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1.
Conducting polymer composites of polypyrrole (PPy) and silver doped nickel oxide (Ag-NiO) nanocomposites were synthesised by in situ polymerisation of pyrrole with different contents of Ag-NiO nanoparticles. The formation of nanocomposites were studied by Fourier transform infrared (FTIR) and UV–vis spectroscopy, field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and AC and DC conductivity measurements. The sensitivity of ammonia gas through the nanocomposite was analysed with respect to different contents of nanoparticles. Spectroscopic studies showed the shift in the absorption bands of polymer nanocomposite than that of pure PPy indicating the strong interaction between the nanoparticles and polymer chain. FESEM revealed the uniform dispersion of nanoparticles with spherically shaped metal oxide particles in PPy matrix. The XRD pattern indicated a decrease in amorphous domain of PPy with increase in loading of nanoparticles. The higher thermal stability and glass transition temperature of polymer nanocomposites than that of pure PPy were revealed from the TGA and DSC respectively. The dielectric properties, DC and AC conductivity of nanocomposites were much higher than PPy and these electrical properties increases with the loading of nanoparticles. The nanocomposites showed an enhancement in sensitivity towards ammonia gas detection than PPy. 相似文献
2.
Ilker Dincer Onur Tozkoparan Sergey V. German Alexey V. Markin Oguz Yildirim Gennady B. Khomutov Dmitry A. Gorin Sergey B. Venig Yalcin Elerman 《Journal of magnetism and magnetic materials》2012
Aqueous colloidal suspension of iron oxide nanoparticles has been synthesized. Z-potential of iron oxide nanoparticles stabilized by citric acid was −35±3 mV. Iron oxide nanoparticles have been characterized by the light scattering method and transmission electron microscopy. The polyelectrolyte/iron oxide nanoparticle thin films with different numbers of iron oxide nanoparticle layers have been prepared on the surface of silicon substrates via the layer-by-layer assembly technique. The physical properties and chemical composition of nanocomposite thin films have been studied by atomic force microscopy, magnetic force microscopy, magnetization measurements, Raman spectroscopy. Using the analysis of experimental data it was established, that the magnetic properties of nanocomposite films depended on the number of iron oxide nanoparticle layers, the size of iron oxide nanoparticle aggregates, the distance between aggregates, and the chemical composition of iron oxide nanoparticles embedded into the nanocomposite films. The magnetic permeability of nanocomposite coatings has been calculated. The magnetic permeability values depend on the number of iron oxide nanoparticle layers in nanocomposite film. 相似文献
3.
H. Ebadi-Dehaghani M. Reiszadeh A. Chavoshi M. Nazempour M. H. Vakili 《Journal of Macromolecular Science: Physics》2014,53(1):93-107
The thermal conductivity (TC) of compression-moulded polypropylene (PP) and PP filled with 5–15% zinc oxide (ZnO) or calcium carbonate (CaCO3) nanoparticles, prepared by extrusion, was studied using a thermal conductivity analyzer (TCA). The effect of nanoparticle content and crystallinity on the thermal conductivity was investigated using conventional methods, including SEM, XRD, and DSC. The incorporation of nanoparticles improved the crystallinity and thermal conductivity simultaneously. The experimental TC values of the PP nanocomposites with different level of nanoparticles concentration showed a linear increase with an increase in crystallinity. The TC improvement in PP/ZnO nanocomposite was greater than that of PP/calcium carbonate nanocomposites. This fact can be attributed to the intrinsic, better thermal conductivity of the ZnO nanoparticles. Several models were used for prediction of the TC in the nanocomposites. In the PP/ZnO nanocomposites the TC values correlated well with the values predicted by the Series, Maxwell, Lewis and Nielson, Bruggeman, and De Loor models up to 10 wt%. 相似文献
4.
Selin P?ravad?l? Mucur Tülay Asl? Tumay Sait Eren San Emine Tekin 《Journal of nanoparticle research》2012,14(10):1-11
We have previously reported that the silane coating of magnetic nanoparticles (MNPs) of maghemite phase could be used to protect iron oxide cores during plasma heat treatment, and even help to reduce their phase to magnetite with higher magnetization. In this work, an additional layer of an electrically conductive polypyrrole was added on top of the silane-coated MNPs, producing core?Cshell particles with sizes ranging from 150 to 500?nm. A microwave plasma heat treatment was used to convert the amorphous, already-conductive polypyrrole coatings into a more electrically conductive graphitic structure, while simultaneously reducing the iron oxide phase to magnetite. The treatment produced core?Cshell particles with better microwave absorption properties over the frequency of 1?C18?GHz, with a maximum reflection loss (absorption) of these MNPs at ?37?dB at 10.3?GHz for samples containing 70?wt% of plasma-treated core?Cshell nanoparticles embedded in wax. By comparison, the maximum absorption for the same amount of untreated nanoparticles was only ?18?dB at 7.5?GHz. The improved electromagnetic wave absorption properties were due to higher electrical conductivity of the more ordered, graphitic-like polypyrrole shell structures. This relatively simple protocol could thus be used to synthesize highly magnetic and conductive nanocomposites for electromagnetic interference shielding applications, particularly at the high frequency range. 相似文献
5.
Superparamagnetic iron oxide nanoparticles are used in diverse applications, including optical magnetic recording, catalysts,
gas sensors, targeted drug delivery, magnetic resonance imaging, and hyperthermic malignant cell therapy. Combustion synthesis
of nanoparticles has significant advantages, including improved nanoparticle property control and commercial production rate
capability with minimal post-processing. In the current study, superparamagnetic iron oxide nanoparticles were produced by
flame synthesis using a coflow flame. The effect of flame configuration (diffusion and inverse diffusion), flame temperature,
and additive loading on the final iron oxide nanoparticle morphology, elemental composition, and particle size were analyzed
by transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), energy dispersive spectroscopy (EDS), and Raman spectroscopy.
The synthesized nanoparticles were primarily composed of two well known forms of iron oxide, namely hematite αFe2O3 and magnetite Fe3O4. We found that the synthesized nanoparticles were smaller (6–12 nm) for an inverse diffusion flame as compared to a diffusion
flame configuration (50–60 nm) when CH4, O2, Ar, and N2 gas flow rates were kept constant. In order to investigate the effect of flame temperature, CH4, O2, Ar gas flow rates were kept constant, and N2 gas was added as a coolant to the system. TEM analysis of iron oxide nanoparticles synthesized using an inverse diffusion
flame configuration with N2 cooling demonstrated that particles no larger than 50–60 nm in diameter can be grown, indicating that nanoparticles did not
coalesce in the cooler flame. Raman spectroscopy showed that these nanoparticles were primarily magnetite, as opposed to the
primarily hematite nanoparticles produced in the hot flame configuration. In order to understand the effect of additive loading
on iron oxide nanoparticle morphology, an Ar stream carrying titanium-tetra-isopropoxide (TTIP) was flowed through the outer
annulus along with the CH4 in the inverse diffusion flame configuration. When particles were synthesized in the presence of the TTIP additive, larger
monodispersed individual particles (50–90 nm) were synthesized as observed by TEM. In this article, we show that iron oxide
nanoparticles of varied morphology, composition, and size can be synthesized and controlled by varying flame configuration,
flame temperature, and additive loading. 相似文献
6.
C. Baker S. Ismat Shah S. K. Hasanain 《Journal of magnetism and magnetic materials》2004,280(2-3):412-418
An inert gas condensation technique was used to prepare nanometer-sized particles of metallic iron and iron oxide. The particles were passivated by the controlled oxidation of the particle surface leading to an Fe-oxide shell-Fe core structure. Nanoparticle–polymer composites were obtained by spin casting mixtures of nanoparticles and polymethylmethacrylate films. The magnetic properties of the nanoparticles compressed into pellets and dispersed in the composites were both studied. The particles were observed to exhibit increased coercivity and exchange bias. The exchange bias was observed to increase with oxide shell thickness. The magnetism in the nanoparticle composites was studied as a function of nanoparticle loading. It was observed that when the particles were dispersed into the nanocomposite the coercivity was increased, suggesting a heightened anisotropy barrier. Similarly, the magnetic relaxation results indicate that the composites exhibit significantly reduced relaxations through the entire temperature range, as compared to the compressed pellet. This observation supports the possibility of heightened anisotropy barriers due to reduced dipolar interactions. 相似文献
7.
Dong Xi XiaoPing Luo QiangHua Lu KaiLun Yao ZuLi Liu Qin Ning 《Journal of nanoparticle research》2008,10(3):393-400
Gold-coated iron oxide nanoparticle Hepatitis B virus (HBV) DNA probes were prepared, and their application for HBV DNA measurement
was studied. Gold-coated iron oxide nanoparticles were prepared by the citrate reduction of tetra-chloroauric acid in the
presence of iron oxide nanoparticles which were added as seeds. With a fluorescence-based method, the maximal surface coverage
of hexaethiol 30-mer oligonucleotides and the maximal percentage of hybridization strands on gold-coated iron oxide nanoparticles
were (120 ± 8) oligonucleotides per nanoparticle, and (14 ± 2%), respectively, which were comparable with those of (132 ± 10)
and (22 ± 3%) in Au nanoparticle groups. Large network aggregates were formed when gold-coated iron oxide nanoparticle HBV
DNA gene probe was applied to detect HBV DNA molecules as evidenced by transmission electron microscopy and the high specificity
was verified by blot hybridization. Our results further suggested that detecting DNA with iron oxide nanoparticles and magnetic
separator was feasible and might be an alternative effective method. 相似文献
8.
Heather J. Shipley Karen E. Engates Allison M. Guettner 《Journal of nanoparticle research》2011,13(6):2387-2397
There is a growing interest in the use of nanoparticles for environmental applications due to their unique physical and chemical
properties. One possible application is the removal of contaminants from water. In this study, the use of iron oxide nanoparticles
(19.3 nm magnetite and 37.0 nm hematite) were examined to remove arsenate and arsenite through column studies. The columns
contained 1.5 or 15 wt% iron oxide nanoparticles and soil. Arsenic experiments were conducted with 1.5 wt% iron oxides at
1.5 and 6 mL/h with initial arsenate and arsenite concentrations of 100 μg/L. Arsenic release occurred after 400 PV, and 100%
release was reached. A long-term study was conducted with 15 wt% magnetite nanoparticles in soil at 0.3 mL/h with an initial
arsenate concentration of 100 μg/L. A negligible arsenate concentration occurred for 3559.6 pore volumes (PVs) (132.1 d).
Eventually, the arsenate concentration reached about 20% after 9884.1 PV (207.9 d). A retardation factor of about 6742 was
calculated indicating strong adsorption of arsenic to the magnetite nanoparticles in the column. Also, increased adsorption
was observed after flow interruption. Other experiments showed that arsenic and 12 other metals (V, Cr, Co, Mn, Se, Mo, Cd,
Pb, Sb, Tl, Th, U) could be simultaneously removed by the iron oxide nanoparticles in soil. Effluent concentrations were less
than 10% for six out of the 12 metals. Desorption experiment showed partial irreversible sorption of arsenic to the iron oxide
nanoparticle surface. Strong adsorption, large retardation factor, and resistant desorption suggest that magnetite and hematite
nanoparticles have the potential to be used to remove arsenic in sandy soil possibly through in situ techniques. 相似文献
9.
《Current Applied Physics》2019,19(4):452-457
Nanoparticles can be added to metals to tune their properties for numerous applications. Recently extensive research has been conducted to measure the mechanical properties of nanoparticle reinforced metals. However, few theories exist to understand how nanoparticles interact with metals to affect their electrical performance, partly due to the difficulty in producing bulk metal samples, containing dispersed nanoparticles. In this work, copper and copper alloys (Cu, Cu-40 wt% Zn, and Cu-60 wt% Ag) containing dispersed tungsten carbide (WC) nanoparticles of more than 20 vol% were successfully fabricated via solidification processing. The experimental results show that copper and its alloys with an increasing volume fraction of nanoparticles, the electrical conductivity of the samples decays exponentially. Therefore, a theoretical model, compatible with the Nordheim's rule was established to predict the electrical behaviour of metals containing dispersed nanoparticles. This new model on the electrical behaviour of copper nanocomposites is experimentally validated by low-temperature resistivity measurements and electronic heat capacity measurements above Debye temperature. 相似文献
10.
Song Zhang Liguang Zou Dong Zhang Xin Pang Hua Yang Ying Xu 《Journal of nanoparticle research》2011,13(9):3867-3876
GoldMag is a kind of bi-functional nanoparticle, composed of a gold nanoshell and an iron oxide core. GoldMag combines the
antibody immobilization property of gold nanoshell with the superparamagnetic feature of the iron oxide core. Rabbit anti-mouse
IgG was immobilized on the surface of GoldMag to synthesize GoldMag-IgG in a single-step process. Transmission electron microscopy,
UV/Vis spectrophotometry, zeta potential analysis, dynamic light scattering, enzyme-linked immunosorbent assay, and magnetic
resonance imaging (MRI) were employed to characterize the nanostructures and the spectroscopic and magnetic properties of
GoldMag and GoldMag-IgG. The antibody encapsulation efficiency of GoldMag was measured as 58.7%, and the antibody loading
capacity was 88 μg IgG per milligram of GoldMag. The immunoactivity of GoldMag-IgG was estimated to be 43.3% of that of the
original IgG. The cytotoxicity of GoldMag was assessed by MTT assay, which showed that it has only little influence on human
dermal lymphatic endothelial cells. MR imaging of different concentrations of ultrasmall superparamagnetic iron oxide, GoldMag,
and GoldMag-IgG showed that 3 μg/mL of nanoparticles could significantly affect the MRI signal intensity of GRE T2*WI. The
results demonstrate that GoldMag nanoparticles can be effectively conjugated with biomacromolecules and possess great potential
for MR molecular imaging. 相似文献
11.
The present study reports synthesis and characterization of poly(MMA–co–BA)/ZnO nanocomposites using ultrasound-assisted in-situ emulsion polymerization. Methyl methacrylate (MMA) was copolymerized with butyl acrylate (BA), for enhanced ductility of copolymer matrix, in presence of nanoscale ZnO particles. Ultrasound generated strong micro-turbulence in reaction mixture, which resulted in higher encapsulation and uniform dispersion of ZnO (in native form – without surface modification) in polymer matrix, as compared to mechanical stirring. The nanocomposites were characterized for physical properties and structural morphology using standard techniques such as XRD, FTIR, particle size analysis, UV–Visible spectroscopy, electrical conductivity, TGA, DSC, FE-SEM and TEM. Copolymerization of MMA and BA (in presence of ZnO) followed second order kinetics. Thermal stability (T10% = 324.9 °C) and glass transition temperature (Tg = 67.8 °C) of poly(MMA-co-BA)/ZnO nanocomposites showed significant enhancement (35.1 °C for 1 wt% ZnO and 15.7 °C for 4 wt% ZnO, respectively), as compared to pristine poly(MMA–co–BA). poly(MMA–co–BA)/ZnO (5 wt%) nanocomposites possessed the highest electrical conductivity of 0.192 μS/cm and peak UV absorptivity of 0.55 at 372 nm. Solution rheological study of nanocomposites revealed enhancement in viscosity with increasing ZnO loading. Maximum viscosity of 0.01 Pa-s was obtained for 5 wt% ZnO loading. 相似文献
12.
Hybrid polypyrrole (PPy)/α-Fe2O3 nanocomposite films were fabricated by spin coating on a glass substrate. X-Ray diffraction analysis revealed the crystalline structure of α-Fe2O3 nanostructures and the nanocomposites. The broad PPy peak weakened in intensity as the α-Fe2O3 content increased in PPy/α-Fe2O3 nanocomposites. Characteristic Fourier-transform IR peaks for pure PPy shifted to higher wavenumbers on addition of α-Fe2O3 to PPy/α-Fe2O3 nanocomposites. This can be attributed to better conjugation and interactions between PPy and α-Fe2O3 nanoparticles. Field-emission scanning electron microscopy, transmission electron microscopy, and atomic force microscopy images of the nanocomposites reveal a uniform distribution of α-Fe2O3 nanoparticles in the PPy matrix. UV-vis absorption spectroscopy revealed a blue shift from λmax= 441 nm for PPy to λmax= 392 nm for PPy/α-Fe2O3, reflecting strong interactions between PPy and α-Fe2O3 nanoparticles. The room-temperature dc electrical conductivity increased from 4.33×10−9 to 1.81×10−8 S/cm as the α-Fe2O3 nanoparticle content increased from 10 to 50 wt.% in PPy/α-Fe2O3 nanocomposites. 相似文献
13.
Improvement of electrical conductivity of poly ethylene oxide (PEO)–LiI polymer electrolytes is necessary for their use in
solid state lithium ion battery. In this study a new kind of PEO–LiI-based polymer electrolytes embedded with CdO nanoparticles
with improved electrical conductivity has been prepared and characterized. The electron microscopic studies confirm that CdO
nanoparticles of average size 2.5 nm are dispersed in the PEO matrix. The glass transition temperature of the PEO–LiI electrolyte
decreases with the introduction of CdO nanoparticle in the polymer matrix. X-ray diffraction, electron microscopic, and differential
scanning calorimetry studies show that the amorphous phase of PEO increases with the introduction of CdO nanoparticle and
that the increase in amorphous phase is maximum for 0.10 wt% CdO doping. The electrical conductivity of the sample with 0.10 wt%
CdO increases by three orders in magnitude than that of the PEO–LiI electrolyte. The electrical conductivity of PEO–LiI electrolyte
embedded with CdO nanoparticle exhibits VTF behavior with reciprocal temperature indicating a strong coupling between the
ionic and the polymer chain segmental motions. 相似文献
14.
W.L. Zhou E.E. Carpenter J. Lin A. Kumbhar J. Sims C.J. O'Connor 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,16(1):289-292
Pure metal iron nanoparticles are unstable in the air. By a coating iron on nanoparticle surface with a stable noble metal,
these air-stable nanoparticles are protected from the oxidation and retain most of the favorable magnetic properties, which
possess the potential application in high density memory device by forming self-assembling nanoarrays. Gold-coated iron core-shell
structure nanoparticles (Fe/Au) synthesized using reverse micelles were characterized by transmission electron microscopy
(TEM). The average nanoparticle size of the core-shell structure is about 8 nm, with about 6 nm diameter core and 1∼2 nm shell.
Since the gold shell is not epitaxial growth related to the iron core, the morié pattern can be seen from the overlapping
of iron core and gold shell. However, the gold shell lattice can be seen by changing the defocus of TEM. An energy dispersive
X-ray spectrum (EDS) also shows the nanoparticles are air-stable. The magnetic measurement of the nanoparticles also proved
successful synthesis of gold coated iron core-shell structure. The nanoparticles were then assembled under 0.5 T magnetic
field and formed parallel nanobands with about 10 μm long. Assembling two dimensional ordered nanoarrays are still under going.
Received 29 November 2000 相似文献
15.
High-density polyethylene (HDPE) nanocomposites reinforced with pristine and vinyltrimethoxysilane (VTMS)-treated alumina nanoparticles of 2, 4, and 6 wt% were melt-compounded in a twin-screw extruder followed by injection molding. Their structure, thermal and mechanical behaviors were studied. Fourier transform infrared (FTIR) spectra showed that VTMS was successfully covalently grafted to the alumina nanoparticles. The X-ray diffraction (XRD) patterns indicated that the alumina nanoparticle additions broadened the characteristic peak width of HDPE, indicating that they reduced the crystallite size of HDPE. The heat deflection temperature and thermogravimetric analyses demonstrated that the dimensional and thermal stability of HDPE were enhanced markedly by adding pristine and silane-treated alumina nanoparticles. The alumina nanoparticle additions were also beneficial in enhancing Young's modulus and yield strength of HDPE. The reinforcing effect was particularly apparent in the silane-treated nanocomposites due to improved filler–matrix interactions. 相似文献
16.
A novel method for fabricating magnetic iron oxide nanoparticles was achieved by using transparent vermicelli template as a new stabilizing material. The morphology of the as-prepared magnetic iron oxide deposited on the surface of vermicelli was observed as nanoclusters. The magnetization of the magnetic iron oxide nanoparticles at room temperature was decreased after carbonization at 200 °C. Therefore the thermal decomposition of iron oxide nanoparticles stabilized by starch vermicelli template yielded iron oxide/carbon nanocomposites with the soft magnetic behavior which are useful for biomedical applications. 相似文献
17.
Ki-Chul Kim Eung-Kwon Kim Jae-Won Lee Sung-Lyul Maeng Young-Sung Kim 《Current Applied Physics》2008,8(6):758-760
We have synthesized the iron oxide nanoparticles using the newly developed mechanical ultrasonication method with the FeSO4 · 7H2O. We have also investigated the crystallographic structural properties, morphology, and magnetic properties of the nanopowders. According to the high resolution X-ray diffraction result, the as-synthesized iron oxide nanoparticles were magnetite (Fe3O4). The particle size of the magnetite nanoparticles was about 6 nm confirmed by transmission electron microscopy image. The particle shape was almost a sphere confirmed by scanning electron microscopy image. The coercivity and saturation magnetization of the as-synthesized iron oxide nanopowders were 114 Oe, and 3.7 emu/g, respectively. 相似文献
18.
This study reports synthesis and characterization of poly(MMA-co-BA)/Cloisite 30B (organo-modified montmorillonite clay) nanocomposites by ultrasound-assisted in-situ emulsion polymerization. Copolymers have been synthesized with MMA:BA monomer ratio of 4:1, and varying clay loading (1–5 wt% monomer). The poly(MMA-co-BA)/Cloisite 30B nanocomposites have been characterized for their thermal and mechanical properties. Ultrasonically synthesized nanocomposites have been revealed to possess higher thermal degradation resistance and mechanical strength than the nanocomposites synthesized using conventional techniques. These properties, however, show an optimum (or maxima) with clay loading. The maximum values of thermal and mechanical properties of the nanocomposites with optimum clay loading are as follows. Thermal degradation temperatures: T10% = 320 °C (4 wt%), T50 = 373 °C (4 wt%), maximum degradation temperature = 384 °C (4 wt%); glass transition temperature = 64.8 °C (4 wt%); tensile strength = 20 MPa (2 wt%), Young’s modulus = 1.31 GPa (2 wt%), Percentage elongation = 17.5% (1 wt%). Enhanced properties of poly(MMA-co-BA)/Cloisite 30B nanocomposites are attributed to effective exfoliation and dispersion of clay nanoparticles in copolymer matrix due to intense micro-convection induced by ultrasound and cavitation. Clay platelets help in effective heat absorption with maximum surface interaction/adhesion that results in increased thermal resistivity of nanocomposites. Hindered motion of the copolymer chains due to clay platelets results in enhancement of tensile strength and Young’s modulus of nanocomposite. Rheological (liquid) study of the nanocomposites reveals that nanocomposites have higher yield stress and infinite shear viscosity than neat copolymer. Nonetheless, nanocomposites still display shear thinning behavior – which is typical of the neat copolymer. 相似文献
19.
Evans BA Fiser BL Prins WJ Rapp DJ Shields AR Glass DR Superfine R 《Journal of magnetism and magnetic materials》2012,324(4):501-507
Magnetic elastomers have been widely pursued for sensing and actuation applications. Silicone-based magnetic elastomers have a number of advantages over other materials such as hydrogels, but aggregation of magnetic nanoparticles within silicones is difficult to prevent. Aggregation inherently limits the minimum size of fabricated structures and leads to non-uniform response from structure to structure. We have developed a novel material that is a complex of a silicone polymer (polydimethylsiloxane-co-aminopropylmethylsiloxane) adsorbed onto the surface of magnetite (γ-Fe2O3) nanoparticles 7-10 nm in diameter. The material is homogenous at very small length scales (<100 nm) and can be crosslinked to form a flexible magnetic material, which is ideally suited for the fabrication of micro- to nanoscale magnetic actuators. The loading fraction of magnetic nanoparticles in the composite can be varied smoothly from 0 to 50 wt% without loss of homogeneity, providing a simple mechanism for tuning actuator response. We evaluate the material properties of the composite across a range of nanoparticle loading, and demonstrate a magnetic-field-induced increase in compressive modulus as high as 300%. Furthermore, we implement a strategy for predicting the optimal nanoparticle loading for magnetic actuation applications, and show that our predictions correlate well with experimental findings. 相似文献
20.
The Fe/Cu nanocomposites with iron as core and copper as shell have been successfully synthesized by a two-step reduction method. A spherical nanoparticle of γ-Fe was first fabricated by the reduction of ferrous chloride, and then the Fe particle was coated by nanocrystalline Cu through the reduction of copper sulfate. The thickness of copper shell has been tuned by varying the initial concentration of copper sulfate. The morphology, crystalline structure, chemical composition and magnetic properties of the products were investigated by using transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and vibrating sample magnetometer (VSM). It was found that the saturation magnetization (Ms) values of the Fe/Cu core–shell particles are varied owing to the different thickness of copper layer. Though the Ms value of the Fe/Cu nanocomposite is lower than that of pure iron nanoparticles, the higher Ms value (22.411 emu/g) of the Fe/Cu composites is also investigated. The result of the thermogravimetric analysis (TGA) showed the enhanced antioxidation capacity of the Fe/Cu nanocomposites. This kind of nanocomposites combined the excellent magnetism of iron and the electronic, thermal conductivity of copper, suggesting potential application as a novel electromagnetic material. 相似文献