scholarly journals Synthesis and Characterization of Functionalized Magnetic Nanoparticles for the Detection of Pesticide

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Shu Taira ◽  
Daisaku Kaneko ◽  
Kazuki Onuma ◽  
Akio Miyazato ◽  
Tomoyuki Hiroki ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Nanoparticles ◽  
Quantum Interference ◽  
Magnetic Particles ◽  
Sodium Metasilicate ◽  
Single Step ◽  
Metal Chlorides ◽  
Potential Measurement ◽  
Transmission Electron ◽  
Subsequent Capture

We synthesized magnetic nanoparticles (MNPs) by mixing aqueous solutions of 3d transition metal chlorides (MCl2·nH2O) and a sodium metasilicate nonahydrate (Na2SiO3·9H2O) in order to produce monodispersed MNPs in a single step. The particle size can be controlled by adjusting the annealing temperature. We characterized the MNPs by X-ray diffraction (XRD), superconducting quantum interference device (SQUID), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), and zeta-potential measurement. Paramagnetic and superparamagnetic behaviors were found for the obtained samples depending on the particle size (d=3.0–4.6 nm). The synthesized MNPs could be modified with the amino-, phenyl-, and carboxy- groups on MNPs' surface by silanization procedure, respectively. The purpose of functionalizing the surface of the nanoscale magnetic particles was to realize subsequent capture and detection with desired other molecules by nanoparticle assisted laser ionization/desorption mass spectrometry.

Synthesis of Responsive Polymer Brushes on Magnetic Nanoparticles

2013 ◽  
Vol 1453 ◽  
Author(s):  
Kamlesh J. Suthar ◽  
Joseph E. Mowat ◽  
Shankar Balasubramanian ◽  
Muralidhar K. Ghantasala ◽  
Derrick C. Mancini
Keyword(s):  
Magnetic Nanoparticles ◽  
Quantum Interference ◽  
Polymer Brushes ◽  
Magnetic Particles ◽  
Polymer Brush ◽  
Precipitation Method ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Co Precipitation ◽  
Microscopy Techniques

ABSTRACTWe report a simple synthesis technique to attached poly(N-isopropylacrylamide) on magnetic nanoparticles. Fe3O4 magnetic nanoparticles were prepared using co-precipitation method. Nearly monodisperse nanoparticles were separated by terminating surface of Fe3O4 with dopamine followed by careful centrifugation and decantation. NHS/EDC coupling chemistry was employed to attached the carboxylic acid terminated poly(N-isopropylacrylamide) to amine end of dopamine on surface of the magnetic particles. Analysis of the polymer brush layers was conducted using UV-Vis spectroscopy, ATR−FTIR, and Transmission electron microscopy techniques. The magnetic property was investigated using direct current superconducting quantum interference device (DC-SQUID) method.

Relationship between Microstructure and Magnetic Properties of Nano-Scale Particles Formed in Cu-Ni-(FeCo) Alloys

2018 ◽  
Vol 941 ◽  
pp. 1324-1329 ◽  
Author(s):  
Shintaro Matai ◽  
Hibiki Sakakura ◽  
Mahoto Takeda
Keyword(s):  
Magnetic Properties ◽  
Quantum Interference ◽  
Magnetic Particles ◽  
Superconducting Quantum Interference Device ◽  
Recording Technology ◽  
Treatment Conditions ◽  
Transmission Electron ◽  
Feco Alloys ◽  
The Relationship ◽  
Microstructure And Magnetic Properties

Numerous studies have been conducted to develop next-generation recording technology in spintronics. Because ultrafine magneitc particles are vital components of the technology, the interplay between the microsturcture and magnetic properties has attracted attention extensively in recent years. We focused on the relationship between the microstructure and magnetic properties of Cu-Ni-X (X=Fe, Co, FeCo) alloys comprising nanogranular magnetic particles. In this work, we prepared Cu-20 at% Ni-5 at% (FeCo), Cu-20 at% Ni-5 at% Fe, Cu-20 at% Ni-5 at% Co and examined the changes of microstructure and magnetic properties associated with heat treatments and composition. To examaine microstructural evolution of the alloy specimens, we conducted transmission electron microscope observations (TEM) with the as-quenched specimens and those aged at at 773-1073 K. We also carried out magneto-thermo gravimetry (MTG) measurements, superconducting quantum interference device (SQUID) measurements, magnetoresistance (MR) measurements and first-principles calculations based on the Koster-Korringa-Rostker (KKR) method with the Coherent Potential Approximation (CPA), to investigate the magnetic properties. The present work confirmed that the microstructure significantly changed, depending on the composition and heat treatment conditions. The present work also revealed that the magnetic properties closely correlated with the microstructure of samples.

Magnetic Polyolefin-based Nanocomposites

2013 ◽  
Vol 1499 ◽  
Author(s):  
Qingliang He ◽  
Suying Wei ◽  
Zhanhu Guo
Keyword(s):  
Thermal Decomposition ◽  
Magnetic Nanoparticles ◽  
Room Temperature ◽  
Magnetic Particles ◽  
Formation Mechanisms ◽  
Gravimetric Analysis ◽  
One Pot ◽  
Metallic Precursor ◽  
Transmission Electron

ABSTRACTMagnetic polyolefin-based nanocomposites were fabricated through a facile one-pot thermal decomposition of organo-metallic precursor, i.e. Fe(CO)5 in polymer-solvent solution condition. The whole fabrication includes dissolution of polyolefin-based hosting matrix in refluxing organic solvent followed by the injection of metallic precursor to perform the in-situ thermal decomposition step. The particle sizes, morphology and dispersion quality of these in-situ synthesized magnetic nanoparticles were investigated by transmission electron microscopy (TEM). Room temperature mössbauer spectrum analysis was used to determine the species of these magnetic nanoparticles. Room temperature magnetic property investigation was utilized to further reveal the magnetic behaviors of these nanocomposites by specifying the saturation magnetization and coercive forces. Thermal gravimetric analysis (TGA) was used to determine the thermal stability of these as-prepared nanocomposites and the particle loadings. The formation mechanisms of these magnetic particles were proposed from the evidence of TEM observations and detailed evolutions are detailed as well.

Antibacterial Magnetic Nanoparticles Functionalized with N-Halamine/Quaternary Ammonium Polymer Coatings

NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650131 ◽  
Author(s):  
Xiaoqin Chen ◽  
Qian Xiang ◽  
Chunyan Yong ◽  
Zuliang Liu ◽  
Xiaodong Xing
Keyword(s):  
Magnetic Nanoparticles ◽  
Quaternary Ammonium ◽  
Polymer Coating ◽  
Polymer Coatings ◽  
Photoelectron Spectra ◽  
Potential Measurement ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Ft Ir ◽  
Soap Free Emulsion Polymerization

The bactericidal magnetic nanoparticles were prepared by modifying magnetic nanoparticles (MNPs) with [Formula: see text]-halamine polymer coating and quaternary ammonium polymer coating via a two-step soap-free emulsion polymerization method. The success of the surface functionalization was confirmed by Fourier transform infrared (FT-IR), X-ray photoelectron spectra (XPS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and zeta-potential measurement. The results of antibacterial tests showed that the functional MNPs exhibited excellent antibacterial efficiency against both Gram negative bacteria E. coli and Gram positive bacteria S. aureus. Meanwhile the nanoparticles could be removed easily from water by an external magnetic field after antibacterial tests.

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.

Synthesis and Characterization of Nanosized Cobalt Manganese Alloys

2018 ◽  
Vol 24 (8) ◽  
pp. 5795-5800
Author(s):  
BlessyBabukutty ◽  
FasalurahmanParakkal ◽  
Swapna S Nair
Keyword(s):  
Particle Size ◽  
Oleic Acid ◽  
Annealed Sample ◽  
Morphological Properties ◽  
Manganese Alloy ◽  
Chemical Route ◽  
Spectra Analysis ◽  
Metal Chlorides ◽  
Transmission Electron

Co–Mn alloy nanoparticles are synthesized by chemical route by the decomposition of metal chlorides by sodium borohydride using oleic acid as the capping agent. SEM, TEM and XRD are used to determine structural and morphological properties of the samples. From XRD spectra analysis, it is confirmed that the sample contains cobalt–manganese alloy. Transmission Electron Microscopy (HR-TEM) is used to estimate the particle size of the Co–Mn sample where a bimodal particle size distribution with one maximum at (3.5 ± 1.8) nm and another maximum at (7.6 ± 2.5) nm is observed. Magnetic investigation employed by Vibrating Sample Magnetometry (VSM) shows that the samples are magnetic with saturation magnetization of 0.018 emu/g for the prepared sample and 0.457 emu/g for the annealed sample. The nature of chemical conjugation of Co–Mn nanoparticles and oleic acid is analyzed by Fourier transform infrared spectroscopy. Thermogravimetric measurements of Co–Mn indicate exothermic peaks at 545 K and 723 K revealing the structural transition from amorphous phase to crystallined form. The chemical composition of the sample is verified using EDX spectra.

Hydrothermal synthesis of well-dispersed TiO2 nano-crystals

2002 ◽  
Vol 17 (9) ◽  
pp. 2197-2200 ◽  
Author(s):  
Juan Yang ◽  
Sen Mei ◽  
José M.F. Ferreira
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Nano Particles ◽  
Homogeneous Distribution ◽  
X Ray Diffraction ◽  
Tetrabutylammonium Hydroxide ◽  
Potential Measurement ◽  
X Ray ◽  
Transmission Electron

Well-dispersed anatase and rutile nano-particles were prepared via hydrothermal treatment of tetrabutylammonium hydroxide-peptized and HNO3-peptized sols at 240 °C. A broad particle size distribution of anatase crystals was observed in the nonpeptized TiO2 species hydrothermally treated at 240 °C. X-ray diffraction and transmission electron microscopy, as well as zeta potential measurement, were used to characterize the particles. The formation of the well-dispersed anatase and rutile particles from the peptized samples could be attributed to (i) homogeneous distribution of the component in the peptized sols, and (ii) the high long-range electrostatic forces between particles in the presence of both peptizers, which were not present in the nonpeptized samples. This work provided a new way to prepare nano-crystals of titania.

scholarly journals Investigations into the Biocompatibility of Nanohydroxyapatite Coated Magnetic Nanoparticles under Magnetic Situation

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Qing Li ◽  
Gang Zhou ◽  
Tong Wang ◽  
Yongzhao Hou ◽  
Xuliang Deng ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Magnetic Particles ◽  
X Ray Diffraction ◽  
New Approach ◽  
X Ray ◽  
In Vitro Experiment ◽  
Transmission Electron ◽  
Mesenchyme Stem Cells

Regenerative medicine consisting of cells and materials offers a new approach for repairing and regenerating the organs and tissues. More and more researches focused on the magnetic nanobiomaterials due to its superior advantages to traditional materials. However, the toxicity of nanosized magnetic particles cannot be ignored, especially under the magnetic situation. This study aims to study the biocompatibility of nanohydroxyapatite (n-HA-) coated magnetic nanoparticles under the magnetic situation. n-HA-coated magnetic nanoparticles were fabricated through an ultrasound-assisted coprecipitation method. Subsequently, these materials were analyzed by transmission electron microscope (TEM) and X-ray diffraction (XRD) and then were cultured with mesenchyme stem cells derived from human bone marrow (hMSC-BM). In vitro experiment proved the satisfactory biocompatibility of n-HA-coated magnetic nanoparticles. These important factors (ALP, OCN, and OPN) influence the osteogenic differentiation of hMSC-BM. It was found that the hMSC-BM with combination of n-HA/Fe3O4and magnetic stimulation presented higher degree of osteoblast-related markers than that in each alone. This research demonstrated that a novel nanohydroxyapatite coated magnetic nanoparticle is safe under the magnetic situation. Therefore, these n-HA-coated magnetic nanoparticles are promising biomagnetic materials for future applications.

scholarly journals Hydrothermal Novel Synthesis of Neck-structured Hyperthermia-suitable Magnetic (Fe3O4, γ-Fe2O3 and α-Fe2O3) Nanoparticles

2011 ◽  
Vol 4 (1) ◽  
pp. 99 ◽  
Author(s):  
M. S. Islam ◽  
J. Kurawaki ◽  
Y. Kusumoto ◽  
M. Abdulla-Al-Mamun ◽  
M. Z. Bin Mukhlish
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Magnetic Nanoparticles ◽  
Quantum Interference ◽  
Heat Dissipation ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Particle Morphology ◽  
Ferrous Chloride ◽  
Size And Morphology

Novel neck-structured Fe3O4, γ-Fe2O3 and α-Fe2O3 magnetic nanoparticles were successfully prepared by a modified hydrothermal method. Ferrous chloride tetrahydrate was solely used as a precursor for the novel nanomaterials. The X-ray diffractometric study revealed the purity of the nanomaterials thus synthesized. All of the products were characterized using a field-emission scanning electron microscope (FE-SEM) and a transmission electron microscope (TEM) for the particle size and morphology. Neck-structured particle morphology was observed for the first time in all of iron oxides with magnetic properties. The particle size observed was 50–60 nm. The synthesized nanomaterials showed excellent magnetization values when magnetic hysteresis loops were measured using a superconducting quantum interference device (SQUID). Moreover, the as-prepared magnetic nanoparticles suspensions showed significant temperature increments under an AC (alternating current) magnetic-field induction condition at room temperature which indicates the hyperthermia feasibility. Keywords: Magnetic materials; Neck-structured; Hyperthermia; Heat dissipation. © 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v4i1.8727J. Sci. Res. 4 (1), 99-107 (2012)

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