Nanotechnology
Muna H. Kareem; Adi M.; Haitham T. Hussein
Abstract
In this paper, Gas sensors for ethanol and methanol were created utilizing porous silicon (PSi).n-type silicon was employed for all PSi samples, photo-electrochemical etching technique (PECE) was used to prepare porous surface. The intensity of the three etchings current densities was 12, 24 and 30 mA ...
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In this paper, Gas sensors for ethanol and methanol were created utilizing porous silicon (PSi).n-type silicon was employed for all PSi samples, photo-electrochemical etching technique (PECE) was used to prepare porous surface. The intensity of the three etchings current densities was 12, 24 and 30 mA / cm2, with 40% hydrofluoric acid concentration (HF) and a time of etching 10 minutes. Porous silicon (100) has been strictly studied by the structure and formation of surface bonding of the PSi layer; the structural properties, morphological characteristics, pore diameter, and roughness were described using X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM). All PSi samples were applied as a sensor for ethanol and methanol at room temperature. The results showed that the best sensitivity of PSi was to ethanol gas compared to methane under the same used conditions at etching current density 30mA/cm2, reaching about 1.809 at a concentration of 500 ppm. From these results, the PSi layers act as high-quality, low-cost gas sensors. It can be used as a replacement for expensive material that is used as gas sensors, which operate at low temperatures, including room temperature. The interest in this material is due to study the effect of extremely high surface to volume ratio (increasing surface area), and easy manufactured and compatibility with modern silicon microelectronics manufacturing technologies.
Applied Physics
Rania Huseen; Ali Taha; Oday Abdulhusein
Abstract
Iron oxides are the most common types of substances available in nature in various forms such as oxides, hydroxides and oxide-hydroxides, which obtained from various aqueous reactions. In the present study, iron oxide (Fe3O4) nanoparticles (NPs) had been synthesized using co - precipitation method and ...
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Iron oxides are the most common types of substances available in nature in various forms such as oxides, hydroxides and oxide-hydroxides, which obtained from various aqueous reactions. In the present study, iron oxide (Fe3O4) nanoparticles (NPs) had been synthesized using co - precipitation method and determined some biological activities. Iron oxide NPs had been characterized by spectrophotometry, X- Ray Diffraction (XRD) analysis and Field Emission Scanning Electron Microscopic (FE-SEM). The XRD analysis confirmed the purity and crystalline nature of fabricated NPs. In contrast, four biological activities of iron oxide NPs were determined. High removal of methylene blue pollutant dye (37.62 %) was observed when iron oxide NPs were used at 400 µg/ml within 48 hrs. Furthermore, iron oxide NPs revealed high inhibition zones of 27.5 and 30 mm, at 1000 µg/ml, toward Staphylococcus aureus and Escherichia coli respectively. The hemolysis activity of fabricated NPs is increases whenever concentrations increased. The lower hemolysis percentage of iron oxide NPs was (69.76%) when the NPs concentration was 250 µg/ml. Finally, cytotoxic activity was estimated against MCF- 7 cell line and normal cell line WRL68 by MTT assay. Significant and decrease in viability of (MCF-7 to 65.1%) when 400 µg/ml of iron oxide NPs was examined, while WRL68 viability was (75.03%).