scholarly journals Effect of the Sodium Polyacrylate on the Magnetite Nanoparticles Produced by Green Chemistry Routes: Applicability in Forward Osmosis

2018 ◽  
Author(s):  
Juan Zufia-Rivas ◽  
Puerto Morales ◽  
Sabino Veintemillas-Verdaguer
Keyword(s):  
Magnetite Nanoparticles ◽  
Forward Osmosis ◽  
Correlation Spectroscopy ◽  
Sodium Polyacrylate ◽  
X Ray Diffraction ◽  
Drastic Reduction ◽  
Aqueous Dispersions ◽  
Transmission Electron ◽  
Oxidative Precipitation ◽  
Magnetite Nanocrystals

Aqueous dispersions of magnetic nanocomposites have been proposed as draw electrolytes in forward osmosis. One possible approach for the production nanocomposites based on magnetite nanoparticles and sodium polyacrylate, is the synthesis of the magnetic iron oxide by coprecipitation or oxidative precipitation in presence of an excess of the polymer. In this work we explored the effect of the polymer proportion on the nanomaterials produced by these procedures. The materials obtained were compared s with the obtained by the coating of magnetite nanocrystals produced beforehand with the same polymer. The samples were characterized by chemical analysis, photon correlation spectroscopy, thermogravimetry, X-ray diffraction, infrared spectroscopy, transmission electron microscopy and magnetometry. The general trend observed is that part of the polymer is incorporated to the magnetic material during the synthesis heavily modifying its texture, with a drastic reduction of the particle size and magnetic response. The aqueous dispersions of the nanocomposites were highly stable with hydrodynamic size roughly independent on the polymer proportion. Their osmotic pressure proportional to the concentration of the polyelectrolyte, was similar than the generated by the equivalent amount of free polymer in the case of samples generated by oxidative precipitation and smaller in the case of samples generated by coprecipitation. Finally the possibilities of using these materials as draw electrolytes in forward osmosis will be briefly discussed.

Synthesis of Monodispersed Fe3O4 Magnetite Nanoparticles by Ethylene Glycol Solvothermal Method

2013 ◽  
Vol 634-638 ◽  
pp. 2276-2279 ◽  
Author(s):  
Gang Xu ◽  
Min Zhang ◽  
Ping Ou ◽  
Yi Zhang ◽  
Gao Rong Han
Keyword(s):  
Ethylene Glycol ◽  
Magnetite Nanoparticles ◽  
Solvothermal Method ◽  
Physical Property Measurement System ◽  
Physical Property ◽  
X Ray Diffraction ◽  
Ferromagnetic Property ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Property Measurement

Monodispersed Fe3O4 magnetite nanoparticles were successfully synthesized via a simple solvothermal method, in which Fe(NO3)3•9H2O was used as the starting materials, KOH as the mineralizer, and ethylene glycol (en) as the solvent. X-ray diffraction (XRD) and selected area electron diffraction (SAED) were employed to characterize the phase composition, transmission electron microscope (TEM) to observe the morphology and the particle size, and physical property measurement system (PPMS) to investigate the magnetic property of the synthesized powders, respectively. The synthesized Fe3O4 magnetite nanoparticles are of 50-100nm in size, and of notable ferromagnetic property. The saturation magnetization, remanent magnetization, and coercive field are 68.8emu•g-1, 12.9emu•g-1, 138.5Oe, respectively. Based on the experimental resuts, the formation mechanism and the well monodispersed reason of the solvothersized Fe3O4 nanoparticles are discussed.

scholarly journals Effect of Tetramethylammonium Hydroxide on Nucleation, Surface Modification and Growth of Magnetic Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Ângela L. Andrade ◽  
José D. Fabris ◽  
José D. Ardisson ◽  
Manuel A. Valente ◽  
José M. F. Ferreira
Keyword(s):  
Zeta Potential ◽  
Magnetite Nanoparticles ◽  
Heat Dissipation ◽  
Tetramethylammonium Hydroxide ◽  
Precipitation Method ◽  
Attenuated Total Reflectance ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Transmission Electron ◽  
Magnetite Particles

Nanoparticles of magnetite (Fe3O4) were obtained by reacting ferric chloride with sodium sulphite, through the reduction-precipitation method. The effects of adding tetramethylammonium hydroxide (TMAOH) during or after the precipitation of the iron oxide were studied in an attempt to obtain well-dispersed magnetite nanoparticles. Accordingly, the following experimental conditions were tested: (i) precipitation in absence of TMAOH (sample Mt), (ii) the same as (i) after peptizing with TMAOH (Mt1), (iii) TMAOH added to the reaction mixture during the precipitation of magnetite (Mt2). Analyses with transmission electron microscopy (TEM), X-ray diffraction, Mössbauer spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), zeta potential, and magnetization measurements up to 2.5 T revealed that magnetite was normally formed also in the medium containing TMAOH. The degree of particles agglomeration was monitored with laser diffraction and technique and inspection of TEM images. The relative contributions of Néel and Brownian relaxations on the magnetic heat dissipation were studied by investigating the ability of suspensions of these magnetite nanoparticles to release heat in aqueous and in hydrogel media. Based on ATR-FTIR and zeta potential data, it is suggested that the surfaces of the synthesized magnetite particles treated with TMAOH become coated with (CH3)4N+cations.

scholarly journals Avrami behavior of magnetite nanoparticles formation in co-precipitation process

2011 ◽  
Vol 47 (2) ◽  
pp. 211-218 ◽  
Author(s):  
R. Ahmadi ◽  
Madaah Hosseini ◽  
A. Masoudi
Keyword(s):  
Magnetite Nanoparticles ◽  
Morphological Characterization ◽  
Precipitation Process ◽  
X Ray Diffraction ◽  
Nanoparticle Formation ◽  
Transmission Electron ◽  
Formation Behavior ◽  
Simplifying Assumptions ◽  
Co Precipitation ◽  
20 Nm

In this work, magnetite nanoparticles (mean particle size about 20 nm) were synthesized via coprecipitation method. In order to investigate the kinetics of nanoparticle formation, variation in the amount of reactants within the process was measured using pH-meter and atomic absorption spectroscopy (AAS) instruments. Results show that nanoparticle formation behavior can be described by Avrami equations. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were performed to study the chemical and morphological characterization of nanoparticles. Some simplifying assumptions were employed for estimating the nucleation and growth rate of magnetite nanoparticles.

scholarly journals Transformation mechanism of magnetite nanoparticles

2015 ◽  
Vol 33 (2) ◽  
pp. 278-285 ◽  
Author(s):  
Umar Saeed Khan ◽  
Abdul Manan ◽  
Nasrullah Khan ◽  
Amir Mahmood ◽  
Abdur Rahim ◽  
...  
Keyword(s):  
Magnetite Nanoparticles ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Transformation Mechanism ◽  
X Ray ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Magnetite Particles ◽  
Size And Morphology ◽  
Lower Temperature

AbstractA simple oxidation synthesis route was developed for producing magnetite nanoparticles with controlled size and morphology. Investigation of oxidation process of the produced magnetite nanoparticles (NP) was performed after synthesis under different temperatures. The phase transformation of synthetic magnetite nanoparticles into maghemite and, henceforth, to hematite nanoparticles at different temperatures under dry oxidation has been studied. The natural magnetite particles were directly transformed to hematite particles at comparatively lower temperature, thus, maghemite phase was bypassed. The phase structures, morphologies and particle sizes of the produced magnetic nanoparticles have been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX) and BET surface area analysis.

scholarly journals Photocatalytic activity of TiO2/stevensite nanocomposites for the removal of Orange G from aqueous solutions

Clay Minerals ◽  
2014 ◽  
Vol 49 (3) ◽  
pp. 417-428 ◽  
Author(s):  
L. Bouna ◽  
B. Rhouta ◽  
F. Maury ◽  
A. Jada ◽  
F. Senocq ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Solvothermal Method ◽  
X Ray Diffraction ◽  
Aqueous Dispersions ◽  
X Ray ◽  
Surface Areas ◽  
Surfactant Solutions ◽  
Transmission Electron ◽  
Orange G ◽  
Specific Surface Areas

AbstractTiO2/stevensite nanocomposite photocatalysts were synthesized by a solvothermal method using TiCl3/HCl as reactants and the stevensite clay mineral extract as support. The prepared photocatalyst samples were then characterized using various techniques such as X-ray diffraction (XRD), Infrared spectroscopy (IR) and Transmission Electron Microscopy (TEM). The Points of Zero Charge (PZC) of the various samples were evaluated by titration of the non-modified and the Ti-modified clay aqueous dispersions, with cationic surfactant solutions. The photocatalytic activity of the resulting nanocomposites samples were evaluated for the removal of Orange G (OG) from aqueous solution as a model dye pollutant. The data indicate that the formation of Na+-stevensite by the TiO2 particles leads to TiO2/stevensite nanocomposites having higher specific surface areas and mesopore volumes, and lower PZC values. Further, the photocatalytic activity was greater for the TiO2/stevensite nanocomposites having the greatest Ti amount, as compared to a pure TiO2 sample, and increased with the increase of the TiO2 content in the TiO2/stevensite nanocomposites.

scholarly journals The Oriented Attachment Crystal Growth Model in Hydrothermal Synthesis of Magnetite (Fe3O4) Nanoparticles

2019 ◽  
Vol 1 (1) ◽  
pp. 15-19
Author(s):  
Ahmad Fadli ◽  
Amun Amri ◽  
Esty Octiana Sari ◽  
Sukoco Sukoco ◽  
Deden Saprudin
Keyword(s):  
Crystal Growth ◽  
Growth Model ◽  
Magnetite Nanoparticles ◽  
Oriented Attachment ◽  
X Ray Diffraction ◽  
Magnetite Nanoparticle ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Magnetite Fe3o4 ◽  
Crystal Growth Kinetics

The magnetite nanoparticles (Fe3O4) are very promising nanomaterials to be applied as drug delivery due to their excellent superparamagnetic, biocompatibility and easily modified surface properties. Those properties are influenced by the structure and size of the material which can be controlled by studying the evolution of crystal growth. The purpose of this research is to study the evolution of crystal growth of magnetite nanoparticles in the hydrothermal system and determine the crystal growth kinetics using the Oriented Attachment Growth model. Magnetite nanoparticles were synthesized using a hydrothermal method from FeCl3, citrate, urea and polyethylene glycol at 210˚C for 1 - 12 hours at a various concentration of FeCl3 (0.05 M, 0.10 M, and 0.15 M). The characterizations were conducted by X-ray Diffraction (XRD), Transmission Electron Microscope (TEM), Particle size analyzer (PSA), and Vibrating Sample Magnetometer (VSM). The XRD difractogram  indicated that the magnetite was begun to form at 3.5 hours synthesis. The crystallinity and the crystal size of magnetite rose with reaction time. The diameter of magnetite crystals was in the range of 9.4-30 nm. Characterization by TEM showed that the particles were formed from a smaller particles which were then agglomerated. The PSA characterization showed that the distribution of diameter size enlarged with the enhancement of  concentrations. VSM result showed that the magnetite nanoparticle has superparamagnetic properties. The magnetite crystal growth can be fitted by the Oriented Attachment Growth model with an error of 29%.

Synthesis and Characterization of Monodisperse Magnetite Nanoparticles by Hydrothermal Method

2017 ◽  
Vol 737 ◽  
pp. 367-372
Author(s):  
Apichon Watcharenwong ◽  
Yotsapon Bailuang ◽  
Puangrat Kajitvichyanukul
Keyword(s):  
Electron Microscope ◽  
Saturation Magnetization ◽  
Hydrothermal Method ◽  
Magnetite Nanoparticles ◽  
Hysteresis Loops ◽  
Spherical Shape ◽  
Pollutant Removal ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Transmission Electron

Monodisperse nanoparticles are materials that are not agglomerate. The good characteristic of these materials is the dispersity in water, so they can better react with target pollutants. Accordingly, in this work, the monodisperse magnetite nanoparticles with the superparamagnetic property were synthesized and characterized. The hydrothermal method with the iron compound and polymer as precursors was conducted. The magnetic nanoparticles were characterized by several techniques including X-ray diffraction, field emission scanning electron microscope, transmission electron microscope, and vibrating sample magnetometer. The saturation magnetization (Ms) value, the coercivity (Hc), and the retentivity (Mr) were measured to demonstrate the paramagnetic behavior of the monodisperse magnetite nanoparticles. The results showed that the Fe3O4 nanoparticle were obtained at 200 °C for 16 h. The particles are monodispersed with the size approximately in the range of 60 - 250 nm as confirmed by FE-SEM and TEM images. These are the single grain and had the spherical shape similar to a blackberry. The saturation magnetization of 17.287 emu/g and ratio of retentivity to saturation magnetization (Mr/Ms) characterized the squareness of the hysteresis loops was 0.03653. It can be indicated that the Fe3O4 nanoparticles had superparamagnetic behavior. This property of Fe3O4 nanoparticles can draw pollutants to absorb on the surface of these nanomaterials. Then adsorbed pollutants can be easily removed by separating the Fe3O4 materials from water. This technique can be applied further in water treatment and pollutant removal.

ZnS nanoparticles synthesis and characterization

2003 ◽  
Vol 789 ◽  
Author(s):  
Yvonne Axmann ◽  
Alke Petri ◽  
Heinrich Hofmann
Keyword(s):  
Fluorescence Quantum Yield ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
Zns Nanoparticles ◽  
Aqueous Dispersions ◽  
X Ray ◽  
Quinine Sulphate ◽  
Transmission Electron ◽  
Wet Chemical ◽  
D Orbitals

ABSTRACTZnS:Mn2+ nanoparticles were synthesized via a wet chemical method with L-cysteine as the stabilizing agent. The obtained aqueous dispersions show an orange luminescence, which is typical for the 4T1 → 6A1 transition within the Mn2+ d-orbitals. The fluorescence quantum yield has been determined with quinine sulphate as a dye reference. It can be increased after formation of a SiO2 shell around the particles by a factor of three. The particle size was determined with transmission electron microscopy (TEM), X-ray diffraction and PCS measurements.

scholarly journals Synthesis and Magnetic Properties of a Superparamagnetic Nanocomposite “Pectin-Magnetite Nanocomposite”

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jude Namanga ◽  
Josepha Foba ◽  
Derek Tantoh Ndinteh ◽  
Divine Mbom Yufanyi ◽  
Rui Werner Maçedo Krause
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Magnetite Nanoparticles ◽  
Quantum Interference ◽  
Size Control ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Drying Conditions

Magnetic nanocomposites composed of superparamagnetic magnetite nanoparticles in a pectin matrix were synthesized by an in situ coprecipitation method. The pectin matrix acted as a stabilizer and size control host for the magnetite nanoparticles (MNPs) ensuring particle size homogeneity. The effects of the different reactant ratios and nanocomposite drying conditions on the magnetic properties were investigated. The nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FT-IR) spectroscopy, and superconducting quantum interference device magnetometer (SQUID). Superparamagnetic magnetite nanoparticles with mean diameters of 9 and 13 nm were obtained, and the freeze-dried nanocomposites had a saturation magnetization of 54 and 53 emu/g, respectively.

Preparation and Characterization of Magnetite Nanoparticles

2014 ◽  
Vol 618 ◽  
pp. 24-27 ◽  
Author(s):  
Fu Yan Zhao ◽  
Ya Ling Li ◽  
Lu Hai Li
Keyword(s):  
Surface Area ◽  
Magnetite Nanoparticles ◽  
High Performance ◽  
Catalytic Performance ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Particles Size Distribution ◽  
Magnetite Particles ◽  
Average Size

The preparation of magnetite nanoparticles with controlled size has attracted of scientific and technological broad attention. Spherical magnetite nanoparticles in the size range from 8nm to 22 nm were synthesized by coprecipiation method using hexadecyl trimethyl ammonium bromide (CTAB) as dispersant. Magnetite nanoparticles have good dispersibility and uniform particles size distribution. The properties were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), automated surface area and pore size analyzer, vibrating sample magnetometer (VSM) and the catalytic performance was measured using high performance liquid chromatography (HPLC). The saturation magnetization is 13.785emu/g, and the coercive force of the sample is 23.738G, the average size of the particles is 13.6 nm, specific surface area is 19.318 m2/g and phenol conversion is up to 99.5%. These results indicate the synthesized magnetite particles have good performance.

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