Loaded Fe3O4 Nanoparticles Research Articles

Polyhydroxybutyrate-co-hydroxyvalerate copolymer modified graphite oxide based 3D scaffold for tissue engineering application

In this study, we have fabricated the PHBV functionalized graphite oxide using freeze drying technique, followed by ‘in situ’ pay loading of Fe3O4 nanoparticles onto the hydrophobic plate of the composite basal plane; thereby, mechanically and thermally stable, bio-imaging Fe3O4/GO-g-PHBV composites have been developed. The synthesis of Fe3O4/GO-g-PHBV composite was confirmed by field emission SEM and TEM analyses, X-ray diffraction and Fourier transform infrared spectroscopy. The wrapping of PHBV copolymer into the graphene layers was investigated by atomic force microscopy and Raman spectral analyses which provided the shifting of the 2D band with low signal intensity in the range of 2600–3000 cm−1. The bactericidal activities of the Fe3O4/GO-g-PHBV composite films were found to exhibit more efficiency against Gram-negative bacteria strains compared to Gram-positive strains. In vibrating sample magnetometer (VSM) analysis, the zero value of coercivity revealed the super-paramagnetic nature of the Fe3O4/GO-g-PHBV composites. The Phantom agar magnetic resonance imaging analysis revealed the efficiency of Fe3O4 nanoparticles as a negative contrast (T2 contrast) along with higher relaxivity value. The significant fibroblast cell (NIH 3T3) adhesion and proliferation (85%) on the Fe3O4/GO-g-PHBV composite surface indicated the physiological and biocompatible stability of that composite along with the presence of large π conjugated aromatic domain.

Enhancement of catalytic performance by regulating the surface properties of Fe3O4 composites

Abstract As magnetic catalyst material, great studies have been made to improve the catalytic performance of Fe3O4 nanoparticles by changing the structure, but little attention has been paid to the relationship between the surface properties (the electronegativity, electron transport capacity) and the catalytic performance of Fe3O4 nanoparticles. Therefore, this work was devoted to the investigation of the relationship by loading Fe3O4 nanoparticles on graphene oxide(GO) grafted with N,N,N',N'-Tetrakis (2-hydroxyethy)ethylenediamine (THEED), which was denoted as TG@Fe3O4. N atoms in THEED and GO have strong electronegativity and electron mobility respectively, which greatly change the surface properties of the Fe3O4 composite. A large number of characterization methods have proved that the original structure of the produced Fe3O4 nanoparticles has not been changed, and the Zeta potential and cyclic voltammetry curves confirmed that the surface properties of Fe3O4 composite have been improved. In the Fenton degradation experiment of MB, TG@Fe3O4 can make the degradation rate of MB reach 100% in 8 min, which verified that the strong electronegativity and electron transport capacity were beneficial to the improvement of the catalytic performance of Fe3O4 composite.

Development of sulfide-doped Graphene/Fe3O4 absorber with wide band electromagnetic absorption performance

Graphene has been confirmed as an ideal lightweight and high-performance electromagnetic (EM) absorber if used to deal with increasingly electromagnetic interference issue. However, the actual EM absorption performance of graphene is not desirable in a thin thickness which is due to poor impedance matching behavior and single conductive loss form. To overcome this difficulty, this research employed S doping and magnetic Fe3O4 nanoparticles loading strategies to boost EM attenuation ability by introduction of various EM loss forms, e.g. dipolar, interface, and magnetic loss ability etc. Besides, the impedance matching ability of SGN/Fe3O4 has significant improved as compared to pure graphene, primarily owing to the sharply decrease of relative complex permittivity (εr) values. The as-prepared S-doped graphene/Fe3O4 (denote as SGN/Fe3O4) absorber shows excellent wideband electromagnetic absorption property at a thin thickness of 2.0 mm which the frequency width with a reflection loss < -10 dB reach 5.3 GHz.

Synthesis of Smart Poly(diphenylamine)/Magnetic Particle Composites and Their Electric/Magnetic Stimuli-Response

Polymer-inorganic composite particles composed of poly(diphenylamine) (PDPA) and Fe3O4 were synthesized to fabricate a smart material that can respond to both electric and magnetic fields. PDPA was synthesized using a chemical oxidative polymerization process, and the PDPA/magnetite (PDPA/Fe3O4) composites were fabricated by loading Fe3O4 nanoparticles onto the surface of PDPA using a coprecipitation method. The surface roughness of the composites was larger than that of pure PDPA, and the composites exhibited paramagnetic properties with a saturation magnetization of 77.1 kA/m. An electrorheological (ER) and magnetorheological (MR) fluid was prepared by dispersing PDPA/Fe3O4 composites in silicone oil. An examination of the responses under an external electric or magnetic field revealed significant ER and MR characteristics.

Curcumin Loaded Fe3O4 Nanoparticles: An MRI Contrast Agent to Investigate the Impact of Curcumin on Maximizing Negative Contrast and r2 Relaxation Rate

The goal of this project was to fabricate a diagnostic system based on polyethylenimine (PEI) coated superparamagnetic iron oxide nanoparticles (Fe3O4 NPs) containing curcumin (CUR) in order to appraise the influence of CUR on increase of r2 relaxation rate of a negative contrast agent in magnetic resonance imaging (MRI). Based on the obtained results, the structural properties of the final product (i.e., Fe3O4-PEI-CUR NPs) were validated according to the initial hypothesis (i.e., NPs of about 50 nm in diameter with proper magnetic properties). Also, the CUR to Fe3O4-PEI NPs weight ratio of 2:1 was determined as an optimal ratio resulting in an 8% increase in the amount of loaded CUR as compared to the weight ratio of 1:1. In addition, CUR release from Fe3O4-PEI-CUR NPs was evaluated at two pH of 5.5 and 7.4 which revealed that the CUR release mechanism was pH-sensitive. The visual and numerical data of in vitro MRI all suggested an increase in negative contrast in the presence of CUR, as the r2 values for Fe3O4-PEI, Fe3O4-PEI-CUR (30% CUR loading), and Fe3O4-PEI-CUR (38% CUR loading) NPs were determined 78.278, 93.854, and 95.685 (1/mM sec), respectively. It was also shown that an 8% increase of CUR content in Fe3O4-PEI-CUR (38%) NPs merely led to a 2% increase in r2 and therefore in negative contrast. This result suggested that increasing CUR content more than a specific amount could not improve contrast considerably, while there was a significant difference (about 20%) between r2 values of Fe3O4-PEI and Fe3O4-PEI-CUR (30%) NPs.

Constructing superior carbon-nanofiber-based composite microwave absorbers by engineering dispersion and loading of Fe3O4 nanoparticles on three-dimensional carbon nanofibers derived from bacterial cellulose

Three-dimensional (3D) carbon nanofibers (CNFs) produced from pyrolysis of bacterial cellulose (BC) were used as the substrate for anchoring Fe3O4 nanoparticles. In order to control the dispersion of Fe3O4 nanoparticles on the surfaces of BC-derived CNFs (BC-CNFs), BC-CNFs were surface-treated in HNO3 solution. The resultant BC-CNF/Fe3O4 nanocomposites possessed ultra-small and highly dispersed Fe3O4 nanoparticles and demonstrated greatly enhanced absorption over their untreated counterparts. Moreover, among all BC-CNF/Fe3O4 nanocomposites, the BC-CNF/Fe3O4 containing 52.7 wt% Fe3O4 exhibited excellent absorption performance with the minimal reflection loss (RL) of −62.1 dB at 9.12 GHz, which is the best among all relevant CNF-Fe3O4 composites reported so far.

Selective and Fast Adsorption of Perfluorooctanesulfonate from Wastewater by Magnetic Fluorinated Vermiculite.

A novel magnetic fluorinated adsorbent with selective and fast adsorption of perfluorooctanesulfonate (PFOS) was synthesized via a simple ball milling of Fe3O4 and vermiculite loaded with a cationic fluorinated surfactant. The loaded Fe3O4 nanoparticles increased the dispersibility of fluorinated vermiculite (F-VT) in water and allowed the magnetic separability. The nanosized Fe3O4 was homogeneously embedded into the adsorbent surfaces, improving the hydrophilicity of F-VT external surface, and this hybrid adsorbent still kept the hydrophobic fluorinated interlayer structure. With this unique property, Fe3O4-loaded F-VT has very fast and selective adsorption for PFOS in the presence of other compounds, due to the fluorophilicity of C-F chains intercalated in the adsorbent interlayers. This novel adsorbent has a high sorption capacity for PFOS, exhibiting PFOS removal from fire-fighting foam wastewater that is much higher than that of powdered activated carbon and resin due to its high selectivity for PFOS. The used Fe3O4-loaded F-VT was successfully regenerated by methanol and reused five times without reduction in PFOS removal and magnetic performance. The Fe3O4-loaded F-VT demonstrates promising application for PFOS removal from real wastewater.

Fabrication of magnetite nanoparticles/polyvinylpyrrolidone composite nanofibers and their application as electromagnetic interference shielding material

Magnetite (Fe3O4) nanoparticles/polyvinylpyrrolidone (PVP) composite nanofibers (FCNFs) have been fabricated to evaluate the potential of FCNFs as electromagnetic interference (EMI) shielding material in the frequency range of 8.2–12.4 GHz. The scanning electron microscope and viscosity analyses confirmed the presence of good dispersion Fe3O4 nanoparticles encapsulated within the electrospun nanofibers and showed FCNF morphologies with diameters of 150–500 nm. The magnetic properties and electrical conductivity of FCNFs were found to be dependent on Fe3O4 nanoparticles concentration and showed an increase with increasing Fe3O4 nanoparticles loading. The EMI shielding efficiency of FCNFs increased up to approximately 22 dB. The EMI shielding results for FCNFs showed that absorption was the major shielding mechanism and reflection was the secondary shielding mechanism. The present study has shown the possibility of utilizing magnetic FCNFs as EMI shielding/absorption materials.

Redox-responsive dextran based theranostic nanoparticles for near-infrared/magnetic resonance imaging and magnetically targeted photodynamic therapy.

Photodynamic therapy (PDT) is a site-specific treatment of cancer using much lower optical power densities with minimal nonspecific damage to normal tissues. To improve the therapeutic efficiency of PDT, we fabricated a multifunctional theranostic nanoparticle system (DSSCe6@Fe3O4 NPs) by loading Fe3O4 nanoparticles in redox-responsive chlorin e6 (Ce6)-conjugated dextran nanoparticles for near-infrared (NIR)/magnetic resonance (MR) dual-modality imaging and magnetic targeting. The obtained DSSCe6@Fe3O4 NPs demonstrated a uniform nanospherical morphology consisting of Fe3O4 clusters. The fluorescence signal of Ce6 of this theranostic system could turn "ON" from a self-quenching state in a reductive intracellular environment. T2-Weighted MR imaging revealed a high transverse relaxivity (r2) measured to be 194.4 S-1 mM-1, confirming that it was also a distinctive contrast agent in T2-weighted MR imaging. Confocal images and flow cytometry results showed that the cellular uptake of DSSCe6@Fe3O4 NPs was enhanced effectively under an extra magnetic field, which resulted in promoted PDT therapeutic efficiency. In vivo MR imaging showed that DSSCe6@Fe3O4 NPs effectively accumulated in tumors under an extra magnetic field. These results illustrated that the DSSCe6@Fe3O4 NPs could be a promising theranostic system for both NIR/MR imaging-guided PDT precision therapy.

Daunorubicin Loaded Fe3O4 Nanoparticles Induce Apoptosis of Glioma Cells and Disrupt Tight Junction at Blood–Brain Barrier

Daunorubicin Loaded Fe₃O₄ Nanoparticles Induce Apoptosis of Glioma Cells and Disrupt Tight Junction at Blood–Brain Barrier

Ultrasound-assisted removal of Acid Red 17 using nanosized Fe3O4-loaded coffee waste hydrochar

The Fe3O4-loaded coffee waste hydrochar (Fe3O4-CHC) was synthesized using a simple precipitation method. The as-prepared adsorbent was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and Fourier transform infrared spectroscopy (FT-IR). The EDX analysis indicated the presence of Fe in the structure of Fe3O4-CHC. The specific surface area of hydrochar increased from 17.2 to 34.7m2/g after loading of Fe3O4 nanoparticles onto it. The prepared Fe3O4-CHC was used for removal of Acid Red 17 (AR17) through ultrasound-assisted process. The decolorization efficiency decreased from 100 to 74% with the increase in initial dye concentration and from 100 to 91 and 85% in the presence of NaCl and Na2SO4, respectively. The synthesized Fe3O4-CHC exhibited good stability in the repeated adsorption-desorption cycles. The high correlation coefficient (R2=0.997) obtained from Langmuir model indicated that physical and monolayer adsorption of dye molecules occurred on the Fe3O4-CHC surface. Furthermore, the by-products generated through the degradation of AR17 was identified by gas chromatography–mass spectrometry analysis.

Wool-SO3H and nano-Fe3O4@wool as two green and natural-based renewable catalysts in one-pot isocyanide-based multicomponent reactions

Natural wool sulfonic acid (wool-SO3H) and wool-supported Fe3O4 nanoparticles (nano-Fe3O4@wool) with highly loaded Fe3O4 nanoparticles were simply synthesized and characterized by flame atomic absorption spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The successful synthesis of 3,4-dihydroquinoxalin-2-amine, 1,6-dihydropyrazine-2,3-dicarbonitrile, (cyanophenylamino)acetamide, tetrahydro-1H-1,5-benzodiazepine-2-carboxamide, and 4,5,6,7-tetrahydro-1H-1,4-diazepine-5-carboxamide derivatives shows that wool-SO3H and Fe3O4@wool nanocomposite have high catalytic activity and can be repetitively used as two biodegradable catalysts.

Folate attached, curcumin loaded Fe3O4 nanoparticles: A novel multifunctional drug delivery system for cancer treatment

Study and development of drug delivery nanosystem for cancer treatment are attracting great attention in recent years. In this work, we studied the role of folic acid as a targeting factor on magnetic nanoparticle Fe3O4 based curcumin loading nanosystem. Characteristics of the nanosystems were investigated by Fourier transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA) and vibrating sample magnetometer (VSM), while targeting role of folic was accessed in vivo on tumor bearing mice. The results showed that folate attached Fe3O4 based curcumin loading nanosystem has very small size and exhibits better targeting effect compared to the counterpart without folate. In addition, magnetic induction heating of this nanosystem evidenced its potential for cancer hyperthermia.

Efficient removal of phosphate by facile prepared magnetic diatomite and illite clay from aqueous solution

We present magnetic diatomite and illite clay nanocomposites by loading Fe3O4 nanoparticles onto the raw diatomite or illite clay surfaces via a simple one-pot solvothermal method. The magnetic clays have ordered structure, rich functional groups and strong magnetism as verified by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning and transmission electron microscope (SEM, TEM), and vibrating sample magnetometer (VSM). Subsequently, the magnetic diatomite (MDC) and illite clay (MIC) were used as adsorbents for fast and efficient removal of phosphate from aqueous solution by batch equilibrium experiments. The adsorption kinetic, isothermal and mechanistic properties were studied. The results demonstrated that the phosphate adsorption onto MDC and MIC was pH-dependent, completed within 30min and possessed higher capacities than the raw clays. The adsorption kinetic and isotherm data followed the pseudo-second-order equation and the Langmuir model, respectively. The adsorption mechanisms of phosphate were ascribed to the electrostatic attraction and ligand exchange. Furthermore, the MDC and MIC endowed a superior selectivity, regeneration, reusability and can be quickly and easily separated using a magnet before and after the adsorption process.

Superparamagnetic Fe3O4/Poly(N-isopropyl acrylamide) Nanocomposites Synthesized in Inverse Miniemulsions: Magnetic and Particle Properties.

In the present study, superparamagnetic Fe3O4/poly(N-isopropyl acrylamide) nanocomposites were synthesized by one-step inverse miniemulsion copolymerization of N-isopropyl acrylamide and N,N'-methylene diacrylamide. The loading of Fe3O4 nanoparticles in the nanocomposites was 27 wt%, and the saturation moment of the nanocomposites was 12.4 emu x g(-1). Fe3O4 nanoparticles were prepared through a coprecipitation method. The amount of stabilizer (poly(acrylic acid)) significantly influenced the size and size distribution of the Fe3O4 nanoparticles, and, therefore, their magnetic properties. Superparamagnetism of the Fe3O4 nanoparticles was preserved in the nanocomposites. The effects of synthetic parameters on the particle properties, namely surfactant loading, concentration of ferrofluid, type of lipophobe and initiator, and amount of cross-linker were investigated. Nanocomposites of Fe3O4/poly(N-isopropyl acrylamide) displayed a guava-like morphology, which they could retain after being redispersed in polar solvents.

Fe3O4@ZIF-8: magnetically recoverable catalysts by loading Fe3O4 nanoparticles inside a zinc imidazolate framework.

A simple methodology for encapsulating ca. 10 nm-sized superparamagnetic Fe3O4 nanoparticles in zeolitic imidazolate frameworks (ZIF-8) crystals was developed. The corresponding Fe3O4@ZIF-8 heterostructured material exhibits bifunctional properties with both high magnetization (Fe3O4) and high thermal stability, large specific surface, and catalytic properties (ZIF-8). The Fe3O4@ZIF-8 catalyst exhibits fair separation ability and reusability, which can be repeatedly applied for Knoevenagel condensations and Huisgen cycloadditions for at least ten successive cycles.

In situ sonochemical synthesis of Fe3O4–graphene nanocomposite for lithium rechargeable batteries

In this paper, we have presented experimental results for preparation of Fe3O4–graphene nanocomposite that uses an ultrasound assisted method. The graphene oxide (GO) was prepared from graphite powder using modified Hummers–Offeman method. Subsequently, the synthesis of graphene-Fe3O4 nanocomposite was carried out by ultrasound assisted co-precipitation of iron (II) and (III) chlorides in the presence of GO. The formation of GO and graphene-Fe3O4 nanocomposite was confirmed by X-ray diffraction (XRD), Energy dispersive X-ray (EDX) analysis and Fourier transform-infrared (FTIR) analysis. The particle size of Fe3O4 nanoparticles loaded on graphene nanosheets (observed from TEM image) was found to be smaller than 20nm. The use of ultrasonic irradiations during synthesis of graphene-Fe3O4 nanocomposite resulted in uniform loading of Fe3O4 nanoparticles on graphene nanosheets. The prepared graphene-Fe3O4 nanocomposite material was used for the preparation of anode for lithium ion batteries. The electrochemical performance of the material was tested by cyclic voltammetry (CV) and charge/discharge cycles. It was observed that the capacity of Li-battery when the anode material was made using graphene-Fe3O4 nanocomposite showed stable electrochemical performance for around 120 cycles and the battery could repeat stable charge–discharge reaction.

Fe3O4@cellulose composite nanocatalyst: Preparation, characterization and application in the synthesis of benzodiazepines

A cellulose-based nanocomposite with highly loaded Fe3O4 nanoparticles was prepared and characterized by Fourier transform infrared spectroscopy (FT-IR) spectra, scanning electron microscopy (SEM) images, energy-dispersive X-ray spectroscopy (EDX) spectra and X-ray diffraction (XRD) measurements. Its catalytic activity was investigated in the condensation reaction between o-phenylenediamines and ketones that produced benzodiazepines in good to excellent yields under mild reaction conditions. A good correlation between the amount of surface acid sites and the morphology of the catalyst and its catalytic activity was observed. The nanocatalyst could be recycled and reused without significant loss of its catalytic activity.

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

ABSTRACTPoly(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.

Multifunctional Co0.85Se‐Fe3O4 Nanocomposites: Controlled Synthesis and Their Enhanced Performances for Efficient Hydrogenation of p‐Nitrophenol and Adsorbents

A new kind of multifunctional Co0.85 Se-Fe3 O4 nanocomposites is synthesized by loading Fe3 O4 nanoparticles (NPs) with a size of about 5 nm on the surface of Co0.85 Se nanosheets under hydrothermal conditions without using any surfactant or structure-directing agents. The Co0.85 Se-Fe3 O4 nanocomposite exhibits remarkable catalytic performance for hydrogenation of p-nitrophenol (4-NP) at room temperature and good adsorption behavior for methylene blue trihydrate in water. This nanocomposite also shows a high specific surface area and magnetic separation capability for recyclable utilization. The enhanced performances both in catalysis and adsorption are better than either individual component of Co0.85 Se nanosheets or Fe3 O4 nanoparticles, demonstrating the possibility for designing new multifunctional nanocomposites with improved performances for catalysis, adsorbents, and other applications.