). Among them, the most important studied is magnetite (Fe3O4) ...
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In recent years, extensive studies have been devoted to iron oxide nanoparticles (IONPs). Iron oxides are chemical compounds that have various polymorphic forms, including maghemite (γ-Fe2O3), magnetite (Fe3O4), and Hematite (α-Fe2O3). Among them, the most important studied is magnetite (Fe3O4) due to its low cost and low toxicity and its unique magnetic and physicochemical characteristics, which qualify it for use in various biomedical and technological applications. Magnetic particles should be small and have a narrow size distribution for these applications. The smaller the size of the iron oxide particles, the greater their reactivity and biodegradability. In this review, we display summary information on magnetite (Fe3O4) nanoparticles in terms of structure, characteristics, and preparation methods. Because the prepared strategy has been proven to be critical for preferable control of the particle size and shape, in addition to producing monodispersed magnetite (Fe3O4) nanoparticles with a direct effect on their characteristics and applications, special attention will be placed on chemical preparation techniques including Hydrothermal synthesis, Coprecipitation technique, Sol-Gel process, and thermal decomposition method. This review offers specific information for selecting appropriate synthetic methods for obtaining appropriate sizes, shapes, and magnetic properties of magnetite (Fe3O4) nanoparticles (NPs) for target applications.
Applied Physics
Eman M. Suliman; Uday M. Nayef; Falah A. Mutlak
Abstract
In this study, Au:TiO2 nanoparticles (NPs) are prepared by using the laser ablation method in liquid at different laser energies (600, 800, and1000 mJ). After that, Au: TiO2 NPs were deposited on porous-Si(PS). Porous silicon (PS) is synthesized by using the photo-electrochemical etching (PECE) of n-type ...
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In this study, Au:TiO2 nanoparticles (NPs) are prepared by using the laser ablation method in liquid at different laser energies (600, 800, and1000 mJ). After that, Au: TiO2 NPs were deposited on porous-Si(PS). Porous silicon (PS) is synthesized by using the photo-electrochemical etching (PECE) of n-type crystalline Si (c-Si) wafers of (100) orientation. The intensity of the etching current density was (4, 12, and 20 mA/cm2), with 16% (HF), and the etching time was 15 minutes. The X-ray diffraction (XRD) techniques, scanning electron microscopy (SEM), UV–visible spectrophotometry, and electrical properties are used to characterize the obtained particles. From the photo-detector measurements, the spectral responsivity curves three inclusive regions; the first peak was due to the absorption of UV light by Au: TiO2 NPs. The second peak was corresponding to the visible light absorption with the PS layer and the third peak was due to the absorption edge of the Si substrate. The higher responsivity of Au: TiO2 NPs/PS photo-detector was found to be 2.56A/W for specimens prepared at laser energy 800mJ.
Chemistry
Alaa A. Majeed; Rashed T. Rasheed
Abstract
Different iron oxide nanoparticles (Fe3O4 and Fe2O3) were prepared by the sol-gel method (titration). The prepared nanoparticles were heated at 90 and 400°C. The morphology surface and structures were characterized by Fourier Transform Infra-Red (FT-IR) and Ultraviolet/Visible (Uv/Visible) measurements, ...
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Different iron oxide nanoparticles (Fe3O4 and Fe2O3) were prepared by the sol-gel method (titration). The prepared nanoparticles were heated at 90 and 400°C. The morphology surface and structures were characterized by Fourier Transform Infra-Red (FT-IR) and Ultraviolet/Visible (Uv/Visible) measurements, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Atomic Force Microscope (AFM). The enzyme mimetic activities of these nanoparticles (Fe3O4 and Fe2O3) such as two enzymes (Catalase (CAT), and Peroxidase (Pxase)) were measured. The results showed the iron oxides (Fe2O3) heated at 90°C, have the maximum activity (189.99 K.min-1) as catalase (CAT). While the iron oxides (Fe3O4) heated at 90°C, have the maximum activity (3.044 U.min-1) as peroxidase (Pxase), and there is a decrease in the activity for both nanoparticles when annealed at 400°C. Despite the average grain size decrease in both samples, however, the mimetic activity decrease that is mean the average grain size is not affected in both mimetic activities as catalase and peroxidase.
Biotechnology
Raghad Jabbar; Nehia N. Hussein
Abstract
Biosynthesis of AgNPs is a new approach in the field of nanotechnology with optimistic implementation in medicine, food control, and pharmacology. In this study, the silver nanoparticles were produced by Lactobacillus gasseri filtrate. The production of AgNPs was confirmed by the color change from yellow ...
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Biosynthesis of AgNPs is a new approach in the field of nanotechnology with optimistic implementation in medicine, food control, and pharmacology. In this study, the silver nanoparticles were produced by Lactobacillus gasseri filtrate. The production of AgNPs was confirmed by the color change from yellow to brown. Using UV visible spectrophotometer at 424 nm wavelength, and X-ray diffraction, it was found that the size of the synthesized particles was 58.5 nm after applying Scherrer’s equation. The inhibitory activity of silver nitrate on the growth of some pathogenic isolates was studied Staphylococcus haemolyticus Gram positive, and Klebsiella pneumoniae Gram negative. The highest inhibitory diameter was 14.6 mm at 100% concentration (stock) against Staphylococcus haemolyticus bacteria was followed by that of Klebsiella pneumoniae bacteria with an average inhibition zone diameter reached 13.6 mm at 100% concentration. The highest effect was of AgNPs on the growth of Staphylococcus haemolyticus bacteria, as it found the average diameter of the inhibition zone reached to 29.3 mm, followed by Klebsiella pneumoniae with the average diameter of the inhibiting zone it was 22.6 mm at 100% concentration (stock). This study showed AgNPs have more antibacterial activity against Gram positive bacteria than Gram negative bacteria. The importance of this study lies in testing the effectiveness of by Lactobacillus gasseri bacteria in the biosynthesis of silver nanoparticles and studying their antibacterial activity on pathogenic bacteria.
Nanotechnology
Maha A Al-Kinani; Adawiya Haider; Sharafaldin Al-Musawi
Abstract
Drug delivery using nanocarriers is recommended to decrease the drug amount. To improve the different therapeutic characteristics of curcumin (CU) such as solubility, bioavailability, maintenance endorsement, and make it a promising, successful antitumor drug used for prostate cancer treatment. It was ...
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Drug delivery using nanocarriers is recommended to decrease the drug amount. To improve the different therapeutic characteristics of curcumin (CU) such as solubility, bioavailability, maintenance endorsement, and make it a promising, successful antitumor drug used for prostate cancer treatment. It was introduced to folate decorated chitosan (CS) coated Fe@Au NPs (FA-CU-CS-Fe@Au NPs). Fe@Au nanoparticle contains magnetic Fe NP’s core with a fine layer of Au NP’s synthesized using the method Pulsed, Laser, Ablation in Liquid (PLAL). These Fe@Au NP’s characterized by UV-Visible Spectrophotometer, High-Resolution, Transmission Electron Microscopy, (HRTEM), and Field Emission Scanning, Electron, Microscopy (FESEM). The smallest nanosize and the best result was obtained at different laser wavelength (532, 1064) nm. The mean size gained of Fe@Au NPs were (67.65, 77.88) nm. Obtained results exhibited that the laser wavelength plays a key role in the size, and dispersity of Fe@Au NPs. CU loaded FA-CS-Fe@Au NPs MTT assay on human prostate cancer cell line (PC3) proved that CU cytotoxicity can improve when they are loaded on (FA-CS-Fe@Au NPs) when comparing it with free CU.
