Preparation of Epoxy-Functionalized Magnetic Polymer Nanospheres for Magnetically Targeted Radiotherapy

The synthesis of magnetic protein nanospheres via a modified sonochemical route was described. The effects of experimental parameters, such as bovine serum albumin dosage, ferrofluid concentration, ferrofluid dosage, ultrasonic power and time on the morphology, and dispersibility of magnetic protein nanospheres, were investigated. The final magnetic protein nanospheres were characterized by Fourier‐transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, and vibrating sample magnetometer. The results showed that the superparamagnetic protein nanopsheres had small particle size of 100 nm, high saturation magnetization, high magnetite content, and abundant functional groups. These biocompatible protein nanospheres have biomedical applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Preparation and characterization of polyimide magnetic hollow nanospheres

Magnetic nanospheres are becoming a promising platform for a wide range of applications in pharmacy, life science, and immunodiagnostics due to their high surface area, ease of synthesis and manipulation, fast separation, good biocompatibility, and recyclable performance. In this work, an innovative and efficient method is developed by in situ reducing and growing Ni(OH)2 for the preparation of dendritic mesoporous nanocomposites of silica@Fe3O4/tannic acid@nickel hydroxide (dSiO2@Fe3O4/TA@Ni(OH)2). The flower-like nanospheres have good magnetic response, large surface area, and high histidine-rich protein (His-protein) purification performance. The dSiO2@Fe3O4/TA@Ni(OH)2 nanospheres were synthesized on the basis of a φ(NaSal/CTAB) of 1/1 and a mass of ferrous chloride tetrahydrate of 0.3 g, resulting in a saturation magnetization value of 48.21 emu/g, which means it can be collected within ∼1 min using a magnetic stand. Also, the BET test showed that the surface area is 92.47 m2/g and the pore size is ∼3.9 nm for dSiO2@Fe3O4/TA@Ni(OH)2 nanocomposites. Notably, the nickel hydroxide with unique flower-like structural features enables the combination of a large number of Ni2+ ions and His-proteins for high performance. The isolation and purification experiments of the synthesized dSiO2@Fe3O4/TA@Ni(OH)2 were performed by separating His-proteins from a matrix composed of bovine hemoglobin (BHb), bovine serum albumin (BSA), and lysozyme (LYZ). The result showed that the nanospheres have a high combination capacity of ∼1880 mg/g in a rapid equilibrium time of 20 min, which was selective for the adsorption of BHb. In addition, the stability and recyclability of BHb are 80% after seven cycles. Furthermore, the nanospheres were also used to isolate His-proteins from fetal bovine serum, proving its utility. Therefore, the strategy of separating and purifying His-proteins using dSiO2@Fe3O4/TA@Ni(OH)2 nanospheres is promising for practical applications.

Epoxy adhesives are widely used as structural adhesives distinguished by a significant degree of cross-linking, resulting in their brittle characteristics. Some specialized applications require improved thermal stability and adhesive strength. The incorporation of zinc oxide nanoparticles into a core–shell rubber (CSR) structure composed of poly(butyl acrylate-allyl methacrylate) core and poly(methyl methacrylate-glycidyl methacrylate) shell will enhance the adhesion, toughness, and thermal stability of epoxy adhesives. We synthesized CSR particles using a two-stage emulsion polymerization method, characterizing them through Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC) analyses. We synthesized epoxy adhesives with different CSR particles ratios (1.25, 2.5, and 3.75 phr) and zinc oxide nanoparticles (1, 2, and 5 phr) using mechanical stirring and ultrasonication (a two-step mixing process) to enhance dispersion. We cured the epoxy adhesive samples for 7 days for tensile tests and 2 days for lap shear tests at room temperature. We employed the tensile and lap shear tests to assess the mechanical properties of the samples. The samples underwent thermogravimetric analysis (TGA) to assess their thermal stability. We assessed the fracture surface of the optimum samples using field-emission scanning electron microscopy (FESEM). We utilized design-of-experiments (DOE) and artificial neural network (ANN) approaches to model the mechanical properties. The outcomes of FTIR, SEM, TEM and DCS analyses validated the successful synthesis of CSR particles. The tensile test findings on the dumbbell-shaped samples show a 51%, 30%, and 218% enhancement in tensile strength, modulus, and toughness for the samples containing 2.5 phr CSR particles and 2 phr zinc oxide nanoparticles, respectively. Furthermore, the lap shear tests revealed that the addition of 3.75 phr CSR particles and 5 phr zinc oxide nanoparticles increased the shear strength to 19.5 MPa. This is 127% higher than the pure epoxy. The TGA data indicated that both additions improved the thermal stability of the pure epoxy. Additionally, the predictions of shear strength, toughness, tensile modulus, and tensile strength by DOE and ANN were very close to the experimental results (R2adj > 0.95 for DOE and MREave < 3.2 for ANN).

Mn(III) porphyrins immobilized on magnetic polymer nanospheres as biomimetic catalysts hydroxylating cyclohexane with molecular oxygen

Folic acid-conjugated Fe3O4 magnetic nanoparticles for hyperthermia and MRI in vitro and in vivo

The aim of the present study was to load docetaxel (DCT) and Fe3O4 magnetic nanoparticles (MNPs) in polymeric micelles to concentrate them by an external magnetic field in target tissues. Oleic acid (OA) coated MNPs were prepared by hydrothermal method. The micelles were characterized for their zeta potential, particle size, drug loading and release efficacy. Fe loading efficacy was determined by atomic absorption. The magnetic micelles were characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), transmission electron microscopy and vibrating sample magnetometer (VSM). The cytotoxicity of the micelles was studied by MTT assay on L929 fibroblast cells and also on two breast cancer cell lines of MCF-7 and MDA-MB-231. The optimum formulation showed 70% drug loading efficiency, zeta potential of −2.58 mV, particle size of 144.3 nm and drug release efficiency within 24 h of 68.9% at pH 5.5. Fe was loaded in these nanomicelles 290 μg/100 ml. TGA results confirmed the coating of MNPs with OA and polymeric micelles. The VSM analysis confirmed superparamagnetic property of the micelles. DCT loaded in micelles showed significantly more cytotoxicity compared to free drug on MCF-7 and MDA-MB-231 cells, but blank magnetic micelles had no significant cytotoxicity on normal fibroblast cells.

Fe3O4@C/Au nanoparticle (AuNP) nanocomposites were prepared through electrostatic adsorption of AuNPs onto PDDA-functionalized core/shell Fe3O4@C magnetic nanospheres, which had been synthesized by a facile solvothermal method. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), etc. Moreover, highly electrocatalytic activity to the reduction of hydrogen peroxide (H2O2) was also exhibited on the Fe3O4@C/AuNP-modified indium tin oxide (ITO) electrode. The effect of solution pH and the modification amount of Fe3O4@C/AuNPs on the performance of electrocatalytic H2O2 reduction was investigated. Under the optimal conditions, the catalytic current showed a linear relationship with the increase of H2O2 concentration in the range of 0.007–15 mM and a detection limit of 5 μM. The H2O2 sensor showed high selectivity for H2O2 detection, which could effectively resist the interference of ascorbic acid (AA), uric acid (UA), and citric acid (CA). Finally, the H2O2 sensor was used in the real fetal bovine serum to detect H2O2 and obtained satisfactory results with the recovery values ranging from 95.14 to 103.6%.

Synthesis of Fe3O4@SiO2–branched polyethylenimine nanospheres for removal of Cr(VI) and anionic dyes

Preparation and characterization of iron oxide (Fe3O4) nanoparticles coated with polyvinylpyrrolidone/polyethylenimine through a facile one-pot deposition route

In the present study, an attempt has been made for synthesis, characterization and photocatalytic application of pure and Ni-doped α-Fe2O3 (hematite) nanoparticles by chemical co-precipitation method. The synthesized products have been studied by Thermo Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Fourier Transform Infra-Red (FT-IR), Raman spectroscopy, Ultraviolet–Visible (UV–Vis) analysis and Vibrating Sample Magnetometer (VSM). The TGA showed three mass losses, whereas DTA resulted in three endothermic peaks. XRD measurements confirm that all the prepared nanocrystals consist only in nanocrystalline hematite phase. TEM and SEM show that the size of the nanoparticles decreases with Ni-doping. FTIR and Raman spectroscopies confirm the phase purity and the phonon modes of the synthesized nanoparticles. The UV–Vis absorption measurements confirm that the decrease of particle size is accompanied by a decrease in the band gap value from 2.02 eV for α-Fe2O3 down to 1.81 eV for 8 mol% Ni-doped α-Fe2O3. Furthermore, the magnetic properties demonstrated that all of the samples exhibited ferromagnetic behavior at room temperature. On the other part, the photocatalytic activity of Ni-doped α-Fe2O3 particles was studied using methylene blue (MB) as model organic pollutants. The 8 mol% Ni-doped α-Fe2O3 nanoparticles disclosed that the discoloration of MB reached 86% after irradiation of 140 min.

The β-cyclodextrin coated magnetic nanoparticles were prepared by the surface modification of Fe3O4 magnetic nanoparticles using carboxymethyl-β-cyclodextrin. Prepared nanoparticles were characterized by X-ray diffraction analysis, transmission electron microscope, Fourier transform infrared spectroscopy, dynamic light scattering and vibrating sample magnetometer. The β-cyclodextrin modified Fe3O4 nanoparticles have a narrow size distribution with mean diameter about 10 nm. They exhibit superparamagnetic properties at room temperature with saturation magnetization of 48 emu/g. Since, the most reported technologies for arsenic removal are more effective in removing As(V) rather than As(III), the adsorption ability of these nanoparticles was investigated for removing As (III) from aqueous solution. The adsorption behavior of this material can be influenced by various factors such as contact time, pH, adsorbent dosage and initial concentration of As(III), which their effects were studied. Equilibrium data were fitted by Langmuir isotherm and the maximum removal percentage was obtained about 85% at optimum conditions. Using these modified Fe3O4 nanoparticles, the arsenic concentrations can be reduced to the allowed limits declared by the World Health Organization.

Effect of the dispersing agent on the structural and magnetic properties of [formula omitted] nanocomposites

The green, cost-effective and sustainable synthesis of nanomaterials has been a key concern of scientists and researchers. In this view, MNPs were prepared using a sapota plant leaf extract and the surface of the magnetite nanoparticles was engineered with unsaturated fatty acids. The first report on the effect of unsaturation on the size and magnetic properties of magnetite nanoparticles (MNPs), prepared by the co-precipitation method, has been studied by coating surfactants on MNPs based on their unsaturation from zero to three (lauric acid, oleic acid, linoleic acid, linolenic acid). The size effect and magnetic properties of MNPs coated with a surfactant have been studied in comparison with uncoated magnetite nanoparticles. After the surface modification of the magnetite particle, it is necessary to check whether the magnetic property has been restored or not. Therefore, the magnetic property was studied. The presence of a surfactant on the surface of MNPs was confirmed by Fourier-transform infrared spectroscopy (FTIR), which was later confirmed by scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The atomic structure was studied by X-ray diffraction (XRD) and the size of uncoated and surfactant-coated MNPs was determined by transmission electron microscopy (TEM) and the Scherrer equation by following XRD data. The magnetization property was analyzed by a vibrating sample magnetometer (VSM) at 10, 100 and 300 K and both bared and surfactant-coated MNPs exhibited a superparamagnetic nature at room temperature. The saturation magnetization (Ms) study shows that MNPs coated with a surfactant have a lower saturation magnetization value in comparison to uncoated NPs, confirming surface layering. Because the magnetic fluid has been stabilized in the aqueous medium, the double-layer model is expected to prevail.

This article describes the use of β-cyclodextrin-based carbonate nanosponges (NSs) decorated with superparamagnetic Fe3O4 nanoparticles to study and investigate the potential removal of dinotefuran (DTF) from wastewater. The NS-DTF inclusion compound was characterized by transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), UV-visible spectroscopy (UV-VIS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD) and proton nuclear magnetic resonance (1H-NMR). The adsorption efficiency of NSs was evaluated as function of different contact times. The results confirmed that the NSs have a favourable sorption capacity for the chosen guest, as the polymers exhibited a maximum adsorption of 4.53 × 10−3 mmol/g for DTF. We also found that magnetic NSs show good reusability as they maintain their efficiency after eight adsorption and desorption cycles. Our studies and characterization by means of SEM, TEM, EDS, vibrating sample magnetometer (VSM) and UV-VIS also show that NSs with magnetic properties are excellent tools for insecticide removal from aqueous environments.