Microstructure control of iron hydroxide nanoparticles using surfactants with different molecular structures

Magnetite-gaize composite stabilized with polyacrylic acid

The surface-active substances stabilization are used to prevent aggregation of magnetite sorbents in the solvent, to protect against oxygen oxidation in the air as well as to combine several components with their specific properties in one material. In this work, the Elmore method synthesized a composite of magnetite-gaize stabilized with polyelectrolyte - anionic polymer polyacrylic acid. The stabilized gaize-magnetite composite is considered by physical and chemical methods. When studying a stabilized magnetite-gaize composite using transmission electron microscopy, a change in the size of magnetite particles in the structure of a clay space with a molding form is observed. Stabilization with polyacrylic acid reduces the value of the ζ-potential of composites from -18.5 mV to -19.9 mV. The effect of medium pH on the potential work of the magnetite-gaizecomposite and stabilized composite was observed. Increasing of the pH value leads to decreasing of the ζ-potential of gaize-magnetite composite from 4.2 mV to -32.6 mV and from 11.9 mV to -35.5 mV in the cause of stabilized composite. The effect of the stabilization of the composite on the adsorption was characterized using methylene blue was observed. Processing of adsorption by Langmuir and Freundlichmodels shows the effectiveness of stabilization. The maximum adsorption of methylene blue by Langmuir is 152.73 mg/g. The Freundlich constant 1/n shows that there is high compatibility between the adsorbat and the adsorbent.

Sodium Dodecyl Sulphate-Supported Nanocomposite as Drug Carrier System for Controlled Delivery of Ondansetron

Sodium dodecyl sulphate-supported iron silicophosphate (SDS/FeSP) nanocomposite was successfully fabricated by the co-precipitation method. The SDS/FeSP nanocomposite was investigated as a drug carrier for ondansetron. The cumulative drug release of ondansetron was observed at various pH values for different time intervals, i.e., from 20 min to 48 h. A ranking of the drug release was observed at different pHs; pH 2.2 > saline (pH 5.5) > pH 7.4 > pH 9.4 > distilled water. Maximum release of encapsulated drug was found to be about 45.38% at pH 2.2. The cell viability tests of SDS/FeSP nanocomposite concluded that SDS/FeSP nanocomposite was non-cytotoxic in nature.

Magnetic iron oxide nanoparticles for biomedical applications

Due to their high magnetization, superparamagnetic iron oxide nanoparticles induce an important decrease in the transverse relaxation of water protons and are, therefore, very efficient negative MRI contrast agents. The knowledge and control of the chemical and physical characteristics of nanoparticles are of great importance. The choice of the synthesis method (microemulsions, sol-gel synthesis, laser pyrolysis, sonochemical synthesis or coprecipitation) determines the magnetic nanoparticle's size and shape, as well as its size distribution and surface chemistry. Nanoparticles can be used for numerous in vivo applications, such as MRI contrast enhancement and hyperthermia drug delivery. New developments focus on targeting through molecular imaging and cell tracking.

Microwave Assisted Synthesis of Iron(III) Oxyhydroxides/Oxides Characterized Using Transmission Electron Microscopy, X-ray Diffraction, and X-ray Absorption Spectroscopy

Microwave assisted synthesis of iron oxide/oxyhydroxide nanophases was conducted using iron(III) chloride titrated with sodium hydroxide at seven different temperatures from 100 degrees C to 250 degrees C with pulsed microwaves. From the XRD results, it was determined that there were two different phases synthesized during the reactions which were temperature dependent. At the lower temperatures, 100 degrees C and 125 degrees C, it was determined that an iron oxyhydroxide chloride was synthesized. Whereas, at higher temperatures, at 150 degrees C and above, iron(III) oxide was synthesized. From the XRD, we also determined the FWHM and the average size of the nanoparticles using the Scherrer equation. The average size of the nanoparticles synthesized using the experimental conditions were 17, 21, 12, 22, 26, 33, 28 nm, respectively for the reactions from 100 degrees C to 250 degrees C. The particles also had low anisotropy indicating spherical nanoparticles, which was later confirmed using TEM. Finally, XAS studies show that the iron present in the nanophase was present as iron(III) coordinated to six oxygen atoms in the first coordination shell. The higher coordination shells also conform very closely to the ideal or bulk crystal structures.