2024-03-29T20:29:00Z
https://www.ijnnonline.net/?_action=export&rf=summon&issue=805
International Journal of Nanoscience and Nanotechnology
1735-7004
1735-7004
2011
7
2
Synthesis of Three-Layered Magnetic Based Nanostructure for Clinical Application
M. E.
Khosroshahi
L.
Ghazanfari
The main objective of this research was to synthesize and characterize gold-coated Fe3O4 /SiO2 nanoshells for clinical applications. Magnetite nanoparticles (NPs) were prepared via co-precipitation. The results showed that smaller particles can be synthesized by decreasing the NaOH concentration, which in our case this corresponded to 35 nm by using 0.9 M of NaOH at 750 rpm. The NPs were then modified with a thin layer of silica using Stober method. The surface of Fe3O4 /SiO2 nanoshells was then terminated with amine groups with 3-aminopropyltriethoxysilane (APTS) in ethanol. Small gold colloid (1-3 nm) were adsorbed on the particle surface via the interaction between the negative charge on the Au nanoparticles and the positive charge of -NH3 on the SiO2 shell modified by APTS. Gold nanoshell formation, morphology and dimensions were assessed with a UV-Vis spectrophotometer, atomic force microscope (AFM), and transmission electron microscope (TEM). The synthesized nanostructures exhibited an absorption peak at ~550 nm with a magnetization value of 1.3 emu/g. Based on the X-ray diffraction (XRD) results, three main peaks of Au were identified. The formation of each layer of a nanoshell is also demonstrated by Fourier transform infrared (FTIR) results.
Multilayer nanostructure
Magnetic Properties
UV-Vis Spectroscopy
2011
06
01
57
64
https://www.ijnnonline.net/article_3941_238cb31aa941657e125c7e7b04e6cd0d.pdf
International Journal of Nanoscience and Nanotechnology
1735-7004
1735-7004
2011
7
2
Electronic Properties of a Concentric Triple Quantum Nanoring
H. K.
Salehani
M.
Esmaeilzadeh
Kh.
Shakouri
M. R.
Abolhassani
E.
Faizabadi
M. H.
Majlesara
In this paper, we study the electronic properties of a concentric triple quantum ring using exact diagonalization technique. The energy spectra and magnetization for a single electron and two electrons, in the presence of an applied magnetic field, are calculated and discussed. It is shown that, for two-interacting electrons, the period of Aharonov-Bohm oscillations decreases to the half of that for non-interacting electrons which shows the fractional Aharonov-Bohm oscillations for interacting electrons. It is found that the spin-singlet state for two electrons is more stable than the spin-triplet states. Also, magnetization effect decreases due to the electronelectron interaction.
Quantum rings
Electronic properties
Energy spectra
Magnetic flux
2011
06
01
65
71
https://www.ijnnonline.net/article_3942_0596e7b3519a2a8a422846c327f0256c.pdf
International Journal of Nanoscience and Nanotechnology
1735-7004
1735-7004
2011
7
2
Multilayer Nano Films for Corrosion Control
S.
Sabbaghi
R.
Bazargan Lari
M.
Zeraatkar
Nano films consisting of an alternating sequence of positively and negatively charged polyelectrolytes have been prepared by means of the electrostatic layer-by-layer (LBL) sequential assembly technique on treated and untreated mild steel wires. Inhibitor was encapsulated between cationic and anionic polyelectrolyte nano films. This paper mainly focuses on the effect of these nano-films of polyelectrolytes with different functional groups on corrosion protection. Weight loss method was used for measuring the corrosion rate of coated and uncoated mild steel substrate. Scanning Tunneling Microscope (STM) and Scanning Electron Microscope (SEM) were used for monitoring the surface morphology of the obtained nano films. Finally, the best efficiency was realized with 40 layers deposited on treated mild steel in the presence of 1mM benzotriazole inhibitor.
Corrosion
Nano films
Nanotechnology
2011
06
01
72
77
https://www.ijnnonline.net/article_3943_4c52d9cde7154192baa4c809c58394cd.pdf
International Journal of Nanoscience and Nanotechnology
1735-7004
1735-7004
2011
7
2
Formic Acid Decomposition Using Synthesized Ag/TiO2 Nanocomposite in Ethanol-Water Media Under Illumination of Near UV Light
E.
Pipelzadeh
M.
Valizadeh Derakhshan
A. A.
Babaluo
M.
Haghighi
A.
Tavakoli
The effect of ethanol-water media on the synthesis of Ag/TiO2 nanocomposite was investigated with 0.05, 0.1 and 0.5 (wt.%) of Ag content. Ethanol was used as hole-scavenger enhancing the photodecomposition of Ag+ ions under illumination of near-UV light. The nanocomposites were further calcined to 300˚C and 400˚C under controlled atmosphere. The synthesized nanocomposites were tested for photocatalytic efficiency decomposing formic acid as an organic pollutant under irradiation of a 4W near UV lamp with lmax at 365nm and the results were compared with that of non-modified commercially available Degussa TiO2 (P25). The synthesized nanocomposites were characterized using XRD and SEM micrographs. The photocatalytic studies have revealed a constant overall performance for all synthesized nanocomposites. The initial rate of decomposition was observed to increase with decreasing Ag content, in the case of 0.05 wt.% having the best initial rate. Calcination of the nanocomposites was found to have activating properties on the synthesized nanocomposites where nanocomposite with 0.05 (wt.%) Ag content calcined at 300°C was distinctively advantageous overother calcined nanocomposites.
Nanocomposite
TiO2
Ag
Calcination
photocatalytic activity
Ethanol-water media
2011
06
01
78
86
https://www.ijnnonline.net/article_3944_00d686d587cfcd5a3a7d27ef13f08f90.pdf
International Journal of Nanoscience and Nanotechnology
1735-7004
1735-7004
2011
7
2
Application of Molybdophosphoric Acid as Reducing Agent/ Stabilizer in the Synthesis of Gold Nanoparticles under UV Irradiation
A.
Ayati
A.
Ahmadpour
F. F.
Bamoharram
M. M .
Heravi
H.
Rashidi
B.
Tanhaei
In this paper, we have described the size-controlled synthesis of gold nanoparticles based on the reduction of Au3+ (HAuCl4 ) using molybdophosphoric acid (H3[PMo12O40 ], HPMo) under UV-irradiation. In the process, HPMo plays the role of photocatalyst, reducing agent and stabilizer and propan-2-ol acts as a sacrificial agent. This method allows the synthesis of uniform hexagonal nanoparticles with an average size that is tunable between 1.93 and 119 nm by varying the gold ion concentration, HPMo dose (or molar ratio of gold ion to HPMo) and Propan-2-ol amount. We have found that there is a critical ratio for [Au3+]/[HPMo], in which two opposing trends in the size of gold nanoparticles would happened.
Polyoxometalate
Molybdophosphoric acid
Gold
Nanoparticle
UV irradiation
2011
06
01
87
93
https://www.ijnnonline.net/article_3945_d4ce36e5eff68b5636794bedcdd44a2b.pdf
International Journal of Nanoscience and Nanotechnology
1735-7004
1735-7004
2011
7
2
Simple and Low Temperature Method for Preparation of Nanocrystalline ZnO in Presence of [EMIM][EtSO4] and Their Photocatalytic Activities
V.
Taghvaei
A.
Habibi-Yangjeh
M.
Behboudnia
Simple, low temperature and environmentally benign green route is proposed for preparation of nanocrystalline ZnO in presence of a low-cost and halide-free room-temperature ionic liquid (RTIL) by refluxing at 95 °C for 60 minutes. The X-ray diffraction (XRD) studies display that the products are well-crystallized in the form of wurtzite hexagonal. Morphology of the as-prepared ZnO was characterized by scanning electron microscopy (SEM) and the results demonstrate that the prepared nanocrystalline ZnO in presence of the RTIL is smaller than that of prepared in water. Energy dispersive X-ray spectroscopy (EDX) investigations reveal that the products are extremely pure. Diffuse reflectance spectra (DRS) of the prepared sample in the neat RTIL shows blue shift (0.33 eV) relative to the bulk ZnO that can be attributed to quantum confinement effect of nanocrystalline ZnO. Investigation of photocatalytic degradation of methylene blue (MB) on the prepared samples demonstrates that rate constant of the reaction increases with the RTIL content of the media.
Zinc oxide
Room-temperature ionic liquid
Nanocrystalline
Photocatalysis
2011
06
01
94
101
https://www.ijnnonline.net/article_3946_6b09621a3b4a4f520a1300e1a2c313bf.pdf
International Journal of Nanoscience and Nanotechnology
1735-7004
1735-7004
2011
7
2
Intracellular Biosynthesis of Gold Nanoparticles by the Fungus Penicillium Chrysogenum
Z.
Sheikhloo
M.
Salouti
In this study, the biosynthesis of gold nanoparticles by Penicillium chrysogenum, isolated from Ahar copper mine, was investigated. The gold nanoparticles were synthesized by reducing the aqueous gold ions using the culture supernatant of the filamentous fungi. The UV–vis spectrum displayed a characteristic peak at 532 nm that is very specific for gold nanoparticles. The XRD spectrum confirmed the presence of crystalline gold nanoparticles. Transmission electron microscopy exhibited the intracellular formation of gold nanoparticles in spherical, triangle and rod shapes with the size range of 5 to 100 nm.
Gold nanoparticles
Biosynthesis
Penicillium chrysogenum
2011
06
01
102
105
https://www.ijnnonline.net/article_3947_37c90565faf74a81804dca14d363f606.pdf