Synthesis and Characterization of Magnetic Mesoporous Ɣ-FE2O3/SIO2

2014 ◽  
Vol 879 ◽  
pp. 128-133
Author(s):  
Nur Shuhada Shaari ◽  
Suhaina Mohd Ibrahim ◽  
Farinaa Md Jamil ◽  
Zuhana Ahmad Zubir ◽  
A.M. Abdullah ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Self Assembly ◽  
Quantum Interference ◽  
Silica Matrix ◽  
Synthesis And Characterization ◽  
Vibrating Sample Magnetometer ◽  
Superconducting Quantum Interference Device ◽  
Evaporation Induced Self Assembly

Magneticmesoporousɣ-Fe2O3/SiO2 synthesized using an evaporation-induced self-assembly (EISA) approach. The non-ionictriblock copolymer P123 was used as surfactant template with various amounts of iron oxide (1.8g-2.4g) and varied during the synthesis. Characterizations of the surface area and magnetic properties for prepared materials were done using N2-sorption analyses, and a superconducting quantum interference device interfaced with a vibrating sample magnetometer (SQUID-VSM) respectively. From this study, N2-sorption analysis indicated that most of the ɣ-Fe2O3domains of several nanometres were embedded in the silica matrix. In addition, the obtained magneticmesoporouscomposite which contains 2.3g amount ofiron oxide has revealedhigher magnetism saturation value of (4.564 emu/g) compared to other prepared samples which been evaluated by VSM analysis.

Dendrimer Mediated ‘Bricks and Mortar’ Self-Assembly of Nanoparticles

2002 ◽  
Vol 739 ◽  
Author(s):  
Benjamin L. Frankamp ◽  
Andrew K. Boal ◽  
Vincent M. Rotello
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Self Assembly ◽  
Quantum Interference ◽  
Pamam Dendrimers ◽  
Interparticle Spacing ◽  
Blocking Temperature ◽  
Oxide Nanoparticles ◽  
Particle Spacing

ABSTRACTControl of particle-particle spacing is a key determinant of optical, electronic, and magnetic properties of nanocomposite materials. We have used poly(amidoamine) (PAMAM) dendrimers to assemble carboxylic acid-functionalized mixed monolayer protected clusters (MMPCs) through acid/base chemistry between particle and polymer. IR spectroscopy and selective dendrimer staining, observed by Transmission Electron Microscopy (TEM), establish that the PAMAM dendrimers are the mortar in the assembly and act to space the MMPCs in the resulting aggregates. Small angle X-ray scattering (SAXS) was then used to establish average interparti cle distances; five generations of PAMAM dendrimer (0, 1, 2, 4, 6) were investigated and monotonic increase in interparticle spacing from 4.1 nm to 6.1 nm was observed.Initial studies involving the application of this methodology to control the magnetic properties of 3-iron oxide nanoparticles have been completed. γ-Iron oxide nanoparticles (6.5 nm in diameter) have been assembled with PAMAM dendrimers generations 2.5, 4.5, and 6.5. The resulting aggregates were characterized with SAXS and magnetization obtained on a super conducting quantum interference devise (SQUID). An observed correlation between the blocking temperature (TB) and the average interparticle spacing suggests that our methodology could be used to tailor the magnetic profile of the nanoparticles.

scholarly journals Synthesis and characterization of dextran-coated iron oxide nanoparticles

2018 ◽  
Vol 5 (3) ◽  
pp. 171525 ◽  
Author(s):  
Andra Mihaela Predescu ◽  
Ecaterina Matei ◽  
Andrei Constantin Berbecaru ◽  
Cristian Pantilimon ◽  
Claudia Drăgan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Quantum Interference ◽  
Synthesis And Characterization ◽  
Oxide Nanoparticles ◽  
Transmission Electron ◽  
Molar Weight ◽  
Co Precipitation

Synthesis and characterization of iron oxide nanoparticles coated with a large molar weight dextran for environmental applications are reported. The first experiments involved the synthesis of iron oxide nanoparticles which were coated with dextran at different concentrations. The synthesis was performed by a co-precipitation technique, while the coating of iron oxide nanoparticles was carried out in solution. The obtained nanoparticles were characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction spectrometry, Fourier transform infrared spectroscopy and superconducting quantum interference device magnetometry. The results demonstrated a successful coating of iron oxide nanoparticles with large molar weight dextran, of which agglomeration tendency depended on the amount of dextran in the coating solution. SEM and TEM observations have shown that the iron oxide nanoparticles are of about 7 nm in size.

SYNTHESIS AND CHARACTERIZATION OF FeRh NANOPARTICLES

2007 ◽  
Vol 21 (18) ◽  
pp. 1153-1159 ◽  
Author(s):  
DIANA CIUCULESCU ◽  
CATHERINE AMIENS ◽  
MARC RESPAUD ◽  
PIERRE LECANTE ◽  
ANDREA FALQUI ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Quantum Interference ◽  
Hydrogen Pressure ◽  
Mossbauer Spectroscopy ◽  
Synthesis And Characterization ◽  
Superconducting Quantum Interference Device ◽  
Mild Conditions ◽  
Mößbauer Spectroscopy ◽  
Average Size

Fe 0.8 Rh 0.2 nanoparticles with an average size of 1.8 nm have been synthesized by simultaneous decomposition of stoichiometric quantities of Fe[N(Si(CH 3)3)2]2 and Rh(C 3 H 5)3 in mild conditions of temperature and hydrogen pressure, using hexadecylamine as stabilizer. These nanoparticles display a magnetization of 1.13 μ B per iron atom, which is more than two times smaller than the bulk value with the same composition. No surface contamination with iron oxides was detected by Mössbauer spectroscopy. Superconducting quantum interference device and Mössbauer spectroscopy investigations reveal that the origin of this variation may be a core-shell Rh/Fe chemical arrangement.

Synthesis, structure, and magnetic properties of iron-oxide nanowires

2006 ◽  
Vol 21 (11) ◽  
pp. 2955-2962 ◽  
Author(s):  
Matej Pregelj ◽  
Polona Umek ◽  
Boštjan Drolc ◽  
Boštjan Jančar ◽  
Zvonko Jagličič ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Iron Oxide ◽  
Quantum Interference ◽  
Superconducting Quantum Interference Device ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
Oxide Nanowires ◽  
Transmission Electron ◽  
Electron Paramagnetic

Iron-oxide nanowires were synthesized by a hydrothermal treatment of Fe(OH)3 dispersion in NaOH. The obtained materials were first structurally investigated by scanning electron microscopy, transmission electron microscopy, x-ray diffraction, and thermogravimetric analysis techniques. Their magnetic properties were then examined by superconducting quantum interference device and electron paramagnetic resonance methods. A typical nanowire measured 10–15 nm in diameter and 600 nm in length. All the structural and magnetic investigations were consistent with the nanowire goethite structure. The nanowire Neél transition temperature occurred at 375 K; i.e., it was lowered by 25 K with respect to the corresponding goethite bulk value. The shift in the ordering temperature was suggested to be a consequence of a growing importance of strains and surface effects at the nanoscale. We were also able to irreversibly convert goethite nanowires into hematite, by warming the sample to temperatures exceeding 530 K.

scholarly journals Synthesis and characterization of boron-doped ordered mesoporous carbon by evaporation induced self-assembly under HCl conditions

RSC Advances ◽  
2017 ◽  
Vol 7 (14) ◽  
pp. 8250-8257 ◽  
Author(s):  
Yan Zhang ◽  
Wenwen Dai ◽  
Yujian Liu ◽  
Binge Ma
Keyword(s):  
Self Assembly ◽  
Driving Force ◽  
Mesoporous Carbon ◽  
Boron Content ◽  
Mesoporous Structure ◽  
Synthesis And Characterization ◽  
Boron Doped ◽  
Ordered Mesoporous ◽  
Evaporation Induced Self Assembly

With double-layer hydrogen bonding and electrostatic Coulomb forces acting as the driving force, the obtained B-OMC has the well-ordered mesoporous structure, highest surface area (689.85 m2 g−1) and boron content (1.96 wt%) when pH = 4.

Synthesis and Characterization of Yttria-Doped Mesoporous Zirconia

2014 ◽  
Vol 602-603 ◽  
pp. 212-215
Author(s):  
Rui Ping Liu ◽  
Chang An Wang
Keyword(s):  
Thermal Stability ◽  
Specific Surface ◽  
Self Assembly ◽  
Pore Volume ◽  
Textural Properties ◽  
Synthesis And Characterization ◽  
Bet Specific Surface Area ◽  
Mesoporous Zirconia ◽  
Evaporation Induced Self Assembly

The yttria-doped mesoporous zirconia was successfully synthesized by evaporation induced self-assembly (EISA) method, and the microstructure and textural properties of the as-made product were studied extensively. The results showed that the as-made product possessed crystallized framework walls and a worm-like mesopore with a narrow pore distribution. The BET specific surface area and pore volume of the as-made product calcined at 500°C are 111 m2/g and 0.16 cm3/g respectively, and the corresponding data changed to 73 m2/g and 0.052 cm3/g after calcined at 700°C, which indicated that the as-made yttria-doped mesoporous zirconia possess a higher thermal stability.

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