Infrared study of biocompatible magnetic nanoparticles

Abstract. Magnetic fluids mainly consist of nano sized iron oxide particles (F

Dielectric properties of nematic liquid crystals with Fe₃O₄ nanoparticles in direct magnetic field

Researched within the frequency range 10⁻¹–10⁶ Hz were dielectric properties of pure 6CHBT liquid crystals and 6CHBT ones with the impurity of Fe₃O₄ nanoparticles that have the mean diameter 5 nm and weight concentration 10⁻⁴ %. The study was performed without and under the influence of direct magnetic field with the induction 0.45 and 0.60 T. It has been shown that the magnetic field influences on the parameters of the near-electrode area of liquid crystal. In the case of liquid crystal with magnetic nanoparticles, the parameter changes caused by the magnetic field depend on the induction value

Morphology and dielectric properties of polymer dispersed liquid crystal with magnetic nanoparticles

It has been shown that introduction of magnetic nanoparticles (MN) of various shapes with the concentration 10⁻¹ wt.% into polymer dispersed liquid crystal (PDLC) causes two effects: the size of liquid crystal droplets decreases, and the amount of the latter with through holes increases. MN increase the effective value of permittivity by more than one order within the frequency range 10⁻¹⁺ -10² HZ , as well as the electron and ion components of conductivity. MN reduce the exponent in the frequency dependence of the electron component of conductivity. The changes caused by the presence of the nanoparticles quantitatively depend on their shape

Immobilization of a Neutral Protease in Magnetic Particles Using Direct Binding Procedure

In a recent study we have found that Bovine serum albumine (BSA) can be bound to freshly precipitated magnetic particles directly by a novel procedure. In this procedure BSA linked covalently to the -OH group of Fe3O4 using Carbodiimide. The binding was confirmed by FTIR spectra and electron microscopy. We have also immobilized several enzymes which have biomedical application using this procedure and confirmed the binding by the above mentioned method. In the present experiment we have immobilized Dispase, a neutral protease using the direct binding procedure. We have found that the protein was bound to the extend of 90% using the dye binding procedure. We have measured the activity of this enzyme by its proteolytic property and showed that it retained 80% of its activity after immobilization

Study of Composites Consisting of High-Tc\text{}_{c} Superconductor and Fine Magnetic Particles

The composite systems as a mixture of fine magnetic particles of Fe$\text{}_{3}$O$\text{}_{4}$ and superconducting powder such as Bi$\text{}_{1.8}$Pb$\text{}_{0.2}$Sr$\text{}_{2}$Ca$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{10+x}$ were prepared. The influence of internal magnetic field (generated by magnetic particles) on the superconducting properties of prepared composites were studied as a function of concentration of magnetic particles and their magnetic state. The observed data both of the shielding and the Meissner effect were compared with corresponding linear combination of pure signals of magnetite and superconductor, respectively. The large differences were observed for demagnetized samples. It means that result must be discussed in the frame of the distribution of internal magnetic field created by the magnetic particles

SANS Study of Poly(ethylene glycol) Solutions in D2OD_2O

Poly(ethylene glycol) is used for coating of colloidal particles and other surfaces for gaining biocompatibility. Particularly, it can be introduced into magnetic fluids. The aim of the current study was to reveal the structural characteristics of poly(ethylene glycol) in neat $D_2O$ using small-angle neutron scattering technique. Solutions of poly(ethylene glycol) (at temperature of 37°C) with different molecular weights in an interval of 400-20000 were investigated. It is concluded that at low concentrations (less than 2% of mass fraction) poly(ethylene glycol) molecules behave as Gaussian coils