Characterization and Stability Monitoring of Maghemite Nanoparticle Suspensions

2012 ◽  
Vol 576 ◽  
pp. 398-401 ◽  
Author(s):  
Irwan Nurdin ◽  
Idris Yaacob Iskandar ◽  
M. Rafie Johan ◽  
Bee Chin Ang
Keyword(s):  
Zeta Potential ◽  
Magnetic Measurement ◽  
Average Crystallite Size ◽  
Precipitation Method ◽  
Hydrodynamic Diameter ◽  
Maghemite Nanoparticles ◽  
Nanoparticle Suspensions ◽  
Maghemite Nanoparticle ◽  
The Stability ◽  
Co Precipitation

Maghemite nanoparticle suspensions were synthesized using a co-precipitation method and characterized by a variety of techniques including XRD, TEM, magnetic measurement, DLS, and zeta potential. The stability of the suspension was monitored by measuring the particle size distribution using DLS over a period of two months. The diffraction pattern from XRD measurement confirmed that the particles were maghemite with an average crystallite size of 9.4 nm. TEM observations and analyses showed that the geometry of maghemite nanoparticles were nearly spherical with a mean physical diameter of 9.9 nm. The maghemite nanoparticles showed superparamagnetic behavior with saturation magnetization value of 32.20 emu/g. The mean hydrodynamic diameter of the suspension remained unchanged after two months which indicated no formation of aggregation. The hydrodynamic diameters recorded were 45.1 nm and 48.4 nm, respectively. Additionally, lack of sedimentation indicated that the suspension was stable. The suspension’s zeta potential values were 41.5 mV and 40.4 mV for as synthesized and after two month of storage respectively.

Fe3O4.SiO2: A Study of Structural and Magnetic Properties in Various Volume of Tetraethyl Orthosilicate

2020 ◽  
Vol 860 ◽  
pp. 83-88
Author(s):  
Togar Saragi ◽  
Hotmas D. Sinaga ◽  
Feni Rahmi ◽  
Gustiani A. Pramesti ◽  
Adi Sugiarto ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Zeta Potential ◽  
Hexagonal Phase ◽  
Tetraethyl Orthosilicate ◽  
Crystal Quality ◽  
Hydroxyl Group ◽  
Precipitation Method ◽  
The Stability ◽  
Co Precipitation

Magnetic nanofluids are a category of nanomaterial which exhibit simultaneously liquid and superparamagnetic properties. These nanofluids are magnetic nanoparticles stably dispersed in liquid carrier. Magnetic nanoparticles with and without SiO2 encapsulation have been successfully synthesized by co-precipitation method from ferrous and ferric precursors dispersed in various liquid. Fe3O4 nanoparticles were investigated by Zeta Potential and HR-TEM to determine the stability of nanoparticles, average particles size and microstructure of nanoparticles. From zeta potential measurements, is was found that the value of zeta potential for Fe3O4 dispersed in ethanol was ± 0,9 mV, while dispersed in di-water was ± 31,1 mV, indicating that nanoparticles Fe3O4 are more stable in DI-water. The increasing of zeta potential indicated the adsorption of negatively charged hydroxyl group to the surface of Fe3O4 nanoparticles. From XRD measurements, it was found that crystal quality of Fe3O4.SiO2 sintering at 80 °C decreased by increasing the volume of tetraethyl orthosilicate (TEOS), while that samples sintering at 1000 °C have a good crystal quality with hexagonal phase of a-Fe2O3.SiO2. From SQUID measurements, it was found that samples of Fe3O4.SiO2 sintering at 80 °C with TEOS volumes of 1 ml and 2 ml showed a paramagnetic like while samples of a-Fe2O3.SiO2 sintering at 1000 °C with the same TEOS volume showed ferrimagnetic properties.

Formulation, Physical and Chemical Stability of Ocimum gratissimum L. Leaf Oil Nanoemulsion

2021 ◽  
Vol 901 ◽  
pp. 117-122
Author(s):  
Netnapa Ontao ◽  
Sirivan Athikomkulchai ◽  
Sarin Tadtong ◽  
Phuriwat Leesawat ◽  
Chuda Chittasupho
Keyword(s):  
Essential Oil ◽  
Zeta Potential ◽  
Chemical Stability ◽  
Polydispersity Index ◽  
Hydrodynamic Diameter ◽  
Potential Value ◽  
Yellow Color ◽  
Leaf Oil ◽  
The Stability ◽  
Physical And Chemical

Ocimum gratissimum L. leaf oil exhibited many pharmacological properties. This study aimed to formulate and evaluate the physical and chemical stability of O.gratissimum leaf oil nanoemulsion. O.gratissimum leaf oil was extracted by hydrodistillation. The major component of the essential oil eugenol, was analyzed by UV-Vis spectrophotometry. Nanoemulsions of O.gratissimum leaf oil were formulated using polysorbate 80, hyaluronic acid, poloxamer 188, and deionized water by phase inversion composition method. The hydrodynamic diameter, polydispersity index, and zeta potential value of O.gratissimum leaf oil nanoemulsion was evaluated by a dynamic light scattering technique. The %remaining of eugenol in the nanoemulsion was analyzed by UV-Vis spectrophotometry. The essential oil extracted from of O. gratissimum leaf oil was a clear, pale yellow color. The %yield of the essential oil was 0.15 ± 0.03% v/w. The size of the nanoemulsion was less than 106 nm. The polydispersity index of the nanoemulsion was ranging from 0.303 - 0.586 and the zeta potential value of the nanoemulsion was closely to zero, depending on the formulation component. O. gratissimum leaf oil at concentrations ranging from 0.002 - 0.012% v/v contained 35 - 41% of eugenol. The size of nanoemulsion was significantly decreased after storage at 4 °C, while significantly increased upon storage at 45 °C. The size of nanoemulsion stored at 30 °C did not significantly change. The %remaining of eugenol in the nanoemulsion was more than 90% after storage at 4 °C and 30 °C for 28 days. The percentage of eugenol remaining in the nanoemulsion stored at 45 °C was more than 85 - 90%, suggesting that the temperature affected the stability of eugenol in the nanoemulsion.

scholarly journals Crystallographic, Energy Gap, Photoluminescence and Photo-Catalytic Investigation of Cu Doped Cd0.9Zn0.1S Nanostructures by Co-Precipitation Method

2021 ◽  
Author(s):  
P. Raju ◽  
Joseph Prince Jesuraj ◽  
S. Muthukumaran
Keyword(s):  
Crystallite Size ◽  
Energy Gap ◽  
Wavelength Region ◽  
Lattice Parameter ◽  
Precipitation Method ◽  
Optical Absorbance ◽  
Stability Measurement ◽  
Cubic Structure ◽  
The Stability ◽  
Co Precipitation

Abstract The controlled synthesis of Cd0.9Zn0.1S, Cd0.89Zn0.1Cu0.01S and Cd0.87Zn0.1Cu0.03S nanostructures by simple chemical co-precipitation technique was reported. The XRD investigation confirmed the basic CdS cubic structure on Zn-doped CdS and also Zn, Cu dual doped CdS with no secondary/impurity related phases. No modification in cubic structure was detected during the addition of Zn/Cu into CdS. The reduction of crystallite size from 63 Å to 40 Å and the changes in lattice parameter confirmed the incorporation of Cu into Cd0.9Zn0.1S and generation of Cu related defects. The shift of absorption edge along upper wavelength region and elevated absorption intensity by Cu doping can be accredited to the collective consequence of quantization and the generation of defect associated states. The enhanced optical absorbance and the reduced energy gap recommended that Cd0.87Zn0.1Cu0.03S nanostructure is useful to enhance the efficiency of opto-electronic devices. The presence of Cd-S / Zn-Cd-S /Zn/Cu-Cd-S chemical bonding were confirmed by Fourier transform infrared investigation. The elevated green emissions by Cu incorporation was explained by decrease of crystallite size and creation of more defects. Zn, Cu dual doped CdS nanostructures are recognized as the possible and also efficient photo-catalyst for the removal dyes like methylene blue. The enhanced photo-catalytic behaviour of Zn, Cu dual doped CdS is the collective consequences of high density electron-hole pairs creation, enhanced absorbance in the visible wavelength, surface area enhancement, reduced energy gap and the formation of novel defect associated states. The stability measurement signified that Cu doped Cd0.9Zn0.1S exhibits superior dye removal ability and better stability even after 6 repetitive runs with limited photo-corrosion.

XRD and Photoluminescence Properties of CaSO4:Dy Phosphor Synthesized by New Co-Precipitation Method

2017 ◽  
Vol 888 ◽  
pp. 333-337 ◽  
Author(s):  
Nadira Kamarudin ◽  
Wan Saffiey Wan Abdullah ◽  
Muhammad Azmi Abdul Hamid
Keyword(s):  
Calcium Sulfate ◽  
Average Crystallite Size ◽  
Information Storage ◽  
Precipitation Method ◽  
Photoluminescence Properties ◽  
Orthorhombic Crystal ◽  
Phosphor Material ◽  
X Ray ◽  
Wide Range ◽  
Co Precipitation

This paper presents the luminescence properties of dysprosium (Dy) doped calcium sulfate (CaSO4) phosphor material produced by co-precipitation technique with 0.1 - 0.5 mol% concentration of dopant. The crystallinity of the produced powder was studied using x-ray powder diffraction (XRD). The XRD spectrum shows high purity anhydrite CaSO4 phosphor material produced. The average crystallite size of 74 nm with orthorhombic crystal system was obtained. The luminescence behavior of produced CaSO4: Dy was studied using a photoluminescence (PL) spectrometer. The excitation and emission spectrum peaks associated with defects and vacancies of the phosphor material at claimed crystalline phase. The mixed peaks of excitation and emission that corresponds to micro and nano sized particle was shown for the produced powders. These properties show that the produced powders have wide range of luminescence detection with many electron traps ready for thermoluminescence (TL) information storage.

scholarly journals Synthesis of BaTi5O11 by an aqueous co-precipitation method via stable organic titanate precursor

2021 ◽  
pp. 14-14
Author(s):  
Pelin Aktaş
Keyword(s):  
Aqueous Media ◽  
Average Crystallite Size ◽  
Phase Evolution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Ft Ir ◽  
Scherrer Formula ◽  
Co Precipitation

BaTi5O11 has been widely researched due to its unique microwave properties. Conventionally it is challenging to obtain this compound as a single phase. The BaTi5O11 was synthesized via co-precipitation technique using an aqueous solution of titanium(IV)(triethanolaminato) isopropoxide, barium nitrate and ammonia as precursors which are stable in an aqueous media. The phase evolution, purity, and structure were identified by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy analysis. The desired BaTi5O11 structure was obtained by calcination at 900?C. Furthermore, the structure is characterized by TGA, FT-IR and Raman studies. The study showed that the particles were between 80 and 120 nm in size and the average crystallite size was determined from the Scherrer formula as 68.1 nm at 900?C.

scholarly journals Corrosion Protection of 6061 Aluminum Alloys by Sol-Gel Coating Modified with ZnLaAl-LDHs

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 478
Author(s):  
Youbin Wang ◽  
Qiuyu Huang ◽  
Bingtao Zhou ◽  
Zengyin Yuan ◽  
Yuezhou Wei ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Corrosion Protection ◽  
Sol Gel ◽  
Precipitation Method ◽  
Corrosion Mechanism ◽  
Corrosion Performance ◽  
The Stability ◽  
Co Precipitation ◽  
Double Hydroxides

In this work, ZnLaAl layered double hydroxides (LDHs) were prepared by the co-precipitation method, and the ZnLaAl-LDHs nanosheets were embedded in sol-gel coating for the corrosion protection of 6061 aluminum alloys. The structure, morphology, and long-term anti-corrosion performance of sol-gel coating modified with ZnLaAl-LDHs were investigated. The structure and morphology analysis showed that nanosheets of ZnLaAl-LDHs are finer than those of ZnAl-LDHs, with the results suggesting that the La can refine the size of LDHs’ nanosheets and improve their nucleation rate. The results of long-term corrosion tests showed that the sol-gel coating with ZnLaAl-LDHs exhibits higher corrosion resistance and better stability compared with the sol-gel coating with ZnAl-LDHs, which indicates that the addition of La enhances the anti-corrosion performance of the LDHs and improves the stability of sol-gel coating with LDHs. Finally, the formation mechanism of ZnLaAl-LDHs and the corrosion mechanism of sol-gel coating with ZnLaAl-LDHs on 6061 aluminum alloys are both discussed in detail.

scholarly journals Synthesis and Characterization of Magnetic Iron Oxide Nanoparticles by Co-Precipitation Method at Different Conditions

2018 ◽  
Vol 24 (10) ◽  
pp. 60 ◽  
Author(s):  
Ahmed Faiq Al-Alawy ◽  
Entisar Eliwi Al-Abodi ◽  
Raya Mohammed Kadhim
Keyword(s):  
Iron Oxide ◽  
Zeta Potential ◽  
Precipitation Method ◽  
Ferrous Ions ◽  
Magnetic Iron Oxide Nanoparticles ◽  
Atomic Force ◽  
Opposite Process ◽  
Methods Of Synthesis ◽  
Co Precipitation

Magnetic nanoparticles (MNPs) of iron oxide (Fe3O4) represent the most promising materials in many applications. MNPs have been synthesized by co-precipitation of ferric and ferrous ions in alkaline solution. Two methods of synthesis were conducted with different parameters, such as temperature (25 and 80 ̊C), adding a base to the reactants and the opposite process, and using nitrogen as an inert gas. The product of the first method (MNPs-1) and the second method (MNPs-2) were characterized by x-ray diffractometer (XRD), Zeta Potential, atomic force microscope (AFM) and scanning electron microscope (SEM). AFM results showed convergent particle size of (MNPs-1) and (MNPs-2) with (86.01) and (74.14) nm respectively. Also, the zeta potential values of (MNPs-1) and (MNPs-2) were (2.77) and (-12.48) mV, respectively, which indicates more stability of (MNP-2).  

scholarly journals Synthesis and Characterization of Pure and Rare-Earth Metal Gd Doped SnO2-CuO Nanoparticles by Co-Precipitation Method

2018 ◽  
Vol 4 (5) ◽  
pp. 478-482
Author(s):  
L. Prakash ◽  
C. Tirupathi
Keyword(s):  
Rare Earth ◽  
Band Gap ◽  
Crystallite Size ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Average Crystallite Size ◽  
Cuo Nanoparticles ◽  
Precipitation Method ◽  
Pure Sno2 ◽  
Co Precipitation

Pure and rare-earth metal Gd doped SnO2-CuO nanoparticles were successfully prepared from the starting materials SnCl2, CuCl2 and doping element gadolinium nitrate. Pure and Gd doped SnO2-CuO were synthesized by co-precipitation method. The samples were characterized using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), UV-Vis, SEM, EDX and dielectric studies. The XRD analysis reveals that the rare-earth metal Gd dopants were substituted into rutile SnO2-CuO nanoparticles. Pure SnO2-CuO nanoparticles have an average crystallite size of 15 nm and rare-earth metal Gd doped SnO2-CuO nanoparticles have 18 nm. The average crystallite size of the sample increases when dopant was used and XRD peak intensity also increases when compared to pure SnO2-CuO nanoparticles. The optical absorption measurements exposed the nanometric size of the materials influences the energy band gap. Optical band gap was found to be 5.08 eV for pure SnO2-CuO nanoparticles and 5.14 eV for Gd doped SnO2-CuO nanoparticles. Surface morphology of pure and Gd doped SnO2-CuO nanoparticles annealed at 400 °C shows that most of the particles are rod shaped and hence it may have better sensitivity. Dielectric constant and dielectric loss decrease with increasing frequency at 100 °C and 200 °C. Doped samples show larger dielectric properties than pure SnO2-CuO nanoparticles.

scholarly journals Effect of Ni doping on structural, optical and photocatalytic properties of Zn1-XNiXO nanoparticles prepared by different pH conditions

2013 ◽  
Vol 12 (6) ◽  
pp. 4097-4107 ◽  
Author(s):  
R. Jeyachitr ◽  
N. Sriharan ◽  
V. Senthilnathan ◽  
T. S. Senthil
Keyword(s):  
Average Crystallite Size ◽  
Hexagonal Wurtzite Structure ◽  
Photocatalytic Properties ◽  
Precipitation Method ◽  
Ni Doping ◽  
Zno Nanocrystals ◽  
Structure Morphology ◽  
Ph Conditions ◽  
Doped Zno ◽  
Co Precipitation

Zn1-XNiXO (x = 0.00, 0.02, 0.04 & 0.06 mol %) nanoparticles were prepared by simple co-precipitation method. The influences of Ni doping on structure, morphology, optical and photocatalytic properties were investigated by means of Xray diffraction, scanning electron microscopy, UV–Vis spectrophotometer and photochemical reaction method. The obtained result shows that the prepared ZnO nanocrystals were hexagonal wurtzite structure and the average crystallite size decreases with increase of Ni doping. The increase of visible light absorption and increase of band gap were found with the increase of Ni doping concentration, which enable the sample harvest more photons to excite the electron from valence band. The photocatalytic properties of Ni doped ZnO nanocrystals shows enhanced activity that the pure ZnO nanocrystals. The photocatalytic activities were not significantly affected by the particle size and 0.04% Ni doped ZnO nanocrystals shows best catalytic activity than the other catalysts.

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