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.

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.

Two Schiff-base Complexes of Copper and Zirconium Oxide Fabricated on Magnetic Nanoparticles as Practical and Recyclable Catalysts in C-C Coupling Reaction

2020 ◽  
Vol 17 ◽  
Author(s):  
Mohsen Nikoorazm ◽  
Masoomeh Naseri
Keyword(s):  
Schiff Base ◽  
Magnetic Nanoparticles ◽  
Zirconium Oxide ◽  
High Efficiency ◽  
Coupling Reaction ◽  
Schiff Base Complexes ◽  
Precipitation Method ◽  
The Stability ◽  
Co Precipitation ◽  
Fe3o4 Mnps

: Fe3O4 magnetic nanoparticles (MNPs) were prepared via a chemical co-precipitation method. Then, the surface of Fe3O4 MNPs was modified by (3-Chloropropyl)trimethoxysilane and then two Schiff-base complexes of zirconium oxide and copper were stabilized on modified Fe3O4 MNPs. These catalysts were characterized using SEM, EDS, WDX, FTIR, XRD, TGA, VSM and AAS techniques. The catalytic activity of these catalysts was described in the carbon-carbon coupling reaction. VSM analysis of these catalysts indicate the high magnetic performance, therefor these catalysts can be recovered by an external magnet and reused for several times without missing in the amount of catalysts. Reusability, excellent yields and high TON values indicate the high efficiency of these catalysts. Leaching of these catalysts was studied by AAS which leaching of copper or zirconium was not observed. Also, the stability of these catalysts was confirmed by characterization of recovered catalysts and comparing with fresh catalysts.

scholarly journals Photoluminescent Properties of Hydroxyapatite and Hydroxyapatite/Multi-Walled Carbon Nanotube Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Hexagonal Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Co Precipitation ◽  
Functionalized Mwcnts

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.

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.

Preparation and characterization of iron oxide nanoparticles coated with chitosan for removal of Cd(II) and Cr(VI) from aqueous solution

2014 ◽  
Vol 70 (6) ◽  
pp. 1004-1010 ◽  
Author(s):  
Th. I. Shalaby ◽  
N. M. Fikrt ◽  
M. M. Mohamed ◽  
M. F. El Kady
Keyword(s):  
Electron Microscope ◽  
Magnetic Nanoparticles ◽  
Magnetic Nanomaterials ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Toxic Heavy Metals ◽  
Transmission Electron ◽  
Magnetite Fe3o4 ◽  
Co Precipitation

This study investigated the applicability of magnetite Fe3O4 nanoparticles coated with chitosan (CMNs) for the removal of some toxic heavy metals from simulated wastewater. Magnetic nanomaterials were synthesized using the co-precipitation method and characterized by transmission electron microscope, scanning electron microscope, X-ray diffraction, and Fourier transformer infrared spectroscopy. The magnetic properties of the prepared magnetic nanoparticles were determined by a vibrating-sample magnetometer. Batch experiments were carried out to determine the adsorption kinetics of Cr(VI) and Cd(II) by magnetic nanoparticles. It is noteworthy that CMNs show a highly efficient adsorption capacity for low concentration Cr(VI) and Cd(II) ions solution, which can reach 98% within 10 min.

Study on γ-Fe2O3 Magnetic Fluid by Thermal Oxidizing of Fe3O4 Nanoparticles

2015 ◽  
Vol 713-715 ◽  
pp. 2916-2919
Author(s):  
Hang Zheng ◽  
Hui Ping Shao ◽  
Zi Fen Zhao
Keyword(s):  
Surface Modification ◽  
Oleic Acid ◽  
Magnetic Nanoparticles ◽  
Saturation Magnetization ◽  
Sodium Oleate ◽  
Magnetic Fluid ◽  
Silicone Oil ◽  
Precipitation Method ◽  
Carrier Liquid ◽  
Co Precipitation

In this paper, Fe3O4magnetic nanoparticles were synthesized by chemical co-precipitation method and their surface was modified by sodium oleate. The γ-Fe2O3magnetic nanoparticles were achieved by thermal oxidizing of Fe3O4. The γ-Fe2O3magnetic fluid was prepared by using silicone oil as carrier liquid and oleic acid as surface modification agent, and the saturation magnetization of prepared γ-Fe2O3magnetic fluid hits 14.25emu/g.

Assessment of polydopamine coated magnetic nanoparticles in doxorubicin delivery

RSC Advances ◽  
2016 ◽  
Vol 6 (7) ◽  
pp. 5936-5943 ◽  
Author(s):  
Radosław Mrówczyński ◽  
Justyna Jurga-Stopa ◽  
Roksana Markiewicz ◽  
Emerson L. Coy ◽  
Stefan Jurga ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Hela Cells ◽  
Oxidative Polymerization ◽  
Precipitation Method ◽  
Doxorubicin Delivery ◽  
Co Precipitation

Magnetic nanoparticles coated with bioinspired polydopamine were obtained via a co-precipitation method and oxidative polymerization of dopamine. Obtained particle were used for carrying doxorubicin to HeLa cells.

Synthesis and Optical Properties of Annealed Cr Doped ZnS Nanoparticles

2013 ◽  
Vol 678 ◽  
pp. 163-167 ◽  
Author(s):  
D. Amaranatha Reddy ◽  
G. Murali ◽  
N. Madhusudhana Rao ◽  
R.P. Vijayalakshmi ◽  
B.K. Reddy
Keyword(s):  
Optical Properties ◽  
Hexagonal Phase ◽  
Blue Emission ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Structural And Optical Properties ◽  
Zns Nanoparticles ◽  
Blue Emission Peak ◽  
Co Precipitation ◽  
Surface Morphologies

Undoped and Cr doped ZnS nanoparticles with Cr concentrations of 3.0 at.% were prepared by a chemical co-precipitation method for the fist time, using 2-Mercaptoethanol as the capping agent and annealed the synthesized particles at 600°C for 3h in air. The effect of annealing on morphological, structural and optical properties of ZnS and ZnS:Cr have been studied and compared with as prepared samples. EDAX measurements confirmed the presence of Cr in the ZnS lattice and it also confirms the conversion of ZnS into ZnO after annealed at 600 0C/3h. Surface morphologies of all samples were characterized using scanning electron microscopy (SEM). XRD spectra of as synthesized nanoparticles of ZnS and ZnS:Cr exhibited cubic phase. After annealing, the cubic phase is transformed into hexagonal phase. The particle sizes of the ZnS:Cr powders were increased from 5 to 30 nm when the powders were annealed at 600°C. A stable blue emission peak at 445 nm is observed from the as prepared samples (pure ZnS and Cr doped ZnS) but annealed at 600 0C the PL peaked at 500 nm for pure ZnS and Cr doped ZnS nanoparticles exhibited PL peak at 500 nm as well as 654 nm. The emission intensity decreased in annealed particles compared to as synthesized samples.

Synthesis and Characterization of Mesoporous Hydroxyapatite

2010 ◽  
Vol 63 ◽  
pp. 152-157 ◽  
Author(s):  
Kien Seng Lew ◽  
Radzali Othman ◽  
Fei Yee Yeoh
Keyword(s):  
Self Assembly ◽  
Bone Cells ◽  
Hexagonal Phase ◽  
The Body ◽  
Precipitation Method ◽  
Hexadecyltrimethylammonium Bromide ◽  
Phosphate Solution ◽  
Decyltrimethylammonium Bromide ◽  
Constant Ph ◽  
Co Precipitation

Among the porous media, hydroxyapatite (HA) possesses good biocompatibility and bioactivity properties with respect to bone cells and tissues, due to its similarity with the hard tissues of the body. In this study, mesoporous HA was synthesized using a soft-templating technique via a self-assembly between HA and cationic surfactant decyltrimethylammonium bromide (C10TAB), which is analogous to the synthesis of mesoporous silica MCM-41. This co-precipitation method involved formation of hexagonal-phase micelle template by the surfactant and the precipitation of HA surrounding the micelle. After ageing, calcination was carried out to remove the templates, revealing the pores as well as to produce more crystalline and more stable HA structure. This study showed that instead of hexadecyltrimethylammonium bromide (C16TAB) which was conventionally used, C10TAB could also be used to synthesize single-phase mesoporous HA with pore size ca. 3 nm. Ageing temperature of 120 °C, for 24 hours was found sufficient for the formation of mesoporous HA. The adsorption properties of mesoporous HA was able to be improved by increasing the water content of C10TAB-phosphate solution and by constant pH adjustment during the mixing of solutions.

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