Synthesis of Small-Sized, Porous, and Low-Toxic Magnetite Nanoparticles by Thin POSS Silica Coating

2015 ◽  
Vol 21 (10) ◽  
pp. 3914-3918 ◽  
Author(s):  
Swee Kuan Yen ◽  
D. Prathyusha Varma ◽  
Wei Mei Guo ◽  
Vincent H. B. Ho ◽  
Vimalan Vijayaragavan ◽  
...  
Keyword(s):  
Magnetite Nanoparticles ◽  
Silica Coating ◽  
Low Toxic

New product from old reaction: uniform magnetite nanoparticles from iron-mediated synthesis of alkali iodides and their protection from leaching in acidic media

RSC Advances ◽  
2014 ◽  
Vol 4 (43) ◽  
pp. 22606-22612 ◽  
Author(s):  
R. P. Pogorilyi ◽  
I. V. Melnyk ◽  
Y. L. Zub ◽  
S. Carlson ◽  
G. Daniel ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Magnetite Nanoparticles ◽  
Acid Leaching ◽  
New Product ◽  
Silica Coating ◽  
Acidic Media ◽  
Industrial Synthesis

Magnetic material stable to acid leaching was produced by silica coating of byproduct from the industrial synthesis of alkali iodides.

scholarly journals Magnetite–Corrole Hybrid Nanoparticles

2018 ◽  
Vol 4 (3) ◽  
pp. 37
Author(s):  
Rute Pereira ◽  
Tito Trindade ◽  
Joana Barata
Keyword(s):  
Magnetite Nanoparticles ◽  
Silica Coating ◽  
Hybrid Nanoparticles ◽  
Hydrothermal Route ◽  
Shell Nanoparticles ◽  
Lower Efficiency ◽  
Oxygen Generation ◽  
Transmission Electron ◽  
Pyridine Complex ◽  
Core Shell Nanoparticles

This study describes the first example of a hybrid material comprising corrole- and silica-coated magnetite nanoparticles. Firstly, cuboid and spheroid magnetite nanoparticles were prepared using a simple hydrothermal route, followed by a silica coating. The hybrid nanoparticles were obtained by promoting a covalent link between a gallium (III)(pyridine) complex of 5,10,15-tris(pentafluorophenyl)corrole (GaPFC) and the surface of magnetite–silica core/shell nanoparticles (Fe3O4@SiO2), shaped both as cuboids and spheroids. The hybrids were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultraviolet-visible spectrophotometry (UV-Vis) and transmission electron microscopy (TEM). Preliminary studies on the capacity of singlet oxygen generation of the hybrid nanoparticles showed that these have lower efficiency values when compared to the pure corrole compound.

scholarly journals Improving Longitudinal Transversal Relaxation Of Gadolinium Chelate Using Silica Coating Magnetite Nanoparticles

2019 ◽  
Vol Volume 14 ◽  
pp. 7879-7889
Author(s):  
Kai Xu ◽  
Heng Liu ◽  
Junfeng Zhang ◽  
Haipeng Tong ◽  
Zhenghuan Zhao ◽  
...  
Keyword(s):  
Magnetite Nanoparticles ◽  
Silica Coating ◽  
Gadolinium Chelate

Effects of silica coating on the magnetic properties of magnetite nanoparticles

2019 ◽  
Vol 14 ◽  
pp. 34-43 ◽  
Author(s):  
Estelle Silva Diorato Teixeira de Mendonça ◽  
Anna Carolina Britto de Faria ◽  
Sílvia Cláudia Loureiro Dias ◽  
Fermin F.H. Aragón ◽  
John C. Mantilla ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetite Nanoparticles ◽  
Silica Coating

scholarly journals Synthesis and characterization of magnetic nanoparticles coated with silica through a sol-gel approach

Cerâmica ◽  
2009 ◽  
Vol 55 (336) ◽  
pp. 420-424 ◽  
Author(s):  
A. L. Andrade ◽  
D. M. Souza ◽  
M. C. Pereira ◽  
J. D. Fabris ◽  
R. Z. Domingues
Keyword(s):  
Fourier Transform ◽  
Magnetic Nanoparticles ◽  
Magnetite Nanoparticles ◽  
Sol Gel ◽  
Reaction Medium ◽  
Fourier Transform Infrared ◽  
Silica Coating ◽  
Precipitation Method ◽  
Pure Silica

This paper investigates the influence of reaction medium pH on silica-coating of magnetite nanoparticles. Magnetite nanoparticles were prepared by means of a reduction-precipitation method using ferric chloride as a starting material, which was partially reduced to ferrous salts by Na2SO3 before alkalinizing with ammonia. The particles were coated by sol-gel method with either ammonia or HCl aqueous solutions for either base- or acid-catalyzed hydrolysis, respectively. Powder X-ray diffraction, Fourier-transform infrared, and Zeta Potential were used for the characterization of oxides and of the coated magnetic nanoparticles. The observed difference of pH IEP in KCl solution for pure silica (2.0), magnetite (5.0), and silica-coated magnetite (2.3) samples confirms that the coating process was effective since the charge surface properties of coated magnetic nanoparticles are close to that of pure silica, even though the Fourier-transform infrared spectra did not evidence the formation of Fe-O-Si bonds.

scholarly journals Aggregation state and magnetic properties of magnetite nanoparticles controlled by an optimized silica coating

2017 ◽  
Vol 121 (4) ◽  
pp. 044304 ◽  
Author(s):  
Nicolás Pérez ◽  
C. Moya ◽  
P. Tartaj ◽  
A. Labarta ◽  
X. Batlle
Keyword(s):  
Magnetic Properties ◽  
Magnetite Nanoparticles ◽  
Silica Coating ◽  
Aggregation State

Amorphous silica coating on α-alumina particles

1995 ◽  
Vol 53 ◽  
pp. 210-211
Author(s):  
J. W. Mellowes ◽  
C. M. Chun ◽  
I. A. Aksay
Keyword(s):  
Amorphous Silica ◽  
Heterogeneous Nucleation ◽  
Homogeneous Nucleation ◽  
Silica Coating ◽  
Full Density ◽  
Optimal Conditions ◽  
Fine Grained ◽  
Alumina Particles ◽  
Complete Mullitization ◽  
Powder Compacts

Mullite (3Al2O32SiO2) can be fabricated by transient viscous sintering using composite particles which consist of inner cores of a-alumina and outer coatings of amorphous silica. Powder compacts prepared with these particles are sintered to almost full density at relatively low temperatures (~1300°C) and converted to dense, fine-grained mullite at higher temperatures (>1500°C) by reaction between the alumina core and the silica coating. In order to achieve complete mullitization, optimal conditions for coating alumina particles with amorphous silica must be achieved. Formation of amorphous silica can occur in solution (homogeneous nucleation) or on the surface of alumina (heterogeneous nucleation) depending on the degree of supersaturation of the solvent in which the particles are immersed. Successful coating of silica on alumina occurs when heterogeneous nucleation is promoted and homogeneous nucleation is suppressed. Therefore, one key to successful coating is an understanding of the factors such as pH and concentration that control silica nucleation in aqueous solutions. In the current work, we use TEM to determine the optimal conditions of this processing.

Functional surfaces produced by foam coating

TAPPI Journal ◽  
2016 ◽  
Vol 15 (8) ◽  
pp. 515-521 ◽  
Author(s):  
EIJA KENTTÄ ◽  
HANNA KOSKELA ◽  
SARA PAUNONEN ◽  
KARITA KINNUNEN-RAUDASKOSKI ◽  
TUOMO HJELT
Keyword(s):  
Life Time ◽  
Silica Coating ◽  
Foaming Properties ◽  
Coated Paper ◽  
Paper Properties ◽  
Foaming Agent ◽  
Foaming Agents ◽  
Size Stability ◽  
Stability Measurement ◽  
Standard Paper

This paper reports experiments on silica coating formulations that are suitable for application as a thin pigment layer with foam coating technique on a paper web. To understand the foaming properties of nanosilica dispersions, the critical micelle concentration, foam half-life time, and foam bubble size stability were determined with three different foaming agents. The results indicate that the bubble stability measurement is a useful characterization method for foam coating purposes. Pilot foam coating trials were done and the effects of the chosen foaming agents were studied on the properties of the nanosilica-coated paper. The surface hydrophilicity of silica coated paper was related not only to silica pigment, but also to the chemical nature of the foaming agent. Standard paper properties were not affected by the thin silica coating.

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