Synthesis and characterization of novel core‐shell magnetic nanogels based on 2‐acrylamido‐2‐methylpropane sulfonic acid in aqueous media

Ultrafine well‐dispersed Fe₃O₄ magnetic nanoparticles were directly prepared in aqueous solution using controlled coprecipitation method. The synthesis of Fe₃O₄/poly (2‐acrylamido‐2‐methylpropane sulfonic acid) (PAMPS), Fe₃O₄/poly (acrylamide‐co‐2‐acrylamido‐2‐methylpropane sulfonic acid) poly(AM‐co‐AMPS) and Fe₃O₄/poly (acrylic acid‐co‐2‐acrylamido‐2‐methylpropane sulfonic acid) poly(AA‐co‐AMPS) ‐core/shell nanogels are reported. The nanogels were prepared via crosslinking copolymerization of 2‐acrylamido‐2‐methylpropane sulfonic acid, acrylamide and acrylic acid monomers in the presence of Fe₃O₄ nanoparticles, N,N′‐methylenebisacrylamide (MBA) as a crosslinker, N,N,N′,N′‐tetramethylethylenediamine (TEMED) and potassium peroxydisulfate (KPS) as redox initiator system. The results of FTIR and ¹H‐NMR spectra indicated that the compositions of the prepared nanogels are consistent with the designed structure. X‐ray powder diffraction (XRD) and transmission electron microscope (TEM) measurements were used to determine the size of both magnetite and stabilized polymer coated magnetite nanoparticles. The data showed that the mean particle size of synthesized magnetite (Fe₃O₄) nanoparticles was about 10 nm. The diameter of the stabilized polymer coated Fe₃O₄ nanogels ranged from 50 to 250 nm based on polymer type. TEM micrographs proved that nanogels possess the spherical morphology before and after swelling. These nanogels exhibited pH‐induced phase transition due to protonation of AMPS copolymer chains. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of alkali‐soluble photosensitive polysiloxane urethane acrylate

A new negative temperature coefficient of resistor (NTCR) thermistors based on nitrile butadiene rubber/magnetite (NBR/Fe₃O₄) nanocomposites were successfully fabricated by conventional roll milling technique. X‐ray diffraction and transmission (TEM) analysis showed that the product is mainly magnetite nanoparticles with diameter of 10‐13 nm. The microstructure of (NBR/Fe₃O₄) nanocomposites were examined by scanning electron microscopy (SEM) and FTIR spectroscopy. The dispersion of magnetite nanoparticles in the NBR rubber matrix and interfacial bonding between them were rather good. The thermal stability of nanocomposites was also obviously improved with the inclusion of the magnetite nanoparticles. The thermal conductivity, thermal diffusivity and specific heat of nanocomposites were investigated. The electrical conductivity of the NBR/Fe₃O₄ increases with the rise in temperature exhibiting a typical negative temperature coefficient of resistance (NTCR) behavior like a semiconductor. The nature of the temperature variation of electrical conductivity and values of activation and hopping energy, suggest that the transport conduction process is controlled by hopping mechanism. Values of characteristics parameters of the thermistors like thermistor constant, thermistor sensitivity and thermistor stability is quite good for practical application as NTCR devices at high temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Fabrication,characterization, and properties of poly(ethylene‐co‐vinyl acetate)/magnetite nanocomposites

Poly(ethylene‐co‐vinyl acetate) (EVA)/magnetite (Fe₃O₄) nanocomposite was prepared with different loading of Fe₃O₄ nanoparticles. The mixing and compounding were carried out on a two‐roll mixing mill and the sheets were prepared in a compression‐molding machine. The effect of loading of nanoparticles in EVA was investigated thoroughly by different characterization technique such as transmission electron microscopy (TEM), X‐ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), limiting oxygen index (LOI), and technological properties. TEM analysis showed the uniform dispersion of filler in the polymer matrix and the dispersion of filler decreased with increase in filler content. XRD of the nanocomposite revealed the more ordered structure of the polymer chain. An appreciable increase in glass transition temperature was observed owing to the restricted mobility of Fe₃O₄‐filled EVA nanocomposite. TGA and flame resistance studies indicated that the composites attain better thermal and flame resistance than EVA owing to the interaction of filler and polymer segments. Mechanical properties such as tensile strength, tear resistance, and modulus were increased for composites up to 7 phr of filler, which is presumably owing to aggregation of Fe₃O₄ nanoparticle at higher loading. The presence of Fe₃O₄ nanoparticles in the polymer matrix reduced the elongation at break and impact strength while improved hardness of the composite than unfilled EVA. The change in technological properties had been correlated with the variation of polymer–filler interaction estimated from the swelling behavior. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40116.     

Preparation and Characterization of Fe2O3/Ammonium Perchlorate (AP) Nanocomposites through Ceramic Membrane Anti‐Solvent Crystallization

A novel ceramic membrane anti‐solvent crystallization (CMASC) method was proposed to prepare Fe₂O₃/AP nanocomposites with core‐shell structure. For the preparation of Fe₂O₃/AP nanocomposites, several key advantages of the CMASC method are as follows. Firstly, both well‐dispersed Fe₂O₃ nanoparticles and the superfine AP preparation can be achieved at one step. Secondly, no non‐component of solid propellant was involved in this composite process. Thirdly, the size and morphology of Fe₂O₃/AP nanocomposites can be effectively controlled by using the ceramic membrane with regular pore structure as feeding template. The morphology and structure of Fe₂O₃/AP nanocomposites were characterized by inductively coupled plasma spectrophotometry (ICP), IR spectroscopy, SEM, and HRTEM. The results verified that the size and morphology of Fe₂O₃/AP nanocomposites are controllable, and the dispersion of Fe₂O₃ nanoparticles is greatly improved in Fe₂O₃/AP nanocomposites. Moreover, the thermal decomposition of the as‐prepared Fe₂O₃/AP nanocomposites was measured with TG‐DSC. The results showed that the Fe₂O₃ nanoparticles in Fe₂O₃/AP nanocomposites exhibit better catalytic activity on the thermal decomposition of AP. In addition, the mechanism was also discussed.     

Microwave‐Assisted Synthesis of Magnetic Hydroxyapatite for Removal of Heavy Metals from Groundwater

A simple, fast, and economic methodology to fabricate a highly efficient superparamagnetic Fe₃O₄/hydroxyapatite nanocomposite (MHAP) was successfully developed. Hydroxyapatite was functionalized with magnetite nanoparticles through coprecipitation‐assisted microwave processes to improve the magnetic properties. The synthesized magnetic hybrid adsorbent matrix was investigated by different methods. Transmission electron microscopy demonstrated a good impregnation of Fe₃O₄ on the hydroxyapatite matrix with uniform morphology. Magnetic hysteresis measurement revealed that MHAP nanocomposites exhibit excellent strong, soft‐magnetic properties. The synergistic effect was an evidence for iron and manganese ion removal, enlightening their potentialities in treatment of polluted ground water.     

Synthesis and characterization of magnetite (Fe3O4)—Polyvinyl alcohol‐based nanocomposites and study of superparamagnetism

The aim of this investigation was to design iron oxide containing nanocomposites which could display superparamagnetic behavior and thus find application in biomedical and allied fields. To achieve the proposed objectives methyl methacrylate was polymerized by a redox system comprising of metabisulphite and persulphate in the immediate presence of a crosslinker, N,N′‐methylene bis acrylamide and a preformed polymer, i.e., polyvinyl alcohol. Into the prepared polymer matrix nanosized magnetite (Fe₃O₄) particles were evenly dispersed by in situ precipitation of Fe²⁺/Fe³⁺ ions. The nanocomposite materials were characterized by techniques like FTIR, SEM, TEM, XRD, and DSC. The magnetic behavior of nanocomposites and bulk magnetite particles was studied under varying applied magnetic fields and their superparamagnetic property was examined. The iron‐oxide polymer nanocomposites were also studied for microhardness. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

New Magnetic Polymer Nanocomposites on the Basis of Isotactic Polypropylene and Magnetite Nanoparticles for Adsorption of Ultrahigh Frequency Electromagnetic Waves

In this study, we report about the preparation of magnetic polymer nanocomposites on the basis of isotactic polypropylene and magnetite Fe₃O₄ nanoparticles. The structure and composition of polymer nanocomposite materials have been studied by scanning electron microscopy, atomic force microscopy, and X-ray dispersive analysis. The magnetic properties of polymer nanocomposites based on PP+Fe₃O₄have been investigated. It is found that not significant adhesion and agglomeration of nanoparticles occur, by increasing the nanoparticle content in polymer matrix up to 40%, and therefore they act as single-domain nanoparticles. The samples of nanocomposites based on PP+Fe₃O₄, with up to 40% content of Fe₃O₄, exhibit superparamagnetic properties. It was also found out that the magnetic polymer nanocomposite material based on PP+Fe₃O₄ is able to absorb ultrahigh frequency electromagnetic waves in the frequencies range from 0.1 to 30?GHz. The increase in Fe₃O₄ concentration from 5 to 40% at the 400?µm thicknesses of the films leads to an increase in absorption of electromagnetic waves of high frequency from 15 to 22.7%.     

Preparation of magnetite and silver poly(2‐acrylamido‐2‐methyl propane sulfonic acid‐co‐acrylamide) nanocomposites for adsorption and catalytic degradation of methylene blue water pollutant

The aim of the present work was to prepare microgel nanocomposites based on silver and magnetite to apply as adsorbents and heterogeneous catalysts for removal of methylene blue (MB) cationic dye from aqueous solution. For this, 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) and acrylamide (AAm) monomers were used to prepare AMPS/AAm microgel based on the emulsion technique. Ag and Fe₃O₄ nanoparticles were embedded into the AMPS/AAm microgel using the in situ technique. Their particle sizes, surface charges, crystalline lattice structure, morphology, magnetic properties and thermal stability were investigated. The AMPS/AAm hydrogel nanocomposites were used as an adsorbent to remove MB dye. The AMPS/AAm microgel nanocomposites were tested as catalysts to reduce MB and degrade its chemical structure with heterogeneous Fenton oxidation using Ag and Fe₃O₄ nanocomposites, respectively. This study presents promising data as the prepared materials used as adsorbents and catalysts show competitive features compared with the data presented in the literature. © 2019 Society of Chemical Industry     

Facile preparation of poly(ε-caprolactone)/Fe3O4@graphene oxide superparamagnetic nanocomposites

The main goal in this work was to prepare and characterize a kind of novel superparamagnetic poly(ε-caprolactone)/Fe₃O₄@graphene oxide (PCL/Fe₃O₄@GO) nanocomposites via facile in situ polymerization. Fabrication procedure included two steps: (1) GO nanosheets were decorated with Fe₃O₄ nanoparticles by an inverse co-precipitation method, which resulted in the production of the magnetite/GO hybrid nanoparticles (Fe₃O₄@GO); (2) incorporation of Fe₃O₄@GO into PCL matrix through in situ polymerization afforded the magnetic nanocomposites (PCL/Fe₃O₄@GO). The microstructure, morphology, crystallization properties, thermal stability and magnetization properties of nanocomposites were investigated with various techniques in detail. Results of wide-angle X-ray diffraction showed that the incorporation of the Fe₃O₄@GO nanoparticles did not affect the crystal structure of PCL. Images of field emission scanning electron microscope and transmission electron microscopy showed Fe₃O₄@GO nanoparticles evenly spread over PCL/Fe₃O₄@GO nanocomposites. Differential scanning calorimeter and polar optical microscopy showed that the crystallization temperature increased and the spherulites size decreased by the presence of Fe₃O₄@GO nanoparticles in the nanocomposites due to the heterogeneous nucleation effect. Thermogravimetric analysis indicated that the addition of Fe₃O₄@GO nanoparticles reduced the thermal stability of PCL in the nanocomposites. The superparamagnetic behavior of the PCL/Fe₃O₄@GO nanocomposites was testified by the superconducting quantum interference device magnetometer analysis. The obtained superparamagnetic nanocomposites present potential applications in tissue engineering and targeted drug delivery.     

Synthesis and characterizations of magnetite nanocomposite films for radiation shielding

Polyvinyl alcohol (PVA) films containing magnetite Fe₃O₄ nanoparticles have been prepared by co‐precipitation method for use in gamma ray shielding and protection. Characterizations of the magnetite/PVA nanocomposite films were investigated by X‐ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis spectroscopy, and magnetization measurements. TEM images showed that the synthesized magnetite particles had about 6–11 nm dimensions. Optical study's results revealed that the optical energy band gaps of thin films range between 1.82 and 2.81 eV at room temperature using UV–visible absorption spectroscopy. The saturation magnetization (MS) value measured by vibrating sample magnetometer VSM was found to be 8.1 emu/g with superparamagnetic nature. The radiation shielding properties such as linear attenuation coefficients (μ ) and half‐value thickness (HVT) for the magnetite nanocomposite films have been obtained experimentally for different photon energies. The results imply that these nanocomposites films are promising radiation shielding materials. POLYM. COMPOS., 38:974–980, 2017. © 2015 Society of Plastics Engineers     

Synergistic effect of carbon nanofiber decorated with iron oxide in enhancing properties of styrene butadiene rubber nanocomposites

Elastomer nanocomposites reinforced with carbon nanofiber (CNF) decorated with metal nanoparticles exhibit excellent thermal, mechanical, and magnetic properties with low volume fraction of the reinforcement. Generally, metal nanoparticles are used to modify the surface of CNF, to improve their dispersion and contact resistance in the polymer matrix. In this study, Fe₂O₃ metal nanoparticles were decorated on CNF by electrostatic attraction via a green and facile solution‐based method. Interestingly, the CNF decorated with Fe₂O₃ (CNF‐Fe₂O₃)/elastomer improved both the tensile strength and the fatigue property of plain CNF/elastomer by as much as 57.2% and 27.2%, respectively. Moreover, the CNF‐Fe₂O₃/elastomer exhibited superior thermal conductivity, a twofold enhancement compared with carbon fibers. The elastomer nanocomposites consisting of CNF‐Fe₂O₃ also exhibited enhanced magnetic properties due to synergies between the Fe₂O₃ nanoparticles and the CNF. The elastomer nanocomposites prepared with CNF‐Fe₂O₃ will open significant new opportunities for preparing advanced elastomer nanocomposites for future engineering applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45376.     

Fabrication of PMMA/PANI/Fe3O4 as a Novel Conducting Hybrid Coating

In this paper, an excellent new hybrid coating including poly(methyl methacrylate) (PMMA), polyaniline (PANI), and magnetite nanoparticles (Fe₃O₄) was obtained. Fe₃O₄ nanoparticles were synthesized using coprecipitation method, and then magnetite nanoparticles have been dispersed into the PANI to increase compatibility with PMMA. Also, PANI/Fe₃O₄ nanocomposites were synthesized through in situ emulsion polymerization, and then PMMA/PANI/Fe₃O₄ hybrid coating was successfully synthesized using batch emulsion polymerization method. Structure, morphology and thermal stability of the samples were characterized using Fourier transform infrared, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and thermal gravimetric analysis (TGA). The synthesized samples were well distributed with an average diameter smaller than 20?nm. Microscopy and X-ray photoelectron spectroscopy results illustrated a great dispersion of magnetite nanoparticles in hybrid matrix. Moreover, the TGA results demonstrated that the PMMA/PANI/Fe₃O₄ hybrid coating nanoparticle is an excellent hybrid coating with high thermal resistance.     

Synthesis and Characterization of Novel Heat Resistant,Superparamagnetic Poly(ether-imide) Nanocomposites Containing Xanthene: Representing a Strategy for Improving Thermal Stability of Magnetic Polymer-Based Nanocomposites

Two superparamagnetic and heat resistant xanthene based poly(ether-imide) nanocomposites were successfully synthesized. Field emission scanning electron microscopy, transmission electron microscope, X-ray diffraction, thermal gravimetric analysis, vibrating sample magnetometer, Energy-dispersive X-ray spectroscopy and Fourier-transform infrared (FTIR) techniques were used for studying the morphology, crystalline phase, thermal stability and magnetization properties of the nanocomposites. The neat form of the corresponding poly(ether-imide) was also prepared by thermal imidization method and its structure was confirmed by FTIR, proton nuclear magnetic resonance (¹H NMR), UV–Vis and photoluminescence (PL) spectroscopies. In order to investigate the effects of modifying the surface of Fe₃O₄ nanoparticles on thermal properties of the nanocomposites, the surface of Fe₃O₄ nanoparticles was coated with SiO₂ and polysuccinimide (PSI), sequentially. Then, both the unmodified Fe₃O₄ and surface-modified Fe₃O₄ (Fe₃O₄@SiO₂–PSI) nanoparticles were used as fillers for the polymer matrix. According to the results, the prepared nanocomposites were superparamagnetic and showed higher thermal stability in comparison to the neat poly(ether-imide). Furthermore, poly(ether-imide)/Fe₃O₄@SiO₂–PSI (PIEN 10b) nanocomposite showed higher thermal stability and dispersed better in the polymer matrix [in comparison to poly(ether-imide)/Fe₃O₄ (PIEN 10 a)] due to the presence of imide groups and high hydroxyl content of the functional Fe₃O₄ nanoparticles which caused high interactions between poly(ether-imide) and functional Fe₃O₄. Furthermore, the presence of methyl, ether and bulky xanthene groups in the poly(ether-imide(backbone improved the solubility of the neat polymer in organic solvents. These properties can be very helpful for extending new applications of poly(ether-imide)s.     

Gold deposition on Fe3O4/(co)Poly(N‐octadecyl methacrylate) hybrid particles to obtain nanocomposites With ternary intrinsic features

Here, nanocomposite particles with three domains including magnetite nanoparticles, poly(N‐octadecyl methacrylate) (PODMA) or poly(N‐octadecyl methacrylate‐co‐1‐vinylimidazole) (P(ODMA‐co‐VIMZ)), and gold nanoparticles were prepared. Fe₃O₄ nanoparticles with narrow particle size distribution were prepared through a synthetic route in an organic phase in order to achieve good control of the size and size distribution and prevent their aggregation during their preparation. These magnetite nanoparticles, ～ 5 nm in size, were then encapsulated and well‐dispersed in PODMA and P(ODMA‐co‐VIMZ) matrices via a miniemulsion polymerization process to obtain the corresponding nanocomposite particles. The results revealed that Fe₃O₄ nanoparticles were encapsulated and did not migrate towards the monomer/water interface during polymerization. The resulting latex was used as a precursor for the adsorption of Au³⁺ ions on the surface of the polymeric particles and subsequent reduction to produce Fe₃O₄/P(ODMA‐co‐VIMZ)/Au nanocomposite particles. The morphology of the particles from each step was fully characterized by TEM and AFM, and the results of DLS analysis showed their size and size distribution. Measurement of magnetic properties illustrated the superparamagnetic characteristic of the products and it was observed that the encapsulation process and deposition of gold had no effect on the magnetic properties of the resulting particles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and characterization of a novel thermally stable water dispersible polyurethane and its magnetic nanocomposites

In this work, a novel water dispersible polyurethane (WDPU) was synthesized from the reaction of hydroxyl-terminated polybutadiene (HTPB), 2,2 bis(hydroxymethyl) propionic acid (DMPA), and 1,5-naphthalene diisocyanate (NDI) and its magnetic nanocomposites were prepared by incorporation of modified Fe₃O₄ by 3-aminopropyltriethoxysilane (Fe₃O₄@APTS) nanoparticles (0.5, 1.5, and 3 wt%) via in situ polymerization method. Use of NDI as a high melting point diisocyanate by having the rigid naphthalene structure imparts physical strength as well as thermal stability to the resulted polyurethane. The synthesized WDPU based on NDI was characterized by using Fourier transform infrared spectroscopy (FTIR) technique. In addition, the morphology, mechanical, and magnetic features of the prepared polyurethane nanocomposites were investigated by X-ray diffraction (XRD), dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), magnetic force microscopy (MFM), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMTA), and vibrating sample magnetometer (VSM) methods, respectively. Data from DLS experiment showed that the average particles size of the WDPU nanocomposites increased by increasing the nanoparticle contents in comparison with bare WDPU. AFM and MFM analyses indicated that the magnetic nanoparticles (MNPs) were well dispersed in the polyurethane matrices via the formation of covalent bonding between the functionalized magnetic nanoparticles and polymer chains. TGA results demonstrated that adding MNPs increased the temperature of the thermal degradation of the polyurethane nanocomposite. VSM analysis showed that the super paramagnetic behavior of the prepared nanocomposites depended on the Fe₃O₄@APTS nanoparticle content, as well.     

Preparation and characterization of novel optically active poly(amide‐imide)/α‐Fe2O3 nanocomposites containing l‐alanine moieties

An optically active poly(amide‐imide) (PAI) was synthesized from the polymerization reaction of N,N′‐(Pyromellitoyl)‐bis‐l ‐alanine diacid chloride with 2,5‐diaminotoluene. The obtained inorganic metal oxide nanocomposites composed of PAI/nanostructured hematite (α‐Fe₂O₃) were synthesized through ultrasonic irradiation. The resulting nanocomposites were characterized by Fourier transform infrared spectroscopy, powder X‐ray diffraction, transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The TEM results indicated that the nanoparticles were dispersed homogeneously in PAI matrix on nanoscale. TGA confirmed that the heat stability of the nanocomposites was improved in the presence of α‐Fe₂O₃ nanoparticles. POLYM. COMPOS., 37:1805–1811, 2016. © 2014 Society of Plastics Engineers     

Synthesis and thermal stability of polystyrene and poly(vinyl chloride) coated with polythiophene and modified with Fe2O3 nanoparticles

In this study, polystyrene and poly(vinyl chloride) particles were coated successfully with polythiophene in aqueous media. These nanocomposites were prepared in situ by polymerization of thiophene in the presence of FeCl₃ as an oxidant and poly(vinyl pyrrolidone) as a surfactant. The effect of Fe₂O₃ nanoparticles on the characteristics of products such as thermal stability and morphology was investigated. The chemical structure, morphology, and thermal stability of these core‐shell nanocomposites were studied by Fourier‐transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, and thermogravimetric analysis. Thermal stability of the nanocomposites was compared and indicated that the thermal stability of polythiophene/polystyrene was better than the polythiophene/poly(vinyl chloride) nanocomposite. Also, the presence of Fe₂O₃ nanoparticles can drastically increase the thermal stability of polythiophene nanocomposites. J. VINYL ADDIT. TECHNOL. 20:212–217, 2014. © 2014 Society of Plastics Engineers     

Synthesis and characterization of (Fe3O4/MWCNTs)/ epoxy nanocomposites

A sonochemical technique is used for in situ coating of iron oxide (Fe₃O₄) nanoparticles on outer surface of MWCNTs. These Fe₃O₄/MWCNTs were characterized using a high‐resolution transmission electron microscope (HRTEM), X‐ray diffraction, and thermogravimetric analysis. The as‐prepared Fe₃O₄/MWCNTs composite nanoparticles were further used as reinforcing fillers in epoxy‐based resin (Epon‐828). The nanocomposites of epoxy were prepared by infusion of (0.5 and 1.0 wt %) pristine MWCNTs and Fe₃O₄/MWCNTs composite nanoparticles. For comparison purposes, the neat epoxy resin was also prepared in the same procedure as the nanocomposites, only without nanoparticles. The thermal, mechanical, and morphological tests were carried out for neat and nanocomposites. The compression test results show that the highest improvements in compressive modulus (38%) and strength (8%) were observed for 0.5 wt % loading of Fe₃O₄/MWCNTs. HRTEM results show the uniform dispersion of Fe₃O₄/MWCNTs nanoparticles in epoxy when compared with the dispersion of MWCNTs. These Fe₃O₄/MWCNTs nanoparticles‐infused epoxy nanocomposite shows an increase in glass transition (T_g) temperature. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and characterization of conductive and magnetic PPy/Fe3O4/Ag nanocomposites

In this article, conductive and magnetic nanocomposites composed of polypyrrole (PPy), magnetite (Fe₃O₄) nanoparticles (NPs), silver (Ag) NPs, have been successfully synthesized with a two step process. First, the PPy/Fe₃O₄ was prepared by the ultrasonic in situ polymerization. Next, the PPy/Fe₃O₄/Ag was synthesized through the electrostatic adsorption. The products were characterized by fourier‐transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), Thermogravimetric (TG), conductivity and magnetization analysis, and the results showed that the Ag NPs with the good conductivity coated uniformly on the surface of PPy/Fe₃O₄ and improved the conductivity of PPy/Fe₃O₄/Ag composites. In addition, as compared with PPy/Fe₃O₄, PPy/Fe₃O₄/Ag composites also have the excellent electro‐magnetic property and enhanced thermostability. POLYM. COMPOS., 35:450–455, 2014. © 2013 Society of Plastics Engineers     

Crystallinity,conductivity, and magnetic properties of PVDF‐Fe3O4 composite films

The formation of Fe₃O₄ nanoparticles by hydrothermal process has been studied. X‐ray Diffraction measurements were carried out to distinguish between the phases formed during the synthesis. Using the synthesized Fe₃O₄ nanoparticles, poly(vinyledene fluoride)‐Fe₃O₄ composite films were prepared by spin coating method. Scanning electron microscopy of the composite films showed the presence of Fe₃O₄ nanoparticles in the form of aggregates on the surface and inside of the porous polymer matrix. Differential Scanning calorimetry revealed that the crystallinity of PVDF decreased with the addition of Fe₃O₄. The conductitivity of the composite films was strongly influenced by the Fe₃O₄ content; conductivity increased with increase in Fe₃O₄ content. Vibration sample magnetometry results revealed the ferromagnetic behavior of the synthesized iron oxide nanoparticles with a Ms value of 74.50 emu/g. Also the presence of Fe₃O₄ nanoparticles rendered the composite films magnetic. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011