Materials Science
Faisal J. Kadhim; Mohamed Hedi Bedoui; Ali A. Turki Aldalawi
Abstract
In this study, Fe₂O₃ nanoparticles were synthesized by a hydrothermal method using chitosan extract and ferric chloride (FeCl₃) as precursor at 150 °C. The hydrothermal approach provides precise control over the size and morphology of the nanoparticles by promoting the decomposition and crystallization ...
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In this study, Fe₂O₃ nanoparticles were synthesized by a hydrothermal method using chitosan extract and ferric chloride (FeCl₃) as precursor at 150 °C. The hydrothermal approach provides precise control over the size and morphology of the nanoparticles by promoting the decomposition and crystallization of the precursors near their evaporation temperatures. The aim of this study was to quantify the antibacterial activity of the nanoparticles to regulate the production of Fe₂O₃ NPs. The optical and structural properties of Fe₂O₃ nanoparticles (NPs) were investigated and tested using various techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV-vis) spectroscopy and photoluminescence (PL). The crystal size and hexagonal structure of Fe₂O₃ NPs in the range of 10 to 25 nm were determined by XRD. In addition, FESEM images were used for measurement. The morphology and particle size of the Fe₂O₃ NPs, which is between 15.63 and 56.84 nm due to the aggregation of the nanoparticles. The UV-visible spectra were used to calculate the direct and indirect optical band gap versus hν of the Fe₂O₃ NPs prepared by the hydrothermal method from chitosan extract NPs. These are 3.8 eV and 3.6 eV, respectively. The band edge emission of Fe₂O₃ NPs was about 2.57 eV as measured by photoluminescence (PL) spectroscopy. Inhibition zones of 40 mm in size were observed for Staphylococcus aureus and Escherichia coli.
Laser Science and Technology
Asraa B. Radhi; Khawla S. Khashan; Ghassan M. Sulaiman; Hamdoon A. Mohammed
Abstract
In this work, room temperature laser ablation with an iron target in water was used to create iron oxide nanoparticles (IONPs) with a different number of pulses (100, 200, 300, 400 and 500) at a constant energy of 200 mJ. The colloidal solutions of the IONPs were studied and the effects of the number ...
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In this work, room temperature laser ablation with an iron target in water was used to create iron oxide nanoparticles (IONPs) with a different number of pulses (100, 200, 300, 400 and 500) at a constant energy of 200 mJ. The colloidal solutions of the IONPs were studied and the effects of the number of pulses on the properties were investigated by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), ultraviolet-visible spectroscopy (UV-VIS) and photoluminescence (PL). The FTIR spectra showed that the synthesised IONPs were formed, and the peaks appeared between (500-600) cm-1. FESEM images showed that the IONPs have hemispherical structures and become spherical with increasing laser pulses. They also exhibited a small aggregation due to electrostatic forces. The UV-VIS results showed that the IONPs had an absorption shoulder at 300-400 nm, which increased with the laser pulses. The PL spectra of the IONPs showed strong, sharp peaks in the UV region at 370 nm, the intensity of which increased with increasing pulse duration, while the density of the nanoparticles in the solution increased. In addition, the antibacterial activities were evaluated using an agar well diffusion assay against Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans) and Acinetobacter baumannii (A. baumannii). The result showed that the IONPs have good antibacterial activity, which increased with the laser pulses due to the increased concentration of IONPs. A hemolysis and in vitro toxicity test also evaluated the compatibility with human blood on red blood cells.
Nanotechnology
Zeena R. Rhoomi; Duha S. Ahmed; Majid S. Jabir; Anjan Kumar
Abstract
Bismuth tungstate (Bi2WO6) is an aurivillius oxide with potential as a visible light-active photocatalyst. However, its wide band gap limits absorption of visible light. Decoration with multi-walled carbon nanotubes (MWCNTs) has been shown to enhance photocatalytic properties. This study reports the ...
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Bismuth tungstate (Bi2WO6) is an aurivillius oxide with potential as a visible light-active photocatalyst. However, its wide band gap limits absorption of visible light. Decoration with multi-walled carbon nanotubes (MWCNTs) has been shown to enhance photocatalytic properties. This study reports the hydrothermal synthesis of pure Bi2WO6 and Bi2WO6-MWCNT nanocomposites using a 1:2.5 molar ratio of Bi2WO6:MWCNTs. Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy analysis were used to characterize the morphology, chemical bonding, and composition. Adding MWCNTs reduced particle size, increased surface area, and prevented aggregation. Antibacterial testing showed the Bi2WO6-MWCNT nanocomposite inhibited Pseudomonas aeruginosa, a multidrug-resistant bacterium, more effectively than pure Bi2WO6. Investigation of morphology and bonding revealed the influence of decorated and embedded MWCNTs on bismuth components and particle size. Enhanced antibacterial and anti-biofilm activity of the nanocomposite may be due to increased oxidative stress from reactive oxygen species generation. This facile hydrothermal method synthesizes a Bi2WO6-MWCNT nanocomposite combining the properties of both materials, showing promise for biomedical applications.
Laser Science and Technology
Sara Fadhil Abbas; Adawiya J. Haider; Sharafaldin Al-Musawi; Bakr Ahmed Taha
Abstract
In this study, we synthesized magnesium oxide (MgO) nano flakes (NFs) through pulsed laser ablation of magnesium ribbons, investigating their potent antibacterial properties for potential biomedical applications. Thorough characterization utilizing advanced analytical techniques verified the phase purity ...
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In this study, we synthesized magnesium oxide (MgO) nano flakes (NFs) through pulsed laser ablation of magnesium ribbons, investigating their potent antibacterial properties for potential biomedical applications. Thorough characterization utilizing advanced analytical techniques verified the phase purity and functionality of the fabricated MgO NFs. Results revealed a distinctive flake-like structure with an average diameter of 100-400 nm and a slender wall thickness of 24 nm. The efficiency of the laser ablation method was validated by EDX imaging, showing high purity in the MgO sample. XRD analysis further confirmed the polycrystalline nature of MgO NFs, with dominant peaks at 2θ values of 38.86°, 59.46°, 62.83°, and 73.87° corresponding to (111), (110), (220), and (311) diffractions, respectively. UV-visible spectroscopy exhibited a broad absorption peak, and Tauc's formula yielded an energy band gap of 5.8 eV. FTIR spectroscopy detected Mg–O–Mg bending vibration, O−H stretching vibration, O=C=O stretching, and O−H bending vibration. Optimized MgO-NFs demonstrated remarkable antibacterial efficacy against both gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli) bacteria. Maximum antibacterial activity was observed at a high MgO NFs concentration (200 µg/mL), resulting in 15 mm ±0.5 mm and 16 mm ±0.5 mm inhibition zones for E. coli and S. aureus, respectively. The minimum inhibitory concentration (MIC) for both pathogens was determined to be 25 µg/mL, emphasizing the promising antimicrobial potential of the MgO NFs.
Materials Science
Shatha Sh. Batros; Mohammed H. Ali; Ali J. Addie
Abstract
Tin oxide (SnO2) nanoparticles were synthesized via a facile chemical precipitation route using tin chloride (SnCl2•2H2O) as precursor and ammonia as precipitant. The as-synthesized nanoparticles were subjected to post-calcination at 300°C, 400°C and 500°C and thoroughly characterized ...
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Tin oxide (SnO2) nanoparticles were synthesized via a facile chemical precipitation route using tin chloride (SnCl2•2H2O) as precursor and ammonia as precipitant. The as-synthesized nanoparticles were subjected to post-calcination at 300°C, 400°C and 500°C and thoroughly characterized by advanced techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy. XRD patterns revealed the formation of a tetragonal SnO2 crystalline phase with average crystallite sizes of 11.9 nm, 13.9 nm, and 17.2 nm for the samples calcined at 300°C, 400°C and 500°C respectively. SEM micrographs demonstrated agglomerated and irregular morphology of the calcined SnO2 nanoparticles. FTIR spectra confirmed the presence of characteristic Sn-O and O-Sn-O vibrational modes in the calcined SnO2 samples. The antibacterial activity of the synthesized nanoparticles was evaluated against model Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacterial strains by standard zone of inhibition assays. The SnO2 nanoparticles exhibited excellent antibacterial activity due to their high specific surface area. A systematic increase in the inhibition zone diameter was observed with a decrease in the crystallite size of SnO2 for both bacterial strains, suggesting an inverse relationship between crystallite size and antibacterial behaviour. The present work demonstrates a simple, eco-friendly synthesis of antibacterial SnO2 nanoparticles with controlled crystallite size by tuning the calcination temperature.
Materials Science
Hajer A. Ali; Nahida J. Hameed
Abstract
To develop bio-packaging materials, nanocomposite films of cellulose acetate reinforced with titanium dioxide and zinc oxide nanoparticles were prepared, by the casting method at different weight ratios of ZnO nanoparticles (1.5, 2, and 2.5) wt% and a constant weight ratio of 2 wt% TiO2. ZnO and TiO2 ...
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To develop bio-packaging materials, nanocomposite films of cellulose acetate reinforced with titanium dioxide and zinc oxide nanoparticles were prepared, by the casting method at different weight ratios of ZnO nanoparticles (1.5, 2, and 2.5) wt% and a constant weight ratio of 2 wt% TiO2. ZnO and TiO2 nanoparticles were tested using scanning electron microscopy (SEM). The mechanical properties (tensile strength and elongation) were improved at a fixed level of Cellulose Acetate+ 2% TiO2+1.5wt% ZnO loading. Beyond that level of loading, they decreased. The tensile strength was decreased due to some degrees of agglomeration of filler particles above a critical content. Fourier-Transform Infrared Spectroscopy (FTIR) was conducted to reveal the microstructures and chemical composition of as-prepared composite films. The wettability of the films was also determined by the sessile drop method. An increase in contact angle was also observed by the addition of ZnO content from 70.6° to 77.1° compared to pure Cellulose Acetate, which indicated a value of 61.3°. Antibacterial activity against Escherichia coli and Staphylococcus aureus was enhanced after incorporation of ZnO-TiO2 compared with pure CA. The enhanced wettability and antibacterial activity of the prepared films suggest that they could be used for packaging applications.
Materials Science
Ishraq A. Fadhil; Balqees M. Aldabbagh; Wijdan T. Mahdi
Abstract
Chitosan holds net ionic positive charges, which contribute its ability to chemically bind with negatively charged fats, lipids, metal ions, proteins, and microorganisms. Magnesium oxide (MgO) nanoparticles are important inorganic materials with a wide band-gap used in many applications such as catalysts, ...
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Chitosan holds net ionic positive charges, which contribute its ability to chemically bind with negatively charged fats, lipids, metal ions, proteins, and microorganisms. Magnesium oxide (MgO) nanoparticles are important inorganic materials with a wide band-gap used in many applications such as catalysts, antibacterial and medical products. The aim of this study was to investigate the effect of Chitosan (CHT) hydrogel loaded MgO nanoparticles on the bacterial growth. CHT/ poly vinyl alcohol (PVA)/ poly ethylene glycol (PEG) hydrogel was blended with various amounts of MgO nanoparticles. The surface morphology of the obtained blends was investigated by Field Emission Scanning Electron Microscope (FE-SEM). Evidently, surfaces with appropriate roughness were obtained for most of the prepared hydrogels. Fourier Transform Infrared Spectroscopy (FT-IR) and Energy Dispersive X-Ray analysis (EDX) were also included in this paper. Thermal properties of all samples was studied by DSC-TGA curves. The antibacterial activity of the prepared hybrids CHT/PVA/PEG/MgO nanoparticles have performed against gram positive bacteria Staphylococcus aureus (S.aureus) and Streptococcus, as well as gram negative bacteria Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E.coli). In this study, MgO nanoparticles various proportions presented high efficiency towards gram positive microorganisms. High resistance of gram negative bacteria against the final products was extremely detected according to measured inhibition zones which were between (0-9) mm.
Biotechnology
Rana A. Hikmet; Nehia N. Hussein
Abstract
This study was carried out for the mycosynthesis of silver nanoparticles by Candida albicans supernatant. All the isolates used in this study were taken from the patients who existed at Al-Elweya children's teaching hospital in Baghdad, Iraq. Mycosynthesized silver nanoparticles were characterized ...
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This study was carried out for the mycosynthesis of silver nanoparticles by Candida albicans supernatant. All the isolates used in this study were taken from the patients who existed at Al-Elweya children's teaching hospital in Baghdad, Iraq. Mycosynthesized silver nanoparticles were characterized by color visualization, ultraviolet-visible (UV) spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The UV-Vis spectroscopy examination has shown the highest absorbance (λmax) at the wavelength of 429 nanometers, which indicated the creation of silver nanoparticles. Furthermore, the results of the antibacterial potential of AgNO3 and AgNPs against Klebsiella pneumoniae and Staphylococcus haemolyticus bacteria showed the highest effect of AgNO3 against Staphylococcus haemolyticus when the diameter of the inhibition zone reached (14.00 mm). In contrast, the lowest effect of the AgNO3 was with the diameter of the inhibition zone that reached (11.66 mm). The highest effect of the AgNO3 against Klebsiella pneumoniae by the diameter of the inhibition zone was reached (12.66mm), while the lowest effect was (9.00mm). The highest effect of the AgNPs against Klebsiella pneumoniae by the diameter of the inhibition zone reached (16.00mm), while the lowest effect was (13.00mm). The highest effect of the AgNPs against Staphylococcus haemolyticus by the diameter of the inhibition zone was reached (17.33mm). Where the lowest effect by the diameter of the inhibition zone was reached (14.00mm). Interestingly, this revealed that Staphylococcus haemolyticus was more susceptible to silver nitrate (AgNO3) and silver nanoparticles (AgNPs) than Klebsiella pneumoniae.
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.
Zahraa Khedaer; Duha Ahmed; Selma Al-Jawad
Abstract
In this research, raw multiwalled carbon nanotubes (R-MWCNT) was successfully functionalized using sulfuric acid and nitric acid. Then a hybrid (ZnO-MWCNT) synthesized by the sol-gel method where diethylene glycol was used as a solvent and stabilizer that works to prevent the accumulation of nanoparticles ...
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In this research, raw multiwalled carbon nanotubes (R-MWCNT) was successfully functionalized using sulfuric acid and nitric acid. Then a hybrid (ZnO-MWCNT) synthesized by the sol-gel method where diethylene glycol was used as a solvent and stabilizer that works to prevent the accumulation of nanoparticles and reduces the viscosity of the solution. A group of diagnostic techniques, including XRD, UV-Vis, EDX and microscopy has recognized the structural and optical properties of the prepared nanoparticles. High Resolution Electronic Scanner (FE-SEM) was also used in the investigation. FE-SEM images showed the formation of the hybrid (ZnO-MWCNT) by the growth of spherical clusters on the surface of the cross-linked tubes (MWCNT). In addition, FE-SEM images confirmed the success of a ZnO-MWCNT hybrid. The emergence of spherical shapes deposited on cylindrical tubes and associated with a wrinkled surface was recognized. In addition, the particle size ratio increased. The UV-Vis spectra revealed that all the composites had good absorbency with a shift towards short wavelengths. While it was observed from the analysis of X-ray diffraction (XRD) the formation of a hexagonal wurtzite crystal structure due to zinc oxide with a polycrystalline nature. The average crystal size calculated from the Debye-spark equation increased with the increase in the concentration of the streaked material. Antibacterial activity was studied for all prepared samples against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) at different μg/ml concentrations (500, 750, and 1000). It was observed that the highest inhibition Zone for functionalized multiwalled carbon nanotubes (F-MWCNT) and ZnO-MWCNT hybrid was (17.3, 12.3mm), (22.5, 19mm) for Escherichia coli and Staphylococcus aureus, respectively.
