scholarly journals Design, Optimization Process and Efficient Analysis for Preparation of Copolymer-Coated Superparamagnetic Nanoparticles

2017 ◽  
Vol 7 (3) ◽  
Author(s):  
Mahnaz Mahdavi Shahri
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Saturation Magnetization ◽  
Magnetic Particles ◽  
Superparamagnetic Nanoparticles ◽  
Effluent Treatment ◽  
Degree Of Saturation ◽  
Transmission Electron ◽  
Average Size

Magnetic nanoparticles (MNPs) are very important systems with potential use in drug delivery systems, ferrofluids, and effluent treatment. In many situations, such as in biomedical applications, it is necessary to cover inorganic magnetic particles with an organic material, such as polymers. A superparamagnetic nanocomposite Fe3O4/poly(maleic anhydride-co-acrylic acid) P(MAH-co-AA) with a core/shell structure was successfully synthesized by a dispersion polymerization route. Iron oxide nanoparticles were used as a core, and P(MAH-co-AA) as a shell was covered on the surface of the Fe3O4 magnetic nanoparticles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the Fe3O4/P(MAH-co-AA) magnetic nanocomposite were highly uniform in size and cubic shape with the average size about 17.06 nm. X-ray diffraction confirmed magnetite cores and also indicated that the binding process did not change the phase of Fe3O4. Vibrational sample magnetometer (VSM) revealed the nanoparticles were superparamagnetic and the saturation magnetization was 83.6 and 46.6 emu g-1 for pure Fe3O4 and composite nanoparticles, respectively. Measurements by VSM also showed that the degree of saturation magnetization increased with increasing iron oxide concentration from 1% to 7 wt % of Fe3O4.

scholarly journals A new route of emulsifier-free emulsion polymerization for the preparation of polymer coated magnetite nanoparticles

2014 ◽  
Vol 32 (2) ◽  
pp. 264-271 ◽  
Author(s):  
Q. Nguyen ◽  
D. Quyen ◽  
T. Hoang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Nanoparticles ◽  
Emulsion Polymerization ◽  
Magnetic Particles ◽  
Mass Ratio ◽  
Transmission Electron ◽  
Magnetization Saturation ◽  
Polymer Thickness ◽  
Polymer Layer Thickness

AbstractA new route of emulsifier-free emulsion polymerization based on the homogenous mechanism was investigated to prepare magnetic nanoparticles coated by poly (methyl methacrylate) (PMMA). The experimental results confirm the formation of PMMA thin and unique layers covering magnetite cores. The polymer layer thickness, determined from transmission electron microscopy (TEM) images, increases from 4.3 nm to 6.8 nm with increasing mass ratio of MMA to magnetite from 3:1 to 11:1. The increase of the polymer thickness results in the decrease in magnetization saturation of polymeric coated magnetic particles. However, this reduction, no more than 13 emu g−1, is much lower compared to that in other studies with the presence of surfactants or emulsifiers. Besides, the dispersion stability of the prepared particles is significantly improved.

scholarly journals Fibrillar biocomposite on the base of poly(3-hydroxybutyrate) nanofibers and iron oxide magnetic nanoparticles

2019 ◽  
Vol 489 (2) ◽  
pp. 157-160
Author(s):  
V. E. Prusakov ◽  
Yu. V. Maksimov ◽  
V. A. Beglov ◽  
M. V. Gerasimov ◽  
A. V. Bychkova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Oxide Nanoparticles ◽  
The Novel ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Iron Oxide Magnetic Nanoparticles

The novel biodegradable biocomposites on the base of poly(3-hydroxybutyrare) nanofibers with embedded iron oxide nanoparticles have been studied by transmission electron microscopy (TEM), Mssbayer spectroscopy, small angle X‑ray scattering (SAXS), and macroscopic magnetization techniques.

scholarly journals Study on Structure, Thermal Behavior, and Viscoelastic Properties of Nanodiamond-Reinforced Poly (vinyl alcohol) Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1426
Author(s):  
Tomáš Remiš ◽  
Petr Bělský ◽  
Tomáš Kovářík ◽  
Jaroslav Kadlec ◽  
Mina Ghafouri Azar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Analysis ◽  
Single Step ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Primary Particles ◽  
Solution Casting Method ◽  
Average Size

In this work, advanced polymer nanocomposites comprising of polyvinyl alcohol (PVA) and nanodiamonds (NDs) were developed using a single-step solution-casting method. The properties of the prepared PVA/NDs nanocomposites were investigated using Raman spectroscopy, small- and wide-angle X-ray scattering (SAXS/WAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was revealed that the tensile strength improved dramatically with increasing ND content in the PVA matrix, suggesting a strong interaction between the NDs and the PVA. SEM, TEM, and SAXS showed that NDs were present in the form of agglomerates with an average size of ~60 nm with primary particles of diameter ~5 nm. These results showed that NDs could act as a good nanofiller for PVA in terms of improving its stability and mechanical properties.

Preparation and physical characterization of cobalt iron oxide magnetic nanoparticles loaded polyvinyl alcohol

2021 ◽  
pp. 089270572098557
Author(s):  
M Abu-Abdeen ◽  
O Saber ◽  
E Mousa
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Polyvinyl Alcohol ◽  
Saturation Magnetization ◽  
Polymer Films ◽  
Magnetic Hysteresis ◽  
Thermal Method ◽  
Cobalt Iron Oxide ◽  
Cobalt Iron ◽  
Iron Oxide Magnetic Nanoparticles

A solvent thermal method which depends on a thermal process under critical temperature and pressure was used to prepare cobalt iron oxide magnetic nanoparticles with a molar ratio 2. The prepared particles were in the form of nanoparticles with diameter ranging from 5 to 10 nm and with amorphous structure. Magnetic hysteresis behavior with saturation magnetization 36.31 emu/g and coercivity 4 Oe were observed for the nanoparticles. Polyvinyl alcohol was loaded with different concentrations of cobalt iron oxide nanoparticles using casting technique. Hysteresis loops for the polymer films were observed and both the saturation magnetization and coercivity were increased from 0.36 to 16.03 emu/g and 115 to 293 Oe for samples containing 5 and 20 wt% of nanoparticles, respectively. The elastic modulus of films was increased from 2.7 to 4.9 GPa for unloaded and loaded samples with 20 wt%, respectively. The storage modulus of the polymer films was found to obey the percolation behavior.

scholarly journals Characterization of glycidyl methacrylate based magnetic nanocomposites

2019 ◽  
Vol 73 (1) ◽  
pp. 25-35
Author(s):  
Bojana Markovic ◽  
Vojislav Spasojevic ◽  
Aleksandra Dapcevic ◽  
Zorica Vukovic ◽  
Vladimir Pavlovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Nanoparticles ◽  
Glycidyl Methacrylate ◽  
Mercury Porosimetry ◽  
Magnetic Nanocomposite ◽  
Magnetic Nanocomposites ◽  
Tem Analysis ◽  
X Ray ◽  
Force Microscopy ◽  
Transmission Electron

Magnetic and non-magnetic macroporous crosslinked copolymers of glycidyl methacrylate and trimethylolpropane trimethacrylate were prepared by suspension copolymerization and functionalized with diethylenetriamine. The samples were characterized by mercury porosimetry, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy analysis (FTIR-ATR), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM) and SQUID magnetometry. The FTIR-ATR analysis of synthesized magnetic nanocomposites confirmed the presence of magnetite and successful amino- functionalization. Non-functionalized and amino-functionalized nanocomposites exhibited superparamagnetic behavior at 300 K, with a saturation magnetization of 5.0 emu/g and 2.9 emu/g, respectively. TEM analysis of the magnetic nanocomposite has shown that magnetic nanoparticles were homogeneously dispersed in the polymer matrix. It was demonstrated that incorporation of magnetic nanoparticles enhanced the thermal stability of the magnetic nanocomposite in comparison to the initial non-magnetic macroporous copolymer.

Preparation of Poly(Vinylbenzyl Chloride)@Lead Sulfide (PVBC@PbS) Core-Shell Nanospheres and Adsorption of Phenol

2013 ◽  
Vol 704 ◽  
pp. 270-274 ◽  
Author(s):  
Jian Ye ◽  
Lan Ping Sun ◽  
Sheng Ping Gao
Keyword(s):  
Electron Microscopy ◽  
Lead Sulfide ◽  
Chemical Structure ◽  
Methyl Chloride ◽  
Core Shell ◽  
Subsequent Reaction ◽  
Chloride Lead ◽  
Transmission Electron ◽  
The Fourier Transform ◽  
Average Size

We have demonstrated the fabrication of novel poly(vinylbenzyl chloride)@lead sulfide (PVBC@PbS) core-shell nanospheres via the atom transfer reversible polymerization (ATRP) of lead dimethacrylate (Pb(MA)2) initiated from methyl chloride groups on surfaces of PVBC nanoparticles and subsequent reaction with ethanethioamide. The chemical structure of the PVBC@PbS nanospheres was confirmed by the fourier transform infrared (FTIR) spectroscopy, and the morphology of the nanospheres were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The average size of the nanospheres was determined to be about 100 nm. The PVBC@PbS nanospheres were able to absorb phenol in the solution, and the balanced adsorption capability of phenol to nanospheres could reach to 7.2 μg/mg.

Formation of bismuth iron oxide based core–shell structures and their dielectric, ferroelectric and magnetic properties

2019 ◽  
Vol 7 (5) ◽  
pp. 1280-1291 ◽  
Author(s):  
Alaka Panda ◽  
R. Govindaraj ◽  
R. Mythili ◽  
G. Amarendra
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Iron Oxide ◽  
Shell Structures ◽  
Core Shell ◽  
Bismuth Iron Oxide ◽  
The Core ◽  
Shell Nanostructures ◽  
Transmission Electron

Bismuth and iron oxides subjected to ball milling followed by controlled annealing treatments showed the formation of core–shell nanostructures with Bi2Fe4O9 as the core and a shell of BiFeO3 and Bi25FeO40 phases as deduced based on the analysis of transmission electron microscopy results.

scholarly journals Formation of ZnO/Zn0.5Cd0.5Se Alloy Quantum Dots in the Presence of High Oleylamine Contents

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 999
Author(s):  
Yi-An Chen ◽  
Kuo-Hsien Chou ◽  
Yi-Yang Kuo ◽  
Cheng-Ye Wu ◽  
Po-Wen Hsiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Particle Size ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Average Size ◽  
Alloy Quantum Dots ◽  
First Time

To the best of our knowledge, this report presents, for the first time, the schematic of the possible chemical reaction for a one-pot synthesis of Zn0.5Cd0.5Se alloy quantum dots (QDs) in the presence of low/high oleylamine (OLA) contents. For high OLA contents, high-resolution transmission electron microscopy (HRTEM) results showed that the average size of Zn0.5Cd0.5Se increases significantly from 4 to 9 nm with an increasing OLA content from 4 to 10 mL. First, [Zn(OAc)2]–OLA complex can be formed by a reaction between Zn(OAc)2 and OLA. Then, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) data confirmed that ZnO is formed by thermal decomposition of the [Zn(OAc)2]–OLA complex. The results indicated that ZnO grew on the Zn0.5Cd0.5Se surface, thus increasing the particle size. For low OLA contents, HRTEM images were used to estimate the average sizes of the Zn0.5Cd0.5Se alloy QDs, which were approximately 8, 6, and 4 nm with OLA loadings of 0, 2, and 4 mL, respectively. We found that Zn(OAc)2 and OLA could form a [Zn(OAc)2]–OLA complex, which inhibited the growth of the Zn0.5Cd0.5Se alloy QDs, due to the decreasing reaction between Zn(oleic acid)2 and Se2−, which led to a decrease in particle size.

Iron in Hydrothermal Clays from the Galapagos Spreading Centre Mounds: Consequences for the Clay Transition Mechanism

Clay Minerals ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 641-655 ◽  
Author(s):  
M. D. Buatier ◽  
K. Ouyang ◽  
J. P. Sanchez
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Mössbauer Spectra ◽  
Analytical Electron Microscopy ◽  
Secondary Phase ◽  
Precipitation Process ◽  
Mossbauer Spectra ◽  
Octahedral Sites ◽  
Transition Mechanism ◽  
Transmission Electron

AbstractGlauconite and Fe-smectite, which can be distinguished by their peculiar morphology and stacking sequences, coexist in the Galapagos Spreading Centre hydrothermal mounds. Analytical electron microscopy (AEM) data suggest that Fe is entirely in octahedral sites in Fe-smectite whereas glauconite is K-rich with Fe in tetrahedral and octahedral sites. However, the Mossbauer spectra, recorded at various temperatures for samples containing both smectite and glauconite, were satisfactorily analysed with three overlapping doublets corresponding to Fe in octahedral sites. The contradictory results obtained with the two methods are explained by the presence of small particles of iron oxide intimately associated with glauconite. These particles were detected in Mossbauer spectra obtained at 77 K and 4·2 K and were observed by transmission electron microscopy. Iron oxide is a secondary phase formed by alteration of smectite. These data are in good agreement with the hypothesis that the smectite-glauconite reaction, which occurs at 30 m and low temperature in the Galapagos hydrothermal mounds, is a dissolution-precipitation process, dissolution of Fe-rich smectite being followed by precipitation of glauconite and iron oxides.

Sign in / Sign up

Export Citation Format

Share Document